4 log 3 - a new cosmic constant? John Baez (UC Riverside) has a "news and views" piece in the February 13 2003 Nature entitled "The Quantum of Area?". We start by asking whether black holes have a discrete spectrum of energy levels. According to Baez, a complete answer would require an understanding of "how quantum mechanics and general relativity fit together -- one of the great unsolved problems in physics." But two completely different ways of guessing have recently come to the same answer: the spectrum of discrete energy levels is related to the surface area of the black hole, and the quantum of surface area is exactly 4 times the natural logarithm of 3 times the Planck area (which itself is about 10-70 m2). The "surface" is actually the event horizon - "the closest distance an object can approach a black hole before being sucked in," so it is an imaginary boundary, but nevertheless acts in many ways "like a flexible membrane," and has a geometry of its own: it is flat except at points where it is punctured by one of the "threads" postulated by loop quantum gravity theory. Recent work by Shahar Hod (Hebrew University), Olaf Dreyer (Penn State; available online) and Lubos Motl (Harvard; available online) relates to earlier research by Hawking, Ashketar and Baez himself.
[via Math in the Media]
[via Math in the Media]
integrator - am Sonntag, 30. März 2003, 18:42
