The Year in Review

Plotina: the author’s 130mm f/5 travelling Newtonian sampling the beautiful autumnal skies of Dumfries & Galloway, southwest Scotland.

Anno Domini MMXVIII

We’ve reached the end of yet another year; and boy do they come round fast and furious! It seems like yesterday when the freezing Beast from the East was upon us, and that gave way to a unusually warm summer. Our family ventured across the waters to visit my brethern remaining in the south of Ireland and to catch up with old friends and acquaintances. But it was also a year where I made considerable progress establishing how good the British Isles are for doing all kinds of astronomy, having completed a survey of a dozen or so different sites across the British Isles. Despite the prognostications of casual observers, Britain and Ireland possess many prime locations to conduct visual astronomy, and in particular, high-resolution double star astronomy using small and medium-sized Newtonian reflectors.

In August, I conducted a month-long observational program to establish to what extent the Jet Stream affected my ability to resolve a variety of double stars ranging from between 1 and 2″ angular separation, finding no real evidence in support of its alleged effects and that it need not deter a determined observer to enjoy visual astronomy. It was, to my knowledge, the first such survey to be conducted on the subject.

My scepticism concerning the virtues of small, expensive refractors grew ever stronger throughout 2018, when I finally rid myself of the last remaining apochromatic refractor in my stable. As I have exhaustively shown, a much simpler and less expensive 130mm f/5 Newtonian proved superior to a 90mm ED glass on all sky targets. The former instrument has become my grab ‘n’ go telescope of choice, based solely on optical performance.

I will not be updating my book on refractors, as my conscience will not countenance the continued cultivation of untruths about their supposed virtues in the field.

I’m a Newtonian convert!

In another project, I tested a variety of optical devices that enable observers to use Newtonian reflectors during daylight hours, finding that the 130mm f/5 Newtonian coupled to a Vixen erect image adapter to be a fine, cost-effective alternative to large, expensive ED spotting ‘scopes.

Schmokin; the Vixen terrestrial image adapter.

My continuing blog entitled: the War on Truth: the Triumph of Newtoniasm, I have collated the opinions of a large volume of observers and authorities in the field from around the world, both historical and contemporary, which clearly show that Newtonian reflectors in the 8- to 12-inch aperture class will outperform smaller refractors at a fraction of the price, in sharp contradistinction to two decades of nefarious promotion by so-called ‘experienced’ amateurs. One of the key reasons for this blurring of the truth pertains to my suspicion that many refractor enthusiasts either don’t know, or are unwilling, to accurately collimate these instruments and/or are too lazy to allow adequate thermal acclimation of the same.

That being said, I have been very encouraged by the response of the amateur community to this legitimate protest. It seems many more former refractor onlyists are willing to consider the Newtonian once more and that’s a good thing!

2018 has also been a year where I have re-discovered the considerable virtues of binoculars. As a series of recent blogs showed, I have found a range of optically excellent roof prism binoculars that suit the budgets of many more amateurs, enabling the hobby to grow and not stagnate. Although I have certainly not spent a small fortune buying every other model, as others have done, I quickly gravitated towards two instruments, both made by Barr & Stroud, a 10 x 50 unit for dedicated binocular astronomy using a monopod, and a most excellent 8 x 42 Savannah wide-angle instrument for casual stargazing and nature observation. The latter has become a constant companion on my long country walks. I sincerely wish that others will test these binoculars themselves and spread the love.

An amazing, general purpose binocular; the Barr & Stroud  Savannah 8 x 42 wide angle.

I intend to drastically cull my current crop of astronomy equipment in 2019 as it has weighed heavy on my mind of late. I have retired mighty Octavius, my 8 inch f/6 Newtonian reflector, as it has achieved everything I intended for it and much more besides. My intention is to eventually gift it to some keen amateur who will use it productively. My 5 inch f/12 refractor is similarly retired. The little Orion SpaceProbe 3 alt-azimuth reflector and my old 7 x 50s were bequeathed to Gavin, a very enthusiastic young man of 8, who showed unusual interest in astronomy, and uses them regularly to stargaze from his home just outside our village.

I plan to use just three instruments in the coming year:

A 12″ f/5 Newtonian(Duodecim)

A 130mm F/5 Newtonian(Plotina)

Binoculars.

These three instruments will enable me to enagage with the full gamut of amateur astronomy. They are all I could possibly want!

Duodecim: a fine 12″ f/5 Newtonian reflector.

I would like to produce more blogs on binocular astronomy in the coming year, Lord willing, as well as produce new reports with both the 130mm f/5 and 12″ f/5 instruments.

2018 marked the end of a long slog to get my new book into shape; Chronicling the Golden Age of Astronomy. It’s been five years in the making, but it was an enjoyable and worthwhile project, bringing together the selected works of many amateur and professional astronomers across four centuries of time, who used their telescopes, both great and small, to create the wonderful hobby we enjoy today. What I learned from their diligent adventures under the stars is incalulable and I have tried hard to capture the essence of their life and researches in this large, historical work. It is my fondest hope that it will be well received by my peers. Please check out the reviews as they appear.

A work dedicated to the heroes & heroines of our hobby.

Finally, I am in the process of writing a new book dedicated to the ShortTube 80 achromatic telescope which ought to be available at the end of 2019. I have amassed a large body of notes from several years of using this quirky little telescope in the field, which I hope will be of interest to the many amateurs, young and old alike, who use or have used the instrument in the past.

So, there it is!

God bless you all!

Neil.

 

De Fideli.

Living without Lasers

Collimation tools; from left right: a SkyWatcher Next Generation laser collimator, a collimation cap, a well made Cheshire eyepiece and a Baader lasercolli Mark III.

 

It is undoubtedly true that by far the most prevalent reason why so many amateurs have dissed Newtonian reflectors in the past boils down to poorly collimated ‘scopes which lead to less than inspiring images. The amateur who pays close attention to accurate collimation will however discover the solid virtues of these marvellous telescopes and will soon forget the bad experiences of the past.

I’ve noticed a trend over the last few decades, where more and more amateurs have become lazy and impatient. They want instant gratification. This is one of the main reasons why many have turned to hassle-free instruments such as small refractors and Maksutov Cassegrains. It’s an entirely understandable trend, but in other ways it is lamentable. One of the downsides of this trend is that amateurs have become less concerned with learning practical optics, deferring instead to higher tech ways of obtaining optimal results in the field. One such technology is the laser collimator; a very useful device that has made accurate collimation far less of a chore than it was just a few decades ago. But while many have defaulted to using such tools as labour-saving devices, they have, at best, become less familiar, or at worst, all but forgotten the traditional tools used in the alignment of  telescope optics; tools such as the collimation cap and the Cheshire eyepiece, and in so doing have less and less understanding of how their telescopes actually work.

The desire for super-accurate collimation has undoutedly been fuelled by the advent of faster optical systems; often supporting sub-f/5 primaries. Once, the traditional Newtonian was almost invariably made with higher f ratios:- F/7 to f/10 and beyond, and requiring very little in the way of maintenance. This is abundantly evidenced by the scant attention astronomy authors of the past gave to such pursuits. In contrast, modern Newtonians are usually f/6 or faster, necessitating much greater attention to accurate optical collimation if excellent results are to be consistently attained during field use.

In my chosen passtime of double star observing, I have acknowledged the need for accurate collimation. Such work often requires very high magnifications; up to and in excess of 50x per inch of aperture, to prize apart close double stars, some of which are below 1 arc second in angular separation. At such high powers, sub-standard collimation results in distorted images of stellar Airy disks, and that’s something that I’m not willing to put up with. In this capacity, I have tested a number of collimaton techniques using a few different laser collimating devices but have also spent quite a lot of time comparing such methods to more traditional techniques involviing the tried and trusted collimation cap and Cheshire eyepiece.

To begin with, it is important to stress that the methods covered in this blog can be achieved easily with a little practice, and I will gladly defer to recognised authorities in the art of Newtonian collimation, such as the late Nils Olif Carlin and Gary Seronik, who have done much to dispel the potentially stressful aspects of telescope collimation. Nothing I will reveal here goes beyond or challenges anything they have already said. My goal is to reassure amateurs that one can happily live without lasers, especially if your Netwonians are of the f/5 or f/6 variety.

Many of the entry-level laser collimators often manifest some issues; partcularly if they are not collimated prior to use. Thankfully, the inexpensive SkyWatcher Next Generation that I have used for a few years did come reasonably well collimated, but others have not been so fortunate. One easy way to see if your laser collimator needs collimating is to place it in the focuser of the telescope and rotate it, examining the behaviour of the beam on the primary. If the beam does not stay in place, but traces out a large annulus, you will have issues and will need to properly collimate the laser. This is not particularly difficult to do and many resources are available on line to help you grapple with this problem. See here and here, for examples.

Of course, you can pay extra for better made laser collimators that are precisely collimated at the factory. Units that have received very good feedback from customers include systems manufactured by Hotech, AstroSystems and Howie Glatter. Some of these are quite expensive in relative terms but many amateurs are willing to shell out for them because they deliver consistently good results. My own journey took me in a different direction though. Instead of investing in a top-class laser collimator, I re-discovered the virtues of traditional techniques involving the collimation cap and Cheshire eyepiece.

My personal motivation to return to traditional, low-tech tools was stoked more from a desire to understand Newtonian telescopes more than anything else. Any ole eejit can use a laser collimator but it deprives you of attaining a deep understanding of how Newtonians operate. In addition, I have frequently found myself dismantling whole ‘scopes in order to get at the mirrors to give them a good clean and this meant I had to learn how to put them back together from scratch. The simpe collimation cap has been found to be an indispensable tool in this regard, allowing one to rapidly centre the secondary mirror in the shadow of the primary.

Singing the virtues of simple tools, such as the tried and trsuted collimation cap.

 

Using just this tool, I’ve been able to set up all my Newtonians rapidly to achieve good results from the get go, at both low amd medium powers more or less routinely.

For the highest power applications  more accuracy is required and I have personally found that a quality Cheshire eyepiece to be more than sufficient to accurately align the optics in just a few minutes. Not all Cheshires are created equal though; some are less accurate than others. For my own use, I have settled on a beautifully machined product marketed by First Light Optics here in the UK ( be sure to check out the reviews while you’re at it). For the modest cost of £37, I have acquired a precision tool to take the hassle out of fine adjustment. The unit features a long sight tube with precisely fitted cross hairs that are accurately aligned with the peep hole. It needs no batteries and comes with no instructions but with a little practice, it works brilliantly!

The beautifully machined and adonised Cheshire eyepiece by First Light Optics, UK.

A nicely finished peep hole.

The precisely positioned cross hairs on the under side of the Cheshire.

 

Because all of my Newtonians are of the closed-tube variety, they are robust enough to only require very slight tweaks to the collimation. I would estimate that 80 per cent of the time, it is only the primary mirror that requires adjusting in field use. I have found this overview by AstroBaby to be very useful in regard to using the Cheshire and would recommend it to others.

The Cheshire eyepiece is a joy to use when collimating my 130mm f/5. Because the tube is short, I can access both the primary and secondary Bob’s Knobs screws to whip the whole system into alignment faster than with my laser. With my longer instruments; partcularly my 8″ f/6 and 12″ f/5, collimation using the Cheshire is decidely more challenging as they both have longer tubes. That said, by familiarising one’s self with the directions of motion executed with the three knobs on the primary, one can very quickly achieve precise collimation. One useful tip is to number the knobs individually so that you can dispense with the guesswork of which knob to reach for to get the requisite adjustment. At dusk, with the telescopes sitting pretty in their lazy suzan cradles, and with the Chesire eyepiece in place in the focuser, I swing the instrument back and forth to alternately view the position of the primary in the eyepiece and the knob(s) I need to turn. Doing this, I get perfect results in just a few minutes; a little longer than can be achieved with a laser, admittedly, but not long enough to render the process exhausting or boring. It’s time well spent.

Know thy Knobs: by spending some time getting to know which directions each of the collimation knobs move the primary mirror, it makes collimation with a Cheshire eyepiece hassle free.

The proof the pudding, of course, is in the eating, and in this capacity, I have found the Cheshire to achieve very accurate results each time, every time. Indeed, it has made my laser collimator blush on more than a few occasions, where high power star tests and images of close double stars reveal that the laser was out a little, requiring a collimation tweak under the stars. Indeed, the Chesire is so accurate that it has become my reference method to assess the efficacy of all the laser collimators I’ve had the pleasure of testing.

While I fully acknowledge the utility of good laser collimators, I get much more of a kick out of seeing, with my own eyes, how all the optical components of the Newtonian fall into place using the Cheshire. Furthermore, the fact that it requires no batteries (and so no issues with the unit failing in the field for lack of power, as has happened to me on more than a few occasions), deeply appeals to my longing for low-tech simplicity in all things astronomical. The fact that the aforementioned amateurs also recommend the Cheshire as an accurate tool for collimating a Newtonian makes it all the more appealing.

Having said all this, the utility of a Cheshire eyepiece lessens as the f ratio of your telescope gets smaller, so much so that for f/4 ‘scopes ar faster, the laser technique will, almost certainly, yield more accurate results. But that’s OK. We are blessed in this day and age with many good tools that can make Newtonian optics shine!

 

Note added in proof: August 14 2018

A really good laser collimator: the Hotech SCA, which can be used with both 1.25″ and 2″ focusers and comes in a very attractive little box with straightforward instructions on how to use it. You will still need the collimation cap to centre the secondary though.

 

If you do decide that you don’t like using a good Chesire eyepiece for precise collimation of your Newtonian reflectors, then I would highly recommend the Hotech SCA laser collimator. It’s an ingenious device (but costs significantly more than a regular laser collimator), but in this case you really do get what you pay for. I have tested the device on all three of my Newtonians and it gives accurate and reproducible results that agree perfectly with the Chesire. It yields perfect star tests at appropriately high powers (I’d recommend a magnification roughly equal to the diameter of your mirror in millimetres for such field tests) both in focus and defocused. I’d go for it if you can afford it. You will still need the collimation cap to centre the secondary before use however. See here and here for more details.

Neil English is author of Choosing and Using a Dobsonian Telescope.

 

 

De Fideli.

Pulcherrima!

Beauty and the beast: my 130mm f/5 Newtonian versus a 90mm f/5.5 ED refractor

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Date: Wednesday March 28 2018

Time: 22:00UT

Temperature: −2C

Seeing: III, bright gibbous Moon, small amounts of cloud cover in an otherwise clear sky.

It is often claimed that refractors give more aesthetically pleasing images of celestial objects than reflectors. But how true is this statement? Last night, I learned yet another instructive lesson that shatters this myth once and for all.

