Why couldn't rocket escape black hole? I keep hearing stuff about how the escape velocity is the speed of light and nothing can go the speed of light. So? The Earth's escape velocity is seven miles per second and none of the probes we sent out into the solar system ever went seven miles per second. Instead, they gradually speed up over time to get away from gravity. Likewise, why couldn't a probe with lots of rocket fuel be sent into the event horizon of a black hole and then fire the rockets to escape?
2007-12-06 16:09:05 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
Rockets can, indeed, escape black holes... with a "catch" to it. There is a limit called the "event horizon" at which everything disappears into the hole. End of story.
If you are outside the event horizon, you have a chance if your engines are strong enough and you have fuel enough to maintain the burn for long enough to pull out of the gravity well. But there's the catch-word... "enough." A black hole is SO massive that the thrust-to-fuel-weight ratio of current rockets would not be strong enough. Not because it cannot be done at all, but because the rockets we use now cannot do it.
You say... rockets just speed up to get away from the gravity well. Here's the comparison you have to make. You are in a rocket ship with engines that provide some amount of thrust. That thrust acts as "acceleration" to move the ship away from the direction the engines are pointing.
The black hole has a super-massive gravity well that acts as "acceleration" - to move objects towards the event horizon and inward.
So it's a race between the black hole's gravitic acceleration and the rocket's Newtonian acceleration (action and reaction). Today's rockets would lose the race. It is not out of the question for SOME rocket to be able to do this. But not what we have now.
2007-12-06 16:18:50 · answer #1 · answered by The_Doc_Man 7 · 5⤊ 0⤋
As long as an object does not cross the event horizon, it could escape from a black hole assuming it can muster enough thrust to do it. Once it crosses the event horizon however, escape is impossible because in order to get back out it would have to exceed the velocity of light. As an object accelerates towards the speed of light, it's mass increases exponentially. By the time it's traveling at 99 percent of the speed of light, each increase in speed could require millions or trillions of times more energy than the spacecraft is using at it's present speed. That trend is just not sustainable. Eventually converting the entire spacecraft into energy would not be enough to get back out. There's no way for a spacecraft to get to that last decimal point and travel at the speed of light. Since no object made of matter can do this, it or its remains would fall straight to the singularity where it would be totally destroyed. The black hole would be a little more massive and no trace or signal of the event would ever escape from the event horizon.
2007-12-07 01:34:15 · answer #2 · answered by Anonymous · 1⤊ 0⤋
A rough analogy would be you trying to push the Statue of Liberty. Even having all the fuel you could hold, you'd never move it. The escape velocity of a black hole is incalculable, certainly more that the speed of light, since not even light escapes its pull.
2007-12-07 00:21:20 · answer #3 · answered by LDJ 3 · 0⤊ 2⤋
Lets make this clear that light cannot escape a black hole. So the escape velocity is insignificant because your doomed anyway.
2007-12-07 02:41:51 · answer #4 · answered by Agent Fox 6 · 1⤊ 1⤋
Well black holes pull in mass so it can't escape it
Not even light can escape becasue light is made up of photons. nope once you go past the event hurison your out of luck you will get sucked in.
2007-12-07 00:13:28 · answer #5 · answered by Mr. Smith 5 · 0⤊ 1⤋