ATM answers to "Is gravity energy?"

[grav]

(from the thread, "Is gravity energy?" in Q&A)

Yes, well they will say that this is pure Newtonian Physics.

[I don't see how it can "create" more gravity]

But, yes, I still have a problem with this.


So in theory, if 'zillions' of smaller objects would interact the same way on jupiter, it would imply that Jupiter would eventually run out of energy?

That's what I had in mind as well, but note there is a sticky problem. With EM radiation, and I presume this is also true for quadrupole radiation, the fields get stronger in magnitude when the wave passes. For gravity, if we wanted there to be an energy density in the waves, and the energy is negative in the fields, then we'd have to make the field magnitude drop within the wave. That doesn't sound like what would happen, so I have no clue how you can have a field theory for gravitational radiation....!

Okay, I didn't want to present this as an ATM theory, but only as a consideration to be explored, in line with the questions asked above, but it certainly isn't mainstream, so I figured I'd better post it here. If I read all of that thread correctly, gravity requires a negative energy field. This implies a negative energy density. Now, a negative energy density is really a negative pressure, and is different from a negative energy itself, since a negative energy is directional while a negative energy density can only be negative relative to a larger positive background density. In other words, a negative energy density really means a reduction in the background density itself.

So consider this. All of space is filled with gravitons (or neutrinos or whatever you wish to call them) and they create a positive energy density, or pressure. Large bodies of mass absorb some of this pressure in proportion to its mass (the number of pressure-absorbing particles it contains). This creates a negative energy density in the immediate region in comparison to the total background pressure which diffuses with the square of the distance from the body (over the surface area of a sphere placed at that distance). Another body absorbs gravitons in the same way, in proportion to its mass, but it absorbs less from the direction of the first, producing a force imbalance in that direction, which is therefore proportional to the multiple of the masses and inversely proportional to the square of the distance. This is gravity.

Now, as the gravitons are absorbed by a body, the mean travel path between the gravitons decreases in the direction of the body, so the gravitons travel more freely in that direction. So gravity creates more gravity. They do not actually produce a gravitational force on each other since that would require even smaller particles that create their gravity. Also, the energy of the gravity of a body never runs out because it is not the body itself that loses energy. It absorbs a very miniscule amount of energy over time from the surrounding graviton medium. If anything, the body might actually gain mass.

[Bogie]

It sounds like you are talking about a push instead of a pull.

[publius]

Grav,

That is indeed "pushing gravity". Look up LeSage gravity. I think LeSage was the first one to propose this particle flux model.

IIRC, Van Flandern has become enamored with this as well. He (stubbornly) holds that the speed of propagation of gravity much be much, much greater than c (a billion times greater or something) -- rejecting GR's "extrapolation of acceleration in addition to velocity".

In this particle model, the "speed of gravity" would be the speed of the particles, so he has his little gravitons travelling at some ridiculous speed.

-Richard

[grav]

Yes. It is indeed push gravity. And through computer similations, I have also found that the speed of gravity must travel at tens of billions of times greater than the speed of light if it is to produce the effects seen in binary star systems through purely Newtonian means, which is probably why gravity waves were originally thought to travel at such speeds, but which I don't agree with. That is part of the reason why I am now attempting to recreate GR. It is my firm belief that everything requires a mechanism, or cause. But I also don't believe that it is the warping of space and time that causes gravity or produces the slight variation from Newtonian mechanics, but something more conventional. Different model, same mathematics. So I am determined to find the "cause" of GR effects on my own, whether there be some sort of Doppler shift involved or a distortion of bodies themselves due to rotation, revolution, or otherwise.

[Nereid]

Yes. It is indeed push gravity. And through computer similations, I have also found that the speed of gravity must travel at tens of billions of times greater than the speed of light if it is to produce the effects seen in binary star systems through purely Newtonian means, which is probably why gravity waves were originally thought to travel at such speeds, but which I don't agree with. That is part of the reason why I am now attempting to recreate GR. It is my firm belief that everything requires a mechanism, or cause. But I also don't believe that it is the warping of space and time that causes gravity or produces the slight variation from Newtonian mechanics, but something more conventional. Different model, same mathematics. So I am determined to find the "cause" of GR effects on my own, whether there be some sort of Doppler shift involved or a distortion of bodies themselves due to rotation, revolution, or otherwise.Just so that I don't misunderstand ... you intend to account for all the tests which GR has passed today, using the grav alternative?

Specifically, we would, at some time in the future when you're done, be able to go through Clifford Will's paper (http://relativity.livingreviews.org/Articles/lrr-2006-3/index.html), page by page, and ask you to show how your idea addresses everything covered there?

[grav]

Just so that I don't misunderstand ... you intend to account for all the tests which GR has passed today, using the grav alternative?

Specifically, we would, at some time in the future when you're done, be able to go through Clifford Will's paper (http://relativity.livingreviews.org/Articles/lrr-2006-3/index.html), page by page, and ask you to show how your idea addresses everything covered there?
Well, sort of. I intend to account for all of the tests which GR has passed, by finding the specific mechanism through which GR operates. I do not believe that we should think of GR as a distortion of time and space. We have made precise definitions for each that should be left alone, and only supplemented. We have very simple ways of thinking about them which work, and we should only build on this. Time dilation, for instance, should only be considered as a slowing of physical processes in "real" time. To observers within an entire system that is being slowed down on the atomic scale, it would appear that everything else is speeding up. So I am really just attempting to find an alternative to our way of thinking about it, through what I consider to be real physical means. Thank you for the paper, by the way. It should be very informative. It would be a wonderful thing indeed if and/or when I succeed in all of this to be able to go through that paper and match every one. :)

[grav]

I just thought of something. Could the "gravity creates more gravity" thing be the "cause" of GR? What about the gravity dependence on mass plus kinetic energy? How does that work?

I'm posting this here, too, in case anybody reading this section has any "ATM" insights. This might be important.

[gzhpcu]

Just a question here: you speak of gravitons permeating space. The standard model of QM predicts the Higgs boson permeating space everywhere. What is the interaction between the two (if both of them exist)?

[Tensor]

Just a question here: you speak of gravitons permeating space. The standard model of QM predicts the Higgs boson permeating space everywhere. What is the interaction between the two (if both of them exist)?

Whoever figures this out, would probably get a nice all expense paid trip to Stockholm. ;)

[grav]

Just a question here: you speak of gravitons permeating space. The standard model of QM predicts the Higgs boson permeating space everywhere. What is the interaction between the two (if both of them exist)?
Well, I'm not sure how to define an interaction between particles. But I would think that with the presence of gravitons, the Higgs boson is unnecessary. Mass would be measured by the resistance of the motion of particles through the medium, in proportion to their surface areas, so that M/A is a constant. The greater the surface area of a particle, the greater the force that acts upon it due to the pressure of the medium times the area of the particle, and the harder it is to move.

[gzhpcu]

The Higgs boson is supposedly massive, the gravition is massless. How can you replace one with the other?

[gzhpcu]

Also:

Gravitons need to be spin 2 since they interact with photons. Higgs bosons can be spin 0, because they do not.

[grav]

I originally considered them to be neutrinos, but I could not say which one or how they would interact. I changed it to gravitons in this thread in order to conform, but apparently that's not working either. I do not know enough about particle physics to say precisely what particle would be required, but only know a few of its necessary properties. It would have be be very small in apparent mass (energy), neutral in charge, very abundant in number, travel at the speed of light, and be capable of penetrating large quantities of matter in a single bound (with very little interaction). Since they must interact to some degree with matter and light, although miniscule, I suppose a spin 2 might be about right, I don't know.

[RussT]

I'm posting this here, too, in case anybody reading this section has any "ATM" insights. This might be important.

BINGO.......BUT Grav.......You won't like the answer, because it is PURE GR, which of course is...

Real, PHYSICAL, Singularities and Massive Black Holes!

I will be posting something on this Very soon.

[RussT]

I was going to put this in the Q&A section on this and then figured...I better not.


In a nutshell, gravity depends on "stress-energy", which is a way of saying the source of gravity is mass-energy, mass-energy flow, momentum, and momentum flow. Well, really momentum and mass-energy flow are the same thing.

But the math is only meaningful if it is being used in association with the right correlations. Inflation (the math is impeccable) for example is 'unfalsifiable' without overthrowing all of the BBT (Not overthrowing GR).


As long as we don't have a quantum theory of gravity, why is gravity being discussed here as if it were a force? As long as GR reigns, it is only a spacetime distortion.

And I was going to find this today and reintroduce it, but it has already been done, and it is the key.

The stress energy tensor is 'artificial'. It is the only way they have been able to 'make 'space' (they say 'describe space'), and to make that work they have to have a way for 'gravity to make gravity' and for 'space' to make more 'space'.

Think about this.

When the Earth is 'following' it's curved path in the gravity well of the sun, it has a forward momentum of ?kps. Now, how is the Earth 'reaching forward' and creating a gravity field that extends out and then pulls whatever back in.
Answer...it doesn't...it has it's own gravity well that whatever must follow the path of. So, there is no gravity radiation/energy.

The real answer here is that the universe is 100% gravity and the Baryonic matter has enveloped 4% (this will be higher) of it so far, and by enveloped, I don't necessarily mean 'trapped' inside at a stand still.

If we all keep honing in on this, it will come together.

[RussT]

http://www.bautforum.com/showpost.php?p=831784&postcount=35

From here.


I've never thought of gravity as not being a force. That's an interesting way of looking at it. But there is a problem. If the presence of mass/energy distorts space-time, then a force must be applied to space-time itself in order to distort it, and space-time must be a substance with real physical features, and should be very flexible in order to curve smoothly as the mass moves. But then, if the curved path of space-time then causes another mass/energy to follow its path, then the force must be inevitably transferred to it anyway, and space-time should be very rigid, in order to force the second body to follow that path precisely, and only deviates according to the extra kinetic energy involved.

