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As if I already didn't have to worry about black holes, now I have to worry about black holes with speeding stars circling around them.
damric
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As if I already didn't have to worry about black holes, now I have to worry about black holes with speeding stars circling around them.
how do you think astronomers find black holes? by measuring the gravitational effects of it. an example would be a star orbiting super fast around something.
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Really, the star might be a plus. Might give you an early warning that you're approaching a black hole.Originally Posted by RagingCain
Statistically, you are safe.
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more like a minus, despite what i said in an earlier post(even if it was possible) ..would it really be a good idea to see certain death? since there would be no way to push out solar system out of it, let alone have enough energy to do itOriginally Posted by WeirdSexy
Really, the star might be a plus. Might give you an early warning that you're approaching a black hole.
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Yes, except when you get close enough to a black hole the escape velocity is higher than the speed of light which theoretically isn't possible to do if you have mass. Unless if you have an infinite amount of energy which again theoretically isn't possible lol.Originally Posted by AznDud333
seeing how blackholes are just a super dense gravitational field i dont see how this is impossible...and after learning some high school physics wouldnt it be possible to escape that pull if a certain object orbiting it could accelerate enough?
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This news isn't super exciting, there are plenty of stars orbiting the black hole at the center of the galaxy, this one is just the closest found so far.
Absolutely, unless you've crossed the event horizon, at which point there is no speed you can travel to escape the pull.Originally Posted by AznDud333
seeing how blackholes are just a super dense gravitational field i dont see how this is impossible...and after learning some high school physics wouldnt it be possible to escape that pull if a certain object orbiting it could accelerate enough?
This news isn't super exciting, there are plenty of stars orbiting the black hole at the center of the galaxy, this one is just the closest found so far.
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btw i thought energy doesnt get used up..just converted..so in theory it is infinite?
so it is possible to escape if you are far enough..thats good to know..anyone else up for turning our solar system into a giant space station?Originally Posted by andrews2547
Yes, except when you get close enough to a black hole the escape velocity is higher than the speed of light which theoretically isn't possible to do if you have mass. Unless if you have an infinite amount of energy which again theoretically isn't possible lol.
btw i thought energy doesnt get used up..just converted..so in theory it is infinite?
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I think it is in fact. Very. They will be using this star along with the 2nd closest star to test Einsteins general relativity theory near a black hole. I find that very exciting.Originally Posted by lordikon
Absolutely, unless you've crossed the event horizon, at which point there is no speed you can travel to escape the pull.
This news isn't super exciting, there are plenty of stars orbiting the black hole at the center of the galaxy, this one is just the closest found so far.
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Also, not to worry, it'll be hella long time before we'll have to worry about black holes.
No, since mass = energy, infinite energy would mean infinite mass. There's a finite amount of energy in the universe that is either contained in mass or constantly being converted.Originally Posted by AznDud333
so it is possible to escape if you are far enough..thats good to know..anyone else up for turning our solar system into a giant space station?
btw i thought energy doesnt get used up..just converted..so in theory it is infinite?
Also, not to worry, it'll be hella long time before we'll have to worry about black holes.
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i meant like..its kinda hard to say this..let say we have a motor..part of that energy goes to the motor spinning, part of it to heat and part of it to sound..doesnt that mean the energy is just converted?Originally Posted by crust_cheese
No, since mass = energy, infinite energy would mean infinite mass. There's a finite amount of energy in the universe that is either contained in mass or constantly being converted.
Also, not to worry, it'll be hella long time before we'll have to worry about black holes.
I think we should, like, ban blackholes, because, they're all, like, bad for our health and stuff.
"I'm extremely pleased to find two stars that orbit our galaxy's supermassive black hole in much less than a human lifetime,"
-Star hater (known as Ghez at source).
That is pretty cool, though. Good read!
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"I'm extremely pleased to find two stars that orbit our galaxy's supermassive black hole in much less than a human lifetime,"
-Star hater (known as Ghez at source).
That is pretty cool, though. Good read!
