3 ms·
Why is there a band of decelerating matter right near the top? I thought it was all accelerating outwards? Also what's the gap between the blue bits?
by sideshowb 6y ago
Why is there a band of decelerating matter right near the top? I thought it was all accelerating outwards?
Also what's the gap between the blue bits?
- terramex 6y agoThe gap is part of the universe we have trouble seeing because it is obscured by Milky Way.
- astro123 6y agoThe early universe's expansion was not accelerating, as the early universe was not dominated by dark energy. I don't know off the top of my head exactly when that changed, but z=0.76 seems about right. So I'm pretty sure that is what that is. The reason the dominant form of matter changes is fairly simple. As the universe expands, the amount of matter doesn't change, so the matter density goes as 1/r^3. The amount or radiation goes as 1/r^4 as there is an extra loss of energy due to redshifting (E = hc/wavelength). Dark energy though is (we think) a constant, so as the universe expands, the amount of it stays constant.
- sideshowb 6y agoThat took a long time to process! What's z? Your username checks out :-)