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That was how I interpreted it, but that seems to say that although gravity creates more gravity, gravitons play no part in it.

Thus you have proved to yourself the real problem that has stumped everyone with quantum gravity.

What is going on is with all the other fundamental particles they don't self interact. Lets break this down to a really simple body example

So when I add energy to an electric field on a body it increases the field by a proportional amount and the energy adds to gravity of the body (E=MC2).

Mathematically: Field increase = constant * Energy

You can see that in the classical formula's of force as the force is directly related to the field strength and energy
F magnetic = qB
E electric = qE

Now try it with gravity

So when I add energy to a gravity field on the body it increases the field by a proportional amount and the energy
adds to the gravity of the body ..... WOAH say what!!!!!!.

Mathematically: Field increase = constant1 * Energy + (Taylor series expansion(Field increase * constant2 * Energy)).

Background: https://en.wikipedia.org/wiki/Taylor_series

Each time you add energy to the gravity field energy a percentage is added into the field itself. That percentage
is a taylor iteration of the percentage to infinity because it self adds.

So lets look at this in classical physics
https://en.wikipedia.org/wiki/Gravitational_potential

I took some liberties and hand waving shortcuts but I got to the same point

I note they also give the other result I was going to handwave my way to:

So now we have the final nightmare piece that our horrible taylor series expansion result is going to also self interact
based on its speed thru space .... mathematics nightmare.

So we have a taylor expansion (speed) of another taylor expansion (energy)

This is called an Analogue version of gravity and complex analysis of it is the only other current option besides string theory. Sabine has a basic background (http://backreaction.blogspot.com.au/2014/02/what-is-analogue-gravity-and-what-is-it.html)

I will however warn you that such a classical answer is at odds with QM. Lubos gives you a simple enough approach here (http://motls.blogspot.com.au/2012/01/why-semiclassical-gravity-isnt-self.html?)

Orac, I haven't had time to follow those links yet, but I would like to check that I am on the right path. I never think I understand something unless I can explain to someone else; so please bear with my attempt.

I gravitons exist, this would seem to indicate that a quantum theory of gravity is, in principle, a distinct possibility in the near future. However, it is experimentally established (and experiment trumps theory) that gravity creates more gravity, which presents a couple of serious questions.

1. If gravity creates gravity, why doesn’t every gravitating body spontaneously develop into a black hole?

2. Can the introduction of gravitons to our theory of gravity provide an answer to Q1?

A graviton can “split” into gravitons of lower energy, but a graviton cannot produce another graviton of any energy if the total energy is greater after the reaction than it was before, as this would involve creating energy.

Certainly this would prevent run-away gravity, but it would also prevent quantized gravity from producing more gravity, which, as we have seen, would be contrary to physical evidence.

It follows, therefore, that if gravity creates gravity, gravitons cannot play a part in this process without violating the law of conservation of energy.

Correct in fact in theory according to GR anything over 22 micrograms can collapse to a black hole. The question why it doesn't is the one I thought you might be interested in following.

You sort of have all the pieces conservation of energy, curved spacetime, and Spin of particles both classical spin and QM angular momentum to reach at least the most basic solution.

So conceptually you could imagine a spin trying to twist space with it's motion and creating torsion in space itself. There is a long list of people who looked at this being a solution to our problem above.

Einstein-Cartan theory

It is not the most favoured way currently to solve the problem but it is one easy enough for you to understand because it is entirely classical. The solution clearly isn't compatible with the full QM theory but its fine in the QM spin consideration.


Hopefully you get what happens that your matter has to have a classical spacetime volume it can't be a true point and hence no runaway collapse.

So you have reached the simplest viable process to stop our matter instantly dropping into a black hole.

In fact under the theory the smallest black hole you can create requires 1.1245 x 10E16 kg to overcome the torsional force.

It does come with other predictions listed in the link, I will leave you to mull over.


No they are just the force carrier particle of the field they don't change the problem.


Yes but the process is highly unlikely without finding a mediation scheme for a gravitional field. No such mediation is known either physically or conceptually to be viable and it would lead to a scheme of gravitational shielding.

Why we are dealing with speculation along this line you might as well look at virtual black holes by Mr Hawking.

I think this is the point at which I am stuck.

We established that a graviton could not give rise to another graviton (or gravitons) if the total energy of the daughter graviton(s) was greater than that of the parent. Conservation of energy, and all that.

However, we seem to be saying that if we ignore gravitons, gravity creates more gravity.

So where does the additional energy come from, and why does the process not violate conservation of energy?

The problem comes from classical physics versus GR/QM.

Try the generalized FAQ on the problem
http://math.ucr.edu/home/baez/physics/Relativity/GR/energy_gr.html

We have been thru this but energy in classical physics is poorly defined and not even consistent. In trying to drag your answers back to classical physics the answer becomes yes/no/maybe/never/I cant work it out ... choose which one applies.