Earlier in the evening, I fielded my 8″ f/6 Newtonian against a very good 90mm f/5.5 ED apochromat. The target was Theta Aurigae, then sinking into the western sky and so past its best position for observing. Seeing was only average. Both telescopes had been fielded about 90 minutes earlier with the optics capped, so both were completely acclimated. I charged the apochromat with a 2.4mm Vixen HR eyepiece yielding 208x. The 8 inch Newtonian was charged with a 6mm Baader orthoscopic ocular delivering 200x.

Examining the system in the 8 inch reflector showed the primary star as a slightly swollen Airy disk but the faint companion was clearly visible. In contrast, the view through the 90mm refractor showed a less disturbed primary but the secondary(for the most part) couldn’t be seen!

Question: How can an image be deemed more aesthetically pleasing when a prime target (the secondary) in that said image can plainly be seen in one instrument and not in the other?

Date: Thursday March 29 2018

Time: 00:05 UT

Temperture:−3C

Seeing; II/III, slight improvement from earlier, otherwise very similar.

Later the same night, I fielded my 130mm F/5 Newtonian along side the 90mm refractor and  turned my attention to a spring favourite; Epsilon Bootis, now rising higher in the eastern sky.

This time, I charged the refractor with a 2.0mm Vixen HR eyepiece yielding 250x. The Newtonian was fitted with a Parks Gold 7.5mm eyepiece coupled to a Meade 3x Barlow lens giving a power of 260x.  Examining the system, I was quite shocked by the difference between the images; the refractor did show a dull, greenish companion but it was entangled in the diffraction gunk from the orange primary. What’s more, the entire system was surrounded by chromatic fog owing to the imperfect colour correction of the refractor (an FPL 51 doublet). In contrast, the 130mm f/5 Newtonian image was far superior in every way; the Airy disks were smaller, tighter and more cleanly separated, and with zero chromatic fog to be seen. The Newtonian image remained just as stable as in the refractor image throughout the observation! The components also displayed their pure colours (as only a reflector can yield); the primary orange and the secondary, blue. In a phrase, the differences between the images was like night and day!

Conclusions: The 130mm Newtonian provided a much more aesthetically pleasing image than the refractor, which was compromised by its smaller aperture and less than perfect colour correction. As a small portable telescope, the Newtonian is far more powerful and is capable of delivering images that are simply in a different league to the refractor.

ED 90 Refractor: Proxime accessit.

130mm f/5 Newtonian(Plotina): Victrix/Pulcherrima!

 

Postscriptum: As always, I would encourage others to test these claims. Truth matters.

 

 

Neil English is author of Grab ‘n’ Go Astronomy.

 

De Fideli.

 

 

Bible Culture.

The author’s red letter Holman NKJV bible, used for his daily devotionals.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Dedicated to Billy Graham (19182018).

 

Have you not known?
Have you not heard?
The everlasting God, the Lord,
The Creator of the ends of the earth,
Neither faints nor is weary.
His understanding is unsearchable.

                                                                       Isaiah 40:28

 

 

 

In many ways, bibles are a lot like telescopes; both have the potential to transform your perspective. Some folk struggle to find even one. Others collect many different kinds. Some bibles are small and ultraportable, while others are large and unwieldy. Some copies of Holy Scripture are beautiful and ornate, lavished with fine art, and painstakingly assembled from the choicest natural materials. Still others are plain Jane, simple, with no frills; just the text, and maybe a concordance. Some folk parade their bible as if it were a measure of how well one walks with Christ. But many, not seeking to be ostentatious, quietly and modestly read their bibles in complete privacy. Some like to look at their bibles and never really look through them. Some learn a great deal from their bibles, others, little or nothing.

There has never been a better time to read the bible, for it is the only collection of books that makes sense of our earthly predicament and provides a coherent and just solution. The world is changing too fast and too much, and I fear that many have no real idea of where our kind is destined to end up. But by studying the biblical narrative, we can get a clear picture of where the world is headed for and what its fate will be. The bible shapes your worldview like no other body of literature, and keeps you moored in a view of morality that is absolute, and which cannot be changed by the fickle and ephemeral nature of human culture.

Today, many excellent translations in hundreds of languages are now available online or in traditional form. But are some translations better than others? Let’s look at the kinds of English bible translations that are now available.

‘Word for Word’ or ‘Thought for Thought’?

As any linguist will tell you, the process of translation is a task that cannot, by definition, satisfy all of the people all of the time. This is particularly true of the bible, where the original manuscripts were written in Hebrew, Aramaic and so called Koine (read common man’s) Greek. Thus, any translation involves a fair degree of discernment in choosing the right words to express, as precisely as possible, the original meaning conveyed in these texts. That has led modern biblical translation scholarship to adopt two basic philosophies; ‘word for word’ and ‘thought for thought.’ The former variety strive to exchange the words written in these ancient texts with modern words that, as far as possible, adhere to the original wording found in the most ancient texts. The latter adopt an entirely different, but no less important approach, taking the ancient texts and imparting a modern rendering that captures the essential thoughts conveyed by the original authors. Examples of good ‘word for word’ translations in the English language include the English Standard Version(ESV), the Modern English Version (MEV), the King James Version (KJV), the New King James Version (NKJV) and the New American Standard Bible(NASB). Examples of popular ‘thought for thought’ translations include the New International Version (NIV), the Christian Standard Bible (CSB), the New Living Translation (NLT) and the Good News Bible(GNB).

Still other translations seek to reach a particular subset of society. For example, so−called Messianic Bibles, such as the fairly new Tree of Life Version (TLV), was compiled by Messianic Jewish scholars with the express intention to impart a distinctive Jewish voice to the Scriptures, removing words like ‘Lord’ and ‘Jesus’ and replacing them with their Hebrew equivalents, ‘Adonai’ and ‘Yeshua,’ respectively. Not a bad idea! Finally, there are very loose paraphrases of the bible, where the author’s intent is to summarise whole paragraphs of biblical text with a wording that departs quite a bit from the originals, and for the purposes of conveying the key ideas therein. Examples of these include the Message Bible (by Eugene Peterson) and the older but still highly popular Living Bible (by the late Kenneth Taylor). I use the latter to read extended passages of the biblcal narrative to my sons; a duty I take very seriously.

An aside: Did you have your children Christened? If so, you made an oath that you would bring them up in the Christian faith. Do they know the Lord’s Prayer? How about John 3:16? Do they know anything of the Gospels? Can they recite something from the Psalms?

The Living Bible: great for biblical narration.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Finally, there are corruptions of the biblical text that should be avoided at all cost. Examples include the New World Translation (NWT), used by the Jehovah’s Witnesses, which has monkeyed with the divinity of Christ, portraying Him not as God but merely a powerful angel, and the Book of Mormon, used by the Church of Latter Day Saints, which concocts an entirely fabricated narrative that mimics the bible (they’re bible wanabees). Another is the tongue−in−cheek Queen James Bible, which has removed all references to the abominable practice of homosexuality.

Choosing a bible can be a daunting task for a beginner, especially when one is confronted with the proliferation of translations. Having read and enjoyed many bible versions, I have found all of them to be useful and enriching. The ‘thought for thought’ versions are very easy to assimilate but at the cost of veering away from the technical precision of the ‘word for word’ varieties. In the end, I have found it helpful to enjoy a good example of both; the NKJV (for accuracy) and the NLT (for readability).  We’re all different though, and get different things from different translations.. And that’s OK too.

                                       Features to Look for in a Good Bible

All that having been said, there is another aspect of bible culture that is of some importance and this pertains to how well made the copies are. In short, a bible that is to be used regularly must ideally be well made and last many years if it is to be of maximal value. So, here I wish to offer some thoughts on my own experiences with a variety of bibles, and what features I tend to look for when shopping for a good, durable bible.

I have found hardback versions of the Holy Bible to be the least durable. They are generally quite poorly bound and tend to fall apart quickly with continued use. If you use a hardback version, chances are you’ll be taping it up before long. Much better are the soft covered bibles, which come as simple paperbacks, imitation leather (usually polyurethane or ‘trutone’) and bona fide leather bound incarnations. I avoid bibles that are heavily glued and not Smyth−sewn.

Smyth sewn bibles are much stronger and more durable than other kinds of binding.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Soft covers also open out flat on a table or in your hand, largely avoiding the tendency for the pages to flip over accidentally or haphazardly.  The font size can also be an issue. If the font is too small, it will be difficult to read, even with eyeglasses. If it is too large, the bible will have to be bigger and heavier than is desired. That said, there are many thinline versions now available in 8 point or larger font, and which can be carried around easily in a rucksack or handbag.  The font should be clear and distinct, ideally with good line matching, so as to minimise the effects of text ghosting. Ideally, the bible will have a decent number of cross references, so that you can quickly find quotations taken from other parts of the bible that have a bearing on the part of Scripture being studied.  A comprehensive concordance (normally placed at the back of the bible) and a few relevant maps of the biblical world is also a godsend. Some folk like to have wide margins, so as to make notes. Others simply want the text, pure and simple.

 

Online Resources

In this digital age in which we live there are many excellent online resources to help you study the bible. Bible Gateway and Bible Hub.com provide the entire text of the bible in many different versions, only a few of which I have mentioned in this blog. Perhaps the most comprehensive online resource is the NEW English Translation (NET) bible, which is a novel translation compiled by a team of biblical scholars accessing the best currently available Greek, Aramaic and Hebrew, together with over 58,000 translators’ notes. The NET bible is also available in conventional form. I should also mention Biblia.com which seems to offer a similar service to the NET bible. One can also buy Kindle versions of most any bible translation for use on your electronic devices.

                                              My Personal Favourite Bible

While I certainly enjoy and cherish many English translations of the bible, I wanted to share with you some of the qualities I looked for in my own personal quest for a bible for study and use in my daily devotionals. I narrowed the translations down to two; the ESV or the NKJV. And while I can recommend both wholeheartedly, I gravitated toward the latter, owing to its literary ‘cadence’ and its devotion to the tradition of the original King James Version (though the author does not endorse so−called King James ‘onlyism’). I felt the ESV had developed too much of a ‘cult’ following and I’ve always been one to go my own way, championing the ‘underdog,’ as it were.

The author’s favourite Bible from his small collection.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Having read the NKJV through a few times, I have never come across a typographical error in this version, unlike others I’ve encountered. For example, while reading the book of Jeremiah in the otherwise excellent Tree of Life Version(TLV) of the Bible, I encountered a clear error in this translation (see the TLV Jeremiah 34:14), which (for me) was slightly annoying. The same bible also has printing errors in the short book of Obadiah.  Errors are more likely to occur when small teams of biblical scholars are involved and the TLV had a smaller scholarship base than many of the more established English translations. I hope the committee responsible for the TLV can sort out these errors in due course. The NKJV has been around since 1982 (Thomas Nelson publishers) and so any bugs in this version have long been sorted out. Indeed, I was just a boy when the NKJV first hit the shelves; and yet, in the rapidly changing world in which we live, the NKJV is now considered somewhat of a classic lol.

Errors are irksome to find in a bible.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

It is also noteworthy to mention that the older Thomas Nelson rendition of the NKJV also featured asterisks alongside passges from the Old and New Testaments, indicating where prophecies were either fulfilled or had yet to be fulfilled. But these are eisegenic interpretations (reading into the text) and I liked the way the new Holman publication removed them so that the reader could interpret them in his or her own way.

I wanted a Smyth−sewn binding for my bible as these are very strong and durable, but also because they open flat without much effort. I also considered buying a copy bound in high quality leather (like with my NIV 2011), but yet again I have found the modern polyurethane (trutone) covers to be just as good. What’s more, unlike leather, they don’t need to be nourished from time to time with conditioning agents in order to keep them in tip top condition. In addition, leather, being organic, is biodegradable, so will decay with time; something the synthetic polymers won’t do to the same degree(so long as you don’t sit it out in the hot sun, day in day out lol).

I wanted a bible with only the text, neither with introductions or other distractions from the text itself. And while I used to take copious notes during my earlier bible studies, these days I just enjoy the bare text without margins.

Taking notes while studying the bible is useful but in the end I just wanted to read the text with no distractions.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I wanted a fairly large font, so I could read it without using my glasses, even in fairly dim light.The quality of the paper had to be good too, but not so good that I would be afraid to soil it. The Holman has a single ribbon page marker, and while I would have preferred two, I can live with having only one. The text is printed in American English but that was never an issue for me. It had to be reasonably well line matched and I wanted the words of the Messiah in red lettering. All these requirements led me to a very useful version, published by Holman Bible Publishers, Nashville, Tennessee, USA. Unlike the cheap, bonded leather of the older Nelson version (the newer Nelson NKJV are better made though) of the NKJV, the Holman iteration has a beautiful but not overly showy trutone cover. Finally, I didn’t want to spend too much on yet another bible. The Holman was priced very economically and was well worth the modest price I paid for it.  I hope to be able to use it well into my old age.

The Holman NKJV (with gold gilded pages) has a beautifully simple trutone covering that won’t make you stand out in a crowd.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

So, in summary, there are many beautiful bibles available today; something to suit everyone’s taste, and for all occasions. My hope is that this short article will inspire others to begin a new study of the bible and to keep the words of our Creator alive and well in our hearts.

Postscript: Thomas Nelson have now brought out a brand-new Deluxe Reader’s Bible  which is beautifully made and very reasonably priced. You can see a review of it here.                    

 

 

De Fideli.

Cleaning Newtonian Mirrors.

I’ve noticed that one issue that seems to give folk concern about investing in a good Newtonian pertains to having to clean the optics every now and again. I’ve never really understood this mindset though. Having had my closed-tube 8-inch Newtonian for about 18 months now, and having clocked up a few hundred hours of observations with it, I felt it was time to give the mirrors a cleaning. Here’s how I do it:

The mirrors are removed from the tube.

Two fairly grimy mirrors

Two fairly grimey mirrors.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

First I make sure that all the loose dust and debris has been blown off using an air brush. Next, I run some cold tap water into a sink and add a drop or two of washing up liquid. The water we use here is very soft; indeed we are graced with some of the softest water in the British Isles, which also makes drinking tea especially pleasant! If your local water source is hard, I’d definitely recommend using de-ionised/distilled water.

Starting with the secondary mirror, I dip my fingers into the water and apply some of it onto the mirror surface with my finger tips, gently cleaning it using vertical strokes. Did you know that your finger tips are softer than any man-made cloth and are thus ideal for cleaning delicate surfaces like telescope mirrors?

Finger-tip cleaning of the mirror.

Finger-tip cleaning of the mirror.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Next, the mirror reflective surface is rinsed under some cold, running tap water.

Rinse the secondary with some cold tap water.

Rinse the secondary with some cold tap water.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The procedure is repeated for the primary mirror;

Gentle massaging of the mirror using the finger tips.

Gentle massaging of the mirror using the finger tips.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rinsing the primary mirror using cold tap water

Rinsing the primary mirror using cold tap water.

The mirrors are then supported on their sides to allow them to drain excess water, and then left to dry in a warm, kitchen environment. Stubborn water droplets nucleating on the mirrors are removed using some absorbent tissue.

