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Piero

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Everything posted by Piero

  1. I don't think your implication is sound. Arriving to the same conclusion (theorem) in one ore more ways (proofs) doesn't necessarily imply that that theorem is universal to me. It rather means that more people induced or deduced or composed pieces of already existing theorems and that this new theorem was mature enough to be formulated. What happens though if you change the initial axioms? Would this theorem be universally correct? And who did define the axioms if not us? What are the bases for them? I think mathematics is an interesting and powerful game but as but you cannot use mathematics to explain its own nature. Therefore, to me this implies that you cannot use mathematics for explaining its own universality. Wonder though whether an order of mathematics higher than ours can explain the universality of our mathematics in our world..
  2. In addition, I think that saying that our mathematics is a universal language implies that has/is the most compact set of tools for describing nature effectively. These tools are deduced by our way of thinking though. Actually, not only our way of thinking, but also our physical view and interpretation of nature. For 2k years we gave the world an Euclidean description, in 2 or 3 dimensions, but this is not necessarily correct.. Just seemed the easiest way to explain the world with our eyes. I think the universality idea is a shortcut way to avoid thinking the limits of our knowledge, a bit like for centuries we thought to be at the centre of the universe. I am not saying that our mathematics is not an universal language. I am just saying that whether this is or not should be proved. And if this problem is proved undecidable, this would still be a great result!
  3. I agree with Rob and from my point of view he explained the concept very clearly. You cannot say a priori that everywhere in the universe our mathematical and physical laws are the same. This is an assumption and should be proved. Regarding the mathematical logic argument, our mathematics relies on specific syntactic and semantic definitions.. Whether this set is complete is a Nobel price question!
  4. Yeah! I'd like to know these too! Great images!
  5. +1 moon fan! I think both the moon and the sun are really underestimated! So close to us, so rich in detail, so beautiful!
  6. I meant 'interesting combination'. Apologise.. typing with the phone.
  7. 20x in an aperture of 60mm is an interesting aperture! I enjoy a lot shifting from 15x to 18x with my telescope. Only 3x difference, but 0.7mm less in exit pupil make a substantial difference in contrast! :-)
  8. Very nice sketch! Can I ask you what Seben 300mm is and which magnifications did you use, please?
  9. If someone does not think that generated hypotheses DO NOT need any form of testing (formal or experimental) is a not working in a scientific manner, but he/she is doing something else. The comment on computer models is irrelevant and unjustified. You need computer models, because without them you would spend a fortune to test every single hypothesis. This does not mean that you use computer models not to test experimentally at all. It just means that you can create some predictions and discard some scenario with a minimum of substance, rather than investing tons of money in testing for whatever idea crosses the mind of a person. Of course, if you find good and interesting predictions, you have to test them experimentally. I don't think this figure is a scientific spectator. Particularly since he/she helps speed up the research process and indicate how and where to invest money..
  10. Even great scientists can be wrong but this does not mean that you reject them just because in different conditions their theories do not work.. One famous case of this is Newton's theory of gravity which does not include relativity... This does not mean that you discard Newton, but just that you accept what Newton said and you apply it only for that specific context. Same for philosophers. Maybe Aristotle created a silly syllogism for twisting the minds of future generations, but this does not mean that all what he said is rubbish, just because you don't have empirical testing for all his prepositions
  11. I like your post and made me think a lot. From my point of you your post is true if you strictly associate Science with hypothesis testing. Therefore, it follows that any means of explaining nature without testing the hypothesis is not science. I agree that a form of hypothesis testing is necessary in Science, but I disagree that a conjecture is not science (or part of it). The way that I see, conjectures and hypothesis testing are two parts of the scientific process, and conjectures are only a primordial step of this process. What I mean is that to me Science is the entire process involving: 1. thinking of a problem 2. conceiving an idea 3. give to this idea a formal structure (hypothesis) 4. finding in literature ways to support or disprove this hypothesis 5. design an Experiment (or formal logic) to disprove / approve your hypothesis 6. finding and designing additional controls to your experiments / reasoning 7. formalise the entire story 8. publish it Therefore, the point to me is the attitude behind. Having a conjecture is only part of this process, but the person formulating it, has to recognise that this is only a conjecture and cannot call it theory or scientific knowledge. Of course, from this conjecture, one can establish novel scientific knowledge through experiments or formal logic, depending on the problem. With this in mind, if a person declares his/her conjecture as a dogma (e.g. religion), that person is clearly not a scientist! No doubt about it. In addition, the scientific method using repeated experiments + statistics is to me, just one way to do science. This is the case of natural and physical sciences for instance. What about formal proofs of mathematical theorems? To me this is still science, because you still are assessing the validity of a hypothesis rigourously. In this case, your background knowledge is theoretical (theorems) and not natural, but you are still applying the same investigation process. In conclusion, what I am saying is that to me your sentence "Any means of explaining nature that is not tested or testable is just conjecture - it ain't science." would be more correct as "Any means of explaining nature that is not tested or testable is just conjecture - it is an incomplete piece of science, and as such, cannot be used for deducing or inferring other scientific knowledge." This is at least my opinion. Anyway, I thank you for your post again. Piero
  12. Sorry, I should have specified that my comment referred to the dobson 6" F8. if you go for an F5 route, like the 130mm you highlighted, you will need to be prepare to potentially invest in better eyepieces and do regular collimation. If you are prepared for this, another portable (with a car) option is a SW 150P mounted on an AZ4. Brantuk said one important thing about expectations and colours. Actually, I think that is an essential consideration to keep in mind, otherwise you can easily be disappointed.
