levi
Still fresh, damnit!
Yes, redshift as a term is only a general term to give you the gist of what they're doing. They're actually measuring things based on the spectral lines of hydrogen, which are well known as wavelengths, but I don't even know if any of them are actually in the visible frequencies. They see spectal lines coming out of these distant stars that are burning bydrogen that look like hydrogen, just shifted right a bit (if your x axis is wavelengths, as is commonly seems to be in this field), but I guess rightshift wasn't as catchy a term as redshift.
At the end of the day it doesn't really matter whether the space between us and distant galaxies is expanding, or the galaxies are all heading away from us. It's the same situation when you think it through.
Edit: Regarding multiverses, most people discussing them think of them as extra dimensions, I think. In terms of 3d they're all in the same place, but in terms of one of the extra dimensions they're just right and up a bit from where we are. They could be out there in the 3d universe, just past the region we can see, but it's harder to think through if you think like that. Most of the people I'm thinking of at least are using multiverses to capture quantum uncertainty though, mind you, probably other people think of them in different ways for different purposes.
I'm not actually sure of the scale of the background radiation, but I think that all the stars we can see haven't redshifted that far. There's also a hard limit due to the speed of light, we can only see light that's been able to reach us so far which is a big sphere and hasn't hit the edge of the universe yet, so we tend to think there's a lot more out there that we simply can't ever know about in our lifetimes anyway. And the thought is that at present, the universe, or the space in it is expanding at an ever increasing rate, so some distant galaxies are currently rushing away from us so fast that the light from them will never reach us.
At the end of the day it doesn't really matter whether the space between us and distant galaxies is expanding, or the galaxies are all heading away from us. It's the same situation when you think it through.
Edit: Regarding multiverses, most people discussing them think of them as extra dimensions, I think. In terms of 3d they're all in the same place, but in terms of one of the extra dimensions they're just right and up a bit from where we are. They could be out there in the 3d universe, just past the region we can see, but it's harder to think through if you think like that. Most of the people I'm thinking of at least are using multiverses to capture quantum uncertainty though, mind you, probably other people think of them in different ways for different purposes.
I'm not actually sure of the scale of the background radiation, but I think that all the stars we can see haven't redshifted that far. There's also a hard limit due to the speed of light, we can only see light that's been able to reach us so far which is a big sphere and hasn't hit the edge of the universe yet, so we tend to think there's a lot more out there that we simply can't ever know about in our lifetimes anyway. And the thought is that at present, the universe, or the space in it is expanding at an ever increasing rate, so some distant galaxies are currently rushing away from us so fast that the light from them will never reach us.
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