astralavista

Black holes have lost some of their enigma at the Physics 2005 conference held this week at the Institute of Physics in Warwick, England. First, Astrophysics professor Andrew Hamilton from the University of Colorado showed that space travelers getting close to the event horizon of a big black hole would be fried to death, rather than torn to pieces. Since gravity at an event horizon is proportional to the mass of a black hole divided by the horizon's area, the bigger the horizon the weaker its gravitational pull. In theory, it would be possible to travel near the surface of a gigantic black hole the size of billions of suns and fly safely back.
Not so, says Hamilton. He says that the core of any black hole is filled with hot, dense plasma slowly sinking into the infinitely dense and infinitely tiny singularity at its center. Anybody approaching the horizon would be incinerated by the plasma before he would have time to take off and write home.
Astronomer Royal Martin Reese and his group later reported that the huge black holes located in the centers of galaxies have been formed by mergers of small black holes rather than by gobbling up galactic material. In a twist, Reese's Cambridge colleague Martin Haehnelt said that a proof for this theory would be finding a galaxy with its central black hole missing. He explained that a black hole merger begins with two holes going into orbit around each other and spiralling ever closer together. In the cataclysmic blast of energy when they finally merge, any asymmetry can send the resulting black hole flying off into space. Said Martin Haehnelt: "If this happened we might find the occasional galaxy with its central supermassive black hole missing."