[then a force must be applied to space-time itself in order to distort it,]

AHHHHHHHHH, here is the culprit!

This 'assumes' that 'space/time', which is DM (Originally Posted by antoniseb
CDM has to be able to go through reactive matter)...

is at rest, to get warped.

Wow, now it even gets trickier.

The trick actually goes something like...when does E=MC^2 not apply? When you are considering the 'inert' non-baryonic DM of space, which is traveling at 'C'.

[RussT]

Whoever figures this out, would probably get a nice all expense paid trip to Stockholm. ;)

Would you like to take this trip???

[Cougar]

If I read all of that thread correctly, gravity requires a negative energy field....
I'm not sure what that thread was going on about, but this "negativity" of gravity reminds me of Alan Guth's argument that the universe is the ultimate free lunch. (http://www.discover.com/issues/apr-02/cover/) Guth's description of the energy of a gravitational field being negative seems to be considerably different than yours....
According to Einstein's theory of relativity, the energy of a gravitational field is negative. The energy of matter, however, is positive. So the entire universe-creation scenario could unfold without breaking conservation-of-energy laws. The positive energy of all matter in the universe could be precisely counterbalanced by the negative energy of all the gravity in the universe.

This also is more than theory. Observations are consistent with the idea, and calculations totaling up all the matter and all the gravity in the observable universe indicate that the two values seem to precisely counterbalance. All matter plus all gravity equals zero. So the universe could come from nothing because it is, fundamentally, nothing.

[grav]

I'm not sure what that thread was going on about, but this "negativity" of gravity reminds me of Alan Guth's argument that the universe is the ultimate free lunch. (http://www.discover.com/issues/apr-02/cover/) Guth's description of the energy of a gravitational field being negative seems to be considerably different than yours....
This does seem to be a slightly different interpretation, but I think it basically means that the energy densities are equal, so if we make one negative and add them together, it comes to zero. Pm=Pg, so Pm-Pg=0 or Pm+(-Pg)=0. In my model, all pressures are related. In this case, Plight/(3/5)=Pgravity=Pmatter, where Plight=(8pi5/15)(kT)4/(hc)3, Pgravity=(4piG)(M/A)2, and Pmatter=Dmatterc2/3. Here, T=2.728390278 K, (M/A) is the mass per area constant for particles, which comes to (m/4pir2)=9.12884121*10-3 kg/m2 when the mass and classical radius of the electron are used, and Dmatter=Hmatter2/[(4pi/3)G], where Hmatter=H0/(3/5a).

[EDIT-Oh, and H0=(3/5a)(4piG)(M/A)=2.099354105*10-18 s-1, where {a} is alpha]

[grav]

http://www.bautforum.com/showpost.php?p=831784&postcount=35

From here.



[then a force must be applied to space-time itself in order to distort it,]

AHHHHHHHHH, here is the culprit!

This 'assumes' that 'space/time', which is DM (Originally Posted by antoniseb
CDM has to be able to go through reactive matter)...

is at rest, to get warped.

Wow, now it even gets trickier.

The trick actually goes something like...when does E=MC^2 not apply? When you are considering the 'inert' non-baryonic DM of space, which is traveling at 'C'.
Sorry I have not replied to you earlier. It's just that when discussions come down to singularities, white holes, worm holes, a big crunch, or the Big Bang, that's where I generally drop out of the conversation. :silenced: Not because I don't think it's interesting or anything, but because I don't personally agree with some of the concepts involved. With my particular model, there are no such things. The "fabric" of space-time is really an energy density of neutrino-like particles. It is warped because some of this pressure is absorbed by matter and leaves a negative pressure imbalance toward the center of mass. This is the GR part of it (or Newton, for this much of it). The other direction of it says that these neutrino-like particles travel at close to the speed of light, rarely interact with matter, so must be extremely abundant, and are about the size of the Planck length. At this level, we must consider the particles as individuals, contrary to the otherwise smooth space at large scales. This is where QM comes in. Also, these same particles create not just gravity, but the redshift of light, by absorbing a miniscule portion of its energy as it travels through space. It does this in proportion to the current energy. This means that there was no Big Bang and the expansion of space-time is not accelerating, since the redshift would mostly be due to distance, not velocity so much. Furthermore, since these particles are about the size of the Planck length, and they also create gravity, there would be no gravity below this length, or even close to it, since gravity is caused by the smooth, even flow of a large number of these neutrino-like particles, and therefore there would be no singularities, wormholes, etc.

[RussT]

Sorry I have not replied to you earlier. It's just that when discussions come down to singularities, white holes, worm holes, a big crunch, or the Big Bang, that's where I generally drop out of the conversation. :silenced: Not because I don't think it's interesting or anything, but because I don't personally agree with some of the concepts involved. With my particular model, there are no such things. The "fabric" of space-time is really an energy density of neutrino-like particles. It is warped because some of this pressure is absorbed by matter and leaves a negative pressure imbalance toward the center of mass. This is the GR part of it (or Newton, for this much of it). The other direction of it says that these neutrino-like particles travel at close to the speed of light, rarely interact with matter, so must be extremely abundant, and are about the size of the Planck length. At this level, we must consider the particles as individuals, contrary to the otherwise smooth space at large scales. This is where QM comes in. Also, these same particles create not just gravity, but the redshift of light, by absorbing a miniscule portion of its energy as it travels through space. It does this in proportion to the current energy. This means that there was no Big Bang and the expansion of space-time is not accelerating, since the redshift would mostly be due to distance, not velocity so much. Furthermore, since these particles are about the size of the Planck length, and they also create gravity, there would be no gravity below this length, or even close to it, since gravity is caused by the smooth, even flow of a large number of these neutrino-like particles, and therefore there would be no singularities, wormholes, etc.

In a post above, I suggested that you would not like it.

But, let's examine this post here, which is fairly defining, and see what we come up with.

[The "fabric" of space-time is really an energy density of neutrino-like particles.]

Good! and in your OP you started with... [So consider this. All of space is filled with gravitons (or neutrinos or whatever you wish to call them)], also Good!
But then you went on to say...[and they create a positive energy density, or pressure.]

And right here is where the first problem occurs! "IF" the smallest Planck size non-baryonic sub element has a tiny, tiny mass, and is traveling at 'C', "BUT" it does not interact with Matter, then what can we say about it?

If 'all' of 'space' is made up of this physical stuff, it would be a gravity field.

However, because it is traveling at "C" it is subliminal, and because it does not interact with Matter, whatever tiny, tiny energy it does have is 'irrelevent'
(it is just potential energy*)!

So, what does that mean? That means that 'space' has a 'background gravity field', and that we then have to define how 'massive baryonic matter' acts in that background gravity field. Which means 'space' is traveling at "C"!


[Also, these same particles create not just gravity, but the redshift of light, by absorbing a miniscule portion of its energy as it travels through space.]

And here is another problem. Since they do not interact with baryonic matter (and I don't think the weak force here would allow them to absorb radiation, but I could be wrong), they are gravity only, with no energy quotient available.


[This means that there was no Big Bang and the expansion of space-time is not accelerating, since the redshift would mostly be due to distance, not velocity so much.]

Translation...the was no BB, space is traveling at 'C', where do these tiny, tiny sub-element gravity field producing things, COME FROM, how are they made?

[Furthermore, since these particles are about the size of the Planck length, and they also create gravity, there would be no gravity below this length, or even close to it]

Exactly!

[since gravity is caused by the smooth, even flow of a large number of these neutrino-like particles, and therefore there would be no singularities, wormholes, etc]

Yes, it would certainly 'appear' that this should be 'smooth'!!!

However, ENTER... GR and String/"M" Theory, and Expansion from...THE VOIDS>

More after you respond to this.;)

[grav]

RussT,

Okay. I like how you think, even though I know it will probably lead to completely different results than what I am demonstrating. But it would be interesting to see.

Well, first of all, the neutrinos do interact with matter and light, but they are so small that they do not fully absorb light as larger particles do, but only detract a miniscule portion of the energy from light over time as it travels through space. Matter does absorb neutrinos, but only a very miniscule portion of the total energy density as well. The total background field is not gravitational, but more on the scale of electric force. The tiny, tiny amount of that which matter actually absorbs is the gravitational amount, and is the negative part.

Indeed, there are some details to be worked out, which I am now attempting to do. GR must be incorporated, and the specific interactions of neutrinos should be identified. But even after that is done, we would still want to determine the true nature of the neutrinos themselves, which would probably require some form of string theory, like you say.

[RussT]

Well, first of all, the neutrinos do interact with matter and light, but they are so small that they do not fully absorb light as larger particles do, but only detract a miniscule portion of the energy from light over time as it travels through space.

How do we 'know' this? or Why do you think this? Also, interact is different than absorb.


Matter does absorb neutrinos, but only a very miniscule portion of the total energy density as well.

Again, how do we know this? Do our bodies absorb neutrinos?

When Nereid was decribing the difference between 'hot' DM and CDM to bogie, and then antoniseb said...that CDM HAD to 'go through' baryonic matter, it dawned on me, that the thing(S) that can 'go through' the earth/our bodies, and all baryonic matter, are probably all the same thing?

So, I think, what may be happening, is that they are defining these things in the environments that they are seeing them in, making them look different in different situations?

[grav]

Originally Posted by grav
Well, first of all, the neutrinos do interact with matter and light, but they are so small that they do not fully absorb light as larger particles do, but only detract a miniscule portion of the energy from light over time as it travels through space.

How do we 'know' this? or Why do you think this? Also, interact is different than absorb.
Well, neutrinos must interact at least a little for us to know about their existence in the first place. If not, we wouldn't see the energy differences in interactions in atoms that their existence was postulated on, and it would be impossible to detect them at all.



