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# All Activity

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1. Past hour
2. ## Relays for Lesvedome

Peter, Here's a quick sketch I did of your circuit which may make the relay/diode connections clearer. I drew the Ground connections as ground symbols to save cluttering the diagram with lines. The ground symbols are of course all connected together in reality. There's also no need for a double pole switch to the 7Ah battery as all the Ground/0V connections can be left connected to avoid things floating when not used. The Rigel motor output connections may need to be swapped over depending on which way the motor turns to make it drive in the same direction as your new system. I didn't draw in the hall effect 12V wire as it would be a bit messy so arrowed the connection instead. Alan
3. ## ES 82° 18 & 8.8mm Eyepieces

May I take the 8.8 please ? PM on its way
4. ## If Canon can, which Canon can?

The Full-Frame camera may well be vignetted, but you can always crop, down to where you would probably crop with a APS-C. Yes EF lenses may well be expensive, but Chaz is hoping to use his EF-S lenses, so maybe Full-Frame is out. Michael
5. ## Where does idea of infinite size of universe come from?

You have to be careful about usage of word infinite. One that contains "everything that exists" is not necessarily infinite. Infinite that we are talking about has very exact meaning and is related to concept of geometry of space. If for any given number, no matter how large you select it to be, you can find two points in space that have separation greater than that number in your chosen units - then universe is infinite in size. Infinite universe in above sense has infinite amount of "stuff" in it if we assume homogeneity, or if we assume that density is finite number.
6. ## Where does idea of infinite size of universe come from?

This asks the question "is there a better way" than our concept of mathematics, nature produces circles (not very good ones most of the time) and plenty of other regular shapes with very few apparent rules.... Alan
7. ## Eyepiece recommendations

My outreach eyepiece set is: - 7.2-21.5mm zoom eyepiece - Baader 2.25x barlow lens - Orion 27mm Edge-On eyepiece This set covers a lot of options, cost relatively little, is easy to view through and all three items can fit in my coat pockets easily In fact I seem to be using these quite often when observing on my own at home as well.
8. ## Help/advice needed! AZEQ5GT vs. HEQ5Pro

Zolten First welcome from Land Down Under I have a SW ED80 on an EQ5pro Find serves me very well Have also recently got the WiFi adapter Down load the SynScan APP Makes life easy Sets GPS, date/time from my Android device Have attached pic of my EQ5, taken at a recent solar viewing night with my club John
9. ## Which ha filter ?

I have the astronomik Ha 6nm filter. I have produced some great images with them.
10. ## Where does idea of infinite size of universe come from?

Actually, I started this thread in search of answer to the question - why do we assume it is infinite in lack of solid evidence. In fact we do not assume that in principle - and as you've said - current data points to near flatness or large curvature radius in case of curved space, and indeed that is a tricky one - you can never measure something to be precisely 0 as there will always be some uncertainty in measurement. It does however seem to be prevailing opinion that universe is indeed infinite (of flat variety) - if it were not so, there would not be many follow up ideas (verifiable or not), like multiverse. It is actually intriguing to me how easily we accepted notion of infinity related to the physical world. It is probably related to mathematics apparatus that we use to describe and formulate our theories. It is easy to forget that we are always working with approximations at best. Good examples are both often used constants, and like you pointed out both GR and QFT are based on continuous space-time. This of course does not mean that these models are 100% true and that our laws need exact pi or e values to be 100% correct. In fact I'm positive that no one ever used exact pi or e value in any of their calculations, ever, let alone in experiments where our theories were confirmed to very high precision. I suspect that same is true for our model of continuous space-time. Regardless of true nature of it, mathematical model we use works extremely well so far, however similar model based on finite distances with "enough granulation" would also work to the same level of empirical precision. Usage of one model over another is matter of convenience rather than proof of underlying reality.
11. ## Where does idea of infinite size of universe come from?

And that is the problem I have with the concept of infinity. The universe at it's beginning no matter how small or large was by definition infinite as it held everything. As that universe expanded it retained its infinite crown as by definition it contained everything. So infinity is not absolute , there are many versions of infinity. I go back to what I said before, I believe it's a mathematical construct resulting from our language mathematics. A curious artefact. Jim
12. ## Star Hopping with a Mak on an EQ mount

Looks like that's the case unfortunately
13. ## Which ha filter ?

I'd +1 the 7nm Baader, they're a great starting point and don't have major issues with halos/reflection in my limited experience. Baader are a lovely midpoint in most things brand-wise - good enough to be effective and useful in almost all their products, even if they're not the best of the best, whereas others in the same price point often end up going for features or spec over functionality. I'd only look at Astrodon or other high high end brands once I had everything else in my system perfect, really - you'll get much better bang for your buck with a flattener, or mount improvements, etc - or accessories like dew heaters if you don't have those already.
14. ## Where does idea of infinite size of universe come from?

By the way I don't know if the Universe is spatially flat or not and is as @vlaiv proposes. All I am trying to do is explain as best I can what the current consensus view is within science community. My understanding is that the best current data indicates that it has a simple topology and is very close to flat. We could as @vlaiv proposes be mistaken and that it is curved and we are making the same mistake as the original flat earth proponents did. However, it is so close to flat that within the currently observable universe we cannot tell the difference so the current working hypothesis is that it is flat. This makes some calculations simpler! Concerns about the I application of if being infinite if true or not are all outside the obsevable universe so it hardly matters if the are real or not -reather a matter of taste.
15. ## Relays for Lesvedome

Alan Good stuff! I'll make a start on wiring up tomorrow night. Thanks, Peter
16. ## Where does idea of infinite size of universe come from?

Oh I need to correct myself before someone spots the mistake and quotes me on it In fact in positively curved space things that are further from us appear larger than they would in flat space and in hyperbolic space - smaller than they would in flat one.
17. ## Where does idea of infinite size of universe come from?

The language we use to define the circle (mathematics) produces what we define as infinity. Infinity is a consequence of that language it does not follow it exits in nature. Jim
18. ## Eyepiece recommendations

I'll be looking at one of the cheaper zoom EPs for the school observing sessions in the autumn. It'll cut down on the time taken to switch EPs.
19. ## when i do polar alignment?

hello everyone! a quick and maybe a weird question when i do polar alignment? when the mount (i have eq6r pro) is turn on or off? if off - i do the alignment, turn on the mount, put my date and time, do the star alignment, and thats it? (this is the way i've done all my nights...) if on - what i do? and also what i do if i do the polar alignment with sharp cap or with polemaster? when the mount is on or off?? thank you very much!!!
20. ## Relays for Lesvedome

Yes, that looks right Peter regarding the 1k resistors. If you want to put a 560R in the 5V to the encoder that should be fine. It could be just to reduce any noise on the 5V supply. Alan
21. ## AR2738 6day line up.

Nice one Charl
22. ## sky quality meters and cloud sensors?????

The hitec won't show you how bright the background sky is if it's clear, no, or at least not appreciably I wouldn't have thought.
23. ## Crescent Nebula in HRGB

Very nice indeed. I very much prefer the one with stars in it; I think you need to see the nebula in its neighborhood!
24. ## Relays for Lesvedome

Alan OK, like this? From another EM14 user I've read that with 5V I need to add a 560 Ohm on the + line into the encoder. I've drawn that in too. Thanks, Peter
25. ## Crescent Nebula in HRGB

Quite amazing what can be achieved in processing. Whilst not astronomically correct, I'm drawn to the starless version - sometimes less is more!
26. ## Focus motor question

Anyone?
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