The Mystery of Time’s Arrow - Issue 9 : Time

/the-mystery-of-times-arrow

  • The Mystery of Time’s Arrow - Issue 9: Time
    http://nautil.us/issue/9/time/the-mystery-of-times-arrow

    As conscious beings, we are constantly aware of the relentless march of time. You can make an egg into an omelet, but you can’t turn an omelet back into an egg. Dropped glasses shatter and do not reassemble themselves. Above all, we age and become decrepit; there is no return to youth. But this is a great scientific mystery. There is nothing in the form of the laws of nature at the fundamental microscopic level that distinguishes a direction of time. They are time-symmetric. But the behavior of macroscopic objects around us is subject to the famous second law of thermodynamics, according to which disorder (as measured by entropy) always increases with time. This puts a direction, or arrow, of time into phenomena. The classical studies by Maxwell and Boltzmann in the second half of the (...)

    • #temps

      A TOY MODEL OF THE UNIVERSE: The paths of three particles in space, considered together, provide a useful model for understanding the nature of time. One particle comes from the bottom left, while another two are orbiting each other and coming from the top right. There is a complicated interaction when they meet, as a result of which there may, as shown, be a swapping of partners. Then the single particle flies off to the top left, while a new pair goes to the bottom right. The arrows correspond to one of the two possible choices for the direction of progression in time. In the other choice (not pictured), each arrow is rever! sed.

      cc : @chirine