Originally Posted by grav
Matter does absorb neutrinos, but only a very miniscule portion of the total energy density as well.

Again, how do we know this? Do our bodies absorb neutrinos?
Everything that has mass would absorb neutrinos. It's what gives them mass in the first place. The real Higgs particle, sorta' speak. Particles will absorb neutrinos according to their surface areas (and interaction ratio, which is 1 for electrons). So their mass is proportional to their surface areas, and any motion through the neutrino medium will cause a resistance against that surface, which is seen as mass. The total mass of a body, then, is actually related to the sum of the surface areas of all of the particles in the body.

Only a miniscule amount of the total pressure is actually absorbed by matter, otherwise it would be a surface pressure, not the extremely penetrating pressure that it is. If matter absorbed all of the pressure that is incident to it, it would not get very far beneath the surface, and neutrinos would become very evident in the universe. The pressure would reduce rapidly and neutrinos would become much less abundant, and gravity would cease to exist in the way we know it. If the nucleus of atoms absorb all of the incident pressure, and they are about 1/10000 of the area of the atom, then after passing through just 10000 atoms of thickness, the pressure would reduce to about one-third (1/e). After about one meter, since atoms are about 2*10^-10 meters wide, the pressure would only be about 1/e(5*10^9/10000)=e(5*10^5) as great as its original value, which is virtually non-existent.

When Nereid was decribing the difference between 'hot' DM and CDM to bogie, and then antoniseb said...that CDM HAD to 'go through' baryonic matter, it dawned on me, that the thing(S) that can 'go through' the earth/our bodies, and all baryonic matter, are probably all the same thing?

So, I think, what may be happening, is that they are defining these things in the environments that they are seeing them in, making them look different in different situations?
Yes. I think so, too. I was originally attempting to work with bogie on that idea, but then it quickly became a thread about big crunches and such, which mine does not deal with, so I left it alone. But otherwise, at least as far as the energy density itself is concerned, there appear to be similarities with many such ideas, including GR, string theory, DM, and even MOND, depending on how each one is perceived. I would say that they are all different ways of looking at the same thing.

[grav]

RussT,

There are a couple of things I have been trying to figure out about these formulas. One is the placement of alpha. I noticed that you had an interest in it from the other threads. In this (http://www.bautforum.com/showthread.php?t=47190) thread, Ken G pointed out that the effective temperature of neutrinos might be about 4 times less than that of the CMB, but 3 is possible. I remember reading also in the very back of Weinberg's book that the temperature should be about 1.4 times smaller (I sent him a copy of my paper by the way, but have had no reply except for some of his recent articles that were sent to me). In my formulas, I have the CMB pressure about (3/5) of that of neutrino pressure. The P/(n/A)2=PA2 factor for black-body radiation to electric force (keq2) is (3/5a). Now, my thinking was that for matter, the rate of interaction would be a. But now I'm thinking that this may be the case for the gravitational pressure after all, making it 137 times smaller, or (5a/3) as great as the CMB. Since the pressure is proportional to T4, this would make the effective temperature of the neutrino pressure about 3 times colder. I may have to change my website about this. But I'm still not sure how alpha would figure in with the gravitational pressure in this case, especially since it is a pure number ratio, with no units to give us a real clue as to its meaning. Do you have any thoughts or ideas on this?

[RussT]

Everything that has mass would absorb neutrinos. It's what gives them mass in the first place.

IS this what the current consensus is???

I will be the first to admit that Quantum Particle Physics gives me "brain freeze" some quantum time after delving into all the different associations and definitions and different 'laws and formulas' are applied!~

I am coming to the opinion the the 'ultra-complexity' is partially self inflicted, because they do not "Really" know how some of these things are created and have a complexity of associations that are not real. And I'm not even sure how 'virtual particles' fits into what I just said!

But, IMHO, the first sentence of this post is 'wrong'!

Even though we can now detect a very few neutrinos (through the weak force, I guess), they are not, again IMHO, getting their mass from any baryonic matter*.


GR must be incorporated, and the specific interactions of neutrinos should be identified.

You said this above.

So, do you think that GR does worl in many individual scenarios in our universe?

Do you think that a massive enough star does have a gravitational collapse to a black hole, with an event horizon, as defined by General Relativity?

[RussT]

RussT,

There are a couple of things I have been trying to figure out about these formulas. One is the placement of alpha. I noticed that you had an interest in it from the other threads. In this (http://www.bautforum.com/showthread.php?t=47190) thread, Ken G pointed out that the effective temperature of neutrinos might be about 4 times less than that of the CMB, but 3 is possible. I remember reading also in the very back of Weinberg's book that the temperature should be about 1.4 times smaller (I sent him a copy of my paper by the way, but have had no reply except for some of his recent articles that were sent to me). In my formulas, I have the CMB pressure about (3/5) of that of neutrino pressure. The P/(n/A)2=PA2 factor for black-body radiation to electric force (keq2) is (3/5a). Now, my thinking was that for matter, the rate of interaction would be a. But now I'm thinking that this may be the case for the gravitational pressure after all, making it 137 times smaller, or (5a/3) as great as the CMB. Since the pressure is proportional to T4, this would make the effective temperature of the neutrino pressure about 3 times colder. I may have to change my website about this. But I'm still not sure how alpha would figure in with the gravitational pressure in this case, especially since it is a pure number ratio, with no units to give us a real clue as to its meaning. Do you have any thoughts or ideas on this?

If you don't think the Big Bang happened, why would you think any of the above applies?

In researching a= 1/137 Fine Structure Constant in the Cahill 'background gravity field' papers, I had suspected that this feature did not get down to the Planck length 'base' element that gives electrons, and protons, their base 'mass' and that therefore this was an asociation with baryonic matter only, and so didn't qualify.

But after reading this, I am not so sure...Enjoy!

http://arxiv.org/ABS/HEP-TH/0110296

I thought I would be able to see problems with this! I couldn't, but until he relates this to cosmology, I won't be able to anyway.

[grav]

Originally Posted by grav
Everything that has mass would absorb neutrinos. It's what gives them mass in the first place.

IS this what the current consensus is???

But, IMHO, the first sentence of this post is 'wrong'!


No. I don't believe this is the current consensus. That would be the Higgs particle. It's the second sentence that might be opening a can of worms in this case since I don't know the specific interactions yet. The first sentence is true according to this model. That makes the second true in a round about sort of way. All mass creates gravity (as far as I know). Gravity is caused by the absorption of neutrinos. So all mass absorbs neutrinos. The second sentence isn't necessarily true but is implied. That would make mass a measure of the resistance to neutrino pressure, both gravitationally and with motion.


Originally Posted by grav
GR must be incorporated, and the specific interactions of neutrinos should be identified.

You said this above.

So, do you think that GR does worl in many individual scenarios in our universe?

Do you think that a massive enough star does have a gravitational collapse to a black hole, with an event horizon, as defined by General Relativity?
Yes. I think GR definitely has its place. I also think that once the specific mechanisms are identified, much, much more can be determined about the nature of space, particles, gravity, and the universe. The nature of black holes is the only thing I disagree with so far. And of course, an event horizon doesn't really exist. The gravity would essentially be the same for that distance, but would be where relavistic effects begin to come into play. Light would not become trapped, but would only become extremely gravitationally lensed. Its path would bend significantly, but it would never slow down in order to be "pulled in", and it will escape again in a path that is symmetrical to its path of entry. Light that is travelling directly outward from the star will also never be slowed down enough to be pulled back in (or at all), but will be tremendously gravitationally redshifted, so that the intensity of the light is barely noticable. So radiation is still emitted. For a star whose surface lies at the Schwarzchild radius, it would only emit 1/e of the original intensity. At one tenth this radius, it would emit 1/e10, and so on.

[nutant gene 71]

In a post above, I suggested that you would not like it.

But, let's examine this post here, which is fairly defining, and see what we come up with.

[The "fabric" of space-time is really an energy density of neutrino-like particles.]

Good! and in your OP you started with... [So consider this. All of space is filled with gravitons (or neutrinos or whatever you wish to call them)], also Good!
But then you went on to say...[and they create a positive energy density, or pressure.]

And right here is where the first problem occurs! "IF" the smallest Planck size non-baryonic sub element has a tiny, tiny mass, and is traveling at 'C', "BUT" it does not interact with Matter, then what can we say about it?
Does this mean at Planck length ~1.6E-35 m, something happens?

If 'all' of 'space' is made up of this physical stuff, it would be a gravity field.

However, because it is traveling at "C" it is subliminal, and because it does not interact with Matter, whatever tiny, tiny energy it does have is 'irrelevent'
(it is just potential energy*)!
Does Planck length act as a 'filter' for this Matter interaction, acting as a kind of 'gate' for Grav's 'neutrino cum gravity' where Matter and Gravity interact?

So, what does that mean? That means that 'space' has a 'background gravity field', and that we then have to define how 'massive baryonic matter' acts in that background gravity field. Which means 'space' is traveling at "C"!
From our point of view, background space is essentially fixed, but from photon's point of view, all background space is moving at C, in opposite direction. Some weird ATM stuff here:

1. Baryonic matter is light C 'sensitive' at Planck's length, so is 'energy filled' matter, but 'spacegravity poor' matter.

2. Non-baryonic matter (e.g. Dark matter) is non-energy filled matter, so space background 'filled' matter, or 'gravity rich' matter.

This could account for all 'empty' intergalactic space gas (about one hydrogen molecule per cubic centimeter) is 'gravity rich' non-baryonic matter... maybe.

