Sunday, March 11, 2007

Scientific American Special Edition on Astrophysics

Scientific American magazine has recently come out with a "Scientific American Reports: Special Edition on Astrophysics," the focus of which is on black holes. Scientific American's website has information on the special issue, although no free full-text access is available.

Many researchers have been exploring the links between astrophysics/cosmology and particle physics, as studied at accelerators such as the upcoming Large Hadron Collider (LHC). In fact, according this MSNBC article, one scenario for the LHC is, "Upon collision, the beams are expected to create many new particles and possibly a reconstruction of the universe in its very first moments."

On a related note, one of the articles in the Scientific American issue, by Bernard Carr and Steven Giddings, talks about the possibility of creating microscopic black holes at the LHC. The article notes that, under conventional thinking, the LHC would not have sufficient energy to produce black holes. However, if there are extra, hidden dimensions there could be sufficient energy. The appearance of black holes at the LHC would then offer "compelling evidence of the previously hidden dimensions of space..." (p. 27).

Convrersely, there is some new research suggesting that, in some sense, the Milky Way galaxy's black hole may emulate what will be happening at the LHC. As reported in this news release from the University of Arizona:

"It's similar to the same kind of particle physics experiments that the Large Hadron Collider being built at CERN will perform," UA astrophysicist David Ballantyne said.

When complete, the Large Hadron Collider in Switzerland will be able to accelerate protons to seven trillion electronvolts. Our galaxy's black hole whips protons to energies as much as 100 trillion electronvolts, according to the team's new study. That's all the more impressive because "Our black hole is pretty inactive compared to massive black holes sitting in other galaxies," Ballantyne noted.


Getting back to the Scientific American special issue, other articles cover topics such as the history of black hole research (which involves, among others, Albert Einstein and J. Robert Oppenheimer), the possibility of time travel, and holographic theories of the universe.