Doesn't the redshift mean space's expansion has slowed?
If further distance means farther back in time and those farther galaxies appear to be moving faster away.
- JonLv 61 month ago
The universe's rate of expansion isn't the speed at which galaxies recede from us. It's the ratio of speed to distance.
- Anonymous1 month ago
Galaxies are going increasingly Republican.
- Bulldog reduxLv 71 month ago
The larger a galaxy's redshift, the faster the galaxy is receding from earth.
- nebLv 71 month ago
For the first 7 billion years of the universe, the expansion rate did indeed slow down because of the pull of gravity.
About 6 billion years ago, expansion started to accelerate due to the effects of dark energy. While we don’t know what dark energy is, it’s predicted effect is to create a kind of repulsive gravity that increases the rate of expansion.
So, why the change 6 billion years ago? Dark energy appears to be a property of space itself. As the universe expanded, it increased the volume of space which in turn increased the amount of dark energy. At 6 billion years, we hit the tipping point where it began to dominate and counter the attractive force of normal gravity. The expansion rate began to accelerate.
If we look at redshift as a function of time, we can see this.
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- 1 month ago
If expansion *was* uniform, then you'd fully expect to see the more distant objects retreating faster than those closer to you. If red shift is relatively constant, that means that the rate of expansion is constant; if it's accelerating, then red shift is increasing. If it's decelerating, then red shift would be decreasing.
It's been seen in the last few decades that the rate of expansion appears to be increasing.
- busterwasmycatLv 71 month ago
The problem with expansion is that it is not the same as one object moving away from another. the very distance between objects, even if not moving, is increasing and thus expansion is not linear (not a first-order process). You need more details than you have. In any expanding system, at any change in rate of expansion as long as it did not reverse direction and start contracting, older objects will appear to be moving faster than younger ones.
- FuhrLv 61 month ago
Time to reread your homework, princess.