I'm hoping to use this site to start some discussions on topics that excite me: mainly physics and alternative energy generation. This blog will be a little bit of musing on where we're headed as a species and a little bit of asking some "why is it that" questions.
So enough with the formality: Let's get right to it.
What is the cause of the irreversibility in the universe?
I've been reading a little bit about quantum entanglement, and I'm trying to find out what's the connection between quantum entanglement and the production of entropy.
My understanding is that there are two requirements for the production (increase) in entropy of an isolated system: 1) a probabilistic/stochastic/non-deterministic process and 2) a gradient in some variable (such as concentration, temperature, etc...) .
It seems to me that the source of the stochastic processes is quantum mechanics, and this is why I'm trying to learn more about this quantum entanglement idea. (Let me know if there's a connection here.)
But even with a stochastic process, there needs to be a gradient, perhaps a gradient in concentration of species or temperature. For example, when an isolated system reaches equilibrium, it stops generating entropy because there's no longer a gradient. So, what's the source of a gradient in the universe? i.e. why is the universe not in equilibrium?
Physicists talk about fluctuations in the cosmic microwave background as the cause of non-equilibrium in the universe, but this argument is a little bit misleading. Some times, when I read articles about fluctuations in the cosmic background, the articles make it sound as if the universe was in equilibrium and the somehow fluctuations pushed it out of equilibrium. But this is not the case. The universe was not in equilibrium to start: not anywhere near equilibrium. It was a lot hotter and a lot denser than the surroundings.
There's diffusion occurring along with expansion of time itself.
The occurrence of irreversible processes, like diffusion, require that, even if the universe were to contract, it would not follow the same path backwards as it went forwards. The universe will not contact back to the same state as the Big Bang.
Let me know what you think.