Friday, October 24, 2014

Tullio Regge passed away

Tullio Regge (July 11, 1931 in Turin - October 23, 2014 in Orbassano)

Theoretical physicist and mathematician Tullio Regge, aged 83, passed away yesterday. He gave fundamental contributions to scattering theory (the theory of Regge poles is named after him) and to General Relativity among many other fields. His "Regge calculus" -based on a discretization of spacetime- is still widely used in Loop Quantum Gravity.

The relevance of Regge's heritage in modern physics is well shown by the fact that something like half of my papers cite the so-called Regge-Wheeler equation which describes how a Schwarzschild black hole vibrates after a perturbation and how it emits gravitational waves. The Regge-Wheeler equation was found in the late 1950s, even before the very concept of "black hole" (a name coined by Wheeler only in the 1960s) was formulated.

The Italian Institute for Nuclear Physics has dedicated its homepage to this news, more details on Regge's work can be found here.

Friday, October 17, 2014

The brightest pulsar ever

Last week the astrophysics community was hit by an exciting news. A very luminous X-ray source located in the "Cigar" galaxy M82 was discovered to be a spinning neutron star (a pulsar) rather than a black hole, as all models have assumed so far. This research was lead by astrophysicist Matteo Bachetti, who also happens to be a writer of this blog. Thus, we take the opportunity to ask Matteo a couple of questions whose answers you will not find in the excellent press (and radio) coverage that has followed the publication of this discovery.

Q: Matteo, first of all congratulations for what sounds like a great scientific achievement! How would you explain this discovery to my grandma?