[Also, these same particles create not just gravity, but the redshift of light, by absorbing a miniscule portion of its energy as it travels through space.]
Cool. Non-baryonic 'energy poor' matter latches onto passing photons, robbing them of some of their zip, so cause light to red shift? (I figured elsewhere (http://www.bautforum.com/showthread.php?p=440830#post440830) that if non-baryonic 'dark' matter were 50,000 greater G than our Newton's G, it would redshift intergalactic light at near Hubble constant.)

And here is another problem. Since they do not interact with baryonic matter (and I don't think the weak force here would allow them to absorb radiation, but I could be wrong), they are gravity only, with no energy quotient available.


[This means that there was no Big Bang and the expansion of space-time is not accelerating, since the redshift would mostly be due to distance, not velocity so much.]
"No energy quotient" means what? Is this non-baryonic, energy-poor, gravity-rich, matter? If so, then distance (intergalactic) would redshift light, if and only if, it were gravity rich, e.g. 50,000 times richer than baryonic matter.

Translation...the was no BB, space is traveling at 'C', where do these tiny, tiny sub-element gravity field producing things, COME FROM, how are they made?
Where do these SUB-ELEMENT GRAVITY PRODUCING THINGS 'COME FROM'? They may come from space (inverse) energy itself, meaning space is a natural gravity field (nature abhors a vacuum) constantly in juxtaposition to photonic energy, where the interaction takes place between Matter and energy at sub-Planck length. I know this sounds weird, but it may not be too far off from what both Grav and RussT are talking about, just connecting the dots. This boils down to this: Where photon energy gets past the Planck's length 'gate' it fills matter up, so it becomes Baryonic matter; if it doesn't fit past the 'gate' it becomes non-Baryonic matter, or 'energy-poor dark' matter.

[Furthermore, since these particles are about the size of the Planck length, and they also create gravity, there would be no gravity below this length, or even close to it]
If the above carries any weight, then the opposite effect is what happens: where photon energy cannot penetrate below this length, gravity in its pure form is what space is made of.

Exactly!

[since gravity is caused by the smooth, even flow of a large number of these neutrino-like particles, and therefore there would be no singularities, wormholes, etc]

Yes, it would certainly 'appear' that this should be 'smooth'!!!

However, ENTER... GR and String/"M" Theory, and Expansion from...THE VOIDS>
Smooooth! :)

More after you respond to this.;)

[RussT]

Yes. I think GR definitely has its place. I also think that once the specific mechanisms are identified, much, much more can be determined about the nature of space, particles, gravity, and the universe.

Very Good! Here is the crux in one short paragraph.

With GR, if you are in for a pound, you're in for a $!!! It is a pure gravitation theory. Gravity wells cause a phyical space to curve (no force). The math shows that extreme gravity must exist and it 'has' to be physical. The math also shows event horizons and singularities and they must be physical, especially since we now "KNOW" that 'space' is physical. The problem....The Big Bang starts off the universe with "FALSE VACUUM/energy), Inflation (more false vacuum energy) and then creates 'space' by saying that 'gravity makes gravity' (false ?) and 'space' makes 'space' (more false ?), and then the ultimate...the cosmological constant...Anti-gravity/DE (false/false ?)

[So all mass absorbs neutrinos]

When this takes place is the real key!!!

If neutrinos are 'the lowest base Planck element', and they are what makes up 'space' (all of it), then the only time they are absorbed (or more correctly, become the base mass) is when the electrons, protons, and neutrons are created! Which means that 'space' must already exist for this to happen.

[RussT]

Welcome back Ivan.


Does this mean at Planck length ~1.6E-35 m, something happens?

Yes, but only when enough heat (Tev ?) is applied to realease the otherwise inert tiny Planck mass to allow E=MC ^2 to apply.


Does Planck length act as a 'filter' for this Matter interaction, acting as a kind of 'gate' for Grav's 'neutrino cum gravity' where Matter and Gravity interact?

See Above.

Quote:Russt
So, what does that mean? That means that 'space' has a 'background gravity field', and that we then have to define how 'massive baryonic matter' acts in that background gravity field. Which means 'space' is traveling at "C"!

Quote:Ivan
From our point of view, background space is essentially fixed, but from photon's point of view, all background space is moving at C, in opposite direction. Some weird ATM stuff here:

Not quite. from our point of view space 'appears' to be fixed, but is really traveling at 'C' (neutrinos, and actually, everywhere at once with no particular direction), but from the point of view of the photons, they are traveling with 'space', everywhere at once, with no particular direction.


1. Baryonic matter is light C 'sensitive' at Planck's length, so is 'energy filled' matter, but 'spacegravity poor' matter.

2. Non-baryonic matter (e.g. Dark matter) is non-energy filled matter, so space background 'filled' matter, or 'gravity rich' matter.

This could account for all 'empty' intergalactic space gas (about one hydrogen molecule per cubic centimeter) is 'gravity rich' non-baryonic matter... maybe.

No, all of 'space' is DM, which is Planck size/mass bits, and 'inert' (just gravity field), UNTIL TEV energy event releases the E=MC^2 potential.


Cool. Non-baryonic 'energy poor' matter latches onto passing photons, robbing them of some of their zip, so cause light to red shift? (I figured elsewhere that if non-baryonic 'dark' matter were 50,000 greater G than our Newton's G, it would redshift intergalactic light at near Hubble constant.)

This is tired light and I do not know if this will apply or not!


Where do these SUB-ELEMENT GRAVITY PRODUCING THINGS 'COME FROM'? They may come from space (inverse) energy itself

The answer to this is surprisingly simple (once seen from the proper perspective), and your answer here could even be considered to be correct, (in a way), but not the way you are thinking of it here. This is though, the answer to the unification of GR and QFT.


If the above carries any weight, then the opposite effect is what happens: where photon energy cannot penetrate below this length, gravity in its pure form is what space is made of.

And then this could be considered a true statement!

[RussT]

I would be very intested to see Publius's and Ken G's input into this thread.

[grav]

With GR, if you are in for a pound, you're in for a $!!! It is a pure gravitation theory. Gravity wells cause a phyical space to curve (no force). The math shows that extreme gravity must exist and it 'has' to be physical. The math also shows event horizons and singularities and they must be physical, especially since we now "KNOW" that 'space' is physical. The problem....The Big Bang starts off the universe with "FALSE VACUUM/energy), Inflation (more false vacuum energy) and then creates 'space' by saying that 'gravity makes gravity' (false ?) and 'space' makes 'space' (more false ?), and then the ultimate...the cosmological constant...Anti-gravity/DE (false/false ?)

One reason a singularity cannot exist is because surface gravity (and electric force) are proportional to the inverse of the square of the radius of a body while the internal energy density that keeps it from collapsing to begin with is proportional to the inverse of the cube of the radius, so that the internal forces would always increase much faster than gravity upon collapse. Also, it could be that gravity is really inversely proportional to (d+rpl)^2 or (d^2+rpl^2) or some such, whereas it would never fall beneath the planck length anyway. It would be difficult to tell for sure if some modification to Newtonian gravity is necessary in this way. But GR itself is really a modification of Newtonian gravity, as well as MOND, if it holds. The "gravity creates gravity" thing would be one of these modifications also, but not like particles creating particles, energy creating more energy, or space making space. In this model, it would actually just be energy density filling in the missing energy density after some of it has been absorbed.

[Tensor]

One reason a singularity cannot exist is because surface gravity (and electric force) are proportional to the inverse of the square of the radius of a body while the internal energy density that keeps it from collapsing to begin with is proportional to the inverse of the cube of the radius, so that the internal forces would always increase much faster than gravity upon collapse.

Grav, this is a blantantly incorrect statement. I told you when you first started posting here you needed to look into the equations of state, to determine this. If you want to claim this, please produce the equations of state and the GR equations that show your statement is correct. The Tolman–Oppenheimer–Volkov equations of state show that if the collapsing mass is more than 1.44 solar masses, gravity overcomes the EM force and the result is a neutron star. If it is greater than 8-10 (in some cases 20, the details depend on the conditions of the collapse) gravity overcomes the strong force, and there is no other force to stop the collapse, resulting in a black hole.

[czeslaw]

The Tolman–Oppenheimer–Volkov equations of state show that if the collapsing mass is more than 1.44 solar masses, gravity overcomes the EM force and the result is a neutron star. If it is greater than 8-10 (in some cases 20, the details depend on the conditions of the collapse) gravity overcomes the strong force, and there is no other force to stop the collapse, resulting in a black hole.

If the collapsing mass is greater than 8 solar masses gravity overcomes strong force.
Yes, there is very high pressure and energy like in Athena colider producing an antimatter too.
Before it collapses it will produce matter/antimatter particles and annihilate.

My question is –
Before the supernova begins to collapse into a Black Hole its pressure in a centre will produce matter/antimatter and annihilate.
This will cause a shock wave towards the surface of the Neutron Star.
What will be faster than –
- the collapse of the matter because a gravity or
- the shock wave because of the annihilation in the centre ?

May be is there a balance preventing a collapse into a Black Hole.

[grav]

Actually, I wasn't referring to a collapse into a black hole. I was referring to a collapse into singularity. The internal pressure would increase faster than the gravitational or electric pressure upon collapse, so equilibrium should be achieved at some at some point. I have no idea where that point would be without looking into those equations you referred to, Tensor, but I do know that it should be greater than r=0, unless, of course, the entire mass radiates away in the process, so that the internal energy density is zero, in which case there would be nothing left for gravity to collapse to begin with, and nothing to produce the gravity anyway. And the Schwarzchild radius would also fall to zero as well, so that nothing is left.

[grav]

Besides, if I'm not mistaken, it would actually be GR that prohibits the collapse into a black hole, at least in the observable universe. Even if we initially allow for almost all of a collapsing star to fall beneath the Schwarzchild radius, that last little bit on the surface, according to GR, would take an infinite amount of time to fall beneath it to an outside observer. This means that we could never actually observe the tranformation of a black hole taking place within any finite amount of time, no surface of stars or galaxies would ever completely fall beneath that radius to an outside observer, and so we could never actually see a black hole. In other words, they wouldn't exist to us.

