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Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: D on 23/04/2016 16:39:36

Title: How are gravitons created?
Post by: D on 23/04/2016 16:39:36
When massive star collapses, the collapse also causes a supernova and black hole is created. Does this mean when objects(particles) fuse gravitons are created. And the bigger and heavier the object gets, the more gvaitons are created. So the black Hole is literally made out of gravitons except the center? And every time when physicist accelerate and collide particles to make heavier particles they are also creating gravitons but unable to detect them?
Title: Re: How Gravitons created
Post by: evan_au on 24/04/2016 00:05:17
Quote from: D
Does this mean when objects(particles) fuse gravitons are created.
I would rather say that when masses are accelerated, gravitons are created, and carry away some of the energy of the masses. This is visible in the fact that orbiting neutron stars and black holes gradually approach each other, losing gravitational potential energy.

This is analogous to the way that when electric charges are accelerated they radiate electromagnetic waves (eg in a radio or TV transmitter), and carry away some of the energy of the electric charges. This is visible in the fact that you have to continue to pump electrical energy into your radio transmitter.

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And the bigger and heavier the object gets, the more gravitons are created.
I had the impression that it is when you have an asymmetrical supernova that you are expected to get the most gravitons, since this causes the mass of the star to be most strongly accelerated after the supernova. So a symmetrical supernova of the same mass would produce a much smaller burst of gravitons.

Merging black holes are probably the most extreme case - when they are almost touching, the gravitational acceleration is maximum, and graviton radiation peaks. However, once they have finished merging (the "ringdown" phase), the mass is almost the same, but graviton emission stops.

Similar, a spherical rotating neutron star would not produce gravitons, but one which is slowly cooling and shrinking, and has built up a "mountain chain" perhaps 1cm high would radiate gravitons, because it is asymmetric.

So it is not the amount of mass that matters, but how strongly these masses are accelerated.

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So the black Hole is literally made out of gravitons except the center?
Gravitons are believed to travel at the speed of light, and the recently detected black hole merger lends support to Einstein's theory.

But even light within a black hole cannot escape the center of a black hole. So I expect that any gravitons trapped inside a black hole will also end up at the center.

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And every time when physicist accelerate and collide particles to make heavier particles they are also creating gravitons but unable to detect them?
Particle physicists like to accelerate charged particles (eg electrons and protons) because they are easier to manipulate than uncharged particles (eg neutrons).

The electric field of these particles is far stronger than their gravitational field (by about 40 orders of magnitude). So when they are bent on their course around the LHC, they produce "synchrotron radiation" which makes it dangerous to be in the tunnel. They would also produce gravitational waves, but their mass is so small that the gravitational waves are immeasurably small.
 
Similarly, when these particles collide, their electric fields, strong & weak nuclear forces produce spectacular fireworks, but their gravitational interactions are negligible, because their mass is so small.

In fact, the huge mass of the Earth orbiting the Sun only produces about 200W of gravitational waves, far less than the hundreds of Megawatts that pour into CERN for accelerating charged particles.
Title: Re: How Gravitons created
Post by: PmbPhy on 24/04/2016 04:55:34
Quote from: evan_au

I would rather say that when masses are accelerated, gravitons are created,
Gravitons mediate the gravitational interaction which means that when two bodies are at rest relative to each other there is still a gravitational interaction between them since there is a gravitational force between them and as such gravitons are working here too. So they aren't just produced only when a body is accelerated.

The same thing holds for the electric force two since two charges at rest relative to each other will still interact by exchanging photons.
Title: Re: How Gravitons created
Post by: evan_au on 24/04/2016 11:47:45
Quote from: PmbPhy
So (gravitons) aren't just produced only when a body is accelerated.
Thanks for clarifying that, Pete...

For further clarification:
Title: Re: How are gravitons created?
Post by: guest39538 on 24/04/2016 17:36:05
When massive star collapses, the collapse also causes a supernova and black hole is created. Does this mean when objects(particles) fuse gravitons are created. And the bigger and heavier the object gets, the more gvaitons are created. So the black Hole is literally made out of gravitons except the center? And every time when physicist accelerate and collide particles to make heavier particles they are also creating gravitons but unable to detect them?


Gravitons are not created they do not exist and you have been wrongly answered by the replier's to your post,  a graviton is of the imagination and there is no proof of existence.

