Re: In defense of physics

From: Eliezer S. Yudkowsky (
Date: Sat Feb 14 2004 - 20:25:04 MST

Metaqualia wrote:

>>In the latest physics, the bound formerly known as Beckenstein (now known
>>as the 't Hooft bound, briefly known as the Susskind bound) is a
>>holographic bound on the entanglement between a spherical volume and the
>>rest of the universe, measured in Planck units of the surface area.
> "all the information content of the inside of the volume
> can be mapped to the surface of the sphere. In effect, the 3-D volume is
> perhaps just a "holographic" projection of a 2-D reality."
> But how can you map all information inside a sphere on its surface?

Amazing, isn't it?

Actually, it's not that all information inside a sphere is being mapped
onto the surface, but that the entanglement between the outside of the
sphere and the inside is bounded by the area of the surface. But it would
apply to any attempt at data storage.

Incidentally, this is Bousso's formulation of the holographic bound, i.e.,
the covariant entropy bound, not 't Hooft's formulation, as I discovered
on Googling (I really have to learn to do that *before* hitting "send").

Eliezer S. Yudkowsky                
Research Fellow, Singularity Institute for Artificial Intelligence

This archive was generated by hypermail 2.1.5 : Wed Jul 17 2013 - 04:00:45 MDT