[nutant gene 71]

Welcome back Ivan.
Thanks Russt, nice to find this ATM discussion, thanks to Grav. I hadn't thought of the Planck length-mass before - interesting. :)
...

This is tired light and I do not know if this will apply or not!
I agree, tired light is out, pretty much disproven. I was thinking more of 'gravitational lightshift', but still not supportable as per my above unless we find Newton's G varies. So for now, that's an open question, nixed if G is indeed 'universal constant', yet possible hypothesis if G is found higher waaaaay out there. MOND may be pointing that waaaay.

The answer to this is surprisingly simple (once seen from the proper perspective), and your answer here could even be considered to be correct, (in a way), but not the way you are thinking of it here. This is though, the answer to the unification of GR and QFT.
Unification of GR with QFT is the 'Holy Grail' of physics! Planck's length might be the key to unlocking this conundrum.

And then this could be considered a true statement!
All of space as gravity at sub-Planck scale might be true, indeed. ;)

-Ivan

[RussT]

Thanks Russt, nice to find this ATM discussion, thanks to Grav. I hadn't thought of the Planck length-mass before - interesting.

You are welcome.


Unification of GR with QFT is the 'Holy Grail' of physics! Planck's length might be the key to unlocking this conundrum.

This is strange, because I thought we had talked about this in some detail. I'll check, but yes, this has been known for a long time.

The problem is, it cannot be done at T=0, T=10^-35, or T=10^-43 in a FWR universe!


All of space as gravity at sub-Planck scale might be true, indeed.

Yes, but the key is...At the speed of light "C"!

[grav]

I agree, tired light is out, pretty much disproven. I was thinking more of 'gravitational lightshift', but still not supportable as per my above unless we find Newton's G varies. So for now, that's an open question, nixed if G is indeed 'universal constant', yet possible hypothesis if G is found higher waaaaay out there. MOND may be pointing that waaaay.
Tired light may be out in the way it is presented now, being entirely absorbed and re-emitted. But this kind of tired light absorbs only the energy of light at the Planck level. It would not be like a single ray of light being entirely absorbed by a body, but on this scale, one can think of it as "stray" neutrinos that carry away only a very small portion of the energy at a time. This can occur either as a transfer of energy between neutrinos as a wave or in particle form of the energy of bursts of neutrinos themselves. The details for that would depend on the precise interactions and abundance of neutrinos in space. Either way, though, it would have less than 100% efficiency, so this can be thought of as sort of a space friction.

Unification of GR with QFT is the 'Holy Grail' of physics! Planck's length might be the key to unlocking this conundrum.I fully agree.


All of space as gravity at sub-Planck scale might be true, indeed. ;)Actually, if you are referring to my model, I meant that it couldn't happen at the Planck scale or even close to it because the size of the neutrinos (or neutrino-like particles) would be about the Planck length, and gravity would require quite a large abundance of them. So gravity (and GR) only occur on large scales (much greater than the Planck length, anyway) where space appears very smooth because the random motions of the neutrinos evens out. QM or QFT would apply more to the motions of individual neutrinos, and so would be mostly at that scale, or at the Planck length. Below this we would probably have to apply some form of string theory to determine the actual make-up of neutrinos themselves. So we have GR at large scales, QM at and around Planck length, and string theory at sub-Planck levels.

[nutant gene 71]

Tired light may be out in the way it is presented now, being entirely absorbed and re-emitted. But this kind of tired light absorbs only the energy of light at the Planck level. It would not be like a single ray of light being entirely absorbed by a body, but on this scale, one can think of it as "stray" neutrinos that carry away only a very small portion of the energy at a time. This can occur either as a transfer of energy between neutrinos as a wave or in particle form of the energy of bursts of neutrinos themselves. The details for that would depend on the precise interactions and abundance of neutrinos in space. Either way, though, it would have less than 100% efficiency, so this can be thought of as sort of a space friction.
...
Actually, if you are referring to my model, I meant that it couldn't happen at the Planck scale or even close to it because the size of the neutrinos (or neutrino-like particles) would be about the Planck length, and gravity would require quite a large abundance of them. So gravity (and GR) only occur on large scales (much greater than the Planck length, anyway) where space appears very smooth because the random motions of the neutrinos evens out. QM or QFT would apply more to the motions of individual neutrinos, and so would be mostly at that scale, or at the Planck length. Below this we would probably have to apply some form of string theory to determine the actual make-up of neutrinos themselves. So we have GR at large scales, QM at and around Planck length, and string theory at sub-Planck levels.
Thanks Grav, wish I knew more of how this works. The 'neutrino-like particles, at Planck scale, might be how you desicribe them. My idea was slightly different, in that these 'Planck particles' throughout the space-vacuum are what is sometimes called 'zero point energy', which I envision as somehow (without knowing how) affect atomic matter, giving it mass and gravity (per equivalence). Beyond that, not knowing the mechanism for how this happens, I can only guess, or await data that gives some revelation. However, the zero-point energy would not be the same as electromagnetic energy, though there would be interaction between them, which might be information carried by the 'neutrino-like' Planck scale particles. However, this is just a wild guess, for now, with no scientific merrit.

[RussT]

[Well this is 10 to the -20 of a millimetre. That's taking a millimetre and dividing it by 10 with 20 zeros after it, so that's very, very small.

That means that it exists only one trillionth of a millimetre from every point in our three-dimensional world.]

grav, how does this size compare to Planck size/length?

[Tensor]

If the collapsing mass is greater than 8 solar masses gravity overcomes strong force.
Yes, there is very high pressure and energy like in Athena colider producing an antimatter too.
Before it collapses it will produce matter/antimatter particles and annihilate.

My question is –
Before the supernova begins to collapse into a Black Hole its pressure in a centre will produce matter/antimatter and annihilate.
This will cause a shock wave towards the surface of the Neutron Star.
What will be faster than –
- the collapse of the matter because a gravity or
- the shock wave because of the annihilation in the centre ?

May be is there a balance preventing a collapse into a Black Hole.

That's why there is so much uncertainty about the minimum amount of mass need to form a black hole from a collapse event. The amount needed really depends on the particulars of the event. At some point (around 20 solar masses) there is no uncertainty, nothing can stop the collapse caused by gravity.

[Tensor]

Actually, I wasn't referring to a collapse into a black hole. I was referring to a collapse into singularity.

In GR, all the collapse events that form a singularity, form a black hole.

The internal pressure would increase faster than the gravitational or electric pressure upon collapse, so equilibrium should be achieved at some at some point.

Assertion on your part. Care to show it explicitly?

I have no idea where that point would be without looking into those equations you referred to, Tensor, but I do know that it should be greater than r=0,

Nope. Those equations, when combined with GR, show that the collapse to a singularity (and the formation of a black hole) is inevitatble. Your job, if you want to claim the above, is to show how this could work according to you, or where they made a mistake.

[Tensor]

Besides, if I'm not mistaken, it would actually be GR that prohibits the collapse into a black hole, at least in the observable universe. Even if we initially allow for almost all of a collapsing star to fall beneath the Schwarzchild radius, that last little bit on the surface, according to GR, would take an infinite amount of time to fall beneath it to an outside observer. This means that we could never actually observe the tranformation of a black hole taking place within any finite amount of time, no surface of stars or galaxies would ever completely fall beneath that radius to an outside observer, and so we could never actually see a black hole. In other words, they wouldn't exist to us.

Your last statement is simply not true. As has been pointed out to you several times. Go get a GR textbook and actually learn GR, if you want to make claims about it. Your claims, it is becoming more and more obvious, are not about GR, they are about either what you think GR says, or a simplified explanation(to give an idea about what is going on), you can find in many popular science books and articles . And, as a result, often quite wrong.

[czeslaw]

That's why there is so much uncertainty about the minimum amount of mass need to form a black hole from a collapse event. The amount needed really depends on the particulars of the event. At some point (around 20 solar masses) there is no uncertainty, nothing can stop the collapse caused by gravity.

After the supernova outburst is there a collapse into a Neutron Star.
We observe a little of it in a thermonuclear fusion when protons are overcoming an EM force and nucleons come together creating a greater nucleon of Helium.

What happens if there is a higher pressure ?
Are we able to create a higher pressure than in a thermonuclear fusion here on the Earth ? What happens then ?

In CERN and Fermilab are they accelerating protons to much higher energies then in fusion process. The collision causes a creation of many new particles/antiparticles. The protons do not disappear - there are even new and they escape with a relativistic velocity just at the moment of the collision. The antimatter annihilate and causes farther oscillation and new collision and creation and annihilation and so on.
This process goes outward usually like outburst.

My question is - a large remnant (10, 20, 50 solar masses)is just in a moment before it may create a Black Hole. The gravitational field causes a relativistic velocity in every directions in the whole space of the collapsing star. It is not still a Black Hole so there are many colliding particles. This relativistic collisions causes a matter/antimatter creation and annihilation and then a shock wave like an outwards outburst.

Here is a question about a speed of the gravitational collapse and speed of the shock wave outburst.
What is faster or is there a balance ?

There are many theories that a Black Hole does not exists - Masur, Mottola, Chapline and others professional physicists even Nobel laureate.

Do you know a link about the relativistic colisions before an Event Horizon is created ?