Please see here for the correct information.

https://en.wikipedia.org/wiki/Graviton


''In physics, the graviton is a hypothetical elementary particle that mediates the force of gravitation in the framework of quantum field theory. If it exists, the graviton is expected to be massless (because the gravitational force appears to have unlimited range) and must be a spin-2 boson. The spin follows from the fact that the source of gravitation is the stress–energy tensor, a second-rank tensor (compared to electromagnetism's spin-1 photon, the source of which is the four-current, a first-rank tensor). Additionally, it can be shown that any massless spin-2 field would give rise to a force indistinguishable from gravitation, because a massless spin-2 field would couple to the stress–energy tensor in the same way that gravitational interactions do. Seeing as the graviton is hypothetical, its discovery would unite quantum theory with gravity.[4] This result suggests that, if a massless spin-2 particle is discovered, it must be the graviton, so that the only experimental verification needed for the graviton may simply be the discovery of a massless spin-2 particle.[5]''


Please do not let fellow members dogma confuse you.

Title: Re: How Gravitons created
Post by: guest39538 on 24/04/2016 17:38:04
Quote from: evan_au

I would rather say that when masses are accelerated, gravitons are created,
Gravitons mediate the gravitational interaction which means that when two bodies are at rest relative to each other there is still a gravitational interaction between them since there is a gravitational force between them and as such gravitons are working here too. So they aren't just produced only when a body is accelerated.

The same thing holds for the electric force two since two charges at rest relative to each other will still interact by exchanging photons.


Please amend you false information, you are applying dogma as fact and not explaining it is hypothetical and of the imagination.

Title: Re: How Gravitons created
Post by: D on 24/04/2016 19:57:17
Quote from: D
Does this mean when objects(particles) fuse gravitons are created.
I would rather say that when masses are accelerated, gravitons are created, and carry away some of the energy of the masses. This is visible in the fact that orbiting neutron stars and black holes gradually approach each other, losing gravitational potential energy.

This is analogous to the way that when electric charges are accelerated they radiate electromagnetic waves (eg in a radio or TV transmitter), and carry away some of the energy of the electric charges. This is visible in the fact that you have to continue to pump electrical energy into your radio transmitter.

Quote
And the bigger and heavier the object gets, the more gravitons are created.
I had the impression that it is when you have an asymmetrical supernova that you are expected to get the most gravitons, since this causes the mass of the star to be most strongly accelerated after the supernova. So a symmetrical supernova of the same mass would produce a much smaller burst of gravitons.

Merging black holes are probably the most extreme case - when they are almost touching, the gravitational acceleration is maximum, and graviton radiation peaks. However, once they have finished merging (the "ringdown" phase), the mass is almost the same, but graviton emission stops.

Similar, a spherical rotating neutron star would not produce gravitons, but one which is slowly cooling and shrinking, and has built up a "mountain chain" perhaps 1cm high would radiate gravitons, because it is asymmetric.

So it is not the amount of mass that matters, but how strongly these masses are accelerated.

Quote
So the black Hole is literally made out of gravitons except the center?
Gravitons are believed to travel at the speed of light, and the recently detected black hole merger lends support to Einstein's theory.

But even light within a black hole cannot escape the center of a black hole. So I expect that any gravitons trapped inside a black hole will also end up at the center.

Quote
And every time when physicist accelerate and collide particles to make heavier particles they are also creating gravitons but unable to detect them?
Particle physicists like to accelerate charged particles (eg electrons and protons) because they are easier to manipulate than uncharged particles (eg neutrons).

The electric field of these particles is far stronger than their gravitational field (by about 40 orders of magnitude). So when they are bent on their course around the LHC, they produce "synchrotron radiation" which makes it dangerous to be in the tunnel. They would also produce gravitational waves, but their mass is so small that the gravitational waves are immeasurably small.
 
Similarly, when these particles collide, their electric fields, strong & weak nuclear forces produce spectacular fireworks, but their gravitational interactions are negligible, because their mass is so small.

In fact, the huge mass of the Earth orbiting the Sun only produces about 200W of gravitational waves, far less than the hundreds of Megawatts that pour into CERN for accelerating charged particles.

As always thanks for the feedback
Title: Re: How are gravitons created?
Post by: evan_au on 25/04/2016 01:09:31
Quote from: TheBox
Gravitons are not created they do not exist and you have been wrongly answered by the replier's to your post,  a graviton is of the imagination and there is no proof of existence.
Please do not let fellow members dogma confuse you...
Please amend you false information, you are applying dogma as fact and not explaining it is hypothetical and of the imagination.
It is true that individual gravitons have not been proven to exist in the lab, because the gravitons that we experience on Earth are thought to carry very little energy individually. This makes gravitons almost impossible to detect in the lab (even detecting gravitational waves containing fantastic numbers of gravitons was a major achievement)!

