The Big Bang was a “special, low entropy arrangement”?
|May 5, 2014||Posted by News under Fine tuning, Intelligent Design, News, Physics|
Eventually, we will get back to work. But if we are talking about loopholes in the laws of physics that might enable light speed to increase anyway, we might as well address the question of why time flows forward.
To physicists, it isn’t self-evident. That is, we take for granted that it is true because all our experience shows that it is. Physicists call that the “psychological” arrow of time, not because they doubt it is a correct observation but because we tend to think that things “must run” that way. Not necessarily.
At Inside Science, we learn:
The principles of thermodynamics show that large collections of particles, like the trillions upon trillions of liquid molecules in a coffee cup, always move toward more disorganized arrangements. For instance, hot water molecules clumped together in a cold room need a lot of organization, so warm drinks eventually cool to the surrounding temperature. Physicists say such disorganized arrangements have high entropy, whereas ordered arrangements have low entropy.
Yet the equations physicists use to describe the simultaneous motions of large numbers of particles are equally valid whether time runs forward or backward. Therefore, almost any complex arrangement of matter will gain entropy no matter which direction time flows.
Our universe apparently began with the Big Bang, which was a special, low-entropy arrangement. This seemingly unlikely and as-yet-unexplained observation gives rise to the thermodynamic arrow of time, which leads cosmologists to observe that the universe is evolving from a lower-entropy past to a higher-entropy future.
So just dumb luck?
Meanwhile, two physicists have proposed an interesting thought experiment on whether particles can “remember” the future. More.
See also: The Science Fictions series at your fingertips (cosmology).