Zermelo

If you are able to leave the tripod/mount undisturbed between sessions, you can get it to hibernate and continue on the next session. I have to bring all my gear in, so I do an alignment each time. I prefer the "north level" flavour, but if I'm trying to align at dusk then the stars may not be obvious, so "brightest star" is sometimes better. You will get better with practice. I find that mine is always good enough to get me within my finder, and usually within a long eyepiece fov. That's all you need.

This page has pictures of some common aberrations: https://www.skyatnightmagazine.com/advice/understanding-optical-aberrations/ For a more technical explanation: https://www.telescope-optics.net/coma.htm

I'm also wanting this, ideally combined with light pollution levels. The best I've found so far is this: https://stargazerslounge.com/topic/275117-uk-map-combo-of-light-pollution-and-clear-nights/#comment-3013632 which is quite low-res. I think you can download cloud cover data from Meteoblue, but you have to pay.

I am mid Bortle 4 (SQM 21.02 is the best I've measured). With a 6" on the best nights, I've seen the cores of M51/NGC5195 and some light patches where the arms would be, but no continuous arms. I think I would see them if my eyes were 30 years younger. But I did see definite arms on M51 when I viewed it with a 5" Mak from a Bortle 3 site.

Well that's interesting, given the statement on that other thread that I can't find now. Perhaps they did it just for you?? But now you've also removed one of the reasons why I wasn't going to be tempted by this offer Only a few more days to stay strong ...

I think we are identifying two different senses of "consistent" here. (1) In the purely mathematical/logical sense, a set of (well-formed) statements is consistent if they cannot be used together to derive a contradiction, using the agreed rules of inference for that system. In particular, when applied to a proposed set of axioms for a formal system, that axiom set is said to be consistent if it is not possible to derive a contradiction, i.e. ⱯP ⌐(P V ⌐P) where P is any well-formed statement. Godel showed that any system complex enough to contain normal arithmetic must either be inconsistent or incomplete (in the sense that the system must contain well-formed statements that cannot be proved either true or false from its axioms). This effectively torpedoed the attempts of Hilbert and others to prove the consistency of mathematics by describing it from "outside", with metamathematics (I think, hinted at in a previous post on this thread). (2) In a more general, physical sense, that property of reality by which it is observed to behave in the same way in different times and places, and hence which behaviour science can then render as "universal laws". This is a bit more debatable, for example do we still count the laws affecting cosmology as "consistent" if the value of the cosmological constant or the speed of light change over time?

Assuming that you mean examples of similar quality, then the received wisdom is that it's about neutral at F/7: https://stargazerslounge.com/topic/328670-mirror-vs-prism-diagonal-for-fast-refractor/ https://www.cloudynights.com/articles/cat/articles/mirror-vs-dielectric-vs-prism-diagonal-comparison-r2877

Yes, I think if I had my time (and money) again, I'd get a 2" Clicklock dielectric. My Revelation diagonal is very decent, but I like the look of the Baader mechanism. I believe Baader do a Clicklock 2" to 1.25" adapter, so I'm thinking of getting one to put in the Revelation.

The other advantage of a 2" diagonal, even if you don't have many 2" eyepieces, is robustness. My heavier EPs feel safer in my 2" than in my 1.25" tak prism. The larger diagonal is significantly heavier, so I do need to think about balance and mount capacity.

I have the GtiX and it does the same. I think it just means that the WiFi is connected, so it is going to be flashing the whole session. Stop it? In my case, thick black tape.

Arguably the single most useful development in mathematics, for modelling the real world, was the invention of calculus, based on the properties of a (continuous) real number system. The continuity leads to irrationals, transcendentals, and more, which some mathematicians have found objectionable. But the usefulness of calculus in science has tended to outweigh the objections from a minority of mathematicians - the universe seems to behave as if it were continuous, whether it is or not. Recent speculation that space and time might be quantized, and not infinitely divisible, would give support to the skeptics, but they seem to be entertained only by a small minority.