Above in your quote you change from graviton energy in QM (very well defined definition of energy) to an ambiguous definition in classical physics or possibly GR it isn't clear to me which you want.

The problem is in classical physics the answer is whatever you want ... pick your own answer !!!!.

At the level you are working classical physics breaks down and there is no patch you can make for it.

Sort of along this line look at the one-minute physics video

What you seem to be saying is that gravity creates gravity, and in classical/GR physics that is no problem because energy is poorly defined, so it doesn’t matter if energy appears to be created.

In QM, energy is well defined, so it cannot be created. This leaves a problem explaining how gravity creates gravity.

Two questions arise from this:

1. If we live in a quantum universe, how can gravitational energy be created?

2. We don’t have a quantum theory of gravity, so how do we know how QM would influence the creation of gravitational energy?

what a BS video.

but I love to see that you guys are really trying and
that does mean something.

so as for your discussion about gravity = energy and momentum
what happens when a atom is drained of almost all of
its energy and as a result all motion within the atom slows to a almost complete stop , are we now to believe that the atom looses a proportional amount of its gravity since gravity is no
longer due to mass but due to a combination of its energy (which has been drained ) and its momentum ( which has also been drained)

?

whats next , I wonder.

I guess that as the atom regains its (energy) heat its gravity also proportionately returns or how do you guys work around that one?

also , the energy of an atom can be bumped up so that the
orbit of the electrons of the atom become further and further
away from the center of the atom , wouldn't your brand of fizzics require the atom to acquire more gravity because its
overall energy and its overall momentum within the atom have increased.

do you guys have a workaround for that one?

if QM is better than or more correct than classical physics
then QM must also overlap into the classical world as in
the two examples above.

else it would simply be philosophical.

is QM actual or is QM philosophy.

just curious because when I see things like the video you posted a link to I become afraid and worried about the future.

Sorry Paul you make me laugh at times with your science

How does an atom become drained of energy, never seen that ... explain please?


QM is neither from a science level QM does not explain anything it simply creates a framework that predicts answers nothing more nothing less.

Science's only roll is to be useful and predict results. In that regard QM is 100% and has never yet been shown to give a wrong answer.

Unfortunately for all that it doesn't explain why things behave like they do.

On the other scale we have Classical physics which gives countless wrong answers which is why we don't use it as it isn't terrible useful beyond stuff layman may encounter.

Probably only 2 or 3% of the planet believe in QM or even understand it enough to make a judgement and yet we don't care because it is more useful than classic physics. It is the understanding behind a lot of science advancement and to be blunt that is why no-one cares what the 97% others think including the religious factions or people like yourself.

Someone always funds us because someone always wants the technical edge and that is why we don't really care what anyone else thinks. We aren't here to convert people and we care little if they believe in what we do, but they always want our developments.

Yes that is a fair summation


We went thru that under QFT it will be spin 2 boson and will self interact as well as a number of predictable properties but there are things not predictable which needs more theory. So we know why and how it creates more gravity, what we don't know is what stops runaway collapse. No theory of quantum gravity at the moment can predict or produce stability.


The particles of the other forces in an area of space cause curvature of spacetime and create the presence of gravitons. If the gravitons appeared without the energy/momentum presence there would be nothing to stop a pile of them appearing in an empty space and the universe instantly collapsing.

In a really basic laymans terms it sort of like the other forces coax or squeeze the gravitons into existence which we can then measure.


Ask the problem in reverse how is the gravitation force going to work of deal with a mass particle held in entanglement in two places at once.

Is the gravity at one or other position or split between the two different physical locations? How does it do this if it isn't quantum in nature itself?

You probably get why there is a lot of interest in that problem and experiments around it.

This probably answers the question for someone with more knowledge of QM than I have. I can’t make the link between being a spin 2 boson that will self interact, and being able to – seemingly – violate conservation of energy.

I couldn't explain that link to someone else, and unless I can do that I don't consider that I understand whatever it is.

Perhaps we could take one step at a time.

Assume our theory of gravity includes gravitons, which are the particles that mediate the gravitational force.

If this gravity gives rise to more gravity, would that not mean that graviton A must be able to give rise to graviton B, such that the energy of A+B is greater than the energy of A alone?

Don't Worry, that's entirely understandable as this stuff
is found in the realm of actual science and real physics , and it just doesn't blend in well with the fantasy science and fizzix that you have your head stuck into most of the time
... heres a non layman explanation that you might be capable of comprehending and understanding at the same time in this universe.

Interesting video, Paul.

A couple of things I'm not absolutely clear about.

When an atom absorbs a photon it acquires more energy. The impact slows it down, so it loses kinetic energy. Is the kinetic energy lost greater than the energy of the acquired photon, or is something else going on?

Where does the energy go? Does the laser beam become hotter? Where does the heat go?