Washed and drying out in the kitchen.

Washed and drying out in the kitchen.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Finally, the mirrors are placed back in the telescope tube, making sure not to over-tighten the screws which hold the primary in place inside its cell. All that remains then is to accurately align the optical train, as described previously.

There we are! Not so difficult after all; and all done in about 40 minutes! The soft water doesn’t show up any significant spots after cleaning unlike hard water sources and now the optics are as clean as the day they were produced.

With a busy season of optical testing and planetary observing ahead, I know that my 8-inch will be operating as well as it possibly can. And that’s surely good to know!

Gosh!

I feel a nice, hot cuppa is in order!

De Fideli.

Planetary Telescopes.

The author's plnetary telescope; a 8 inch f/6 Newtonian reffector.

The author’s planetary telescope; a 8 inch f/6 Newtonian Reflector.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

But thou shalt have a perfect and just weight, a perfect and just measure shalt thou have:

Deuteronomy 25:15

Comments on planetary telescopes by established authorities** in the field over the last 130 years.

As a really efficient tool for systematic work on planets, telescopes of about 8 inch aperture cannot be surpassed. It is useless waiting for the two or three serene nights in a year when the whole diameter of a big instrument is available to really good effect. Amateurs urgently require the appliances most efficient under ordinary conditions and they will find a larger aperture of little avail until it is much reduced by a system of gagging and robbed of that very advantage which is extolled so much; namely grasp of light. The 18.5 inch equatorial of the Dearborn Observatory cost £3700, the great Washington refractor £9000, the great Melbourne Cassegrainean (reflector) of 4 feet aperture cost £14,600, and at first it would appear preposterous that a good 8.5 inch With or Calver mirror, that can be purchased for some £30 will effectively rival these expensive and elaborate instruments. Many people would consider that in any crucial tests the smaller instrument would be utterly snuffed out: but such an idea is entirely erroneous. What the minor telescope lacks in point of light it gains in definition. When the seeing is good in a large aperture, it is superlative in a small one. When unusually high powers can be employed on the former, far higher ones proportionally can be used with the latter. We naturally expect that very fine telescopes, upon which so much labour and expense have been lavished, should reveal far more detail than in moderate apertures, but when we come to analyze the results it is obvious such an anticipation is far from being realized.

From W.F. Denning’s, The Defining Powers of Telescopes, Anno Domini 1885.

The planet looks as if cut out of paper and pasted on [the] background of sky. It is perfectly hard and sharp with no softening of edges. The outline and general definition are much superior to that of a refracting telescope.

E.E. Barnard comparing the views of Saturn seen with the newly erected 60-inch reflector atop Mount Wilson, with the 36-inch Lick Refractor, Anno Domini 1908

Source: Sheehan, W. The Immortal Fire Within: The Life and Work of Edward Emerson Barnard, Cambridge University Press, pp 398. Anno Domini 2007.

Although something worth recording may be seen even with a 3-inch, the intending student of Jupiter should have available a telescope of not less than 6 inches aperture. With such an instrument a great deal of first-class systematic work can be accomplished and only the smallest of the really important markings will be beyond its reach; indeed, until only a year or two before his death Stanley Williams made all his invaluable observations with a 6-inch reflector. An 8-inch is probably adequate for all purposes; a 12-inch certainly is. The bulk of the author’s work has been done with a 12-inch reflector; and although it would not be true to say that he has never yearned for something larger when definition was superb, the gain would have been mainly aesthetic and he has never felt that anything important was being missed owing to the inadequacy of his equipment.

Peek, B.M., The Planet Jupiter:The Observer’s Handbook, Faber, pp 36-37, Anno Domini 1981.

If the aperture exceeds about 12 inches , the atmosphere will seldom allow the full aperture to be used……..Direct comparisons of performance on different occasions have revealed an 8-in refractor showing more than a 36-in reflector; an 11-in refractor surpassing a 12-in reflector; canali invisible in the Greenwich 28-in stopped down to 20 ins, but visible in an 8-inch by T.E.R. Philips; apertures less than 20 ins showing more than the Yerkes 40-in stopped to 30 ins.

From Mars by J.B Sidgwick, Observational Astronomy for Amateurs, (pp 118) Anno Domini 1971.

One of the greatest Jupiter observers, Stanley Williams, used only a 6-inch reflector, but most serious students of the planet now would look for at least an 8-inch, although a good 5-inch OG can reveal surprising detail. This is not the place to debate the relative performance of refractors and reflectors, but good resolution, high contrast and faithful colour rendition are essential. A good long focal ratio Newtonian , a Maksutov, or an apochromatic refractor is probably the best but, as in every field, the quality of the observer is the most important factor, and good results can be obtained with any reasonable instrument.

Moseley T., from the chapter on Jupiter in The Observational Amateur Astronomer, (Moore, P. ed), Springer, pp95, Anno Domini 1995.

To recapitulate: Mars is not an easy target. Because the disc is generally small, it is essential to use a fairly high power telescope if it is hoped to see anything except for the most prominent features. Of course a small telescope such as a 7.6cm refractor or a 15cm reflector will show something under good conditions, but for more detailed work a larger aperture is needed. A 20cm telescope is about the minimum for a reflector; I would not personally be happy with anything below 20cm, though opinions differ, and no doubt observers more keen sighted than I am will disagree.

Moore, P., from the chapter on Mars in The Observational Amateur Astronomer, (Moore, P. ed), Springer, pp78, Anno Domini 1995.

A 3-inch refractor with a magnification of around 50x will show the planet and its ring system, but an aperture of no less than 6-inches is needed for observations to be of value; ideally one should aim for an aperture of at least this size – the larger the better. It has been claimed that the best magnification for planetary observation is about equal to the diameter of the object glass or mirror in millimetres. To see the fine details of Saturn’s belts and ring structure, a magnification of 150x to 300x is necessary, and therefore, according to the above rule, telescopes of 150mm or more are clearly required.

Heath, A.W., from a chapter on Saturn in:The Observational Amateur Astronomer, (Moore, P. ed), Springer, pp113, Anno Domini 1995.

Seeing varies from 0.5 arc seconds on an excellent night at a world class observatory site to 10 arc seconds on the worst nights. On nights of poor visibility, it’s hardly worth observing the Moon with anything but the lowest powers, since turbulence in the Earth’s atmosphere will make the lunar surface appear to roll and shimmer, rendering any fine detail impossible to discern. For most of us, viewing rarely allows us to resolve lunar detail finer than 1 arc second, regardless of the size of the telescope used, and more often than not a 150mm telescope will show as much detail as a 300mm telescope, which has a light gathering area 4 times as great. It is only on nights of really good visibility that the benefits of the resolving power of large telescopes can be experienced. Unfortunately, such conditions occur all to infrequently for most amateur astronomers.

Grego, P., The Moon and How to Observe It, Springer, pp244, Anno Domini 2005.

As a choice for planetary observations then, there is a lot to be said for the Newtonian reflector in the 6- to 10-inch aperture range.

F.W. Price, The Planet Observer’s Guide (2nd Edition), Cambridge University Press, pp 41. Anno Domini 2000

 

It allowed visual scrutiny with very high magnifications, each time it was necessary.

Adouin Dollfus (2002) in a comment pertaining to the efficacy of the Great Meudon Refractor.

A high quality Newtonian reflector is a very powerful instrument, fully capable of superb performance in viewing the planets, when the optics are kept clean and properly aligned. They have been among the favorite instruments of serious planetary observers for many decades.

Bengton, J.L., Saturn and How to Observe It, Springer, pp57, Anno Domini 2005.

As good as my 6-inch f/9 is, the 8-inch f/6 I built soon after is crushingly superior in virtually every way — including planetary performance. This is something to keep in mind if you’re considering a long-focus Newtonian. A long f-ratio helps, but aperture is much more important. Would an 8-inch f/9 be better than my f/6? Probably. But mounting and using a scope with a tube more than 6 feet long is would be a challenge. And when the aperture gets much bigger, it’s easy to keep the secondary size small without resorting to extremely long focal lengths.

From an article entitled,The Big Red One, Sky&Telescope Associate Editor and veteran ATMer, Gary Seronik, commenting on the superiority of a 8-inch f/6 reflector over an optically superlative 6-inch f/9 reflector ‘Planet Killer,’ Anno Domini 2009.

I was once loaned a 4.5 inch refractor by the British Astronomical Association back in the 1990s; it was an excellent instrument, but the optical tube was longer than me! These days refractors come with much shorter tubes, but at considerable cost and apertures of 5 in., or more, however the cost of smaller refractors have come down in recent years. Although they look splendid, remember it is aperture(size of the telescope) that is the most important. Ideally you should get the largest telescope you can for your money.

Abel, P.G, Visual Lunar and Planetary Astronomy, Springer, pp 13, Anno Domini 2013.

All in all, if you can afford it, and if you have the room to house it in some sort of observatory, I would say go for a Newtonian reflector of 10 inches -14 inches aperture and as large a focal ratio as you can reasonably accommodate…..My second choice would be a 5 inch refractor…..having a focal ratio of f/12……or an ED apochromat ( f/8).

North, G., Observing the Moon, Cambridge University Press, pp 52, Anno Domini 2014

When Mars was closest to the Earth in August 2003, the Macclesfield Astronomical Society held a star party at Jodrell Bank Observatory with quite a number of telescopes set up to observe it. As the evening progressed a consensus arose that two scopes were giving particularly good images; my FS102 4-inch Takahashi Fluorite refractor (at around £3500, or $5000, with its mount) and an 8-inch Newtonian on a simple Dobsonian mount newly bought for just £200($300). I personally preferred the view through the f/6 Newtonian but others thought that the FS102 gave a slightly better image, so we will call it a draw. It is worth discussing why these performed so well and, just as importantly, why perhaps the others did not.

From A Prologue of Two Scopes: Morison, I. An Amateur’s Guide to Observing and Imaging the Heavens, Cambridge University Press, xiii, Anno Domini 2014.

** The author chose these individuals based on both published and unpublished observations of planets available from historical archives and/or books, and having (ostensibly) sustained these observations over many years.

                                   Relevant Physical Principles

 

Resolution:

A telescope of diameter D cuts off a wavefront and blurs a point source to an image size, I,  given by I = lambda/D (radians). This can be converted to arc seconds by multiplying this result by 206265 giving I = (lambda x 206265)”/D.

Making both units of diameter and wavelength (arbitrarily set to 5.50 x 10^-9 m)  the same we obtain:

I = 0.116/D

This is similar to the more familiar Dawes formula (expressed in inches given by 4.56/D)

Thus resolution scales linearly with aperture e.g. a telescope with a diameter of 20cm will have an angular resolution twice that of a 10cm instrument.

Contrast Transfer:

Optical engineer, William Zmek, in the July 1993 issue of Sky&Telescope magazine, analysed the effects of a central obstruction on contrast transfer, arriving at this simple rule:

Contrast Transfer of an Obstructed Telescope = Full Aperture – Aperture of Obstruction.

Consider this author’s chosen planetary telescope, a 203 mm Newtonian with a secondary minor axis of 44mm (22% linearly), the resulting contrast transfer will be the equivalent of a 203-44 = 159mm unobstructed aperture, the effects of the spider vanes being essentially negligible (~1-2 %).

This result has been amply borne out by the author’s extensive field testing.See here for details.

Larger apertures also allow the observer to enjoy a larger exit pupil, which is of paramount importance in studying low contrast details at magnifications typically employed in planetary studies. See this link to see how a consideration of the size of the exit pupil can radically change the direction of a discussion about two very different telescopes.

Light Gathering Power:

Image brightness is proportional to the number of photons collected, which in turn scales as the area of the optical surface. Thus a 20cm telescope collects four times more light than a 10cm, all other things being equal. Refractors, having no central obstruction and multi-coatings applied to the glass surfaces have the greater light transmission. Reflective surfaces exhibit proportionally less transmission to the eye due to less efficient reflection off optical surfaces. In the same article highlighted above, the author described the acquisition of ultra-high reflective coatings (and greatly reduced light scatter) to both mirrors (97 per cent). Thus the overall transmission is (0.97)^2 =0.94 and subtracting the obstructing area of the secondary reduces the overall light gathering power to ~0.9. Compared with an almost perfectly light transmitting refractor object glass, this represents a 10% reduction in light, a value that even a seasoned observer would be hard pressed to see. Thus, the author’s 20cm Newtonian has a broadly equivalent light transmission to an unobstructed refractor of equal aperture.

Atmospheric Turbulence, Seeing Error & Viewing Altitude

The astronomical seeing conditions at a given site can be well described by the so-called Fried parameter r0. We need not wade into the mathematical details to understand the basic ideas behind this model. In this scheme of events the air consists of moving cells which form due to small-scale fluctuations in both the density and temperature above the observer, resulting in the blurring and/or moving of the image. The larger these cells are (which is a measure of r0) the greater the aperture that can be profitably employed. For telescopes with diameters smaller than r0, the resolution is determined primarily by the size of the Airy pattern (which scales as 1/D) and thus is inversely proportional to the telescope diameter. For telescopes with diameters larger than r0, the image resolution appears to be determined primarily by a quantity known as seeing error and scales as (D)^5/6. So, for example, a doubling of aperture results in a 1.78x i.e. (2D)^5/6 increase in seeing error. Interestingly, while the seeing error does scale with aperture, the rate of increase is not nearly as rapid as one might anticipate. This implies that large apertures can work at or near optimally, though maybe not as frequently as smaller apertures.

Reference here.

The best estimates of r0 for typical observing sites used by the amateur astronomers seems to be in the range of 5–20cm (2-8 inches) and generally larger in the better sites at high altitude, where bigger telescopes are pressed into service. Intriguingly, r0 also appears to scale somewhat with wavelength, being as high as 40cm at 900nm(near infrared).

Reference here.

Seeing is also dependent on the altitude of the planet owing to the variation in air mass through which it is viewed. If one observes a planet at the zenith, one looks through 1 air mass. At 30 degrees altitude, the air mass through which the observer views is fully doubled and at 10 degrees altitude it shoots up to 5.6 air masses!

Reference: Morison, I., An Amateur’s Guide to Observing and Imaging the Heavens, Cambridge University Press (2014), pp 22.

In general, a long-held tradition recommends waiting for the planet to rise above 30 degrees altitude to begin to exploit the potential of any given telescope, large or small.

Taken together, these physical parameters can be used to adequately explain all of the aforementioned comments made by celebrated planetary observers over the decades and centuries.

Discussion:

Unbiased testimonies provide a bedrock upon which sound conclusions can be formulated. It is self evident that aperture plays a crucial role in seeing fine detail and it is reassuring that basic optical principles reaffirm this.

