How Your Thumbdrive Is Like a Black Hole
Scientific Blogging explains how a black holes are like memory chips, so the next time you say your data went down a black hole, you may be closer to the truth than you think.
Follow the link to see what this has to do with cats.
As we saw, black holes are matter crushers that translate matter in to radiation. But black holes do not do this in a random way. It is done in such a way that no information gets lost. When all the matter has been transferred into radiation, by measuring the state of each photon that has been emitted by the black hole, one can in principle calculate back the precise configuration of matter that entered the black hole. Each photon of radiation that leaves the black hole caries away some bits of information. The total number of photons that get emitted during the evaporation of the black hole is roughly equal to the number of Planck areas that fit onto the black hole horizon. This all hints towards a fundamental constraint on storage of information: in a given spherical region of space nature can store an amount of information that is proportional to the area of that sphere. This is the holographic principle, proposed 16 years ago by Gerard ‘t Hooft. It seems that the holographic principle sets a clear constraint to the yet-to-be-found theory of quantum gravity.