Many Body Physics
Published in

Many Body Physics

How chaos drives the arrow of time

On the left, many balls are assembled in one corner of the box — a state with very low disorder, i.e. low entropy. On the right, the opposite is the case. The second law of thermodynamics states that configurations like the left one will evolve to one like the right one and never the other way around — this is what some people call the arrow of time.
Reversible dynamics und Newton’s equations: A car is made to move along a road because of a force F acting on it. If we let it drive for some time t it will end up at the end of the road. But equally as well, we could then make the car move back to its initial place again by acting on it with the opposite force, or, put differently, let it evolve for the same amount of time, but “backwards”.

It took another discovery to enable full understanding why at least classical many body systems effectively forget their initial state: Chaos!

Very slight changes in the position where the ball is dropped onto the slope mean enormous changes in its final position when it hits the ground. (adapted from our earlier post)

--

--

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store
Alex Schuckert

Alex Schuckert

Trying to make sense of quantum physics with the help of green tea.