The list of British observers quoted above; Denning, North, Moore, Abel, Grego, Heath and Sidgwick etc, highlight the efficacy of moderate but not large apertures in divining fine detail on planets. The consensus appears to be that apertures of between 6 and 10 inches are most efficacious in this regard. This may be explained in terms of the size of the atmospheric cells that move over British skies, which allow telescopes in this aperture range to be exploited. My own discussions with many experienced planetary observers abiding in Britain affirm the truth of this; British skies seem to favour these moderate apertures. It is important to note that this conclusion has little to do with planetary imaging, which often employs significantly larger apertures to excellent effect.

The testimony of Gary Seronik shows that an optimised 6-inch f/9 Newtonian – which presumably would provide views rivaling a 6-inch apochromatic refractor, was comfortably outperfomed by an 8-inch f/6 Newtonian, again confirming the superiority of a little more aperture.

The testimony of E.E Barnard at Mount Wilson and Adouin Dollfus at Meudon shows that larger apertures can be used to much greater effect if seeing conditions allow. Both Meudon and Mount Wilson have enabled telescopes of 30 and 60-inches to be used visually, indicating that the atmosphere can be particularly good there and for long enough periods to permit a meaningful program of visual study.

There evidently exists regions on Earth where the seeing is poor (small r0) for prolonged periods of time, explaining why amateurs in these regions stick to smaller apertures. This in part explains the popularity of small refractor culture.

The most intriguing testimony is offered by Professor Ian Morison, also based in the UK, which, on the face of it, seems to lend more credence to small refractor culture. The reader will recall that during the August 2003 Martian opposition, a large number of amateurs, fielding various telescopes, were present at Macclesfield, England. Morison claimed that two telescopes were doing particularly well; a Takahashi FS102 Fluorite refractor and a mass produced 8″ f/6 Dobsonian and that there was no clear consensus on which was delivering the better views. Having owned several econo- and premium 4 inch apochromatic refractors (and even a gorgeous 4-inch f15 classical refractor), this author (also based in the UK) has become intimately familiar with their performance. And while they all provided good views of the planets, they come nowhere near the performance of the author’s 8-inch f/6 Newtonian, which, despite its very modest cost, proved ‘crushingly’ superior to the former.

So, Morison’s testimony presents an apparent contradiction, which must have a rational explanation.

Further investigation revealed that during the August 2003 Martian opposition, the maximum altitude of the Red Planet was just 23 degrees at meridian passage as observed from London (51 degrees North latitude).

Reference here

Since Macclesfield (53 degrees North latitude) is further north than London, the maximum altitude of Mars would only have been 21 degrees and thus was significantly below the minimum altitude recommended – 30 degrees – for planetary study. Thus, it is not at all surprising that Morison et al reached the conclusions they did.The Newtonian being more sensitive to the vagaries of the atmosphere would not have been performing optimally at that low altitude, while the smaller refractor was performing much as it always does. In addition, this author observed Mars during the same August 2003 opposition using a 20cm f/10 Schmidt Cassegrain. At 56 degrees North, the planet was only 18 degrees above the horizon at meridian passage. Needless to say, the images of Mars were nothing to write home about.

Interestingly, this author reached the same conclusion whilst comparing visual drawings of Jupiter conducted with a Celestron 8″ f/6 Dobsonian during the mid-1990s with those delivered by a 5-inch refractor in much more recent apparitions. It was subsequently discovered that Jupiter was low in the sky in Aquarius at this time, while the 5-inch refractor enjoyed views of the Giant Planet situated much higher in the sky. Last year’s Jovian apparition revealed the clear superiority of the 8-inch f/6 Newtonian over the 5-inch under these more favourable conditions.

Thus there is no contradiction; aperture rules when conditions are reasonable to good. Anomalies only arise under sub-optimal conditions – persistent bad seeing, low altitude viewing etc – or if one telescope has not fully acclimated when the other has etc, hardly a fair test.

This author has brought the reader’s attention to the efficacy of a modified 8-inch Newtonian on all types of objects; deep sky, planets, lunar and double stars. These testimonies provide further evidence that such an aperture – 20cm – is probably optimal for British skies and many other environs besides.

De Fideli

Taking Back Visual Astronomy II: Resolving Binary Stars with Newtonian Reflectors

Octavius the Progressive.

Octavius the Progressive.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 De omnibus dubitandum

The Newtonian reflector has a long and distinguished history among dedicated observational astronomers. With the advent of generous aperture, silver-on-glass mirrors in the late 19th century, many more amateurs could enter the field and make valuable contributions to the study of the Moon and planets. What’s more, their comparatively enormous light gathering power compared with traditional refractors made it possible to see new morphological details of hitherto elusive deep sky objects, thereby aiding in their classification.

The traditional instrument of choice in double star astronomy has been the classical refractor. With their long, native focal lengths and excellent thermal stability, they are especially adept at separating point sources at very high magnifications, at or near the theoretical limit imposed by their aperture. Refractors don’t scale well though and become impractically cumbersome and expensive in apertures above 6 inches (and if you really want to do sub arc second work you’ll need something larger anyway). I have demonstrated in earlier work that more economical telescope designs – the Maksutov Cassegrain in particular- can be excellent double star instruments. Having used a large, 17cm f/16 Maksutov continuously for a year, this author debunked a long standing assumption about these telescopes that prevented many from exploring their considerable charms. Specifically, some prominent amateurs, perhaps in some desperation to justify the purchase of much more expensive refractors, cultivated the idea that large Maksutovs (and, by implication, other catadioptrics) would not acclimate. This assertion was found to be largely unsubstantiated, after extensive field testing showed that these instruments can and do work well, even in winter.

In more recent times, this author has begun to explore anew the many attributes of the Newtonian reflector. As described in an earlier review lasting about six months, a closed-tube 8” f/6 Newtonian reflector was found to cool quickly (typically 40 minutes for a temperature differential of 20C) – significantly faster than even a 5 inch refractor. What is more, no cooling fan was deemed necessary and the telescope offered up excellent, high resolution images of planets like Jupiter. What was most surprising however, was its ability to split tricky double stars when contemporary wisdom said otherwise. This led to further investigation by examining the historical literature in order to establish whether Newtonians were ever used for double star astronomy and, if so, how efficacious they were in this capacity.

Having explored the life and work of the Reverend T.W. Webb (1806-1885), it came to my attention that the celebrated 19th century observer had indeed used a large 9.25 inch f/8 silver-on-glass reflector made by George With to resolve very tight pairs at or close to the limit imposed by its aperture. As a follow up, double star observer, John Nanson, alerted me to the work of an obscure British 19th century observer – Kenneth J. Tarrant – who employed a 10.25 inch Calver reflector (probably a f/7 or f/8 relative aperture) during the 1880s and 1890s to not only observe double stars, but to measure them also!

I would invite you to examine the documents presented here, noting the dates and seasons when the measures were made, thereby providing information on the frequency and likely conditions (like English summer temperature swings) under which observations were conducted – as well as the measures themselves, some of which show that the mirror was indeed capable of resolving pairs at or near the theoretical resolution of the telescope. I canvassed the opinion of the double star expert, Bob Argyle, based at the Institute of Astronomy, Cambridge, for his take on Tarrant’s data. Specifically, I asked Argyle whether there was anything in the Victorian amateur’s data that would stretch credulity, calling his attention to Tarrant’s measures of 25 Canum Venaticorum.

“As far as I can see, looking at Tarrant’s results, these are what I would expect from a good Calver telescope – in fact he did not seem to stretch the telescope very often. Specifically 25 CVn looks very plausible – the current WDS mags are 5.0 and 7.0 so it’s somewhat brighter than the values Tarrant gives (and currently at 1″.7).”
Tarrant’s measures demonstrate three things;

1. The British climate allowed him to frequently work to very high standards, which included sub arc second pairs.
2. The Calver reflector must have produced images stable enough for mensurative purposes.
3. Tight pairs with very significant brightness differences (up to two or three stellar magnitude differences) were also resolved.

Not much else is known about Tarrant however. “I don’t know of any other references to Tarrant’s work, “ said Arygle, “but he seemed to hold the BAA Double Star Section together before WWI finished it, and probably deserves a paper from one of the historical groups.”

In more recent times, a number of other observers using Newtonian reflectors have come to the fore. This author has already brought to your attention some of the ongoing work of Christopher Taylor, who employs an open-tubed 12.5 inch F/7 Calver reflector to watch a number of sub-arc second pairs moving rapidly in only a few years. You can see a few images of his telescope here. In addition, I am mindful of the work of the French double star observer, Jean-Francois Courtot, who has resolved pairs down to 0.66” using his homemade, 8-inch Newtonian since 1993.

It would also be worthwhile considering the portfolio of the well known astronomical artist, Jeremy Perez, who has sketched many double stars using both a 6″ f/8 and a 8″ f/6 Newtonian reflector, as well as the observations of Mircea Pteancu, who has used a 8″ f/6 reflector to successfully resolve sub-arc second pairs.

Thus, not only is there a historical precedent for the use of the Newtonian reflector in doing the kind of work traditionally associated with the classical refractor, but the notion that the former instruments would only be capable of such work in tropical or temperate climates is not supported by the evidence.

That said, not all Newtonians are equally well favoured to carry out such work!

To see why, we need to explore aspects of the physics of the Newtonian telescope.

Modern parabolic mirrors of decent quality are (or should be) essentially devoid of spherical aberration. The main optical defects in the Newtonian are due to other Seidel aberrations, particularly coma and astigmatism. Let C represent coma and A represent astigmatism.

Mathematically, the angular expansion (theta) of the image due to coma is given;

C = 3theta/(16F^2) where F is the focal ratio (relative aperture) of the telescope.

Astigmatism is given by:

A = ( D/2f) tan^2(theta), where f is the focal length of the telescope.

Since D/f = 1/F and if we consider small angles, where tan (theta) expressed in degrees ~ theta radians, the formula for astigmatism simplifies to;

A = (theta)^2/2F.

We can see from the formula for both C and A that coma (C) scales proportionately with theta while A scales as (theta)^2, so that for very small angles ( << 1 radian) it follows that coma will always overwhelm astigmatism in any properly executed mirror.

Let us now set the resolution of the telescope to the Dawes limit (in arc seconds) given by 4.56”/D
To convert this formula to radians, we need to do some more arithmetic.

1 degree = 60 x 60 = 3600”

Also 1 angular degree = 1/57.3 radians =0.017 radians

Thus if 0.017 radians = 3600” then 4.56” = (0,017/3600) x 4.56 radians = 2.21 x 10^-5 radians

So the Dawes formula expressed in radians is:

(2.21 x 10^-5)/ D where D is in inches.

For critical work at maximum resolution we may equate the expressions for coma and astigmatism with the Dawes limit;

Thus,

A + C = (2.21 x 10^-5)/D

But since A << C for any small angles (which is appropriate here), we may simplify this to just:

C = (2.21 x 10^-5)/D

Thus, since we have C = 3theta/(16F^2)

We get: (2.21 X 10^-5)/D = 3 theta/(16F^2).

Cross multiplying and rearranging, we obtain:

Theta = (16F^2 x 2.21 x 10^-5)/3D

Simplifying gives theta (in radians) = (1.18 x 10^-4 x F^2)/D

For convenience, we can now convert this formula to arc minutes;

1 arc minute = 1/60 degree = (1/60) /57.3 = 2.9 x 10^-4 radians

So, 1.18 x 10^-4 = (1.18 x 10^-4)/ 2.9 x 10 ^-4 = 0.407

Thus our final result is that

Theta (arc minutes) = (0.407F^2)/D.

We are now in a position to analyse what happens when we use various different numbers for the focal ratio (F). The formula predicts that for a constant aperture D, the maximum available field (theta) over which the image contains no appreciable aberrations scales as F^2.

This means that the faster the F ratio, the smaller the true field over which aberrations are minimized.

For example, a 8 inch f/6 mirror would have an optically corrected radius of (0.406 x 6^2)/8 = 1.83 arc minutes or 3.66 arc minutes in angular diameter. Doing the same math for F=5 and F=4 yields diameters of 2.54 and 1.62 arc minutes, respectively.

To see how this impacts work at the eyepiece, consider my own telescope, a 8” f/6 Newtonian. In order to get adequate image scale for sub-arc second pairs, I like to use a magnification of 548x (3.5mm Baader zoom and 1.6x Barlow). Since my eyepiece has an apparent field of 72 degrees, the true field available at this magnification will be 7.88 arc minutes [ that is (72/548) x 60]. Thus, the percentage (linear) of the field that gives perfect definition will be (3.66/7.88) x 100 ~ 50 per cent. When we get to an F/5 system, the percentage falls to just 30 per cent, and at F/4, a pesky 20 per cent!

One can see that at F/5 or faster, positioning the image of the double stars will become problematical, but that’s not the end of the story!

As anyone familiar with the operation of a Newtonian will tell you, the lower the F ratio, the harder it is to collimate the optics accurately. Indeed, the sensitivity to mis-collimation (a quantity called primary mirror axial error) in millimetres is given by the 0.022 x F^3. It follows that the wiggle room for a F/6 Newtonian will be a comfortable 4.8mm but just 2.8mm at F/5 and only 1.4mm at F/4!

What does all this mean?

In a nutshell, the faster the F ratio of the primary mirror, the smaller the true field at any given magnification that is truly free of aberrations and the greater the likelihood of mis-collimation. I was being kind when I described the result linearly; but when you recognise the relevant field area (which scales with r^2), you suddenly realise you’re in deep water. X marks the spot! LOLl

These are the principle reasons why an F/5  or faster Newtonian will be less likely to resolve to the Dawes limit. F/6 is about good enough – thank goodness for small mercies! – and anything slower is a bonus!***

This also agrees with my own experience, having never satisfactorily resolved sub arc second pairs with an F/5 or F/4 Newtonian. It also agrees with the aforementioned historical curiosities!

Look again at Tarrant’s measures of 25 CVn conducted in the summer of 1885.

Octavius; a ‘scope to believe in!

***Note added in proof: The above calculations do not preclude the possibility that a precisely aligned, fast Newtonians (f/5 or slower) can’t do this type of work  but rather serve to illustrate that the difficulty of achieving these high resolution results becomes more difficult as the F ratio falls. Investing more money in precision focusers and more exotic collimating devices can increase the odds of success, as could the possibility of introducing optical accoutrements like coma correctors (now being made by various manufacturers) into the optical train.

References

Bell, L The Telescope, Dover (1971)

R.W. Argyle (Ed.) Observing and Measuring Visual Double Stars, Springer (2012).

Results so far: In the last six months or so, I have had the privilege of using this fine SkyWatcher 8-inch f/6 Newtonian reflector. As explained in an earlier review, I modified the instrument by purchasing a smaller secondary mirror (22 per cent by diameter) made by Orion Optics, Newcastle Under Lyme, England. I could have reduced this further but I wanted the telescope to be an excellent all-rounder rather than just a one trick pony. Both the primary and the new secondary were treated to enhanced Hilux coatings, which significantly increased its light grasp, reduced scattered light around images and has a longevity that is guaranteed for at least 25 years. Such an instrument provides breath-taking views of the Moon and planets and serves up a 2.25 degree true field for stunning deep sky vistas.