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Accelerate enough to escape an object that eats light? 9001m^2/sOriginally Posted by AznDud333
seeing how blackholes are just a super dense gravitational field i dont see how this is impossible...and after learning some high school physics wouldnt it be possible to escape that pull if a certain object orbiting it could accelerate enough?
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It is converted, but that doesn't make it infinite. Given a finite amount of mass it can be converted to an amount of energy equal to it, which would also be finite.Originally Posted by AznDud333
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i meant like..its kinda hard to say this..let say we have a motor..part of that energy goes to the motor spinning, part of it to heat and part of it to sound..doesnt that mean the energy is just converted?Originally Posted by crust_cheese
No, since mass = energy, infinite energy would mean infinite mass. There's a finite amount of energy in the universe that is either contained in mass or constantly being converted.
Also, not to worry, it'll be hella long time before we'll have to worry about black holes.
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what if we can convert that energy back! anyway i get your point about infinity..since DeltaE=F*D and F=m*a, and since we cant get to the speed of light we will hit a brick wall right?Originally Posted by lordikon
It is converted, but that doesn't make it infinite. Given a finite amount of mass it can be converted to an amount of energy equal to it, which would also be finite.
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/analogy. Water and air in this case were energy and matter.
Even with infinite energy you'd theoretically only reach the speed of light so you still could not escape. Beyond that if something with mass, like a person in a spaceship, reaches the speed of light then it would also have reached infinite mass, which would have untold effects (would the spaceship itself become so massive as to cave under its own mass and become its own black hole?).
Think of it like two glasses, one full of water, one full of air. You can pour water from one into the other and back. Now, you can also change the water to air, or air to water. So you could have two glasses of air, or two glasses of water, or anything in between. Now, to escape the black hole you need infinite number of glasses of water, and you have two. You cannot simply create extra glasses of water out of nothing.Originally Posted by AznDud333
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what if we can convert that energy back! anyway i get your point about infinity..since DeltaE=F*D and F=m*a, and since we cant get to the speed of light we will hit a brick wall right?Originally Posted by lordikon
It is converted, but that doesn't make it infinite. Given a finite amount of mass it can be converted to an amount of energy equal to it, which would also be finite.
/analogy. Water and air in this case were energy and matter.
Even with infinite energy you'd theoretically only reach the speed of light so you still could not escape. Beyond that if something with mass, like a person in a spaceship, reaches the speed of light then it would also have reached infinite mass, which would have untold effects (would the spaceship itself become so massive as to cave under its own mass and become its own black hole?).
Hmm, so in those binary star + black-hole systems the orbit time is significantly longer than 11 years? Must be crazy far apart, which makes it even scarier that a black hole can pull matter from that far away.
See Cygnus X-1:
http://upload.wikimedia.org/wikipedia/commons/thumb/a/af/Cygnus_X-1.png/800px-Cygnus_X-1.png
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Any further away means the black hole will act identical to any other object with huge mass, i.e. you can happily orbit around it without falling in and leave the orbit with relative ease.
For example if you swapped our sun with a black hole of exactly the same mass, absolutely nothing would happen (other than a sudden lack of daylight
![tongue.gif]( "tongue.gif")
). All the planets' orbits will stay just as they are, nothing will get sucked in...not even Mercury.
See Cygnus X-1:
http://upload.wikimedia.org/wikipedia/commons/thumb/a/af/Cygnus_X-1.png/800px-Cygnus_X-1.png
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Only once you cross the event horizon, for which you would have to be basically "touching" it (super close to the center). .Originally Posted by BlackVenom
Accelerate enough to escape an object that eats light? 9001m^2/s
Any further away means the black hole will act identical to any other object with huge mass, i.e. you can happily orbit around it without falling in and leave the orbit with relative ease.
For example if you swapped our sun with a black hole of exactly the same mass, absolutely nothing would happen (other than a sudden lack of daylight
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This is such an epic statement.Originally Posted by damric
As if I already didn't have to worry about black holes, now I have to worry about black holes with speeding stars circling around them.
