Slashdot Mirror
NASA Announces Discovery of 30-Year-Old Black Hole
broknstrngz tips news of an announcement today from NASA about the discovery of a black hole in the M100 galaxy, roughly 50 million light-years from Earth. The discovery is notable because, if confirmed, it's now the youngest known black hole, born from the remains of a supernova we observed in 1979. Bad Astronomer Phil Plait explains why scientists think it collapsed to a black hole, rather than a neutron star: "The way a neutron star emits X-rays is different than that of a black hole. As a neutron star cools, the X-ray emission will fade. However, a black hole blasts out X-rays as material falls in; that stuff forms a flat disk, called an accretion disk, around the black hole. As this matter falls onto the newly created black hole, it gets heated to unimaginable temperatures — millions of degrees — and blasts out X-rays. In that case, the X-rays emitted would be steady over time. What astronomers have found is that the X-rays from SN1979c have been steady in brightness over observations from 1995 – 2007. This is very strong evidence that the star’s core did indeed collapse into a black hole." He also warns that we're not certain quite yet, and we'll have to keep our eye on it to make sure it's not a pulsar.
There's an obvious universal frame of reference: measure everything relative to the place where the big bang happened. Your choice of axes is somewhat arbitrary, though.
This is a common misunderstanding of the big bang theory.
There is no center. It didn't start at a "location". The entire universe is evenly expanding, from everywhere.
They common analogy is to reduce the 3D space of the universe to a 2D example. Imagine two points on the 2D surface of a balloon. One point is you ("the observer"), the other point is something distant, like a star, that you are observing. Now inflate the balloon. The result is that the two points move apart, because space (the rubber of the balloon) is expanding. A line drawn between the two points would be longer and longer. Note that neither point is "special". Both points observe the same symmetric effect: the other point moving away.
The real universe is a lot like this, except instead of a 2D surface expanding, it's a 3D volume expanding. There's no "center", all of the points move away from each other. From the point of view of each observer, they are the center.
More accurately speaking, each observer is the center of their own private spherical "observable" universe expanding away from them. The center of the universe is your own head. 8)