Even before I had these modifications done, I was very impressed by its ability to resolve some tricky doubles and triple systems. On the best nights, stars present as tiny Airy disks, round as buttons, even at very high powers ( > 500x). The spherical correction of the mirror is excellent and displays no on-axis astigmatism, which is a definite show stopper for this kind of work. My best images yet came just a few nights ago, where on the mild evening of Friday, June 26 at 22:20 UT, I beheld the most striking image of Epsilon Bootis (340x) I have seen in just about any telescope! The components – a soft yellow primary and a royal blue secondary – were magnificently rendered with acres of dark sky separating them. The same was true when I examined Delta and Mu Cygni, as well as Pi Aquilae (1.5″); text book perfect renderings if ever I have seen them!

At twenty minutes past midnight on the morning of June 9 last, I managed to glimpse the elusive companion to Lambda Cygni (my best yet at this location, 0.9” and 1.6 stellar magnitude differential), convincing me that I could go still further.

My methodology is fairly straightforward and is based on the recommendations of Christopher Taylor, who I mentioned earlier.

• The telescope is checked for accurate alignment using an inexpensive laser collimator before the commencement of each vigil and backed up by careful star testing.

• Only stars above a certain minimum altitude are examined, not less than 35 degrees

• I use a Baader Neodymium Moon and Sky Glow filter, which darkens the twilit sky at my location, reduces glare from very bright stars, and retains a neutral colour balance.

• After charging the telescope with the appropriate optical power, the stellar image is swung to the east of the field and left to drift slowly into the centre, where it is critically examined by my eye. The above is repeated again and again until I am satisfied that what I am seeing is not a diffraction artifact or some such.

• The time, date and conditions, magnification etc are always recorded. And if at first you don’t succeed……. try try again Lol!

In my correspondence with Bob Argyle, he was kind enough to suggest two stellar systems which are especially ripe for study with the 8-inch speculum; 78 UMa, now conveniently located near the bright star Alioth in the Plough Handle (components have magnitudes 5.02 and 7.88, with a current separation of ~0.8”) and Tau Cygni (magnitudes 3.38 and 6.57 with an angular separation of 0.9”).

I will begin with 78 UMa, as it should be fairly easy to find near Alioth in the twilight.  I shall leave Tau Cygni to later in the season.

I will report back on my progress in due course.

If you have a similar ‘scope at home, why not give it a try too?

If these stars are not suitably located for you, seek out others of similar difficulty by looking up the WDS catalog.

This project will certainly tax your powers of observation.

It would be great to hear about your experiences!

 July 1, 2015

NB: Taylor used a ‘routine’ magnification of 825x with his 12.5 inch f/7 Calver to achieve separations of 0.35 -0.40″ pairs. May attempt slightly higher powers on my own (smaller, 8 inch) telescope, perhaps 600x plus?

Nae luck as yet. A heat wave has settled in over the UK. While southern Britain basks in sunshine, conditions have remained stubbornly sultry with lots of cloud hampering any attempts to track down UMa 78.

Attempted a brief vigil late in the evening of Friday, June 26. Although my ‘easier’ test systems mentioned above all looked excellent, cloud prevented me from locating  my target near Alioth. I did however ‘uncover’ a delightful new binary system about half a finder field away from Alioth; STF 1662 ( RA  12h 36 min, Dec: 56 34, magnitudes 7.83 an 9.75, separation 19.3″).

Just received word that my article on modifying the SkyWatcher Skyliner 200P will be featured in the August 2015 issue of Astronomy Now………hallelujah!

July 2, 2015

Time 22:50h UT

Ambient: Clear, good transparency, 14C, slight SW wind, strong twilight, seeing not so hot (Ant III-IV), midge flies legion.

Four ‘warm up’ systems  observed @ 340x

Epsilon 1&2 Lyrae: well resolved.

Epsilon Bootis: resolved with some distortion.

Delta Cygni: Companion seen periodically, but with some considerable distortion.

Pi Aql: Resolved fairly well but only occasionally.

A 1.5″ night. Little point in continuing. Packed up early.

 July 4, 2015

Happy Holidays to all my viewers in the United States!

Moi?

Semper eadem.

Weather still rather unsettled, very humid with lots of heavy down pours, so little else to report from my own observations.

Investigo: I love data and admire diligence. Though I don’t know him from Adam, the American amateur astronomer, Mr. Tom Bryant, gave me both in bucket loads!

Mr. Bryant has been very busy testing the performance of his C8 on hundreds of double stars from all across the heavens.

You can see the fruits of his considerable labours here.

Go on; have a good, long look at that huge list. Dates (all year round!!!), times, instruments, are recorded, and, crucially, the location of those observations.

Input! Input! Input!

Lol!

And I see he’s constantly updating (see the latest dates listed).

Way to go!

He’s done remarkably well on many sub-arc second pairs don’t you think?

0.7″ doesn’t seem too much of a stretch for him and he’s elongated pairs down to 0.5″!

Here’s a recent review of a modern C8.

This instrument has a central obstruction of ~ 35 per cent and takes a while to acclimate…. apparently.

Here’s  the climate data for Bethesda, MD, which is quite near Silver Spring, MD, where Mr. Byrant uses his C8 inside his cosy, wee observatory, Little Tycho.

Typing in the months, one by one, we see diurnal swings of about 10C throughout the year, and which is a little larger than those encountered at my location.

My 8″ f/6 Newtonian, with a 22 per cent central obstruction, ought to do just as well – if not better – would you not think?

Only the seeing and my laziness can limit its performance.

Surely?

 July 5, 2015

Some thoughts on a lazy, Sunday afternoon:

The diligence of Tom Bryant and Carlos has delivered treasures to them. Work pays.

God endowed King Solomon with wisdom because he desired it ahead of wealth and power.Still, because of his faith, the Lord gave Solomon all three, and in great abundance.

Yet, he was better at dispensing that wisdom to others than applying it to himself.

In the proverbs of that ancient King, we learn of the traps laziness sets for us;

No matter how much a lazy person may want something, he will never get it. A hard worker will get everything he wants. 

Proverbs 13:4

A lazy person is as bad as someone who is destructive.

Proverbs 18: 9

Why don’t lazy people ever get out of the house? What are they afraid of? Lions?

Proverbs: 26:13

Nuff said, eh?

20:30 UT

At last, another opportunity will likely present itself later this evening to visit 78 UMa.

With a bit of luck, I’ll have more to report back on soon enough.

But let’s not confuse ourselves. There is one telescope forum in particular that harbours a few lazy liars I’m in the processing of flushing out.

Folk who masquerade as being ‘experienced’ but ostensibly reveal very little of that quality. Nor do they show any real insight except that which they borrow from others.

They neither understand their observing environment, nor the kinds of instruments that would best work there. e.g. using a large, fast reflector to split low-altitude double stars in a desert?!

How dumb is that? Lol!

But this is just ignorance, and I’m willing to overlook that.
That said, there’s a more insidious side to all this, which I am not willing to overlook.

Lies, lies, porky pies.

You see, some individuals spend their time cultivating untruths about what can and can’t be done with certain telescopes, without ever testing these claims in a scientific way.

Worst still, they persist in maintaining these myths, despite the mounting counter-evidence presented to them.

I suppose it’s a form of blindness.

Why shouldn’t a Newtonian deliver the readies?

If you know, tell me; I’m all ears!.

iustitia! iustitia! iustitia!

July 6, 2015

00:20h BST.

Ambient: Mostly clear, tranquil, cool (10C), twilit.

Seeing: II-III

A better night tonight. Seeing fairly good.

All warm up systems beautifully resolved at 340x

0.9″ companion to Lambda Cygni well glimpsed at 548x during moments of better seeing

78 UMa: diffraction pattern examined on and off for 20 minutes at 548x. Higher powers found to be unhelpful. Companion unseen.

Heavy dew this evening.

Good, productive night, all in all.

22:25UT

Teeming down with rain tonight.

Thus far, it’s not the kind of Summer we enjoyed last year.

Still, when are two ever the same? lol

Moi?

Semper eadem.

It occurred to me that I’ve already achieved what I set out to demonstrate; that a decently executed Newtonian can be used to explore the dynamic realm of sub-arc second binary star astronomy; I mean, I’ve already bagged (a few times now) a 0.9″ with a sizable brightness differential (1.7), so anything beyond that just reaffirms my premise.

But I don’t think I’m being overly ambitious to work for something better. Do you?

I will continue to work with 78UMa until the skies get darker.

July 8, 2015

00:30h BST

Test everything; hold fast to what is good.

                                                                   1 Thessalonians 5:21

Ambient; mostly cloudy, 13.5C, a few patchy sucker holes opening and closing. Breezy (7mph westerlies).

Seeing: II, certainly a notch up on last night.

Only three test stars examined tonight; all images at 340x were clean and crisp but shaky in the wind.

Spent a few minutes on and off examining 78UMa at 340x and 544x. Complex diffraction image, no elongation observed at 544x, so the companion must be ‘disembodied’ from the primary (Airy disk round as a button). Wind and cloud making detailed observations very difficult. Companion unseen.

I have noticed, going back through my notes, and again tonight, that on windier evenings, the images through the Newtonian can look especially fine. I have thought about why this might be. Perhaps the breeze circulates the air inside the tube more efficiently and might be ‘brushing off’ any boundary layer that might be on the mirror?

I think there is something in this.

Mother Nature lending a helping hand, just as she must have done with other observers using their specula over the decades and centuries.

Thank goodness for the wind!

09:50h BST

Last night was most interesting. Not much in the way of systems observed but the quality of the images in the modest wind was duly noted.

It was such a simple revelation to me that I cannot help but think it is universally true.

My previous observing records with refractors and a large Maksutov have shown that good to excellent seeing can accompany windy weather. I look back fondly at the wonderful skies of last Summer, where I got superb results with a 17cm Maksutov. I note especially my observations made on the evening of July 16, 2014, where the Maksutov cleanly resolved Lambda Cygni  during a windy (9mph) spell.

In the case of the Newtonian, I think windy conditions can have additional benefits in improving image quality, independent of the seeing.

Open air observing with Newtonians appears to be a good thing and I shall continue with this custom.

Might a fan be beneficial?

Maybees aye, maybees naw.

Would I consider installing one?

No.Ohxi.

I get enough breezy evenings in a year to continue as I am.

Besides, I am willing to bet that the foolishness of the wind is smarter than the ingenuity of any man-made fan.

A curious aside: Our Victorian friend, Kenneth J. Tarrant, observed 25 CVn with his Calver reflector on the 189th day of the year. Curiously this was July 8, 1885 – almost exactly 130 years ago today!

LoL!

I found some old British archives for the general weather for that month here.

I note that in this meteorological document, for the dates July 7-11, there were ‘favorable South-westerly winds in most places’.

Might  Mr. Tarrant have enjoyed a few breezy evenings when he made these measures?

I wonder!

July 9, 2015

00:20h BST

Ambient: Clear, cloudless sky, very beautiful twilight, no ground wind, unseasonably cold (6.5C), seeing III-IV. Cool Arctic air flow tonight; bright stars scintillating strongly.

Test systems all resolved, but the more difficult ones not so cleanly. U78Ma examined at 340x an 544x but too turbulent to study.

Vigil aborted.

11:20h BST

I have been thinking about the wind again and how best to use it. When Mr. Tarrant observed 25 CVn, his telescope would have pointed westward, towards Canes Venatici, and if there were a southwesterly breeze during the time he observed the system, some part of it would have blown over his Calver primary mirror.

This immediately presented a simple activity that I could use profitably during breezy evenings. When first placed outside, I could remove the cap that covers the front of the instrument and point the telescope directly into the prevailing winds. That way, the air would be blown over the mirror and it would help expel any ‘stagnant’ air inside the tube.

When observing an object in a part of the sky away from the natural direction of the wind for any prolonged period of time, I could swing the instrument back into the natural air flow  periodically, for a minute or two perhaps, before resuming my work.

I did some searching this morning to ascertain if anyone had recommended this procedure, either in printed texts or online. To my astonishment, I came up with nothing.

Maybe you know better?

In addition, I have been looking at images of those silver-on-glass reflectors of old (existing before the era of the electric fan) and noticed that many of the tubes have little hinged  ‘windows’ at the side, near the primary mirror, so as to assist (presumably) the circulation of air in the optical train. I may consider something along these lines myself; perhaps drilling a coupe of small holes on opposite sides of the tube and fitting a fine wire gauze over them to enable air to flow through but not particulates.

I can make the wind work harder for me.

Something to think about anyways.

To my chagrin, more unsettled weather is forecast for the weekend ahead.

Mair anon..

July 13, 2015

23:45h BST

Ambient: almost entirely clear, tranquil skies, seeing excellent (I-II), 10C, humidity high.

Success!

Started on Delta Cygni (340x) and was rewarded with a beautiful calm image! Companion resolved from its primary by a veritable country mile.

Pi Aql: Very cleanly resolved (340x) even at less than optimal altitude.

78UMa: Companion seen fairly well, roughly due east of the primary and inside first Fraunhofer diffraction ring. Glimpsed at 22:50h but better seen at 23:30h.  Checked the WDS data on the system Der Admiral sent me the other week. Its estimated position angle of ~118 degrees agrees fairly well with my observation.

No’ bad ken.

Where next Columbus? LOL

Anyone following me?

Vigil ended owing to heavy dew.

July 14, 2015

Bastille Day, New Horizons hurtles past Pluto, ken.

20:00h

Consummatum est.

No more to prove. No more work to be done. No one left to fight.

A 8 inch f/6 reflector can indeed be used to resolve sub arc second pairs. You don’t need an expensive telescope to do it.

A little preparation and the determination to succeed is all that is required.

And one good night.

I contacted Bruce MacEvoy, who I had the pleasure of meeting in California a few years back. He will be editing a brand new edition of the Cambridge Double Star Atlas. Bruce followed my work with the Maksutov and, more recently, the Newtonian reflector. After congratulating him on his new role, I reminded him that he had a responsibility not to cultivate untruths about the types of telescopes that can and cannot do high resolution double star work. He assured me that the atlas will not endorse the fallacy that one type of telescope is superior to others.

Satis.

Nota Bene: November 29, 2015: Dave Cotterell, based in Ontario, Canada, posted a string of high resolution images of double stars – some quite tricky for any telescope – using his 12.5″ f/6.5 Newtonian, thereby providing more evidence that these instruments can and do make excellent double star ‘scopes. In addition, he has reported his visual results here, using the same instrument, showing that he was able to cleanly resolve pairs down to 0.5″ or  0.6″. Well done Dave!

De Fideli

 

Origins of Life: A Closer Look Part II

Imitation is the sincerest form of flattery!

