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gort

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About gort

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    Nebula

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  • Website URL
    http://www.oxford-observatory.org

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  • Location
    Oxford Mills, Canada
  1. Thanks for your interest, Dave and Gina. I can't tell what that vintage scope is. But if the price is right, that's half the battle. I only bid on mine because I was pretty sure it was early 20th century. I like the older scopes - although they may take some time to get back into usable (and pretty) shape. Based on popular request, here are some photos. You can see the screw I'm talking about and the missing finder eyepiece.
  2. I just won a Broadhurst Clarkson scope at a London auction. London, Ontario, Canada, that is! At any rate, it was almost given away - no bidders recognized it for what it was. It's a 3" black tube (brass lens cell) with trunnions to fit an alt-az mount (no mount included). The lens is pristine, and the scope came with one RAS-threaded eyepiece, marked 100X. That said, I'd like to do a bit of restoration. The beautiful black tube is quite scratched, so it needs to be re-finished. Anyone with experience in stripping / refinishing a B-C black tube? What type of lacquer, etc.? The finder is missing two of its four screws which hold it to the main OTA. They're "cheese head" types. Does anybody have any to spare? Finally, the finder is missing its eyepiece end (there are internal threads in the finder tube). Does anybody have a similar B-C OTA who can provide details of what exactly fits into those threads? Thanks in advance for any help you can provide. Cheers, James
  3. We can help stop the madness by signing a petition - https://www.astro.princeton.edu/~gbakos/satellites/index.html Cheers, and Clear Skies, James
  4. As a "mainstream physicist", I'll chime in with my 2 pence. In much of my formal education, the goal was to perform experiments to determine "what is reality". That is, to not just determine laws of motion (for instance) - like the apple falling from the tree - but to determine exactly why the apple falls from the tree. In my old age, I'm becoming more convinced that that's not the goal of science. The goal of science is to model reality. To develop models which will predict outcomes of experiments. The closer those predictions come to measured results, the better model we say we have. The holy grail is to have a "perfect model" - the so-called "Theory of Everything". I feel that science cannot know when it has such a model, because an infinite number of experiments would be required to verify this elusive model. So we'll never know. The best we can hope for is to say that reality = perception. The "true nature" of reality alludes us. James Gort
  5. FWIW, I only accidentally discovered it several years ago when I was designing my own achromat. I downloaded OSLO and ZEMAX, but then discovered a great addition called MODAS (Modern Optical Design and Analysis Software), which was then a beta release by Ivan Krastev. I thought that program was more intuitive than any other I've tried, so I tested it and gave Ivan some feedback for improvements. The result was a quite nice (if little known) optical design program. In the process, Ivan introduced me to his great publication "ATM Letters". Poor name (it's MUCH more than "letters") but great content.
  6. No need to be scanned - they're all in pdfs. But we'd need Ivan's permission to distribute them (or he can make them for sale again).
  7. Although the US ATM magazine had some pretty good practical projects, I think the overall quality of Ivan's publication was much, much better, with a great mix of practical, theory, history, current news, book reviews, etc. The photographs alone were outstanding! Which is why I was surprised that it's received so few mentions in this forum, Cloudy Nights, etc. I wonder what the readership was, and if many people just didn't know about it. I thought it would go on much longer than it did.
  8. I searched the archives, and could find very few mentions of "ATM Letters", a bi-monthly publication put out by Austrian Ivan Krastev. It was published for 10 years (2003 - 2012), and was simply the best, most professional and informative, ATM serial publication to ever make print (IMHO). It would be of great interest to DIY astronomers and anyone interested in historical astronomy, including antique telescopes. I was just going through my collection (entire 10 years), and it's truly a treasure trove. I tried to contact Ivan about making the collection available again, but to no avail. Does anyone here have that collection? If so, do you share my opinion? Shall we petition Ivan? For reference, see http://www.myoptics.at/atmlj/archives.html Thanks, and clear skies (although it's a bit COLD here in Canada), James
  9. Thanks for the reference, Gordon. But I'm confused! Press releases like this touch at what they're trying to say, but raise more questions than they answer (IMHO). I went to the "For More Information" section, but they only point you to the same blumming press release! I wonder why they don't give a reference to the actual published paper?? There may be some real stuff here. But without looking at the paper, I can't figure it out. Unless NASA (and others) use these releases to drum up funding. (cynic, cynic). Cheers, James
  10. I don't know about KK, but I sure enjoyed it. Great reference! Thanks, themos.
