Escaping a Black Hole

swhyland · Mar 1, 2005

Hello and thank you for any comments. I understand the concepts of black holes and event horizons and the various ideas of how information can or cannot escape a black hole. I have a question about escaping a black holes pull from within the event horizon. The idea that I have is two black holes acceleratinig towards each other. Each black hole is feels the gravitational pull of the other increasing the speed of each black hole towards the other. If given enough speed and the momentum of each black hole, could a each black hole enter each others event horizon and still be able to escape? The concept would be similar to how some satellites are accelerated by passing by a large body like a planet. Thanks, Sean

yevaud · Mar 1, 2005

I would find that doubtful. The event horizon of a singularity, according to theory, is fairly deep with the gravity well. If the two were close enough for them to merge, even briefly, they'd already be gravitationally locked together, and thus begin the process of merging into one. Here's some links on the subject: www.space.com/scienceastronomy/integral_gamma_040318.html science.nasa.gov/headlines/y2002/21feb_mwbh.htm chandra.cfa.harvard.edu <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

Saiph · Mar 1, 2005

nope, because as objects with mass they cannot exceed the speed of light. And as such are confined by the same relationships as everything else. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

yevaud · Mar 1, 2005

Also true. I thought I'd deal directly with his "merging event horizon" aspect of it. Still not certain how the exchange of information part figures in. <div class="Discussion_UserSignature"> Differential Diagnosis: "I am both amused and annoyed that you think I should be less stubborn than you are." </div>

claywoman · Mar 1, 2005

But could the two black holes collide and if that happens, what would happen? One would gobble up the other? Massive explosion? Has anyone taken into consideration this supposition? Curious minds want to know.....

Saiph · Mar 1, 2005

They can collide. When they do a immense amount of energy is released as gravitational energy (we believe) and then you end up with...well a bigger black hole. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

main_sequence · Mar 1, 2005

gravitational waves, yet to be detected I believe. Isn't the spin of the 2 holes also changed? depending upon the relative sizes between the two.

Saiph · Mar 1, 2005

:::shrugs::: the spin shift depends on the angular momentum of the system. It could be increased, decreased, reversed even, depending on how it all comes together. And the gravitational waves have escaped detection so far. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

masta_shady · Jul 28, 2005

We already know that to escape a black hole we need a speed greater then speed of light. But that with no acceleration. Let me present my idea: If we were on earth, so to escape the earth gravitational field we have 2 means: 1-start with an initial speed of ~12 km/h 2-or have an acceleration equal or greater of earth itself,then go with any speed and will escape. now here comes my idea why not use some kind of an engine and creat an acceleration greater then the black hole on the ship itself. since we can't exceed the speed of light , we can use the second methode. But I feel I missed something very important. is the acceleration requierd too great to be generated ? or something else i been completly blind and missed it ?

majornature · Jul 28, 2005

now here comes my idea why not use some kind of an engine and create an acceleration greater then the black hole on the ship itself. since we can't exceed the speed of light , we can use the second method./b> It is impossible to create some kind of engine that can escape a black hole. Do not base your calculations on how much speed would it take to escape a black hole because those calculations that scientists made on how powerful is black hole are just estimates. No one really knows the true power of a black hole. If it could work, then maybe scientist can study more on the phenomenal force and maybe calculate it's true power. True Knowledge Exists in Knowing That You KnowNOTHING!!!!! <div class="Discussion_UserSignature"> We are born. We live. We experiment. We rot. We die. and the whole process starts all over again! Imagine That! <img id="6e5c6b4c-0657-47dd-9476-1fbb47938264" style="width:176px;height:247px" src="http://sitelife.space.com/ver1.0/Content/images/store/14/4/6e5c6b4c-0657-47dd-9476-1fbb47938264.Large.jpg" alt="blog post photo" width="276" height="440" /> </div>