[grav]

Thanks Grav, wish I knew more of how this works. The 'neutrino-like particles, at Planck scale, might be how you desicribe them. My idea was slightly different, in that these 'Planck particles' throughout the space-vacuum are what is sometimes called 'zero point energy', which I envision as somehow (without knowing how) affect atomic matter, giving it mass and gravity (per equivalence). Beyond that, not knowing the mechanism for how this happens, I can only guess, or await data that gives some revelation. However, the zero-point energy would not be the same as electromagnetic energy, though there would be interaction between them, which might be information carried by the 'neutrino-like' Planck scale particles. However, this is just a wild guess, for now, with no scientific merrit.
Oh, how I wish I knew more, too. But everything you just said sounds about right to me, according to the model I've been working on, anyway. Except, perhaps, for that last part. I find that for the electron, at least, the ratio of that amount of the pressure which is absorbed (the amount matter actually "feels" as gravity) to the total pressure would be about one part in 10^42. This is the same as the gravitational to electric force ratio for electrons. If matter absorbed all of the pressure incident to it, gravity wouldn't be as penetrating as it is, affecting all of the atoms in a body. It would become a surface pressure only. So my thinking is that electric force is caused by the full pressure acting on the "surface" of particles, but not absorbed. The positive or negative charge, then, would probably be related somehow to the actual physical spin of a particle, or angular momentum, as it moves through space (right-handed or left-handed), whereas the paths of neutrinos would be redirected. This is not conclusive, however, and I also have another possible model for the electric force, much simpler than the first, where neutrinos are absorbed, annihilated or trapped somehow, and their energy released as light. An oppositely charged particle, then, would absorb light and produce neutrinos. There is also a third model where the charge depends on the optic density of the particle and its angular momentum as well, where the index of refraction and possibly relativistic drag play a large part. As you can see, I've got a lot of work to do on this, however, in order to narrow down the possibilities.

[grav]

Originally Posted by grav
Besides, if I'm not mistaken, it would actually be GR that prohibits the collapse into a black hole, at least in the observable universe. Even if we initially allow for almost all of a collapsing star to fall beneath the Schwarzchild radius, that last little bit on the surface, according to GR, would take an infinite amount of time to fall beneath it to an outside observer. This means that we could never actually observe the tranformation of a black hole taking place within any finite amount of time, no surface of stars or galaxies would ever completely fall beneath that radius to an outside observer, and so we could never actually see a black hole. In other words, they wouldn't exist to us.
Your last statement is simply not true. As has been pointed out to you several times. Go get a GR textbook and actually learn GR, if you want to make claims about it. Your claims, it is becoming more and more obvious, are not about GR, they are about either what you think GR says, or a simplified explanation(to give an idea about what is going on), you can find in many popular science books and articles . And, as a result, often quite wrong.
Actually, that would be the first time I said that. I read about it in some of the other threads. I generally try to stay out of discussions like that, though, because of my lack of understanding of the mathematics of GR. Thanks to publius and others, however, I am steadily grasping a little at a time. This one seems pretty simple, though. According to GR, as a body collapses (in freefall), it slows as it reaches the Schwarzschild radius according to outside observers and objects would appear to hover just above it. Well, that's it. That's the whole thing, really. So if it takes an infinite amount of time for the surface of a star or galaxy to collapse to the Schwarzschild radius, then I guess we wouldn't have to worry too much about it crossing it, much less creating a singularity well below it at the Planck length or less within the lifetime of the universe. Technically, though, we would indeed observe a black hole, however, because I forgot about the gravitational redshift. As the matter moved closer and closer to the Schwarzschild radius, the light emitted would redshift exponentially due to gravity, and over again due to time dilation, so that the luminosity is inversely proportional to the square of the redshift altogether, and so a collapsing star or galaxy would indeed "fade to black" over time.

[publius]

Grav,

You got to be careful with that, and not take what I said in those threads as the ultimate description of reality. The infinite-time is in our frame watching (stationary frame a long distance away). That's our coordinates.

For the free-faller, in his coordiantes, he crosses that horizon in finite time, and on to the singularity. If we try to transform his space-time coordinates from below the horizon to the singularity, that is the events inside the horizon in his frame, to our stationary frame, we get garbage.

I like to sort of say those events are "outside" our frame of reference. They don't exist in that frame, but that does not mean they don't exist ultimately. They exist "Elsewhere" :)

We can do the same thing with an accelerating observer -- that roughly the constant g field of the infinite mass sheet an infinite distance away (although GR would change that from Newton somewhat, but it's the same basic principle). The space-time for the accelerating observer is like that of the constant g for stationary observers.

There is an event horizon there, and that observer will never see free-fallers cross that horizon either. They will "freeze" just like with a black hole. However, the "free fallers" are just completely inertial, and no singularity awaits them when they cross the horizon.

They can see the accelerating observer continue to acclerate, inching every so closer to c, but never getting there. Past that event horizon, "reciprocity" has completely broken down. We can see the accelerating observer, but he can't see us. Well, in his frame we are stuck at the horizon. The events in our frame past the horizon don't exist in his frame.

The is the same thing as that simultaneity "conundrum" of T = t/gamma in the t frame, and t = T/gamma in the T frame (and I'll say more about that in that thread when I get a round tuit), but carried to a greater extreme.

One way to sort of resolve that (but not really rigorous) is we can say, we'll that accelerating observer's (from our frame) clock is getting so darned slow as he gets closer and closer to light speed that it's just about stopped, and so he doesn't see our events past the horizon because his clock will never catch up (the key is not how slow it is, but the fact that is slow*ing* down, getting slower and slower with our time).

Now, if you want to argue against black holes, look at the MECO/ECO theory, first proposed by Abhas Mitra, that challenges the "cold dust" collpase model. That says the collapse to a singularity takes a ridiculously long time in its own frame.

-Richard

[grav]

Thanks, publius. But again, I'm not arguing against black holes, just singularities, and I'm not even rightly sure how I fell into this topic again, except by saying that singularities wouldn't occur in my model. I guess I shouldn't have said that GR prohibits a collapse into a black hole, though. I think of this as a collapse below the Schwarzschild radius, but the gravitational redshift and time dilation would of course still tend to make it "black" regardless. Anyway, I don't think it matters how time passes for a free-faller. No matter what the time dilation is compared to another frame of reference, time will always seem to passing by as normal to an observer within that frame. All that would really matter (to us), then, is how we see it, within our own reality, and that is what I was referring to. The freefaller would never reach a singularity (or even the Schwarzschild radius) until an eternity passes by for the rest of the universe. This would mean an end to time and the universe as well. So how could one ever reach it if the universe no longer exists? You do have me curious about another thing, however. If the freefaller seems to freeze just above the Schwarzschild radius, and therefore appears to stop aging, how would the "real" gravitational time dilation affect him as well? Or is this the same thing? Is that what you are referring to at the end of your post? What about for light itself "falling" in? Would it slow down, speed up, or continue at c?

[publius]

Grav,

You are thinking sort of like me. What matters is what I see, in the coordinates that "make sense" to me. But there is more to space-time than what we see. In that thread where I got hot under the collar, it was being claimed the infinite time and freezing (ie slowing down to zero for both light and free fallers) was just a light-travel time illusion and free-fallers "really cross" in our frame. And that of course is not true. It's not an illusion using our clocks (and rulers). That is "our reality".

But the thing to realize is "our reality" is incomplete and doesn't include the "Elsewhere".

The reality of the free-faller is something different. And that's another thing. You said an eternity passes for the universe before he crosses. Well, that's true only in our frame, our reality. :) It is quite different for the free faller.

A stationary observer deeper and deeper down in the Schwarzschild metric (see those ds^2 equations I posted), will see our clocks up high running very fast. In fact, in the limit as he gets closer to R (in our coordinates -- in his, "the closer he gets, the farther away the horizon is" -- that's his rulers shrinking down to nothing radially), our clock rate will go to infinity. So for that stationary observer (feeling a ridiculous g force to hold him still) near the horizon, he will indeed see "an eternity pass in the blink of an eye". Our light will be blue-shifted to hard gamma and beyond to him.

However, the free-faller is very different. Remember he is *moving*, not feeling a force (save for tidal forces, which we're ignoring by saying our free-faller is just a point following a geodesic). The equivalence principle can be our guide here. While the Schwarzschild metric is different from the "psuedo-g" metric of a uniformly accelerating observer, they are close enough to see general principles.

From the POV of a free-faller, feeling no force and completely inertial, we are accelerating away from him. He sees us getting closer and closer to light speed, and our clocks getting slower and slower. When he crosses the horizon, in his frame, our clocks haven't ticked much relative to him. He DOES NOT see "an eternity pass in the blink of an eye". In fact, he doesn't see much time pass for us at all.

For our far away stationary POV, the stationary observer near R and the free-faller near R look about the same, red-shifted to nothing and moving slowly. However, down there, that stationary observer near R will see that free-faller whiz by him at high speed. (Remembering the calculations, the local speed at the "photon sphere" r = 1.5R, will be sqrt(2/3)c. So if our stationary observer was at the photon sphere, he'd see that free-faller whizzing by him at over 80%c. However, in our frame, we'd see a factor of 1/3 in front of that. After that, he start to slow down. He appears to "stop on a dime" really, going from high speed to nothing in that short 1/2R distance!)

Now, really close in, say a stationary observer (thrusting at some ridiculous g level, "milllions and billions" as Carl Sagan would say) at r = 1.0001R, he would see that free-faller whizzing by him at 99%c (but that free-faller would have a long distance to go still to reach the horizon because of his radially shrunken rulers, which would be getting very short there). To us, both are "about the same". But down there, there is enormous relative velocity.

And the distance the free-faller thinks he travelled, his "proper distance", will be different from what any of us stationary observers would think.


-Richard

[grav]

Grav,

You are thinking sort of like me.
Thanks, publius. I'll definitely take that as a compliment. :) In your last post, was gravitational time dilation accounted for, or was it purely SR for the relativity of velocities through acceleration? Also, yesterday, I looked for that thread you're referring to but couldn't find it. Could you post a link?