Physicists can't count the individual photons from an AM radio transmitter; but they still believe that they are quantized, just because other forms of electromagnetic radiation are quantized.

It is a bit bigger step, but most physicists expect that gravity is quantized, just because other fields are quantized.

So I suggest that:
If you doubt the existence of quantized light, look out the window in daytime.
If you doubt the existence of quantized gravity, jump off a high building.
In neither case will it show that the force carrier is quantized, but you can see the macroscopic effects of the underlying quantized vehicle.

You may be confusing Gravitons with the String Theory explanation of Gravitons; String Theory is more hypothetical, since it relies on a so-far-unproven hypothesis of multiple rolled-up dimensions. But it is still a reasonable topic for conversation on a science discussion board.

PS: But seriously, don't jump off a high building! (..and don't look directly at the Sun!)
Title: Re: How are gravitons created?
Post by: Arthur Geddes on 25/04/2016 04:23:17
Physicists can't count the individual photons from an AM radio transmitter; but they still believe that they are quantized, just because other forms of electromagnetic radiation are quantized.

Not 'just because;' because of the way the mechanism is understood.  The quantizing would relate to the outermost orbitals in the conductors etc..
Quote
It is a bit bigger step, but most physicists expect that gravity is quantized, just because other fields are quantized.

You might be right here; if you are then, i'm with The Box.  Black Box radiation is quantized cuz it fits the graph (Newton did the same with gravity; that's the nature of that genius, comfortable with math & measurement.)  Light from the decay of an electron orbital is quantized because of the quantum harmonic oscillator.  There is no such empirical or theoretical support for the quantization of gravity.
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So I suggest that:
  • most theoretical physicists believe that gravitons are real
A common error of argument; nice of you to articulate it so clearly.
Quote
  • the quantum properties of gravitons are fairly well developed (see quote from Wikipedia, above)
Missed it.
Quote
  • The recent discovery of gravitational waves from a billion light-years away demonstrates experimentally that gravitation can propagate through space "to infinity", which is one of the properties of a particle, the "Graviton" 
A tail chasing chicken/egg.

How do you rationalize gravitons with 'gravity is spacetime?'[/list]
Title: Re: How are gravitons created?
Post by: PmbPhy on 25/04/2016 07:08:54
Quote from: Arthur Geddes
How do you rationalize gravitons with 'gravity is spacetime?'[/list]
Where did you get the idea that gravity is spacetime? Spacetime exists in the absence of gravitational fields. A gravitational field can be created by changing the system of spacetime coordinates to a system corresponding to an accelerating frame of reference and a gravitational field will be "produced" in the process.
Title: Re: How are gravitons created?
Post by: guest39538 on 25/04/2016 07:19:17



So I suggest that:
  • most theoretical physicists believe that gravitons are real



Well Evan I hate to say it ,  but if I wanted to learn a system that is based on belief I would be studying the other side and religion. Science is not about belief but about facts.   If there is nothing factual about ''gravitons'' I deem you are teaching harry potter is real.


[/list]
Title: Re: How are gravitons created?
Post by: evan_au on 25/04/2016 11:14:24
Quote from: Arthur Geddes
Quote from: evan_au
the quantum properties of gravitons are fairly well developed (see quote from Wikipedia, above)
Missed it.

The quantum definition of the graviton was posted by TheBox, quoting Wikipedia:

https://en.wikipedia.org/wiki/Graviton


''In physics, the graviton is a hypothetical elementary particle that mediates the force of gravitation in the framework of quantum field theory. If it exists, the graviton is expected to be massless (because the gravitational force appears to have unlimited range) and must be a spin-2 boson. The spin follows from the fact that the source of gravitation is the stress–energy tensor, a second-rank tensor (compared to electromagnetism's spin-1 photon, the source of which is the four-current, a first-rank tensor). Additionally, it can be shown that any massless spin-2 field would give rise to a force indistinguishable from gravitation, because a massless spin-2 field would couple to the stress–energy tensor in the same way that gravitational interactions do. Seeing as the graviton is hypothetical, its discovery would unite quantum theory with gravity.[4] This result suggests that, if a massless spin-2 particle is discovered, it must be the graviton, so that the only experimental verification needed for the graviton may simply be the discovery of a massless spin-2 particle.[5]''

Quote from: TheBox
I hate to say it ,  but if I wanted to learn a system that is based on belief I would be studying the other side and religion.
You evidently have a very strong belief that gravitons are not real.
It is so strong that you can't bear to see other people discussing gravitons - your actions on this thread are based on your belief.