CalliArcale · Jul 28, 2005

<blockquote>In reply to:<hr />It is impossible to create some kind of engine that can escape a black hole. Do not base your calculations on how much speed would it take to escape a black hole because those calculations that scientists made on how powerful is black hole are just estimates. No one really knows the true power of a black hole. <hr /></blockquote> Actually, the calculations are not estimates. A black hole is defined by its escape velocity. If there is some orbit where the escape velocity is at least c, then it's a black hole. If there isn't such an orbit, then it's not a black hole. The true power of a *particular* object might not be known. But once the power is known, then you know whether it's a black hole or not. Scientists determine whether an object is a black hole by observing its gravitational influence on other objects, from which they can extrapolate whether or not there's a point beyond which you cannot escape it. The lower your orbit around an object, the higher the relative velocity you must reach if you wish to escape the object. "Relative velocity" is the key. It is irrelevant how fast the object is travelling through space, with you orbiting it. Consider the object you are orbiting as fixed, and consider your speed relative to it. That's what determines your orbit and how much you'll have to accelerate if you wish to rise to a higher orbit, change your orbital plane, or escape it altogether. You *can* theoretically escape a black hole, by the way, as long as your orbit is higher than the event horizon. The event horizon isn't really the edge of the object itself. It's the altitude at which the escape velocity is c. If you're higher, the escape velocity is less than c. This is why stuff can and does escape black holes (such as the x-ray radiation from the hole's accretion disk, which is being emitted from outside the event horizon). <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

masta_shady · Jul 28, 2005

calli my idea is escaping from the inside of the Event horizon. since on the inside the escape velocity is greater then C.

masta_shady · Jul 28, 2005

my idea is simply stopping the effect of one force by creating an opposit one! same module , same direction, opposite orientation. hence when we do this , we will not exceed the speed of light The sum of external forces equal 0,"not in the mood to apply Relativistic Dynamics" so the movement is done by a cte velocity. got it now ?

CalliArcale · Jul 28, 2005

It doesn't work that way. In order to reach escape velocity, you have to accelerate. You can't escape the black hole without reaching escape velocity. That's just the way it is. And the rules don't really care about whether it's a black hole or not. They apply the same way to all objects; it's just that black holes are so massive you might have to reach or exceed c in order to escape them, and it is not theoretically possible to do so. It's actually not a matter of making the sum of external forces equal to zero. Basically, the force of gravity is causing your ship to accelerate towards the black hole. You can't erase that force; it will always be there. But you can escape it by accelerating faster. Consider this: A G is not a measure of force. It is a measure of acceleration, and 1 G is defined as equal to the acceleration caused by the Earth's gravity at sea level: 9.81 meters per second per second (m/s^2). So if you step off a tall building, you will accelerate downards at that rate (assuming for the moment that wind resistence has no effect). After one second, you'll be travelling 9.81 meters per second. After two seconds, you will be travelling 19.6 meters per second. You will continue to accelerate by 9.81 meters per second each second. So, if you want to hover, you will need to somehow accelerate directly upward by 9.81 meters per second per second to cancel out this downward acceleration, such as with a rocket engine or a helicopter's rotor. When the Space Shuttle first takes off, it goes straight up until it has cleared the tower. For the first few seconds, it is rising directly upwards at 3 Gs. After all, to rise up, you have to accelerate faster than 1 G. But what does this mean about escape velocity? To answer that, you have to understand what an orbit is. An object in orbit is not accelerating. It is in freefall, just like a person who has just stepped off a tall building. The Space <div class="Discussion_UserSignature"> "People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff." -- The Tenth Doctor, "Blink" </div>

masta_shady · Jul 28, 2005

Calli I already know this, for god sake , I"m studying physics this Dynamics is nothing compared to the stuff they make us study. My point was simple , creat a force equal to the one created by the black hole. if the initial velocity was 0 i'll remain still in place. if it was negative i'll go into the black hole center, if positive i'll go outside the event horizon , and then outside the black hole. forget the black hole and the ship and "C" : It's a simple system of one object under the influence of 2 same opposite forces,dynamics tell us that the if the speed was 0 it will remain still , if not the speed will remain cte. now back to the black hole , no matter what's the escape velocity is greater or less then C , it will not matter, cuz the ship will remain at a cte speed while going out of the black hole. PS:~11km/h the escape velocity is when launching some object from earth surface, the mvt is negative acceleration, which the speed 11km/h is the speed which at infinity where the gravitational influence is null , the object will reach infinity with a speed of 0. mean: lim(d --- /> infinity): V -----> 0 it's either i'm not clear , or i'm completly missing the point.