 

 

Continuing a critical analysis of Professor Jack Szostak’s Origin of Life scenario proposed here.

See Part I for comments on earlier sections of the video

The goal: to critically appraise each of the steps Dr. Szostak presents in light of the latest research findings that show that any such scheme of events is physio-chemically untenable from a purely naturalistic perspective.

Video Clock Time 10-30 mins

Dr.Szostak’s RNA chains contain homochiral ribose (D ribose) though he has not disclosed how this D ribose originated. This is a crucially important point that the reader must gain an appreciation of. This will be discussed on this page.

No D ribose, no nucleotides, and no oligonucleotide chains.

                                                            Imago

Dr. Szostak completely avoids another intractable problem for his chemical synthesis scenario; that of the homochirality of sugars and amino acids. As shall be outlined in the next section, this is a very exciting and fast moving arena of research (owing to the pressing nature of the underlying problem), but as I shall demonstrate, it is still a mystery.

One of the key molecular features of life is that its major polymers are built up from chiral molecules. Chiral molecules exhibit handedness. All celllular life on Earth utilises left handed amino acids ( L amino acids) and right handed sugars ( D sugars). The L and D forms of the same molecules are called enantiomers and can be distinguished by how they rotate the plane of plane-polarised light in aqueous solution (either to the left or right) Because amino acids and sugars in all life on Earth exclusively incorporate L and D enantiomers, respectively, they are said to be homochiral.

The problem begins when scientists set out to explore synthetic means of producing molecules such as ribose, which almost invariably produce a 50:50 mixture of both enantiomers. Such a condition is said to be racemic.

To maintain biochemical viability, the ribose must be 100 percent in the D enantiomeric form; mixtures will soon grind any synthetic scheme to a halt.

Reference: Biochemistry Voet, D. & Voet J.D, (2011) Wiley pp 74-75.

Looking for solutions: what the latest research (as of 2015) has revealed

Scientists have been searching for many decades for a solution to the homochirality problem. One source was shown to occur via the production of 100 per cent circularly polarised light derived from the vicinity of black holes and neutron stars. This light selectively destroys one enantiomer over the other, with the result that one chiral form is selected for. The problem with this astrophysical source is that it only generates 20% enantiomeric enrichment, not enough to allow life processes to proceed or to explain the homochirlality problem.

Reference: Hazen, R.M., Life’s Rocky Start, Scientific American (April 2001)  77-85.

Molecules are not the only entities that exhibit mirror images of each other. In physics, the parity principle states that physical processes that display symmetry about a central plane operate as mirror images. According to this principle, nature shows no preference for either left- or right-handedness. In the 1950s however, physicists discovered an exception to this rule, referring to this interesting idea as a parity breaking. Chinese physicists demonstrated that the electro-weak force displays a slight preference for left-handed  amino acid enantiomers . When a radioactive nucleus undergoes decay via the weak nuclear force, it emits polarised light with a slight left-handed bias. Some physicists have suggested that this parity breaking could have led to homochirality. But since the energy difference between enantiomers is only of the order of 10 J Mol^-1 it would have no appreciable effect on chemical reactions, a situation endorsed by leading astrobiologists.

Reference: Rikken, G. L. J. A. Rikken & Raupach, E., Enantioselective Magnetochiral Photochemistry, Nature, 405 ( 2000), 932-35.

The inconvenient truth about homochirality in biochemical systems has led some more zealous scientists to uncover chemical means to surmount the problem. The most promising of these will be discussed here.

One way to create some chiral excess is a process called oligomerisation. Biological polymers are built up of subunits called monomers. By chemically linking up these monomers a polymer is created. An oligomer is an intermediate state between a monomer and a polymer, usually having several tens of monomer units. Some laboratory studies have shown that oligomerisation reactions are inhibited  when a racemic mixture of monomers is incorporated into the reaction.Specifically, if the researchers add the opposite enantiomer of a nucleotide during the oligomerisation of RNA nucleotides, the addition inhibits the reaction. This, some researchers have suggested, provides a way of producing homochiral polymers.

Reference:Joyce et al, RNA Evolution, pp 217-24.

The main problem with this model resides with the probability of assembling sufficiently long RNA oligomers for it to allow the process to occur in a realistic prebiotic setting. To get anything viable, at least 50 subunits must be routinely produced and preferably much longer chains. As a result, most researchers in the field now consider the probability of this mechanism favouring homochirality to be too remote to be a viable option. Others have suggested that enantiomers with the same handedness could react preferentially to form the oligomer chain. However, no such selectivity  has thus far been observed in laboratory experiments.

Theoretical work first conducted in the 1950s by the chemist F.C. Frank showed another way forward; Asymmetric Autocatalysis.

A chemical reaction in which one or more products serve as a catalyst is called autocatalysis. In this process, the enantiometric products selectively exert  their catalytic activity driving the production of one or more compounds of the same molecular handedness. In exact racemic mixtures, asymmetric autocatalysis would lead to no chiral excess. In reality however, chemical reactions are never an exact 50:50 mixture. Statistical fluctuations cause nearly imperceptible imbalances of enantiomers. This slight excess, created by statistical fluctuations- can be amplified. One demonstration of this mechanism is called the Soai Process, after the Japanese chemist, Kenso Soai, how first  elucidated it in the 1990s.

Reference:Blackmond, D.G,  Asymmetric Autocatalysis and its Implications for the Origins of Homochirality, Proceedings of the National Academy of Sciences (PNAS),101, (April 2004) 5732-36.

The Soai process involves the alkylation of pyrimidyl aldehydes by dialylzincs. The product of this reaction is a pyrimidyl alcohol that can exist in left- or right-handed enantiomers. Soai discovered that the alcohol products catalyses this transformation. As the pyrimidyl alcohol products are produced, statistical fluctuations cause these compounds to display a slight excess of one of the enantiomers over the other. This minor imbalance sets up asymmetric autocatalysis i.e. the more abundant enantiomer selectively catalyses the production of its corresponding chiral counterpart Over time, chiral excesses on the order of nearly 99 per cent can be achieved.

Soai’s discovery may sound like a plausible breakthrough to creating homochirality but significant problems remain. For one thing, the Soai reaction has no relevance in biological systems as none of the reactants and products have been documented in bona fide biological systems.In addition to this, this reaction is the only real-life example of asymmetric autocatalysis discovered to date.

Further theoretical studies of asymmetric autocatalysis reveal that the chiral excess produced by this reaction is short-lived; because it rapidly decays from near 99 per cent chiral enrichment back to the racemic condition (50 per cent) caused by the activity of the other enantiomer, which also acts as an autocatalyst, competing with its mirror image. Curiously, this does not occur in the Soai reaction because the enantiomer that achieves an excess not only acts catalytically but also acts as its own anticatalyst. The oddity of the Soai process is more a reflection of the scientist’s genius in recognising the underlying mechanism  and pursuing it experimentally and not a general chemical principle.

Other chemists and astrobiologists have looked for other autocatalytic mechanisms that are relevant to studies of prebiotic chemistry. In particular, chemist Sandra Pizzarello and Arthur Weber have shown that the amino acids alanine and isovaline (which show slight chiral enrichment in the Murchison meteorite) can catalyse the formose reaction leading to ribose.

Specifically, when amino acids that catalyse the formose reaction harbour a chiral  exess, the sugar products generated also display a chiral excess. In other words, the amino acids are able to transfer this chiral excess  to the sugar products. Researchers observed that when the amino acid catalysts were enantiomerically pure, the sugar products displayed a chiral enrichment of up to 10 per cent. Yet, as the enantiomeric purity of the amino acid declined, the chiral excess of the sugar products also decreased. Of particular note is that when the enantiomeric imbalance of the amino acid catalyst reached 10 per cent, the chiral excess in the sugar products became imperceptible.

Further research by the same scientists showed chiral enrichment when homochiral dipeptides were used as catalysts.

Reference: Pizzarello, S., Weber, A.L., Prebiotic Amino Acids as Asymmetric Catalysts, Science 303 ( February 20, 2004), 1151.

A dipeptide consists of two amino acids that have undergone a condensation reaction, linked by a peptide bond. Curiously, the dipeptide catalysts yielded an 80 per cent chiral enrichment, raising hopes that this could have been the breakthrough origin of life researchers were looking for. But, yet again, there are problems with this scheme of events. As shown in Part I, it is not at all clear where such homochiral dipeptides might have originated from. Carbonaceous chondrites have been suggested as a possible source. In addition, relatively high concentrations of these dipeptide catalysts were required in laboratory experiments to generate this chiral enrichment, so much so that stretches credulity that the concentrations required were ever attained on the primordial Earth. But there are more sonorous reasons why either asymmetric or symmetric autocatalysis could ever have been a viable option; which derives from the properties of chiral molecules themselves.

Firstly, the dipeptide catalyts require extremely exacting pH and temperature regulation if they are to act out their roles. In other words, this phenomenon only works within very narrow temperature and pH regimes, something very unlikely to occur on the primordial Earth. A chemical process that does not have geological relevance creates a further problem for chemical evolutionary models for the origin of homochirality. Worst still, the examples explored above which generate homochiral excess are transitory at best. The reasons are due to the fact that enantiomers establish a dynamic equilibrium with each other that cause them to flip flop between enantiomeric states; a process called racemisation. This process causes enantiomerically pure compounds to transform over time back to their racemic form through structural inversion. Laboratory studies estimate that a set of homochiral amino acids would become completely racemic in one thousand years at 50 C and in one million years at O C under dry conditions, but much faster under aqueous conditions.

References:

Bada, J., Origins of Homochirality, Nature 374, (April 13, 1995), 594

Irion, R., Did Twisty Starlight Set Stage for Life, Science, 281 (July 31, 1998), 627.

Curiously, a paper published in Nature Communications in December 2018, raised considerable concern about the practices of prebiotic chemical research. In particular, the author (Richert), expressed concern over the number of human interventions needed for such research to be conducted and that “the hand of God” phenomenon, as the author himself put it, was not being addressed.

Source: Richert, C. Prebiotic chemistry and human intervention, Nature Communications 9, article number 5177 (2018)

https://www.nature.com/articles/s41467-018-07219-5

The consequences of racemisation are troubling for chemical evolutionary scenarios, because even if homochiral excess could be achieved, it could not be realistically maintained  on the primitive Earth. The important point to remember here is that all such studies ignore, or fail to account for, the transitory nature of achieving chiral excess. This means that because the researchers have to stop and start their experiments as soon as they achieve some enrichment, they unconsciously cultivate a false sense of success.This is intelligent design through and through!

                                              A Closer Look at Hydrothermal Vents

Dr Szostak has emphasised prebiotic molecule synthesis at hydrothemal vents. The origin of these ideas come from a team of Japanese researchers who had searched for ways that homochirality could be produced at such sites. In their simulation studies, designed to mimic hydrothermal vents, these investigators noticed that both left-handed and right-handed versions of the amino acid alanine undergo racemisation from a pure state at 230 C in a matter of 30 to 40 minutes. To their surprise however, the left handed enantiomer is racemised to a slightly lesser extent than the right-handed counterpart. This effect was concentration dependent however, occurring when there was only unrealistically high concentrations of alanine present.

Reference:

Atsushi Nemoto et al, Enantiomeric Excess of Amino Acids in Hydrothermal Vents, Origins of Life and Evolution of Biospheres 35 (April 2005), 167-74.

                                                       PNAs and that…...

These studies prompted the late Stanley Miller to formerly acknowledge the intractability of the problem of homochirality’s origin. As a consequence, he proposed that the first replicating molecules were achiral peptide nucleic acids (PNA).

Reference:

Nelson, K.E., et al, Peptide Nucleic Acids Rather Than RNA May Have Been the First Genetic Material,  PNAS, 97 (April 11, 2000): 3368-71.

Miller was drawn to these models because he knew no meaningful progress could be made using sugar- or dipeptide-based catalysts, as discussed above. PNA chemistry is simpler, because neither does it contain sugar or phosphates and because they can form base pairs as well as helical structures. The nucleobases of PNA are joined together through a molecule of acetic acid and a chiral amino acid of non biological origin; 2-aminoethyl glycine (AEG). For a PNA origin-of-life scenario to be viable, a plentiful source of acetic acid, nucleobases and AEG had to identified. To date, only acetic acid synthesis has been achieved and AEG has not been detected either terrestrially or extraterrestrially.

Miller’s PNA molecules  have other problems however; they are stable; too stable.They bond very strongly to any daughter molecules they may have replicated but could only do so very slowly, too slowly to be relevant to realistic origin-of-life scenarios.

                                                             Mineral Surfaces

Another possibility for the origin of homochirality is via mineral surfaces, discussed by Dr. Szostak in his video. Some mineral surfaces can indeed generate chiral excess, which has given rise to some optimism in the prebiotic chemistry community.

Reference:

Hazen, R., et al, Selective Absorption of L-and D-Amino Acids On Calcite: Implications For Biochemical Homochirality, PNAS 98 (May 1, 2001) 5487-90.

This proposal involves clays and mineral surfaces with highly specific chemical and spatial orientations – like quartz and calcite – that can selectively absorb either left- or right-handed enantiomeric substrates. Curiously, it was discovered that when these surfaces were exposed to dilute solutions of amino acids, they will differentially become absorbed onto these surfaces creating a chiral excess.

Reference: Ibid

But let’s take a closer look at this process. For one thing the mineral surfaces must be ultra clean. The actual laboratory protocol for creating these surfaces involves successive washings in this order; deionised water, ultra-pure methanol, methylene chloride, more ultra-pure methanol and finally another soaking in deionised water. No contamination can be tolerated to even get the process started.

This in and of itself raises serious doubts as to the validity of using clay surfaces as loci for the naturalistic generation of chiral excess, as no real life site could be expected to offer such ultra clean surfaces. What is more, such crystal structures actually occur in two forms – opposite in their chiral specificity. This would produce only very small and geographically dispersed opportunities for any absorption to take place, preventing the build up of high enough concentrations of prebiotically relevant reservoirs of such molecules.

References:

Hazen, R., et al, Selective Absorption of L-and D-Amino Acids On Calcite: Implications For Biochemical Homochirality, PNAS 98 (May 1, 2001) 5487-90.

Thomas, J.A & Rana. F, The Influence of Environmental Conditions , Lipid Composition, and Phase Behavior on the Origin of Cell Membranes, Origins of Life and Evolution of Biospheres, 37( June 2007): 267-85

                                    Crystallisaton-induced Homochirality Studies

One more mechanism of achieving chiral excess has been recently explored; crystallisation. The great French chemist and microbiologist, Louis Pasteur was one of the earliest investigators of homochirality, when he was able to distinguish between L tartaric acid and D tartaric acid using a microscope. This chiral preference occurs with other substances too and leads to the formation of enantiomerically pure crystalline forms. This curious phenomenon has encouraged researchers to investigate whether this differential ‘sifting’ of prebiotic molecules on the primitive Earth could have led to homochirality.

