Originally posted by knightmeister
I 've had a light bulb about this.
I've had one too. I am in the process of reading an article in Scientific American which has some very interesting ideas on time that I never understood before (though I have heard of it). I think I'll start a thread in the science forum. But a rough summary is:
The arrow of time is caused by entropy.
The laws of physics all work both ways, so we can think of time moving in either direction and the laws of physics still work.
We can only accurately
remember the past because of entropy. (PinkFloyd's professor apparently understood this.)
It works like this:
When a photon is absorbed, it is often possible to identify exactly which direction it came from in the past.(the eye does this).
When a photon is emitted however it can leave in a totally random direction and there is no direct feedback from the future as to which way it went.
This disparity is due to the flow of entropy with time. If entropy was not increasing with time we would remember the future just as easily as the past.
The interesting thing for me, is the implications for quantum mechanics.
When we are unable to accurately 'remember' the past, the past ceases to exist, or more accurately, becomes a wave function of all possible pasts which fit the memories. When only one past fits the memories then it sort of 'snaps' into place. Schrödinger's cat turns out to be either alive or dead.
We can do the same with the future, except that due to entropy, the wave function always covers such a wide range that the future remains a blur. Schrödinger's cats future remains largely unknown.
I think all this leads to two possible ways of looking at it:
1. There is one continuous time line that we travel through, but we always know more about the past than the future.
2. There is an infinite number of timelines, continuously branching, and we are on one of them.
I don't think either suits knightmeister.