[publius]

Grav,

That black-hole free-fall stuff was spread over several threads. Here's the main one, where I lost my temper :o

http://www.bautforum.com/showthread.php?t=46423

No, I wasn't considering gravitational time dilation. That was just using the Equivalence Principle as guide. Now, if the free-faller's frame was "completely inertial", completely flat, as it would be for the "free faller" watching another observer accelerate away, this would hold exactly.

Consider two free-fallers dropped at different times in the Schwarzschild metric (which is just the GR version of "simple inverse square" g field). Each free faller, feeling no forces themselves, will see the other appear to accelerate, and that's because of the variation in acceleration with radius, usually dubbed tidal forces, tidal acceleration. That comes out of Newton easily. In GR it's there, but a little different, because of the way the local coordinates "warp" with respect to each other, but it's the same basic effect. But in the Schwarzschild metric, the tidal forces are exactly the same as Newton for both stationary and free-fallers. That's a product of the high symmetry of the spherical mass distribution, and does not in general hold between GR and Newton.

Because of that, that different inertial observers, "feeling no force in their own frame" see relative acceleration between them, the each free-faller knows his metric is not "globally flat". That means there will be a difference in the relative clock rates from the pure SR situation of an inertial observer watching something accelerate.

However, while really it's "all in the metric", you can sort of separate gravitational time dilation from "SR time dilation". So, in the "inverse square" free-fall, the SR time dilation would overwhelm the gravitational time speed-up.

In the accelerating observer metric, the free-fallers would be globally flat relative to each other, and there would be no additonal gravitational effects at all in their frame. In the accelerating frame, of course, there are big time "gravitational effects".

-Richard

[grav]

Thank you, publius. This has all been very interesting. :razz: I will read up on it some more.

[publius]

Grav,

Glad you find it interesting. To some it's all just MEGLO(my eyes glaze over). My eyes do glaze abit, but I want to understand it.

Finally, speaking of Carl Sagan's millions and billions of g, let's plug in some numbers and see just how ridiculous the g-forces would be for stationary observers close in to R.

In the Schwarzschild metric, the stationary g-force is

GM/r^2 * 1/sqrt(1 - R/r)
Netwon, with an additional factor that makes it go to infinity at R, rather than zero. For r >>R, Newton is close enough, but down close, that additional factor starts dominating.

At the "photon sphere", r = 1.5R, the extra factor is just the square root of three, it 1/sqrt(1 - 2/3) = sqrt(3).

The Netwon factor is GM/(3/2R)^2. Now R is just 2GM/c^2, so that comes out to be:

1/9 * c^4/GM

Note that c^2 over G. That's a big number! But note something that seems odd at first. That goes inversely with mass. And the reason is R increases with mass -- the larger the black hole, the bigger R is, and so the force at some mulitple of R gets smaller as R gets larger. For an astronomically large black hole, the force at the photon sphere could be reasonable (but think of the distance required at that thrust to get out -- the energy budget for such manuevers will always be enormous).

1 solar mass is about 2*10^30kg. Plug that in and the Newtonian g is
6.7*10^12 m/s^2, and we need to multiply by the square root of three, so we get 1.2*10^13 m/s^2. Divide that by 1 earth g, and we get

1.2*10^12g. That's 2 *trillion* g at the photon sphere of a 1 stellar mass black hole. We need trillions of stellar masses to get g down to earth levels.

Talk about "strong" gravity! But note the time dilation factors would be the same at a given R/r. The "force of gravity" is not proportional to the "strength" of the field in terms of the time dilation and length compression and all that stuff.

-Richard

[Tensor]

Your last statement is simply not true. As has been pointed out to you several times. Go get a GR textbook and actually learn GR, if you want to make claims about it.

Actually, that would be the first time I said that.

My apologies. That should be a comma after the words "several times", not a period.

Actually, that part wasn't what I was objecting to. Actually, your last statement was this:

In other words, they wouldn't exist to us.

Even if we can't see them form, the effects of the curvature around the black hole would be visible. They would very much exist to us.

[RussT]

What about for light itself "falling" in? Would it slow down, speed up, or continue at c?

AFAIK, not considering any EM like effects on the possible slowing of light, light speed stays at 'C', and the consideration is...what affect is gravity having on it in 'its frame of reference'. Once past the event horizon, light traveling at 'C' cannot escape the strength of the gravity well it is in. What happens to light above the event horizon depends on numerous factors, and one of those certainly has to be...Kerr black hole or Schwartzchild?

[grav]

Even if we can't see them form, the effects of the curvature around the black hole would be visible. They would very much exist to us.

That's true. I was just thinking that they would have to form below the Schwarzschild radius to be considered a true black hole.

[grav]

AFAIK, not considering any EM like effects on the possible slowing of light, light speed stays at 'C', and the consideration is...what affect is gravity having on it in 'its frame of reference'. Once past the event horizon, light traveling at 'C' cannot escape the strength of the gravity well it is in. What happens to light above the event horizon depends on numerous factors, and one of those certainly has to be...Kerr black hole or Schwartzchild?
That's what I was thinking also. In order for relativity to work, the speed of light would have to remain constant in all frames of reference, even in the vicinity of a black hole. Only its path would bend and/or the light would redshift. Otherwise, the calculations wouldn't stand, since this is their foundation. So considering this...

At the "photon sphere", r = 1.5R, the extra factor is just the square root of three, it 1/sqrt(1 - 2/3) = sqrt(3).

publius,

At first I thought this could differ due to GR effects or something beyond my understanding, but after considering the above, I don't think so. A body orbits with the square root of two times less speed than is required for its escape. So at constant speed, wouldn't light orbit in the photon sphere at r=R/2, where vorbit at R is c/(2^1/2), so vorbit=c at R/2 (since v^2*d=constant)? In that other thread (page 3) you said that the photon sphere is the inner sphere, didn't you? From the Schwarzschild radius, assuming constant speed for light, the escape velocity is c. At the photon sphere at R/2, the orbittal speed is that of light, but then the escape velocity is (2^1/2)*c, and so is impossible. Only an orbit is possible here. I believe your post in that thread said the escape velocity at the photon sphere would be sqrt(2/3)*c, in which case escape would be possible. Am I missing something?

Oh, that thread was also very interesting and informative, by the way.

[publius]

publius,

At first I thought this could differ due to GR effects or something beyond my understanding, but after considering the above, I don't think so. A body orbits with the square root of two times less speed than is required for its escape. So at constant speed, wouldn't light orbit in the photon sphere at r=R/2, where vorbit at R is c/(2^1/2), so vorbit=c at R/2 (since v^2*d=constant)? In that other thread (page 3) you said that the photon sphere is the inner sphere, didn't you? From the Schwarzschild radius, assuming constant speed for light, the escape velocity is c. At the photon sphere at R/2, the orbittal speed is that of light, but then the escape velocity is (2^1/2)*c, and so is impossible. Only an orbit is possible here. I believe your post in that thread said the escape velocity at the photon sphere would be sqrt(2/3)*c, in which case escape would be possible. Am I missing something?

Oh, that thread was also very interesting and informative, by the way.

Grav,

Yes you are missing something, something I didn't mention at all in those threads. Your orbital speed being less than the escape speed works only in Newton gravity, and in the Schwarzchild metric only for r>>R. :)

I presented the *radial* geodesics, setting the angular coordinates and any intital velocity along them to *zero*. Remember? The radial speed of light (in our distant Schwarzschild coordinates) is indeed +/- c(1 - R/r).

However, there is no length compression (ruler shrinkage) in the tangential directions. The tangential speed of light as seen in our frame (say a stationary observer down there fires a beam off to the side) gets only a factor of the square root on that:

c(r)_tangential = c*sqrt(1 - R/r)

So this all makes the orbital speed vs escape speed relation very different. But the local observer sees the speed as c in all directions, of course. His clock his slowed, but his ruler shrinkage is not the same in all directions, only radial.

Orbits deep down in the well become very chaotic, rarely closed curves at all. There is a Schwarzchild orbit simulator somewhere on the web that will show it. The orbits are insane looking.

-Richard

[publius]

Grav,

And another thing. Rotating black holes got thrown in that thread too. Don't get that confused with the simple, non rotating Schwarzchild metric. The rotating black hole metric is called the "Kerr metric". It is very different and there be frame-dragging going on there, big time.

This thing becomes more axially symmetric than spherical. It has a stationary limit, where things have to start moving around, before the true event horizon. And there are two event horizons in there as well. Two seperate "Elsewheres". Closed time-like curves exist between horizons, which means you could meet yourself and shake hands..........

And there are two photon spheres there as well. One for retrograde light, and the other closer in for prograde light orbits.

-Richard

[grav]

Radial shrinkage only in the radial direction, huh? That does seem to make perfect sense. This would "cause" time dilation, wouldn't it? I was thinking that the speed of light should always be c in any frame of reference, in order for GR formulas to hold ground, but a time dilation for light is also figured into the redshift calculations (for total luminosity). But just to be sure, does this mean the photon sphere is inside or outside of the Schwarzschild radius?

[grav]

Grav,

And another thing. Rotating black holes got thrown in that thread too. Don't get that confused with the simple, non rotating Schwarzchild metric. The rotating black hole metric is called the "Kerr metric". It is very different and there be frame-dragging going on there, big time.

This thing becomes more axially symmetric than spherical. It has a stationary limit, where things have to start moving around, before the true event horizon. And there are two event horizons in there as well. Two seperate "Elsewheres". Closed time-like curves exist between horizons, which means you could meet yourself and shake hands..........

And there are two photon spheres there as well. One for retrograde light, and the other closer in for prograde light orbits.

