entropic gravity

Recently, Erik Verlinde proposed that gravity can be described as entropic force. I am not sure yet what to think about this, but Lubos explains why he is certain this can never work.

Meanwhile, Lee Smolin published a preprint using Verlinde's idea to derive Newton's law from loop quantum gravity. I am not convinced by his argument.

Verlinde considers the change in entropy dS for displacements dx assuming a holographic principle and in his calculation he implicitly assumes the geometry of a smooth and indeed flat geometry.

There is of course nothing wrong about that, but if Lee Smolin wants to use this argument, then he has to first show that there is a reasonable limit of loop quantum gravity which reproduces this smooth and (almost) flat spacetime and I don't see that.



added later:



More discussion Lubos vs. Erik (scroll down through the comments).



Lee Smolin responds to my comment here.



Robert Helling comments on entropic everything.

previously, somewhere else

Just some links to that other blog, which you may or (more likely) may not find interesting..

.. about many worlds (again),

.. lattice gravity models,

.. the impossibility of self-measurements,

.. and a lottery ticket of zero value but with probability to win greater than zero.