If nothing exceeds the speed of light, how does the gravity of a black hole, escape the black hole? Thread started at Forum 4 Politics on 04-06-2012 09:14 PM
^^ What he said. There is no "gravity particle" that goes out and grabs things; gravity is part of the landscape. It is a constant effect. It's like falling in a hole. You are faster than the hole;it doesn't move at all. But it still got you cause you stuck your foot in it.
The problem is disturbances in the gravitational field travel at the speed of light. Therefore, increases in the gravitational field travels at the speed of light.
This is similar to asking "Why does water not escape a swirling whirlpool?". Mass and particles have spin, much like water does in my analogy. When there is a lot of activity, when considering mass and energy, it pulls space in a similar way. Light spirals down the walls of the vortex in a new direction of time. We can watch all of this happen from the shoreline and this is analogous to our time frame. There are still objects and different time frames above us (the clouds, which are also water), and currents below the surface of the water. The vortex appears to be the hole because of where we stand. Also, about this finding a gravitational particle; not all particles are particular -- some are large.
Beyond its event horizon, it doesn't. Although gravity doesn't "escape" in the way light or information does. Gravity is an attractive force that propagates at the speed of light but it doesn't do any actual travelling itself. More specifically, the gravity from a black hole decreases as an inverse square, just like light does. So it gets stronger the closer you get to the black hole until at some point hitting reverse would require an infinite amount of energy. This boundary is the event horizon, and anything outside it is safe. Interestingly, black holes don't have some kind of supernatural reach - even though their mass is enormous their size isn't, and because gravity drops off by the inverse square law for all but the most massive singularities you could get pretty close. If the mass of the earth could form a singularity (which it couldn't - not enough mass) the event horizon would be about the size of a grape.
Wise space telescope finds more blackholes... Supermassive black holes and hot galaxies in giant haul 30 August 2012 - A space telescope has added to its list of spectacular finds, spotting millions of supermassive black holes and blisteringly hot, "extreme" galaxies.
Two black holes found in our galaxy... Twin black holes puzzle astronomers Oct. 3,`12 (UPI) -- Two black holes discovered in an ancient cluster of stars in our galaxy may require rethinking our understanding of such clusters, U.S. astronomers say. See also: Distant planets seen in strange alignment Oct. 3,`12 (UPI) -- Two exoplanets have been detected forming a never-seen-before celestial alignment, a phenomenon so new it doesn't yet have a name, Japanese astronomers say.
The edge of our universe is traveling faster then the speed of light, which we only have theories that attempt to explain how this is possible.
Particle spin doesn't have anything to do with electromagnetic energy and matter falling in a gravitational well. Keep in mind spin is only "like" angular momentum, the particles are not physically spinning. A blackhole essentially is gravity. There is no escaping of gravity it is gravity. Additionally the notion that nothing can escape a black hole is not entirely true. A black hole is a gravitational well just like the 3D square well in quantum mechanics where particles have wavefunctions with nonzero probability of being found in a classically forbidden region.
Nope. Cosmic radiation was predicted to look a certain way before we launched the satellite to take the most detailed picture yet. If the Universe was accelerating there was very precise predictions that were made which ended up being shockingly accurate. The idea that the edge of the universe is accelerating, and is already faster then the speed of light maybe a theory, but it is a theory with massively compelling supporting evidence. This is a theory in the same sense gravity is a theory.
A-T wrote: A blackhole essentially is gravity. There is no escaping of gravity it is gravity. So like, is it the residual gravity left over from the imploding star?... ... Or is it a force generated by the exploding supernova?... ... and BTW, what happens to supernova debris?
It is all the remaining mass of the star compressed into a very small point. The Supernova is the process that compresses the matter.
pt wrote: It is all the remaining mass of the star compressed into a very small point. So the gravity well of the black hole is the result of the gravity of the star being compressed also?... ... sounds like the reverse process of the big bang.
Yeah i think you got it. The gravity generated by a black hole is the result of an incredible amount of mass focused into a very small area. As the sun or earth creates gravity through mass, a black hole is the same idea on steroids.
Thanks. So the amplified effect of the gravity well... ... is due to the compression... ... of the gravity of the originating star... ... rather than being the same as the originating star. I'm having a bit of a problem understanding how... ... the gravity of the gravity well... ... is greater than that of the originating star. Or are they the same in which case the force (i.e. power) of the gravity... ... can be used to determine how big the originating star was?
OK, so there isn't much mass lost from a star when it supernova's, and only really large stars will supernova. For example our sun is not large enough to create a black hole. So, some of these stars that create black holes would stretch out to where Mercury is in our solar system. I mean really huge stars. So this star when in its natural state has this mass spread out over 100,000 miles in area. When the Supernova occurs, and the center of the star collapses, all of this mass is focused into an area smaller than a grain of sand. What creates the increase in gravity is this insane amount of mass concentrated in such a compressed area. The forces at work here are really hard to wrap your mind around as the scale we view the universe in, doesn't transfer well to understanding the scale of forces at work in black holes, and stars the size needed to create a black hole. Here check this out: http://www.google.com/imgres?q=bigg...dsp=19&ved=1t:429,r:16,s:0,i:123&tx=102&ty=70
The force of gravity you feel depends on how far you are from the object's centre of mass. Let's say you were able to compress the Earth into a black hole. It's be about the size of a marble at where the centre of the Earth is now (well, that's how small the Earth would need to be compressed to turn into a black hole. What happens after this point is just hypothesis). The Moon would continue to orbit as if nothing had happened to the Earth. Orbiting spacecraft too would continue to orbit as if nothing had happened. Their distance from the centre of mass has remained the same. They would continue to feel the same force of gravity. However, those who go closer to the centre of mass than the current distance of the surface of the Earth would continue to feel a stronger force of gravity from the Earth mass black hole the closer they got to the centre of mass. Eventually they would get so close that they could not escape. However, as said, other objects wouldn't even notice a difference.
Panzer wrote: Their distance from the centre of mass has remained the same. They would continue to feel the same force of gravity. But wouldn't the force of the explosion of the supernova push them out further away?... ... One would think if the sun went nova... ... we'd find ourselves at least flung out to where Mars is now. Also, is a worm hole a small black hole?... ... could our sun create a worm hole?
There are different types of supernovae - depending on mass, chemical makeup, and possible interactions with other stellar bodies - not all of which result in a black hole. To keep everything in simple terms, stars are basically giant nuclear fusion reactors. They are in a constant state of equilibrium between the explosive force of fusion - which wants to blow itself up - and the gravitational force of such a huge mass of matter - which pulls everything together. A star reaches the end of its life-cycle when it has consumed enough of its fuel such that one of these two opposing forces is able to overcome the other. The vast majority of stars are not massive enough to form a black hole. In these cases, enough mass is lost where the gravity has diminished to the point where it can no longer hold back the force of fusion and it explodes (often leaving behind a white dwarf or neutron star formed from the core). However, if the star is of sufficient mass, the opposite will happen. There is no longer an adequate amount of fuel to continue a strong enough fusion reaction and the force of gravity causes the star to collapse in on itself, forming a black hole. Our sun is no where near massive enough to become a black hole. It will explode and most likely leave behind a white dwarf. The Earth will probably be mostly destroyed with its remnants being ejected outward. Wormholes, at this point, are only hypothetical (although some forms are theoretically possible).
