Last night, Sean Carroll (a cosmologist at CalTech and the Official Website Physicist™), gave the keynote address at the LogiCal meetings. As he told me at dinner beforehand, he was trying to condense all five of his Gifford Lectures (given in Glasgow last year) into a single hour. It was, like his Gifford Lectures, a summary of his excellent book The Big Picture.

Given his task, he did a good job, laying out the reasons why we completely understand all the physics of everyday life (he is of course a physical determinist), explaining why dualism isn’t possible, but also noting that we can talk about things, like meaning and purpose and value, that are “emergent phenomena”, consistent with but not possible to explain in the language of particle physics.

The only part of his talk that baffled me, as it did in his book, is his explanation of why entropy seems to be a violation of the symmetrical laws of physics, since it increases with time, but why (or so I thought), the passage of time from past to future is more or less an illusion. He asked a very good question: “Why do we remember what happened yesterday but don’t remember what hasn’t happened yet?” His explanation—that we don’t fully grasp the Second Law of Thermodynamics—didn’t satisfy me, and I’m still seeking an answer. Any reader who can explain this to me is encouraged to do so below.

Sean has developed into a very dynamic and engrossing speaker, with a lot of humor, and it was a very good after-dinner talk, but one with a lot of brain food.

Sean presenting “The Core Theory”: the equation that completely explains the physics of everyday life. It’s in his book.

I had the pleasure of dining with Sean before the talk, and asked him the perennial question, “Why is there something instead of nothing?” His answer was that the question doesn’t make sense—yet. “Why questions”, he said, always come embedded in a larger framework—often, in my view, a religious one—but in this case, said Sean, it’s possible that that question, meaningless now, might someday find an answer if we learn more about the circumstances that produced our universe and that may be producing other universes.

Anyway, I urge you to read his book, The Big Picture, which is deservedly popular. Although I don’t agree with some of it, most notably his compatibilism on free will, by and large it’s a rewarding read, and accessible to all educated people.

This afternoon, Dan Barker, co-President of the Freedom from Religion Foundation, is giving his own take on the issue: “Free Will, a Beautiful and Useful Illusion.” I’ve read the draft manuscript for him on this issue, and, as you can imagine, we had long and strong disagreements. I’ll see from his talk whether I had any influence on his thinking. Given his responses in our email correspondence, I doubt it. I’ll report back.