Philosophers David Albert and Barry Loewer have long argued that thermodynamics (or, more broadly, statistical mechanics) can explain the direction of time, the regularities of the special sciences, our memories, and our ability to control the future and not the past. As if this weren’t enough, a recent article in the New York Times reports that Dutch physicist Erik Verlinde thinks thermodynamics can explain gravity too!
According to his paper, if we accept the holographic principle (very roughly: that the spatial dimensions of the universe emerge from its boundary conditions) popular among string theorists, then the motions of bodies through that emergent space can take on many possible values. Where does thermodynamics come in? Recall that the most probable arrangement of gas particles in a room is evenly distributed. According to thermodynamics, this is explained by the fact that there are vastly more ways for the particles to be spread out than to be clumped up. Similarly, if there are vastly more ways for massive bodies to behave ‘gravitationally’ in the emergent space than there are ways for them to behave ‘non-gravitationally,’ we can say that the gravitational behavior is most probable.
The scientific reception to Verlinde’s paper has been mixed. According to the Times article, “Some of the best physicists in the world say they don’t understand Dr. Verlinde’s paper, and many are outright skeptical.” However, Andrew Strominger, a string theorist at Harvard said, “Some people have said it can’t be right, others that it’s right and we already knew it — that it’s right and profound, right and trivial.” If Verlinde’s idea is on the right track it would seem that thermodynamics has even more work to do.
The true logic of the world is in the calculus of probabilities.James Clerk Maxwell‘Probability logic’ …
By Alan Hójek