When evaporated to dryness in the presence of a porous material, the amino acids, aspartate and glutamate will form crystals that are enantiomerically pure. But this is the exception rather than the rule because, under, normal circumstances the crystals usually form racemic arrays. However, in the presence of some porous materials, they can form supersaturated solutions during evaporation, and, as a result, produce chirally pure crystals.

Researchers led by Ronald Breslow (whose names also makes an appearance in Szostak’s presentation) of Columbia University suggested that it was in fact the material that was left behind in the solution during the crystallisation  event that was the source of the homochirality and went on to show this was indeed the case for the amino acid phenylalanine. While the crystal contained a racemic mixture of the amino acid, the aqueous phase became enriched with the enantiomer that initially showed a slight statistical excess. Furthermore, Breslow et al showed that a chiral excess of about 1 per cent can be amplified to about 90 per cent after just two successive rounds of crystallisation. They envision a scenario on the early Earth, where carbonaceous chondrites might have seeded the oceans with amino acids. Tides would then wash these amino acids onto ancient beaches and, after evaporation, crystals would form and a slight chiral excess of the other enantiomer. This, they claim, would have slowly caused the build up of one enantiomer over the other, leading the way to homochirality.

Reference:Science Daily, Meteorites Delivered the Seeds of Earth’s Left-Hand Life, Experts Argue, (April 7 2008).

But this reasoning is flawed. Dr. Fazale Rana, in his recent book on the matter, Creating Life in the Lab, presented the reason why; amino acids tend to stay single in aqueous solutions and not form higher order structures like peptides. This is thermodynamically the most stable state for them in this environment. The Columbia University researchers have tried to counter this argument by suggesting that condensation reactions would begin during the drying out phase in this scheme of events.. But as Dr. Rana has pointed out, these amino acids would be a racemic mixture with little or no chiral excess. Thus, the mechanism proposed as the origin of homochirality would in fact inhibit the process! In addition to this, any dipeptide exposed to the fierce UV flux from the Sun (remember there was no ozone layer) would quickly degrade them. One need only look at how biotechnology companies recommend they be stored to verify this (personal communication). See here and here for examples.

Reference:

Rana, F., Creating Life in the Lab, (2011) Baker Books.

Summary:This section discussed at length the concept of homochirality, the handedness of life’s sugars and amino acids. Szostak’s RNA chains were all produced with pre-primed nucleotides, replete with ready made D-ribose. The work illustrated shows that producing D ribose under credible prebiotic conditions (and indeed the L amino acids) has not been satisfactorily achieved and that any process that attains significant chiral excess is actually the result of careful  adjustment of the experimental conditions and artificial selection of specified outcomes; again the manifestation of intelligent design. As we have seen, the inherent tendency for an enantiomeric excess to rapidly return to its thermodynamically most stable state, that is, racemic, would severely curtail or completely halt any realistic abiogenic scheme. The probability of achieving true homochirality via naturalistic mechanisms is very highly unlikely, if indeed well nigh impossible.

I leave you with a quote from Francis Crick and Leslie Orgel’s book: Life Itself

An honest man, armed with all the knowledge available to us now, could only state that in some sense, the origin of life appears at the moment to be almost a miracle, so many are the conditions which would have had to have been satisfied to get it going.

Video Clock Time: 30-54 minutes

On Vesicles:

One of the basic properties of living cells is their ability to maintain a chemical environment distinct from the space surrounding it. Life exists in the world and despite of the world, but is not of the world. This is achieved by creating a membrane which separates internal chemistry from external chemistry. Researchers have known for many years that under laboratory conditions certain kinds of molecules – what Dr. Szostak calls amphiphiles – made from fatty acids and phospholipids, which can form spherical structures called vesicles. An amphiphile is a molecule which has has both hydrophobic and hydrophilic natures. We are all familiar with the old adage; oil and water don’t mix. That’s because oil does not have chemical groups that can stably interact with water, blending with it, to create a solution. They are said to be hydrophobic because their chemistry does not permit them to dissolve in water. Molecules that have the right chemical groups to stably interact with water are said to be hydrophilic. Sugars are good examples of hydrophilic molecules. An amphiphile, as its name implies, has both hydrophilic and hydrophobic properties, allowing them to form unstable suspensions in water, usually in the form of single-layered micelles. Phospholipids – the components of real cells – and fatty acids (discussed by Szostak) possess such amphiphilic properties. When shaken up in an aqueous environment, they arrange themselves in such a way that their hydrophobic ends huddle together, like oil, and their hydrophilic end points outwards to form stronger interactions with water. The most stable (read lowest energy) arrangements are spherical structures – the vesicles that Szostak describes in his video.

Superficially, these vesicles look like cells and have served as a starting point to create the protocells he describes. As Dr Szostak explains, these membrane-bound vesicles can segregate materials located inside them from their surrounding environment.

As well as providing a physical barrier from the outside world, membranes harbour proteins that act as channels and transporters of molecules both into and out of the cell . They also act as sensors of the environment, as well as energy transducers. Synthetic biologists such as Dr. Szostak have to figure out not only how to form vesicles but also enable them with a means of transporting substances across their boundaries. One way forward is to try to manipulate the chemical structure of these amphiphiles in such a way that they can incorporate proteins both inside and on the membrane in order to serve as pores, environmental sensors and energy transducers.

As most any high school student of biology will tell you, reproduction is one of the basic characteristics of all living cells and this ability fundamentally resides in its DNA, which is replicated and then partitioned into two daughter nuclei before the cell fissures. Scientists must thus find ways to encapsulate DNA (or in this case RNA) molecules within the vesicle. When supplied with the right mix of chemicals, the encapsulated genetic material can then be used to synthesise proteins, which in turn could at least set the stage for the replication of the ‘protocell.’ The trick is to find a way to get the vesicle to divide in two, and in such a way that ensures that each new daughter vesicle has a copy of the genetic material.

So the process can best be seen as a series of steps which include;
1. The membrane has to be assembled.
2. Development of an energy transducing capability by the boundary membrane.
3. Genetic material must be encapsulated into the vesicle.
4. Pore proteins must be added that can funnel material into and out of the vesicle.
5. Generation of membrane bound systems that allow complex molecules to grow.
6. Generation of catalysts to speed up any given chemical process within the vesicle e.g DNA/ RNA replication.
7. Introduction of information-rich molecules that can direct the synthesis of other molecules of benefit to the developing chemical environment within the vesicle
8. Development of mechanisms that cause the boundary membrane to subdivide into smaller systems that can demonstrate ‘growth’.
9. Development of a means to pass information containing molecules into the daughter vesicles.

As you imagine, this is an incredibly complex process, effortlessly achieved by even the simplest living cells, but the list serves to illustrate one approach to the creation of artificial life; the so-called ‘ground up’ approach. This is the approach adopted by Szostak and his team.

Starting in the 1990s, he and his colleagues have exerted great effort into getting vesicles to grow and divide, getting genetic material to replicate and evolve within these vesicles and the creation of artificial proteins by either synthesising them under laboratory conditions or utilising pre-existing proteins that have been genetically engineered. Szostak coordinates several teams of scientists who bring as many of these steps together to create states that indeed show some of the characteristics that we would recognise as ‘alive’.

Like all scientists, Szostak builds his work on the shoulder of others who have pioneered methods to produce vesicles from purified phospholipids, trap molecules of interest within them and then incorporate purified proteins into the vesicle walls. Synthetic biologists like Szostak strive to capitalise on the vesicle forming properties of amphiphiles in order to construct protocells. The first such experiments began with the pioneering work of membrane biophysicist Pier Luigi Luisi, who encapsulated ribosomes (the molecular machines which carry out protein synthesis and other chemical components within phospholipid vesicles and, in so doing, managed to create an artificial protein – polyphenylalanine – within the vesicle.

Reference:

Oberholzer, T., Nierhuas, K.H. & Luisi, P.L., Protein Expression in Liposomes, BBRC, 261, (August 1999) 238-41

This work was followed up by other researchers who investigated ways of designing protocells consisting of vesicles made from simpler amphiphiles such as fatty acids, because they were considered more versatile than phospholipids (which are actually found in real cell membranes). Luisi and his collaborator Dr. David Deamer (cited on Szostak’s slides). By the early 2000s, Deamer‘s group showed that fatty acids can indeed assemble into bilayers ( just like real cell membranes) but under highly specific conditions, of concentration, pH, temperature and salt concentration. Furthermore, all of these conditions vary considerably between fatty acid species.

Reference:

Hanczyc, M.M., Fujikawa, S.M.,Szostak, J., Experimental Models of Primitive Cellular Compartments, Science 302 (October 2003): 618-22.

Luisi’s team showed that certain kinds of these vesicles can ‘grow’ if supplied with more fatty acids. This causes the vesicles to enlarge, become unstable, before dividing into two daughter vesicles. The same researchers have used fatty acid vesicles to encapsulate interesting enzymes such as polynucleotide phosphorylase, which uses adenosine diphosphate (ADP) as a substrate to build the DNA analog called polyadenylic acid.

Reference:

Thomas, J.A & Rana. F, The Influence of Environmental Conditions , Lipid Composition, and Phase Behavior on the Origin of Cell Membranes, Origins of Life and Evolution of Biospheres, 37( June 2007): 267-85

This was widely cited in the origin-of-life community as a sort of ‘proof of concept’ that genetic material could indeed replicate inside vesicles and hence a demonstration of the first step towards the generation of self-replicating protocells.

Szostak’s group built on all these successes to attempt to create more life-like protocells. Specifically, they allowed fatty acids to interact with mineral surfaces (discussed above) and showed that this improves the efficiency of vesicle formation.

Reference:

Ibid

But vesicles constructed from fatty acid substrates have marginal long-term stability. Another show stopper is that even small amounts of salts (ionic substances) completely inhibit vesicle formation, a point completely avoided by Dr. Szostak. What’s more, the consensus opinion is that primordial oceans would have had a higher salinity than those existing today. What is more, real cell membranes are not symmetrically arranged but are assymetric, providing much greater compexity than anything utlised by Szostak’s team. See here for a commentray on membrane biochemistry. Yet again, without the maintenance of exacting conditions of pH, temperature, salinity, etc, these vesicles would fall apart. Indeed, no method has been demonstrated that can maintain stable, long-lasting vesicles. Such stability is a necessary pre-condition to the creation of artificial life.

Szostak’s team has explored ways to get vesicles to grow and divide like real cells. By the addition of fresh fatty acids to the medium and studying their behaviour, his team has developed a deeper understanding of how this process works.
Reference:

Chen, I.A., Szostak, J., A Kinetic Study of the Growth of Fatty Acid Vesicles, Biophysical Journal 87, (August 1 2004) 988-98.

While Luisi’s team produced vesicle fissuring, they do so unstably. Szostak’s team have addressed this issue by developing ways to sustain vesicle division after a period of growth. This is achieved by pushing the expanded vesicles through pores (extrusion). In so doing, Dr. Szostak has shown that the process can be repeated indefinitely to create multiple ‘generations’ of protocells.

Reference: Hanczyc, M.M.& Szostak, J., Replicating Vesicles as Models of Primitive cell Growth and Division, Current Opinion in Chemical Biology 8 (December 2004) 600-64

When Szostak et al encapsulated RNA molecules inside such vesicles, they actually promote growth because they produce osmotic pressure on the vesicle walls, increasing membrane stress, which in turn allows fresh fatty acids to become incorporated into the bilayer membrane. He further showed that the RNA molecules are retained inside the vesicle after filter extrusion. Researchers have also encapsulated clay minerals inside vesicles, along with RNA, and demonstrated that the clay is also retained by the vesicles during the growth and division process.

Reference:

Ibid

The next phase in this ‘bottom up’ approach is to provide an energy source for more sophisticated protocell activities. Cells use pH gradients as a way to harvest energy. Indeed this is the fundamental way in which all real cells synthesise the universal energy currency of life: adenosine triphosphate (ATP).

To this end, some researchers have incorporated special molecules which can absorb light into phospholipid membranes to create such pH gradients. Then by adding the pre-existing enzyme complex F0F1 ATP synthase (a remarkable molecular machine in its own right!), they were able to use these pH gradients to synthesise ATP.

Reference:Steinberg,-Yfrach, G. et al, Light-Driven Production of ATP  Catalysed by F0F1 ATP Synthase in Artificial Photosynthetic Membrane, Nature 392 ( April 2, 1998) 479-82.

Szostak’s team has simplified this process. Specifically, they found that the growth of vesicles made from fatty acids naturally generates pH gradients. So, the growth and division of vesicles can provide an energy source.

Reference:Chen, I.A, Szostak, J, Membrane Growth can Generate a Trans-membrane pH Gradient in Fatty Acid Vesicles, PNAS 101( May 25, 2004) 7965-70.

The fatty acid vesicles created by Szostak’s team delivered another advantage over their phospholipid based counterparts; they were more permeable, allowing easier transport of molecules both into and out of the vesicle. Activated (pre-made) nucleotides, which serve as the building blocks for DNA and RNA, were able to move into the vesicles more easily. This led the team to develop systems that could incorporate these activated nucleotides and, using a pre-encapsulated strand of DNA, demonstrated replication capabilities. In addition, his laboratories began experimenting with different types of amphiphiles (including unsaturated fatty acids, alcohols and monoglycerides), mixing them up to try to optimise their stability between the freezing and boiling point of water.

Reference: Mansy, S. & Szostak, J. Thermostability of Model Protocell Membranes,  PNAS 105 (September 9, 2008) 13351-55.

These are important advances, because they have steadily improved the robustness of their protocells and allow scientists to chemically replicate genetic material within the interior of the vesicle.Szostak’s group at Harvard hope to learn how to coordinate the replication of the genetic material encapsulated within these vesicles with the process of vesicle fission. By engineering more and more properties into these vesicles, Szostak and his collaborators hope to create systems tailor made to carry out specific functions.Their ultimate goal is to create synthetic cells that can carry out novel biochemical processes in order to make new biomedical advances and novel pharmaceuticals that will greatly enrich biotechnology. Some foresee that, at the current rate of advancement, these will be a reality as early as a decade from now.

Summary

What Professor Szostak and his colleagues have achieved is truly remarkable! By divesting many millions of dollars from public and private donors, recruiting a very large team of the finest biochemists and molecular biologists, and  utilising the most advanced equipment ever assembled, real progress can be made and his success is bound to continue over the coming years. But, as I have indicated previously, this progress has not come about through Darwinian means, far from it! What Szostak’s work has demonstrated is that by deliberate effort and the harnessing of extraordinary human ingenuity, the era of synthetic biology is well and truly upon us. Their work empirically shows that even the simplest life-form ( which are orders of magnitude more complex than the ‘protocells’ discussed) cannot arise without the involvement of an intelligent agent.