Saiph · Jul 28, 2005

Well, there is one point that makes this moot. The black hole, according to general relativity warps space-time so much there is no path through space or time that leads out. They all head in, and any pointing out loop back on themselves to point back in. There's also the conservation of energy to consider in your scheme. If you cancel the force but have an upwards initial velocity you will continue. However, that initial kinetic energy must be swapped for gravitational potential energy, otherwise you get "free" potential energy. By transfering kinetic to potential energy, you will slow down. To combat this, you must accelerate more than the black hole is pulling down, to resupply your kinetic energy. And that requires more energy than you can generate, as the potential energy required to escape the event horizon is equivelant to the kinetic energy associated with light speed... I think I'm interpreting that close to correct. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

masta_shady · Jul 28, 2005

hmmm that what i was missing out ,it never occured to me to take in consideration that , my idea was correct but .... thx i see the problem now. fine , another question , how do we solve it , my gf really love me and i can't die in a black hole , how do i make her happy and return ?? are my options like stevehw33 said they are ?

Saiph · Jul 28, 2005

invent FTL or time machine are the only ones I can think of (probably same thing actually). Of course, as it stands those aren't even theoretically possible. Or mass quantum tunneling. To bad your information is likely to end up scrambled. Being in a BH is a bad thing, m-kay? There aren't even stable orbits inside, all orbits lead to the singlularity sooner or later. And the tidal stresses inside..bad for anything not atomic in scale. Heck, probably down to subatomic (until you hit the singularity, then we don't know what happens). <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

nexium · Jul 28, 2005

We seem to have two incompatable definitions for event horizon. Where the escape velocity is c and closer to the singularity where no paths lead out, even with almost infinate thrust for a very long time. Billion solar mass black holes do not rip space ships apart at the (escape velosity is c) event horizon. A very dense accreation disk might destroy the space craft, but any size black hole can have a low density acreation disk. In my opinion and masta_shady, near infinate thust allows the craft to move to a higher orbit from a decaying orbit just inside the event horizon (of the escape velosity = c type) Since the new orbit is now outside the event horizon escape is now possible, but an enormous amount of fuel would be required as significant gravity extends for light years from a billion solar mass black hole. The space craft would be climbing out of the gravity well of the billion solar mass black hole for years. Neil

alkalin · Jul 29, 2005

Certain aspects of the relativistic equations should not be taken so seriously, as if they are the only truth available. FTL motion is very likely. You just need to apply derivatives of the Maxwell variety, which I cannot do at this time because I’m caught in a black hole somewhere in time and space and cannot find my way to them. But actually BH’s do not exist because relativity equations are too simplistic and the fact that matter itself occupies certain volume. It must.

dragon04 · Jul 29, 2005

So if negative (note that I didn't say "anti") matter exists, and is clumped into a singularity sufficient to create the analog of a black hole, then FTL velocities should be possible from inside the event horizon, no? <div class="Discussion_UserSignature"> "2012.. Year of the Dragon!! Get on the Dragon Wagon!". </div>

Saiph · Jul 29, 2005

Relativistic equations are very accurate, and are not "simple". There is no force known to exist to stop the collapse of large stars into a BH, so they are quite probable at this point. Sure, matter may be required to have volume (especially from a quantum mechanical point of view). However we don't exactly know what the BH singularity is like. Even so, it's smaller than the Schwarschild radius, and thus will be a black hole. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

nojocujo · Nov 25, 2005

I do think that energy can escape a blackhole. Assume there are two blackholes on a collision course and I don't mean inspiral. The direct merger of the two would create and implosion and then an explosion. The gravitaional wave should cancel the schwartzchild radius as it passes the event horizon. No engine could be that powerful but like I said I do think that energy can escape under certain conditions.

Escaping a Black Hole

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