Replicas

In real life, I am on a mission which led me to move halfway around the world for reasons having nothing to do with quantum gravity, though of course the issues interest me. So imagine my surprise when on local TV yesterday, there was a news story announcing a new institute intended to solve quantum gravity.

Looking at the founding conference, it seemed largely to be about a few rich guys supporting the work of non-string-theorists who are already well connected academically. So it's unclear whether they would ever support my own physics research. But I will probably investigate more about how the sponsors got together, simply to understand philanthropy and the tech scene here, for the sake of my other mission.

I did look into the personal quantum gravity theory of the main physicist among the local organizers. At first it seemed a peculiar and arbitrary exercise in having gravitational interactions between different branches of a superposition. Too bad, I thought, that all that money is going to support such an unmotivated hypothesis.

But then I remembered the appearance of  'replica' space-times, connected by wormholes, in some fashionable recent theoretical studies of the black hole interior. So maybe it's better motivated than I thought.

In other news, I actually linked to this blog, in a new discussion of the "JI/poly" scenario at Scott Aaronson's blog, but unfortunately everyone was distracted by philosophy-of-mind issues and didn't address more technical matters, like whether the time it takes to get out of a traversable wormhole nullifies any computational advantage derived from working inside it.