  11. OK, no one took the bait when I mentioned UFOs. But when we talk about "open scientific minds", that subject is a great example. In last year's forum thread on UFOs, there were 6 respondents, 5 of which basically poo-pooed the whole idea. One person seemed to have an open mind. I suppose that ratio is probably close to that of the general public, but I would have thought that astro-nuts would be more open. Don't get me wrong. Scepticism is a healthy thing. Poo-pooing without proof is another thing. I'll bring up my former prof J. Allen Hynek again. He contended that 95% of sightings could be easily explained - Venus, military craft, inversion layers, etc. But the other 5% was interesting to him. He felt there was something going on beyond our current understanding of physics, but he was cautious to NOT invoke the "alien visitor" concept. But it intrigued him that worldwide correlation was so strong. He interviewed tribes well removed from civilisation (never having access to sci-fi films or books), and their descriptions and drawings coincided exactly with sightings in Europe and N. America. And not just nocturnal lights. Many cases he investigated included detailed sightings of crafts and "occupants". Those of you who are now throwing their keyboards into their screens, I urge you to get any book on the subject by J. Allen Hynek. He's the only astronomer (that I'm aware of) who approached this whole subject in a scientific way, and devoted much of his life to it. He was a true scientist, careful not to jump to conclusion, but equally careful not to discount anything without good reason. And he was perhaps the best educator I ever ran into. Cheers, James
  12. I think part of the problem, Kaptain, is that many (most?) scientists are still close-minded, in spite of appearing very analytical. It happened in Newton's time, and it's happening today. In Halton Arp's "Seeing Red" book, he points out that he was ostracized in the U.S. and basically "run out of town" because his ideas bucked "the norm". He's now (I think) at the Max Planck Institute in Germany. There's often a thin line between wild schemes conceived with little scientific understanding and valid ideas that may be revolutionary but without widespread support. Peer review tries to separate the two, but sometimes that fails, too. I hate to bring up the subject of UFOs, since it may unleash the fury of some and the scorn of others. But Dr. J. Allen Hynek (former chair of the Astronomy Dept, Northwestern Univ., Illinois) used to tell our class that the subject of UFOs deserve scientific study, and he had already made his reputation, so he delved into it. Among other things, he coined the expressions "close encounters of the first, second, and third kind". Needless to say, most of his colleagues never accepted this work. So I think it's important to keep an open mind. Personally, I would never say "never" to faster than light travel, although I recognize the currently understood obstacles. But all progress is based on overcoming obstacles! Cheers, James
  13. Hi John, And many (including Halton Arp) contend that there are other explanations for the microwave background and apparent redshift, and there are reasons the Big Bang can't be correct! BTW, in my little example, I was trying to point out that quark theory is a nice, fairly well tested theory. It does not fall into the untestable category. Just a clarification. Cheers, James
  14. Please bear with me on my little essay. There has recently been a boatload of popular (some of which are quite technical!) books on modern physics and cosmology, many of which are written by well known researchers and even Nobel laureates. That often gets people thinking and developing their own ideas. A very good thing. Great for the brain cells, and good for science in general. New theories are not the exclusive purview of universities and large labs, after all! Amateurs can make (and have made) valuable contributions in both the observational and theoretical sides of science. But I think it is important to understand what is a valid theory in science. Above all, a theory must be testable, and the test that has historically been used to validate the usefulness of any theory is its ability to make predictions. It is not enough to say that bosons consist of certain types of quarks, but what does that tell us about bosons? Does it predict new ones? Does it predict new behaviours? One can argue that there are no "correct" theories in science. Only ones that make valid predictions in a specified experimental context. Newton's Gravitation (a very nice theory) is certainly valid in many experiments, but not in relativistic situations. In fact, it is not the goal of science to understand "what is", but only "what does it predict?" The "what is" question is best left for philosophy and theology. String theory is a very good example of all this. Many have argued that string theory predicts nothing, but tries to explain, in a consistent manner, how elementary particles are put together. An excellent book (popular, yet technical) on the subject is "Not Even Wrong" by Peter Woit. He concludes that one cannot prove that it is a "right" theory, but you can't prove that it's wrong, either. It's untestable. No one knows if QED is "right". Do photons really go in non-straight lines and at various speeds? Who knows! But the theory has produced results agreeing with experiment to many, many decimal places. Cosmology is an area ripe for untestable theories. What happened in the milliseconds following the Big Bang may help "explain" why the universe is as it appears, but does that make it a valid theory? Comments are welcome here! Anyway, just some points of view I thought I'd get off my chest. If nothing else, maybe food for thought. Cheers, James
  15. This is a very interesting article - thanks for bringing it up, Gordon. I think it proves two things - current models of supernova remnants (to black holes) are evolving, and take whatever you read with a grain of salt and a dose of scepticism! Unless I am missing something, the surprise at finding a BH with 16 solar masses is puzzling. Older theories (maybe 5 years old) seem to place an upper limit of stellar BHs (collapse of single star - no accretion afterwards) at about 14 solar masses. Not far from 16. But a recent Astrophysical Journal article (Jan 2007) entitled "Fallback and Black Hole Production in Massive Stars" by Zhang et al says, in part: "For Population III stars above about 25 M? and explosion energies less than 1.5 × 1051 erg, black holes are a common outcome, with masses that increase monotonically with increasing main sequence mass up to a maximum hole mass of about 35 M?". It seems that current models can accommodate larger stellar BHs. The main problem is modelling what happens during and shortly after a supernova. Especially when the core collapse requires everything to be treated relativistically. No doubt the models will continue to evolve. Anyway, interesting subject! Cheers, James
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