Polls taken among mathematicians and scientists tend to agree with you. I think it is also true that the appreciation of relationships in maths like this one can go through three stages: (1) the practitioner does not know enough about the context of the statement to feel any surprise (>unremarkable) (2) the practitioner understands the context, but not enough to understand why the statement is true (>fascinating) (3) the practitioner understands enough to see why the statement is inevitably true (>obvious) Lord Kelvin is said to have used, in one of his lectures, the remarkable(?) fact that: and then commented to his audience, "A mathematician is one to whom this is as obvious as the fact that twice two makes four is to you. Liouville was a mathematician." Liouville had reached stage 3, at least as far as that integral was concerned. Kelvin's audience were probably at stage 2. It's interesting that deep connections between apparently distinct areas of maths keep coming up, and even the most capable researchers find themselves, initially, at stage 1: https://en.wikipedia.org/wiki/Monstrous_moonshine https://en.wikipedia.org/wiki/Langlands_program

I believe Hamilton tried to promote the use of quaternions in physics after he discovered them, and for a period in the 19th century there was some rivalry between advocates for quaternions and those who preferred to use vectors instead. The latter approach was found to be easier for most purposes, but both quaternions and octonions still get used oaccasionally. I came across this paper recently, describing a telescope pointing model based on quaternions.

Some physicists' ideal theory-of-everything is one that can be deduced only from the requirement that it be consistent, which is really quite ambitious. Eugene Wigner wrote about the "unreasonable" effectiveness of mathematics, in its ability to describe the real world. Some of the early quantum physicists took the view that the mathematics was the reality. More recently, there has been a bit of traffic in the other direction: theories developed specifically for a physics context have contributed to progress in some areas of pure maths. My hunch is that maths is not itself fundamental to reality, but is so "close" to it that the two are likely in lock-step for all practical purposes.

If you decided against the turret then the Morpheus are excellent, but I agree with the concerns about weight. If you were going with a turret and did want a 10mm, you could try one of the UFF variants. They have a 60 degree AFOV like the Starguiders, they give sharp, contrasty views, and are light and compact. The Svbony SV190 is possibly the cheapest of these, currently £60 on the big river.

Do you mean that you want to contribute an observing list to the set that users can import from the app, or that you want to add a catalogue of objects to the set that SS uses to create its own consolidated catalogue? For the former, I think you can email Simulation Curriculum and they may add it to their list if they like it (e.g. they include a curated list from Don Pensack). For the latter, I suspect it is more tightly controlled, and they seem only to use those with some provenance.

Sky Safari has component C at 15.8"from B. I think the one you are referring to is the Ab element of the A component, which it gives at +13.0, being 3.2" from Aa. As you say, that would be a good challenge for a smaller scope.

I've not seen anything definitive, but I always assumed this was because the artefacts were specific to the left or right eyeball, and the chances of having an obstruction in both, at the same place at the same time, was low.

https://www.firstlightoptics.com/baader-planetarium/baader-classic-ortho-bco-eyepiece.html They don't seem to have gone up as much as some others have, in the last couple of years.

I've always seen you as very much mainstream, Andrew, at least in the sort of threads that I frequent! Good luck with your new directions, but please keep checking in 😊

My BCO 10mm is probably sharper than any other I own, and has excellent contrast and good control of stray light. It has a narrow FOV by modem standards, but I do all observing with a tracking mount. I also have the 6mm, but find the eye relief quite tight on that one. People who have the discontinued BGOs also rate them highly. My 10mm is a keeper, and I always have it in the bag. It is still very good value for the price.

I saved dozens of the the little ones from COVID tests. I'd assumed that they would need a long bake in the oven, which I decided would be not worth the fuel. I'll definitely give this a go.

Ah, I'm not sure if we already have any members over there, but we may find out shortly. First Light Optics (who support this site) do ship to Iceland: but you may have a more convenient option locally. Hope you're not too near that volcano

Hello, and welcome to the forum. Are you based in the U.K.? These lenses are a good step up from those supplied with a scope: https://www.firstlightoptics.com/bst-starguider-eyepieces.html