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Indeed, we probably wouldn't fall into it at all; it's gravity would just scatter the solar system and Earth could be lost to interstellar space...and we'd all freeze to death. We'd have months if not years of warning before effects became blatantly obvious, then at least a few weeks as the sun got more and more distant and the planet cooled.
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Much of the stuff we've observed orbiting black holes has been there a very long time...like this galaxy, for example.
The gravitational effects would become apparent a long ways off, for a black hole of any significant mass.Originally Posted by WeirdSexy
Really, the star might be a plus. Might give you an early warning that you're approaching a black hole.
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Chances are that if a significant black hole passed through our area, we would not just fall into it with out warning.Originally Posted by AznDud333
more like a minus, despite what i said in an earlier post(even if it was possible) ..would it really be a good idea to see certain death? since there would be no way to push out solar system out of it, let alone have enough energy to do it
Indeed, we probably wouldn't fall into it at all; it's gravity would just scatter the solar system and Earth could be lost to interstellar space...and we'd all freeze to death. We'd have months if not years of warning before effects became blatantly obvious, then at least a few weeks as the sun got more and more distant and the planet cooled.
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Correct.Originally Posted by Tippy
For example if you swapped our sun with a black hole of exactly the same mass, absolutely nothing would happen (other than a sudden lack of daylight). All the planets' orbits will stay just as they are, nothing will get sucked in...not even Mercury.![tongue.gif]( "tongue.gif")
Much of the stuff we've observed orbiting black holes has been there a very long time...like this galaxy, for example.
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But we don't need to worry about black holes destroying Earth or out solar system any time soon
![tongue.gif]( "tongue.gif")
Yes, you are right energy doesn't get used up, but the amount of energy needed to go over the speed of light if you have mass is (theoretically) all the energy in the universe and then some more.Originally Posted by AznDud333
so it is possible to escape if you are far enough..thats good to know..anyone else up for turning our solar system into a giant space station?
btw i thought energy doesnt get used up..just converted..so in theory it is infinite?
But we don't need to worry about black holes destroying Earth or out solar system any time soon
Hi, I am a Theoretical Astrophysicist.
Everything you have said up to this point is wrong.
Thank you.
PS: I got my PhD at DeVry University.
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Everything you have said up to this point is wrong.
Thank you.
PS: I got my PhD at DeVry University.
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Statistically, you are 50% likely to be a test subject living within a simulation.Originally Posted by RagingCain
Statistically, you are safe.
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But afaik relativity is already widely accepted because Mercurius orbits around the sun in a non-Newtonian way.
I think that the point is that due to relativity the star could be rotating faster around the black hole than Newtonian physics would say. If this is really the case then this is good proof that relativity is indeed a valid theory.Originally Posted by AznDud333
seeing how blackholes are just a super dense gravitational field i dont see how this is impossible...and after learning some high school physics wouldnt it be possible to escape that pull if a certain object orbiting it could accelerate enough?
But afaik relativity is already widely accepted because Mercurius orbits around the sun in a non-Newtonian way.
Extreme conditions exist close to a black hole (the larger a black hole - the larger its radius of effect). An object traveling very close around a black hole in an accretion disk could easily get ripped apart by radiation, collisions with other bodies nearby (increased density of "stuff"), and tidal interactions (distortions due to strong gravitational pull).
Gravity affects all bodies with mass - I don't see why it's scary. It's why we don't fly off the Earth into space when going to a store, why the Earth rotates around the Sun, and why galaxies stay together as groups of stars and interstellar medium (they have a massive central black hole to keep everything together). Conservation of angular momentum still stands - things rotate around one another gradually, so there's no need to fear of being suddenly pulled in.
Gravity affects all bodies with mass - I don't see why it's scary. It's why we don't fly off the Earth into space when going to a store, why the Earth rotates around the Sun, and why galaxies stay together as groups of stars and interstellar medium (they have a massive central black hole to keep everything together). Conservation of angular momentum still stands - things rotate around one another gradually, so there's no need to fear of being suddenly pulled in.
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