  13. That is a nice scope and will serve you for a long time. It is a bit long, but its weight is still manageable without too much effort, and the views will be very clear. Plus it is gentle with the eyepieces you will add (unless you get addicted to very large aFOV eyepieces), and will rarely require collimation (not that this is a big deal, but if you don't have to do it regularly, that's better). Anyway, it is a good trade off between aperture and portability (in terms of weight), and won't require expensive accessories.
  14. Very nice review! These are the type of reports I like the most. Great sketch too!
  15. Sorry for confusing. My question "I wonder why?" was referred to Shaun's post.
  16. I wonder why? I think you have a very good setup that can keep you busy for a long time! I can go on with mine for hours. Sometimes I even do *reverse star hopping*: basically I just navigate among the stars in a wide field (15x, 4.3deg) and when I find something interesting I zoom in (51x, 1.5deg). Then I take some reference stars and once back at home, I check what I saw on an atlas. Really funny and a great surprise! You feel a bit like Messier! The reason why I like wide field views so much is that not only you can identify and see a lot of objects, but also you can give them a context in the sky. It is this context that always surprises me, since it makes me think about how these objects, relatively huge if proportioned to us (e.g. DSOs, nebulae etc), are placed and surrounded in this emptiness of space. Nowadays, our lives are incredibly pushed towards idealistic concepts of success, high performance and power, and I think we are forgetting that we are just an incredibly insignificant part of this immense machinery that is the universe. When I observe in wide field, I exactly feel this corrected re-dimensioning of things. And the good thing is that, I don't care at all to be something completely insignificant for the universe, but I thank a lot that I have the fortune to see a little bit of this machinery, in which we live.
  17. John, it seems we have an "aperture ratio" in common! 4": 2.4" = 12" : 8" ~1.5 ! I wonder whether this is true for our body size too!
  18. I might be boring, but my first telescope (which I still have but in Italy) is a classic Newton 114 F8. A nice first experience which continued until I moved to England, and I still use when I go there on holidays. It has served me for 16 years so far. Now I have my lovely super portable wide field TV-60 which I enjoy every time I use it. When I will be more settled, I will probably buy a Newton 150 or 200 (F5 or F6) mainly for DSO and planets occasionally. This will also allow me to reuse my small set of eyepieces largely. Luckily, that's it, just two telescopes again!
  19. Personally I don't like it. I don't dislike it as much as astigmatism, but I would much prefer if it is not there. I don't think there is a problem with aberrations if you know what you are getting. A while ago, I owned a pair of binos Rev 15x70 which showed all kind of possible aberrations. These did not affect me because it was a ~£50 purchase, intentionally made because I was too unsettled to invest in something of better quality. Despite this I enjoyed the views a lot and those binos gave me the possibility to continue observing the sky. Actually, I have to say that I liked wide field views so much that I decided to invest in a tool that solved all those optical issues and that I could still take it wherever I wanted and mount it quickly. What I want to say is that having a tool with some limits/imperfections is not a bad idea at all, as it allows you to understand those limits/imperfections better and to think whether those limits are a concern or not for you. If you are asking this question, it seems to me that CA is a bit a concern for you. Surely it can be improved with an ED or a full Apo. Whether this is worth or not for you, I cannot answer. For me it is worth and I haven't ever regretted it. However, I also considered other factors such as: WF, compactness, lightweight, almost absent cooling time, easy to use, comfortable posture when observing, and use of different magnifications (the reason why I didn't upgrade the binos). For a tool that I can take anywhere, anytime, yes, this is really worth for me. Instead, if I could use it only few times, I would probably accept some aberration and don't look back. This is just my opinion based on my limited experience of course
  20. The link to your gallery in Flickr is one of those bookmarks that I will not ever remove .. and the TV-60 is the scope that I will not ever give away!
  21. I am not so sure about whether SCT or Mak-Cas are fine with that climate. I haven't ever been to Alaska (but I might one day ), but I am aware that many countries located at polar latitudes can have substantial changes in temperatures (even 20C) in a relatively short time. I have a feeling that you will not be able to use these models effectively due to these temperature changes. I would go for a good small refractor (an 80mm as Ronin suggested) or a Newton. The poster in this forum ( http://astro-talks.ru/forum/viewtopic.php?f=7&t=730 ) used his SW Equinox 66ED successfully at -25C.
  22. Yup! Also to me that is likely to be M44! Your binos (8x56) have an exit pupil of 7mm, which can be a good thing particularly under dark skies. However, if the moon is up, the contrast with the background sky is reduced quite a lot. I believe you have been very good at finding it. Congratulations!
  23. This page scared me! John, your monster eyepieces are almost as big as my telescope! I am sure they deliver the best views combined with the largest FOV one can afford for a large class of telescopes, though! I drew a line for the maximum size / weight of mine. My heaviest configuration is Nagler 7mm + Barlow/Telextender 2x. The size is big for my standards, but the weight is limited to ~410g. I am glad that, so far, I have not suffered from Aperture or FOV fevers! Actually, I have to say that I would replace my Nagler 7mm with a Pentax XW 7mm immediately due to better eye-relief and comfort, if the latter were as compact and lighter as the former!
  24. Apologise, but I do not understand the question. Why you don't simply keep the one you feel more comfortable with? I am just trying to understand. Are these two mounts the very similar in terms of weight, tripod height, usability, vibration damping, assembly time, motion controls robustness and accuracy, etc?
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