3 ms·
I've always thought: if the universe was infinite, wouldn't we see light fill all of the sky at night? Curious if my intuition is correct on this or if CMB mean
by MadcapJake 5y ago
I've always thought: if the universe was infinite, wouldn't we see light fill all of the sky at night? Curious if my intuition is correct on this or if CMB means that going backward in time is our current bottleneck for observation.
- krapp 5y agohttps://en.wikipedia.org/wiki/Olbers%27_paradox https://en.wikipedia.org/wiki/Olbers%27_paradox
- Jaruzel 5y ago> Shouldn't we see light fill all of the sky at night No, due to the universe expanding, the wavelength of visible light gets longer as it travels massive distances, as such it moves out of the visible spectrum. This is why most of the deep field mapping of the universe is done via radio waves.
- kelseyfrog 5y agoIf the universe was infinite I would also expect to see the age of stars and by extension galaxies uncorrelated with space and time. Instead we see younger and younger stars and galaxies as we peer farther and father away. It's as if we are standing in the savanna and as we look through our binoculars we see younger and younger giraffes as we look into the distance. At some point there will not be any more giraffes to view as their age intercepts zero as a function of distance(and time).
- John23832 5y agoIf the universe is larger that the distance a light proton could have traveled since it's creation, then there could be a much larger universe outside of our sphere of visibility.
- pydry 5y agoIt's also expanding faster than the speed of light. There are right now some galaxies that are so far and moving away so fast that they will effectively stop existing from our perspective. Overhead, without any fuss, the stars are going out.