Quantum Information Can be Negative

nerdlygirl writes "In a development that would probably even puzzle Claude Shannon, information can be negative -- at least when the information is quantum. The discovery, by Horodecki, Oppenheim, and Winter, appears in the current edition of the leading journal Nature. If I tell you negative information, you'll know less. Apparently, researchers hope to use this to gain deeper insights into phenomena such as quantum teleportation and computation, as well as the very structure of the quantum world. More details can be found here and here A popular account of the article can be found on Oppenheim's homepage, and a free version of the article can be found in the arxiv for those of us without subscriptions to Nature."

Comments

Affects black holes!

[sconeu]

Since a black hole's entropy is directly proportional to it's information content, this, if true, would have an effect on black holes.

If I recall correctly (and I may not -- my physics isn't what it used to be), the amount of information contained by a black hole is directly proportional to its surface area -- specifically, I believe that the total number of bits contained is equal to 1/4 of its surface area as measured in Planck units.

Now, if information can be negative, that would provide another method of shrinking a black hole, in addition to Hawking radiation.