It is true that individual gravitons have not been measured in the lab - and I hope that fact is now abundantly clear to all. But the graviton is a reasonable hypothesis, and we will continue to discuss it as such (until it is convincingly proven or disproven).
Title: Re: How are gravitons created?
Post by: guest39538 on 25/04/2016 14:41:14

It is so strong that you can't bear to see other people discussing gravitons - your actions on this thread are based on your belief.

Well it is not a belief, it is fact that at the present moment in time they do not exist.

Quote
It is true that individual gravitons have not been measured in the lab - and I hope that fact is now abundantly clear to all. But the graviton is a reasonable hypothesis, and we will continue to discuss it as such (until it is convincingly proven or disproven).


I am not biased to discussing a new theory or an old theory, either way it is hypothesis at the best.  My problem is that science seemingly want to turn everything into a particle of some sort or a wave of some sort.   A gravity wave , what suggests it is even a wave?


It is not me who does bad science, it is science who do bad science by dogma, which means science make thinks true although they are not necessarily true.


Most of the forum members also present this dogma, many times you and others tell me I am wrong yet you are not right either.


Science says all these thinks exist in space, I observe nothing in space but an observation emptiness. I know there is air and I know there is light in the space before my eyes, however I do not observe waves of any sort, I do not observe single particles except dust catching the light, I do not understand why science preaches belief as if facts and persecutes those like myself who say it straight.

I can't comprehend a graviton because it is meaningless passing through space.  Gravity is a linearity and not a wave , things fall straight down they do not wobble side to side.




Title: Re: How are gravitons created?
Post by: jeffreyH on 25/04/2016 19:09:21
Thebox, you have an unfailing belief in space and yet no one has ever seen or detected it. It is implicit in certain theories but is as ephemeral as fairy dust. Space is not the vacuum BTW.
Title: Re: How are gravitons created?
Post by: Arthur Geddes on 25/04/2016 19:37:19
    Quote from: Arthur Geddes
    How do you rationalize gravitons with 'gravity is spacetime?'[/list]
    Where did you get the idea that gravity is spacetime? Spacetime exists in the absence of gravitational fields. A gravitational field can be created by changing the system of spacetime coordinates to a system corresponding to an accelerating frame of reference and a gravitational field will be "produced" in the process.
    Page 180ish:
    http://hermes.ffn.ub.es/luisnavarro/nuevo_maletin/Einstein_GRelativity_1916.pdf (http://hermes.ffn.ub.es/luisnavarro/nuevo_maletin/Einstein_GRelativity_1916.pdf)
    Gravitational field exists in the absence of matter ('matter' includes energy.)
    Title: Re: How are gravitons created?
    Post by: evan_au on 25/04/2016 22:14:58
    Quote from: TheBox
    Well it is not a belief, it is fact that at the present moment in time they do not exist.
    Before Einstein explained the photoelectric effect, photons were still quantized. The facts do not wait until we can explain them.

    Either gravitons exist, or they do not exist; they are not waiting for someone to capture one in the lab.

    So you can't dogmatically say they don't exist, and I can't say they definitely do exist; at this point in time we have to work on probabilities. Whether you think gravitons exist or not depends on which evidence you believe; what do you find more convincing?

    So ultimately, it does depend on belief - but this should always be a tentative belief, which is willing to change if and when more evidence comes to hand.

    In the meantime, we just need to avoid dogma, and tolerate the other's belief that gravitons may or may not exist, while we look for more evidence.
    Quote
    A gravity wave , what suggests it is even a wave?
    The gravity wave detected last September was a wave which swept up in frequency from about 40Hz to 400Hz as two black holes spiraled inwards and merged.

    When you can measure a frequency in Hz, that says that it is a wave.

    See the wiggles on the right-hand side of: https://en.wikipedia.org/wiki/First_observation_of_gravitational_waves

    Quote
    Gravity is a linearity and not a wave , things fall straight down they do not wobble side to side.

    That is merely because Earth has a low density; you start off at low altitude, and you run into the surface before you go into orbit.

    If Earth were more compact, or if you started off at a higher speed and altitude (like the ISS), you would find that you don't fall straight down, you fall around, in an ellipse or a circle. So the path of an object in a gravitational field is some version of a conic section, usually an ellipse.

    In general, the path of an object in a gravitational field does wobble side to side. It is this wobbling motion of the orbiting black holes which finally produced some measurable gravitational waves.