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What do you think 45 billion ly deep space would look like, to the naked eye?
by simonh 5y ago
What do you think 45 billion ly deep space would look like, to the naked eye?
- wolverine876 5y agoLike the absence, in the brain, of the grey matter that detects humor. :)
- TeMPOraL 5y agoSomething something lots of Olympic-size swimming pools.
- Sharlin 5y agoBlack.
- pixl97 5y agoYep. If space didn't expand there would be a star or galaxy at every point we looked.
- contravariant 5y agoSo not black then.
- ben_w 5y agoOnly if stars and galaxies were eternal and hadn’t first formed about 13 billion years ago.
- wolverine876 5y agoWe apparently don't know why space looks black. See Olbers' Paradox. https://starchild.gsfc.nasa.gov/docs/StarChild/questions/question52.html https://starchild.gsfc.nasa.gov/docs/StarChild/questions/que...
- Sharlin 5y agoOh, but we do know. It is because the age of the universe and the speed of light are both finite. (We knew that back in 2002 as well; the page you linked seems to be written the way it is mostly for pedagogical reasons.)
- wolverine876 5y agoWell I have a citation from NASA for my claim. What do you have? :) I recently read another article saying something similar but I personally know nothing about it. It definitely looks black to me. Edit: Looking around, some other credible websites agree with you. That would seem to imply that the night sky is very slowly getting brighter.
- Sharlin 5y agoBut nowhere does the page make the claim that we don't know! It only says that it's not a trivial question, and that there was a time that we didn't have a good explanation for that. Like we used to not have a good explanation for gravity or illnesses or earthquakes or what have you. It gives the best explanation that we have which is also overwhelmingly likely to be true given the evidence but of course there's never anything that we can actually prove in science, so in the interest of pedagogy it doesn't outright say that we know. Anyway, as I said, the page is from 2002 and many things have happened in cosmology since then. Indeed there are things that we didn't know back then but are now pretty sure about.