Imagine a ball bouncing in a box for a long time. We know, there is a certain path it can go to bounce off infinitely (see the image). If it gets to this state, it will never be able to get back again.
Now, I suppose, it is as probable for the ball to reach one point in the system (with a random starting position), as to reach any else. And I suppose, there is the same probability for it to come from any direction. With these assumptions, the system unstopably tends to get to the regular state.
I have heard in a pop-sci show, that we could theoretically perfectly detect the past from the data we have today (the locations of all the particles with their characteristics). But we can't really find out how had it all begun if we see a system like on the animation below.
- Sorry for this inappropriate image, there is a bigger probability for the ball to reach the middles of the lines than the corners, let's ignore the bouncing of the walls)
- Note that even though 0.0...1 equals 0, the stable point does exist as any else
- Let's assume the ball gets all it's energy back...I'm interested in something a bit else