# Aging of the Universe?

Does the isotropic expansion of the universe indicate that the past history of Universe ages at approximately the same rate as the event becomes more distant ?

### 3 Answers

- nebLv 75 months agoBest answer
The typical cosmological solution of general relativity has a very simple and symmetric metric based on the large scale homogenous and isotropic assumptions for the universe. This allows us to have a very simple metric in co-moving coordinates that scales space (symmetrically), but leaves the time coordinate unaffected by position or age of the universe. So, you can think of the time coordinate ticking at the same rate everywhere, and at the same rate at every point in time. You would lose that if it wasn’t assumed (by the stress-energy tensor) to be isotropic and homogenous.

Of course, that is an idealization, and in reality there will be small scale variations.

- Bulldog reduxLv 75 months ago
No. Time proceeds at the same rate everywhere because the second law of thermodynamics is the same everywhere. On large scales, entropy increases at the same rate everywhere. Increasing entropy is based in statistics, and statistics doesn't change depending on where or when you're located.

Entropy doesn’t have anything to do with the rate of time. We don’t see the time rate running faster or slower due to different rates of increase or decrease of entropy in any system. Changes in time rates are due to relative motion and/or gravity.