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Slowly Pulling Facts from Black Holes
lee1 writes "Astronomers have proven the existence of the event horizon, the 'point of no return' that surrounds black holes. An MIT and Harvard team said they showed its existence by looking for X-ray bursts from neutron stars and more compact objects thought to be black holes." Relatedly beuges writes "IOL is reporting that by tracking the death spiral of cosmic gas at the center of a galaxy called NGC1097, scientists figured that material moving at 177 000km an hour would still take eons to cross into a black hole. 'It would take 200 000 years for gas to travel the last leg of its one-way journey,' Kambiz Fathi of Rochester Institute of Technology told reporters at a meeting of the American Astronomical Society."
310316400000000 km is the last leg of the journey?
FYI, that's 2,074,335.22 Astronomical Units, or 32.8 Lightyears, or about the distance from Sol to the Cepheids. Dang.
Too bad they don't specify how far out (radially) from the event horizon the last leg starts. Or even loosely define what 'last leg' means in this case.
"Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
so light being emitted from something almost at the Event Horizon but not yet inside the threshold takes a much longer time to escape and be seen by someone then it would in normal space going at 186,000 miles per second.
Not true. The speed of light is a constant, even near a black hole.
As I understand it, what actually happens to the light emitted by an object approaching an event horizon is that it gets increasingly red-shifted. So an observer at a safe distance would see the object "fade" into infrared and then into ever-longer radio waves until it crosses the horizon.
The most rabid believers in American Exceptionalism are the exact same people whose policies are destroying it.
> The Singularity is the true point of destruction, the actual hole part of the black hole
No, the event horizon is the methaphorical "hole in space".
Lots of physicists doubt that singularities even exist. Singularity essentially means "the math broke", a result of applying GR at scales where QM effects almost certainly dominate. If we ever get a theory that unifies GR and QM, we might discern what actually happens at the center of a black hole.
Sheesh, evil *and* a jerk. -- Jade
Hmmm - So friction in the revolving gas could will cause it to heat up and possibly glow, while slowing down its rotation, causing it to cross the event horizon and fall in?
Yes. The only way something can fall into a black hole is by losing energy to fall it. If it doesn't lose any energy it will keep revolving around the black hole. Same thing with Earth, if Earth was in the middle of a cloud of gas that could eat away at very large amounts of the Earth's momentum, then the Earth could spiral into the Sun. Since that gas isn't there our Earth keeps revolving around the Sun, which is good for us.
Only dead fish swim with the stream...