in which he tries to decide the validity of the External Reality Hypothesis, the Mathematical Universe Hypothesis, the Computable Universe Hypothesis, and whether or not we live in the Matrix. ;-)

**Hep-th**

On hep-th, Kallosh and Linde are testing string theory with the CMB. Green, Ooguri, and Schwarz argue that one can't decouple supergravity from string theory in dimensions higher than three and N=8 supergravity probably belongs to the swampland - very much the same arguments we explained at the end of Finiteness of SUGRA.

Very interesting stuff.

ReplyDeleteIs this guy a former student of Seth Lloyd, the guy with "Computational Universe"?

In my opinion, we might be living in a matrix, but we will NEVER be able to determine whether our reality world is a matrix or not. The important thing to note is that our universe is finite, with a finite amount of entropy. That means it can be fully described by a finite number of digits. Those digits could be written onto a book, saved into a computer chip, or stored in a giant quantum computer. You never know.

For example, the whole universe we saw, might just be a giant TV screen some intelligent ET life set up, enclosing our whole solar system, projecting various photons our way emulating what a universe should look like according to certain theoretical model. Making every thing look so real. Such a giant TV screen would be incredibly complicated. But the complexity would be finite, not infinite. And any thing with finite complexity is conceiveable by a super intelligent being. We would not be able to tell whether such a giant TV screen exists or not until we send a spaceship actually check it out.

Of course that's quite a stretch of imagination. But mathematically you can not say it is impossible.

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ReplyDeleteI tried to leave this link to a conversation about the MUT I tried to strike up at Google groups on sci.logic.

ReplyDeleteThe link was way too long, let me try this:

A MUT discussion.

When would we be justified in claiming to have a rational explanation for existence?

ReplyDeleteWhat we really want is a particular structure that has a unique claim to existence.

There is an attempt to find one at http://www.towardsrationalexplanationexistence.blogspot.com/