Fatty acids do not  form bilayered membranes when added to ordinary water. On the contrary, their work shows that it is possible to coax stable vesicles to form only by making conscious choices about the kinds of fatty acids (in Szostak’s case the monounsaturated variety) and other amphiphiles that constitute them. If the wrong choice is made, the vesicles cannot even form. What is more, vesicle formation and stability depend critically on fine-tuning the optimal concentration of the amphiphiles in an aqueous environment carefully controlled for pH (buffers), salinity and temperature. Those clays and minerals must be scrupulously clean. The melting point of the fatty acids employed in the vesicles must also be considered. In a real life laboratory environment, the vesicles must, in some cases, be repeatedly frozen and thawed and, as highlighted above, their physical extrusion through pores must be carried out. Even then, vesicles of only the desired size are selected to optimise the process. Creating the vesicles from scratch requires advanced knowledge of the chemical properties of the amphiphiles making them up. After all, the mantra of the biochemist is ‘structure dictates function.’ Furthermore, Szostak’s progress depends upon the prior work of thousands of intelligent minds across the human world, and from many generations.

Sic transit gloria mundi!

This analysis shows that it is unreasonable to expect life to have arisen without an intelligent agency.

I believe this agency to be a personal being, infinitely good, infinitely powerful and infinitely well funded; the God uniquely revealed in the Bible.

                                                           Imago Dei

I believe in one God, the Father, the Almighty

Maker of Heaven and Earth.

Of all that is seen and unseen.

Through Him all things were made.

For us men and for our salvation, He came down from Heaven.

By the power of the Holy Spirit He became incarnate with the virgin Mary and was made man.

For our sake He was crucified under Pontius Pilate.

He suffered death and was buried.

On the third day, He rose again, in accordance with the Scriptures, and is seated at the right-hand of power.

He will come again to judge the living and the dead.

And His Kingdom shall have no end.

Neil English holds a PhD in Biochemistry from the University of Dundee and has carried out post doctoral work in the field of Cytochrome P450 mediated fatty acid hydroxylation and associated gene expression.

De Fideli

 

 

The Generosity of the Sun

Totality.

Totality.

 An essay dedicated to the Faithless Generation.

For since the creation of the world God’s invisible qualities- his eternal power and divine nature –have been clearly seen, being understood from what has been made, so that people are without excuse. For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened. Although they claimed to be wise, they became fools..

                                                                                                          Romans 1:20-23

Coincidence is God’s way of remaining anonymous

                                                                      Albert Einstein (from The World As I See It)

When the Moon formed, it was much closer to the Earth, and has been steadily retreating as the energy of its orbital motion has gone into stirring up tides….. Just now the Moon is about 400 times smaller than the Sun, but the Sun is 400 times farther away than the Moon, so that they look the same size on the sky. At the present moment of cosmic time, during an eclipse, the disc of the Moon almost exactly covers the disc of the Sun. In the past the Moon would have looked much bigger and would have completely obscured the Sun during eclipses; in the future, the Moon will look much smaller from Earth and a ring of sunlight will be visible even during an eclipse. Nobody has been able to think of a reason why intelligent beings capable of noticing this oddity should have evolved on Earth just at the time that the coincidence was there to be noticed. It worries me, but most people seem to accept it as just one of those things.

                                                                   John Gribbin (from Alone in the Universe)

The noted science writer and astrophysicist, Dr. John Gribbin, raises an interesting point at the end of the excerpt from his 2011 book, Alone in the Universe, quoted above. He describes the coincidence of a total solar eclipse and the emergence of a global human technical civilization as something that ‘worries’ him. I can well understand that position given the inadequacy of the blind forces of Darwinian evolution to explain why these events are coincident in cosmic time. But that’s only an issue if one assumes biological evolution to be watertight. A more rational, and dare I say, compelling answer to Gribbin’s conundrum is that these events are not mere coincidences but were pre-ordained to occur in a unique window of cosmic history to reveal the attributes of an all powerful Creator; a personal God who, like a great king, wishes to demonstrate His omnipotence to an unbelieving population.

Such a world view, which is currently counter to the prevailing secular corpus of scientific thought, would be strengthened if other attributes of the Sun were found to be odd, peculiar or even unique. Intriguingly, great advances in our knowledge of the Sun over the past 30 years has yielded a solid body of evidence pointing to the possible uniqueness of our Sun, the yellow star that has presided over the extraordinary allegory of events that culminated with a global human technical civilization in the present epoch.

                                                Peculiar formation history

Diligent research over the past century has revealed that stars are not born in isolation but are hatched in their thousands inside enormous clumps of gas and dust. Our Sun was formed from the fragmentation of one such cloud under the auspices of magnetic and gravitational forces that led to the contraction of one cloud fragment, culminating with the ignition of the nuclear fires at the centre of the proto-Sun and the formation of a disc of gas and dust in the plane of the solar equator that would form the elegant planetary system we live in today. Yet the Sun was formed with an unusual assortment of heavy elements that originated in not one but two distinct kinds of supernova events that must have occurred in close proximity to our neonatal solar system to enrich it with those elements. What is more, our solar system was formed during the epoch  when the interstellar medium was maximally enriched with the long-lived radionuclides thorium-232 ( half life 14.1Gyr), uranium-235 (half life 0.704 Gyr) and uranium-238 (half life 4.468 Gyr); elements that provided Earth with the thermal energy to maintain plate tectonics on our planet over geologic time. Without large quantities of these elements, the Earth would have been just another lifeless planet.

But forming the right kind of star and the right kind of planets was still not enough though. Had the Sun and its retinue of planetary bodies remained entangled in the star cluster of its birth for very long, gravitational interactions with nearby stars would have wreaked havoc with our orderly solar system. Moreover, had the Sun formed as part of a binary or multiple star system – as have as many as 70 per cent of sun-like stars in the Galaxy – it would have been game over for a life bearing planet like the Earth, as it would not have able to maintain a stable circular orbit about the Sun over the entire duration of its history. For the Sun and its family of planets to proceed to the next stage of development, it had to be ejected from the cluster of its birth to live in safe isolation from the rest of its stellar siblings.

                                              Peculiar physical properties

In the early 19th century, the German optician, Joseph von Fraunhofer (1787-1826), founded the science of stellar spectroscopy. By attaching a diffraction grating to his achromatic refractor (both of his own design) he was able to demonstrate that stars like Sirius differed significantly from the Sun.

Joseph von Fraunhofer demsonstrating the spectroscope.

Joseph von Fraunhofer demsonstrating the spectroscope.

Today, we follow in the great optician’s footsteps, employing diffraction gratings to obtain high resolution spectra of a multitude of stars, allowing astronomers to perform a so-called differential element analysis on a large stellar population.These and other techniques have revealed a curious truth about our star, the Sun. While it is easy to find twins of almost any other star, an exact solar twin has yet to be found. And though quite a few stars can be matched to the Sun with respect to its basic parameters like mass, age and luminosity (G2V spectral class), the Sun stands out like a sore thumb with respect to these solar analogues, showing a 20 per cent depletion in certain refractory (non-volatile) elements such as calcium, aluminium, magnesium and silicon; the elements that wound up inside the rocky terrestrial planets of our solar system.

 The Sun, though widely reported to be an ‘ordinary star’ is actually more massive than 95 per cent of all other stars in the Galaxy. The vast majority of stars, the teeming multitudes of red and brown dwarves, are too cool to hold planets at a safe distance from their fiery surfaces in order that liquid water could be profitably maintained on their surfaces over the aeons. Such stars would need to spawn planets very close in – typically an order of magnitude closer than Mercury is to our Sun – causing them to become tidally locked. This means that they would keep the same face to their parent stars in much the same way our Moon does while orbiting the Earth. This scenario would render life incredibly difficult on such planets. After all, the permanently illuminated hemisphere would be incinerated while the other would be in a perpetual frigid darkness. Lower mass stars, by their nature, emit less ultraviolet (UV) radiation too – a plus you might think – until you learn of how important UV radiation is for generating and sustaining the ozone layer. And no ozone layer would make life very difficult indeed on the landmasses of any putative world orbiting these low mass stars.

But there are yet other perils that attend stars with lower masses than the Sun. In the summer months, I use my 3 inch classical refractor to project an image of the Sun on a piece of white cardboard or by using a full-aperture solar filter. More often than not, I can make out small sunspots – regions of intense magnetic activity that correspond to cooler regions of the solar photosphere – that make an otherwise bland solar disc all the more interesting to observe. Sunspots though, are also strongly correlated with flare activity and it is not an inconsiderable fact that stars even a little lower in mass than the Sun have significantly higher activity in this regard. Ongoing solar research suggests that during sunspot maximum (which follows a roughly 11 year cycle) our Sun already has the ability to inflict potentially serious damage to living cells, as well as hampering human telecommunication  systems, so that any significantly greater activity would prove disastrous for life on Earth in general and human civilization in particular.

Sol, as it appeared at appeared on the sunny afternoon of May 7, 2013.

Sol, as it appeared through the author’s 3-inch Fraunhofer refractor  on the sunny afternoon of May 7, 2013.

The tiny fraction of stars in the Galaxy larger than the Sun have very short lifetimes (scaling with mass as M^-2), insufficiently long to allow even microbial life (if it exists at all) to start the process of heavy metal concentration – which include the so-called ‘vital poisons,’ as well as the heavy metal deposits needed to sustain a high-technology society – in their planet’s crust.

                                                           Peculiar stability

How does flare activity correlate with stellar age? It turns out that solar flaring has continued to decline over time, reaching a minimum in the present epoch, roughly half way through the life of our star and dovetailing nicely with the emergence of humanity in the solar system. What’s more, sensitive measurements reveal that our star varies less in luminosity (typically by less than 0.1 per cent) than any known star.

                                                       Peculiar kinematics

In 2008, a team of astronomers led by Charles Lineweaver based at the Australian National University, conducted a study on a large body of stars taken from the Hipparcos archive and discovered that the Sun has a more circular orbit than 93 per cent of other stars in the distribution. Safely tucked away between spiral arms near the co-rotation axis of our Galaxy (a peculiarly stable place to be!), some 27,000 light years from its centre, we live on a planet spared the deadly effects of short wave radiation that have surely sterilised the down town regions of the Milky Way. Out here, in Galactic suburbia, we move around the centre of the Galaxy once every 0.25Gyr, enjoying transparent, dark skies that allow us to look all the way back in time to the earliest epochs in cosmic history, so enabling humans to elucidate the physical events that shaped the unfolding cosmos in which we find ourselves in.

Stars not only move within the plane of the Milky Way’s thin disc but oscillate up and down as they orbit the Galactic centre. Many years of kinematic studies conducted by astronomers show that its amplitude of oscillation is smaller than many stars in the solar neighbourhood which makes the solar system less susceptible to gravitational perturbations that could potentially destabilise established planetary orbits. Indeed, according to the stellar astronomer, Dr. Guillermo Gonzalez, the Sun’s kinematic attributes are more reminiscent of a young star than one that is 4.57 billion years old!

                                                            Not forever!

As I have attempted to outline thus far, it seems patently clear that the Sun is a very unusual star enjoying a rather unusually stable phase in its life. Over billions of years since its birth, the Sun has grown steadily brighter and life on Earth, particularly the green plants, have worked to compensate for the Sun’s increasing luminosity by removing more of the greenhouse gases (particularly carbon dioxide and water vapour) from the Earth’s atmosphere. But the unchanging laws of physics that govern the Sun’s evolution are the same yesterday, today and tomorrow. This means that the Sun is going to continue to brighten and heat the Earth’s surface. But the levels (currently 392ppm) of carbon dioxide needed to conduct photosynthesis are already close to the minimum necessary (~150ppm) to sustain vigorous plant growth. Clearly, the current situation cannot be maintained indefinitely. Likewise, as it continues to evolve (and stars really do evolve because there is a robust physical theory underpinning that process), flare activity will increase to a point where large animal life cannot be sustained. Clearly therefore, we are living in the best of times.

                                               Just one of those things….

Sol Invictus!

Sol Invictus!

 

 

I suppose one could always shrug one’s shoulders and say something like, “that’s a strange coincidence,” or “it’s mere chance.” But, these answers are not very satisfying to a curious intellect; an intellect hard wired to spot patterns. Cast your mind back once more to the exquisite geometry of a total solar eclipse. A few million years ago, the Moon’s apparent diameter was larger than the Sun’s and the non-human primates – Homo Erectus or some such – that inhabited the Earth at that time, lacked the sophistication – both mentally and spiritually – to appreciate the event. In a few million years hence, the Moon will be smaller than the Sun’s face and the Earth will be unfit for human habitation. Only at a time sandwiched neatly between these epochs did creatures with the necessary cognitive capacities emerge on the scene to understand the significance of this alignment, allowing them to deduce both the geometry and scale of the solar system. Even the mind-boggling logic of Einstein’s theory of general relativity was confirmed during a solar eclipse.

Do you really think these solar peculiarities are just coincidences? How many coincidences and peculiarities does one need to convince one of a greater, underlying truth about the Sun and our relationship with it? And where does Darwinian evolution – the ‘blind watchmaker’ – fit into all of this?

Thank goodness for small mercies!

If you’d like to hear more amazing coincidences about the Universe we inhabit, you might be interested in my new book, Grab ‘n’ Go Astronomy, due out this Summer.

 

De fideli

This essay was inspired by the continuing work of Dr. Hugh Ross, Founder & President of Reasons to Believe and colleagues; truly a candle shining in an ever growing sea of darkness.

Some References for Further Study.

Barrow J.D. & Tippler, F.J. (1988), The Anthropic Cosmological Principle, Cambridge University Press.

Ross, H. (2008), Why the Universe is the Way it is, Baker Books.

Ward, P.D, & Brownlee, D, (2000) Rare Earth: Why Complex Life Is Uncommon in the Universe, Copernicus.

Gribbin, J, (2011), Alone in the Universe, Wiley.

Philips, A.C. (2001), The Physics of Stars, Wiley.

Want to explore More? Follow me on Facetube & Twatter.

 

Pause for Thought: Mars, Barnard and his Byrne.

Young Edward

Edward Emerson Barnard (1857-1923) needs no introduction in the world of amateur astronomy. Emerging from abject poverty, his natural curiosity, regal humility and diligence for his work, set him on a path that would lead to his becoming arguably the greatest visual observer of all time. In this short presentation, the author recounts Barnard’s earliest forays into telescopic astronomy, and in particular, the acquisition of his ‘pet’; a 5-inch achromatic refractor by the relatively obscure New York optician, John Byrne. His devotion to that instrument established his reputation as a gifted telescopist.

While Mars mania was quickly turning the world’s pre-eminent planetologists into imbeciles, this young man, endowed with wisdom far beyond his years, eschewed the unbridled imaginations of his contemporaries, and quietly watched the Red Planet with his ‘large telescope’.

De Fideli.