Guess who is very interested in the history of science? Stephen Wolfram, the guy behind Mathematica and Wolfram Alpha (if you are not a math person, these are powerful computer apps for mathematics), that is who. Specifically, he is interested in the Second Law of Thermodynamics — the law that says, in brief, that the universe is Doomed (Doomed, I tell you!). Recently, he posted a long paper about the law on ArXiv. Indeed, at 161 pages, it might be better to say that he posted a short book about it. The paper is titled “How Did We Get Here? The Tangled History of the Second Law of Thermodynamics” — click here for it.
Wolfram’s abstract describes the paper as “an extensive survey… of the historical origins of the Second Law of thermodynamics, illustrated by excerpts from many original sources”. The paper is the third in a three-part series Wolfram has written about the Second Law, with the first being “Computational Foundations for the Second Law of Thermodynamics” and the second being “A 50-Year Quest: My Personal Journey with the Second Law of Thermodynamics”. What is most interesting about his recent article is those “excerpts from many original sources” (in many cases Wolfram includes images of those sources). The sources Wolfram found show an interesting connection between the Second Law of Thermodynamics and the idea of the multiverse.
The Second Law of Thermodynamics is the idea that things in nature tend toward disorder. The classic example of this is beads in a jar. Imagine that you have a large jar, and you pour a bunch of yellow beads into the jar, and then pour a bunch of red beads into the jar. The beads will be in a sort of order: reds all together on top; yellows all together on the bottom.
But what happens if you disturb the jar? Shake it? Roll it? Do anything to it? The beads will randomly mix. And, no amount of additional shaking and rolling will return the beads to the state of “reds on top, yellows on bottom”. It seems to be a law of nature that the beads tend toward a random, homogeneous mixture. To get the beads back to something like their original order would require a lot of effort — you would have to empty the jar, separate the beads, etc.
Indeed, this tendency toward disorder seems to be in the nature of all things. Imagine a room full of delightful toys for kindergarteners. The room is neat and clean. The toys are lovingly arranged on shelves. Now, let in a bunch of kindergarteners. What will happen? The room will naturally (and rapidly) tend toward disorder! Toys randomly scattered everywhere! You can wait all you want, but the children will not naturally put the room back into order. No, getting the room back in order will take a lot of effort.
What does this have to do with thermodynamics, that is, with heat and temperature stuff, and with the Doom of the universe and the idea of a multiverse? Explaining this will take some effort, too. That is why this post is #1 in a series.
But you can maybe guess at the broad picture. If nature tends toward disorder, then is the universe doomed to eventually be a random, homogeneous mess? — to eventually be a jar of mixed beads or a room full of scattered toys? And if disorder is the nature of things, then how is it that we find ourselves in a universe that has some order in it (and yes, despite the fact that the world may seem to be a random mess, there is a lot of order in the universe — if not, we would not be here). Can we answer this question by imagining a multitude of universes — a multiverse?
We will continue next week!
CLICK HERE for all posts in this series.