No doubt all these questions will be answered, and possibly someone may comment on the fact that the non-layman said the atoms are in a quantum state. Oops!

yes , it acquires the energy of the photon.
the direction of the atom and the direction of the laser beam
determine the amount of energy over and above the energy of the photon itself that the atom acquires just like in a classic physics impact , like pool balls colliding on a pool table sort of. <--- layman description but not a guess or speculation.



yes , the impact slows the atom down , just like in classical physics.

theres a lot more energy in a head on collision.



I couldn't tell you without knowing the energy of the photon and the energy of the impact and the energy of the atom before and after the impact.

from what I understand from the experiments is that
the only time that the atom will absorb the photon is when
the atom is moving towards the laser beam and the frequencies
of the atom and the laser are exact , which is why he dwelt
on the direction in the video because direction is important
just like in classic physics.

we know that when an atom absorbs a photon the atom becomes
excited , we know that the state of the atom changes , we
know that a atoms frequency changes , and we know that the
electrons orbits move outward from the center.
in this excited state the atom has gained energy.
(heated)
then

the atom stabilizes , a photon is emitted , the state changes , the frequency changes , the electrons move closer in towards the center.
(cooled)

in order for the atom to slow down further and further ( or cool down more and more ) energy must be lost from the atom itself repeatedly and the only way possible for that to occur is if the atom emits a photon of a higher energy than the photon that impacted the atom initially.

because a normal change from an excited state to a stabilized state places the energy of the atom back to its initial energy , its frequency returns to its initial frequency and its electrons orbits return to there initial orbits.

and with this experiment we see that energy is lost
because we see the atom slowing down
and the only element involved that could possibly account
for the lost energy would be the emission of a higher charged photon.

so that is where the energy goes !

when the atom emits the higher charged photon the electrons
move closer in to the center than they were initially before
the impact.

as the atom reaches its slowest energy levels in the millionth
of a degree K its mass has not changed , it still has its electrons , they are simply much closer to the center and moving much slower in there orbits than before the experiment began.

and if my brand of physics is correct then its gravity
has also remained the same.

thus , therefore , and hithertooooo

gravity is due to mass , not energy and momentum as the
QM'ers faith would have us believe or speculate or guess or
philosophize.



probably peer pressure... possibly job security ... perhaps
fear of being labeled a heretic and shunned by the QM congregation because he seems like a truly smart smart person not a stupid smart person.

LOL

ROFL I am enjoying this, I love the electron orbitals moving position that is cool except a few problems with the idea which obviously escape you

The bit I really love and need a description, is what exactly does a "COMPLETELY ENERGY DRAINED ATOM" look like.

So does nothing move, the electrons sit right against the nucleus? Does it cease to exist ... can I get a description?

The other obvious question is why atomic energy interactions are quantized, why aren't they linear or logarithmic like classical stuff?

The problem is you keep trying to bring it back to ONE graviton sitting there which is by itself stable, in the same way a car sitting on a hill can be stable. This isn't the problem the next step is.

If I give the car a push then I get a problem. So lets do the same I push more energy into the fields near the graviton such that another graviton appears BUT now my two gravitons must also attract each other.

Mathematically:
X energy gives rise to the first graviton
2X energy gives rise to two gravitons as we have quantization

BUT if two gravitons also attract each other, you now go into runaway.

What we can look at is the strong force in the nucleus which also has a self interacting property and it's force carrier particles the gluon. So what stops runaway in that situation you may ask?

Well the force is opposed by the electromagnetic force repelling the protons. So our nucleus at this level is viewed by the electromagnetic force of the protons trying to push each other apart and opposed by the strong force trying to pull it together.

See the difference there is something opposing the self interaction. Compare that to gravity.

Quarks don't appear free in nature, because their force does not diminish with distance, as you separated two the force between them quickly heads to infinity. What is predicted is color confinement which prevents such a thing.

So what you are probing is a particles self energy and how that relates to energy in general (https://en.wikipedia.org/wiki/Self-energy).

For a graviton you can't do that problem in classical physics because how do we determine the gravitational field of a particle, since under Heisenberg uncertainty principle we can't know the position and velocity together.

Surely the whole point of laser cooling is that the atom does not return to its original frequency between impacts. This was explained in the video, as was the fact that it is kinetic energy that has to be reduced. The bit that was not explained (or perhaps I missed)was what happened to all the energy being introduced to the system, and the energy being removed.



Where would this extra-energetic photon go. Saying it is emitted by an individual atom does not account for its loss in terms of the system.

Now you are talking about introducing extra energy. In the gravity creates gravity situation, where does that come from?

Yeah , that is groovy , isn't it , that was my idea to have them moving around like that.

in the experiment it is not the system that caused the cooling
that is the focus , and as far as I can tell the photon is immediately out of focus as soon as it is emitted.

in the experiment the focus is on the slowing or cooling of the atom itself and everything outside its physical boundaries are of no concern.