Recently scientists noted that Sag A, the black hole at the center of Milky Way, flared up 75 times brighter and thought it might relate to a massive dust cloud that came close to it in 2014.
Relativity state that time slows as you approach a black hole and stop altogether as you fall into it.
If this gas fell into the black hole near light speed, time would have slowed to a near stop. How can a gas cloud that approached in 2014 be the cause of the brightness, wouldn't it now take this light many thousands of "extra years" (compared to our POV) to reach us? I understand what we saw in 2014 actually happened 25,000 years ago, thats not the point
Hello, how is a black hole bright
The light is created by matter being compressed NEAR the black hole, but before it actually enters the black hole.
I'm pretty sure much more light is actually created when the matter finally HITS the black hole, but that light, yes, would not escape.
The matter isn't compressed -- it's being torn apart. The gravity differential becomes so great that even on the atomic scale, the side of an atom nearer to the singularity is pulled far harder than the side opposite...so hard, the nuclear bonds are broken. Each atom being ripped apart releases a burst of X-rays.
That's not accurate. While that may certainly be happening inside the event horizon, closer to the black hole, the gradient is not that strong outside the event horizon. And we could never observe xrays emitted in this manner, as they all end up in the black hole and never escape the event horizon from within it.
What happens to gas near a black hole is that it loses angular momentum due to magnetic fields and friction, and that energy is converted to thermal energy. The gas then heats up so much that it emits xrays.
