Last year I got talking to theoretical physicist Aron Wall about the thermodynamics of quantum gravity. Now that’s a deceptively beautiful phrase: in four words, you get three of the deepest areas in modern science. Their union promises answers to such mysteries as the arrow of time and what the heck time actually is. And in reading one of Wall’s papers, I learned that thermodynamics might finally settle whether time machines are possible. So I invited him to describe his ideas for us. Wall, a postdoc at U.C. Santa Barbara, has his own blog Undivided Looking, and the discussion of this post will continue there; he says he’s happy to answer any questions you may have.