-Richard
Yes. I was just trying to look up about my question, and found something about Kerr black holes. That must be what you were referring to, and it sounds very complicated. Apparently, the event horizon(s) would be the same at the poles, but would spread out around the equator. Now I finally know what you meant by the ergosphere, which is simply the distance in between.

[publius]

Radial shrinkage only in the radial direction, huh? That does seem to make perfect sense. This would "cause" time dilation, wouldn't it? I was thinking that the speed of light should always be c in any frame of reference, in order for GR formulas to hold ground, but a time dilation for light is also figured into the redshift calculations (for total luminosity). But just to be sure, does this mean the photon sphere is inside or outside of the Schwarzschild radius?
Grav,

The *local speed* of light is indeed always c in any frame of reference. Any frame. Basically, you define local coordinate by "factoring out" the metric factors at that point. And that defines the "proper" time and distances *at that point*.

In GR, however, the speed of light can vary in our local coordinates far away. And that's exactly what's happening in the Schwarzschild coordinates. These are technically the "local coordinates" of an observer at infinity. But since the time dilation and radial length compression are small for r >> R, this is "about" what stationary observers any reasonable distance away would see.

For example (see that crazy Geocentrism thread), in a rotating frame of reference, you'd see distant inertial objects whizzing by at tremendous speeds, greatly exceeding c. But in GR, c itself increases to match with distance.

And indeed, in the Schwarzchild metric, that observer way down in the well sees the speed of light high up to be much greater than local c.

So in GR, nothing can go faster than light does at any point in your coordinates, and when you convert that to a local speed, it will always be c anyway.

And yes, the photon sphere for the Schwarzschild black hole is outside the event horizon, at r = 3/2 R = 1.5R. Now, that orbit is very unstable. The slightest perturbation will send it flying off, or flying right in. To see all that, you need the full equations of motion. A stable orbit is one sitting at a minimum of the effective potential (which includes the angular momentum, "centriifugal force" potential). A unstable orbit sits at a local maximum. The photon orbit is one of those unstable ones.

IIRC, the precession terms comes from a slight modification to the "centrifugal" component of the effective potential.

-Richard

[publius]

Yes. I was just trying to look up about my question, and found something about Kerr black holes. That must be what you were referring to, and it sounds very complicated. Apparently, the event horizon(s) would be the same at the poles, but would spread out around the equator. Now I finally know what you meant by the ergosphere, which is simply the distance in between.
Grav,

Careful. The "ergosphere" (actually an ellipsoid -- this looses spherical symmetry and becomes axial) is the "stationary limit", where "frame dragging" requires thing get moving. It is outside the first event horizon. It is an event horizon for a stationary observer so to speak, one trying not to move at all. But if you start moving, you can still remain radially stationary, you just need tangential velocity. This is the "frame dragging" -- dragging inertial frames into an orbit with the rotating mass. :) You can see that as a gravitomagnetic force acting to oppose the normal gravitational field. Without motion, the force would go to infinity at the ergosphere, but get moving and it stays finite.

Until you get to the (first) event horizon. I don't know if there's a name for the region in between the two horizons at all, other than "so weird it couldn't possibly be real". :)

Seriously, I think it turns out that metric is so unstable in between, that the slightest perturbation (like a mass falling in) would change it. No one wants to accept you can shake hands with your future self...........

-Richard

[grav]

But the speed of light is constant regardless of its origin. That is to say, there is no distance or velocity so great in any frame of reference that the speed of c will change. This is true for SR, and all variations of SR with acceleration. In that case, any time dilation observed for light itself could only come from the gravitational time dilation, right? But then, this is already seen in the redshift of light radially. So would that mean that the other part of it is due to a "real" gravitational time dilation for the traveller, in relation to the rest of the universe (in free space)? I say "real" like this, by the way, because there seems to be a very distinct difference between time dilation as observed in SR, by both observers for the other, and that for GR, in which the dilation is maintained independent of the inertial frame of reference.

[grav]

Grav,

Careful. The "ergosphere" (actually an ellipsoid -- this looses spherical symmetry and becomes axial) is the "stationary limit", where "frame dragging" requires thing get moving. It is outside the first event horizon. It is an event horizon for a stationary observer so to speak, one trying not to move at all. But if you start moving, you can still remain radially stationary, you just need tangential velocity. This is the "frame dragging" -- dragging inertial frames into an orbit with the rotating mass. :) You can see that as a gravitomagnetic force acting to oppose the normal gravitational field. Without motion, the force would go to infinity at the ergosphere, but get moving and it stays finite.

Until you get to the (first) event horizon. I don't know if there's a name for the region in between the two horizons at all, other than "so weird it couldn't possibly be real". :)

Seriously, I think it turns out that metric is so unstable in between, that the slightest perturbation (like a mass falling in) would change it. No one wants to accept you can shake hands with your future self...........

-Richard
Huh? :confused:

[publius]

Huh? :confused:

Coming at you too fast? MEGLO? :) Why don't we forget about the Kerr metric and frame dragging for a while.

About SR. There is a type of intermediate thing "between SR and GR" where you calculate things that happen with acceleration. But note these calculations are done in the frame of an inertial observer watching some other observer accelerate. If (ala twin paradox) one comes back where they can compare clocks (and odometers), we can find what the accelerated observer's clock will read compared to ours.

But that works only for the POV of the inertial frame. SR will not work for the accelerated observer while he's accelerating (feeling a force). That is, it can't tell us what the accelerated observer himself sees while the "experiment" is going on. The speed of light does vary with position for such an accelerated observer, although not by much unless he's really accelerating. If we're accelerating, clocks and light way ahead of us do seem to speed up. And they slow down behind us.

-Richard

[grav]

After that last post, I think MBGLO2. I think I'll give it a rest for a while. I appreciate the input, though. As always, it was very interesting. :)

[publius]

Grav,

Rome was not built in a day, as the saying goes.

Some advice about learning this stuff. Just take in for a while, accept the defintions, and don't try to analyze or tear into until you've learned some. The reasons why things are defined the way they are will only become apparent after you've more of it.


-Richard

[czeslaw]

Grav,

Careful. The "ergosphere" (actually an ellipsoid -- this looses spherical symmetry and becomes axial) is the "stationary limit", where "frame dragging" requires thing get moving. It is outside the first event horizon. It is an event horizon for a stationary observer so to speak, one trying not to move at all. But if you start moving, you can still remain radially stationary, you just need tangential velocity. This is the "frame dragging" -- dragging inertial frames into an orbit with the rotating mass. :) You can see that as a gravitomagnetic force acting to oppose the normal gravitational field. Without motion, the force would go to infinity at the ergosphere, but get moving and it stays finite.

Until you get to the (first) event horizon. I don't know if there's a name for the region in between the two horizons at all, other than "so weird it couldn't possibly be real". :)

Seriously, I think it turns out that metric is so unstable in between, that the slightest perturbation (like a mass falling in) would change it. No one wants to accept you can shake hands with your future self...........

-Richard

We observe the Black Hole Like Objects. We see a dragging space around it and an accretion disc but we have no direct evidence that an Event Horizon exists. http://arxiv.org/abs/astro-ph/0207270
http://www.seedmagazine.com/news/2006/07/what_if_black_holes_didnt_exis.php - Chapline and Laughlin (a Nobel laureate)
Many other scientifists reject a traditional Schwarzschild Black Hole.
Welcome in anti Black Hole company.

[RussT]

So we have GR at large scales, QM at and around Planck length, and string theory at sub-Planck levels.

grav, this should mean that there are two DM particles flying around at light speed going through baryonic matter?

I think this may go one level to deep (strings should be at Planck length) which is why I asked this way back.

---------------------------------------------------------------------------
[Well this is 10 to the -20 of a millimetre. That's taking a millimetre and dividing it by 10 with 20 zeros after it, so that's very, very small.

That means that it exists only one trillionth of a millimetre from every point in our three-dimensional world.]

grav, how does this size compare to Planck size/length?
__________________________________________________ ______________

[grav]

grav, this should mean that there are two DM particles flying around at light speed going through baryonic matter?

I think this may go one level to deep (strings should be at Planck length) which is why I asked this way back.

---------------------------------------------------------------------------
[Well this is 10 to the -20 of a millimetre. That's taking a millimetre and dividing it by 10 with 20 zeros after it, so that's very, very small.

That means that it exists only one trillionth of a millimetre from every point in our three-dimensional world.]

grav, how does this size compare to Planck size/length?
__________________________________________________ ______________I'm actually not sure what you were referring to in that post, but the Planck length is about 10^-35 m, or about a million million times smaller than that. And actually, string theory or some version of it would exist at Planck level. This is where it would start. Maybe even much larger for particles, and would probably incorporate quark theory as well. All three of these overlap quite a bit.

[RussT]

And actually, string theory or some version of it would exist at Planck level. This is where it would start.

I agree, so why did you say...
Originally Posted by grav
So we have GR at large scales, QM at and around Planck length, and string theory at sub-Planck levels.

Strings at "sub-Planck"???

[grav]

I agree, so why did you say...
Originally Posted by grav
So we have GR at large scales, QM at and around Planck length, and string theory at sub-Planck levels.

Strings at "sub-Planck"???I was thinking about the Planck sized particles composing the energy density. But now that I think about it, I probably should have said we have GR at a scale where the average effects of an extremely large number of particles acting together is distributed smoothly, QM at a scale closer to that of individual particles where the random fluctuations of their motions are observed, and string theory underlying the composition of the individual particles themselves.

[RussT]

I was thinking about the Planck sized particles composing the energy density. But now that I think about it, I probably should have said we have GR at a scale where the average effects of an extremely large number of particles acting together is distributed smoothly, QM at a scale closer to that of individual particles where the random fluctuations of their motions are observed, and string theory underlying the composition of the individual particles themselves.

Yes, it would certainly seem that this is the correct level structure from top to bottom.

QM is actually at both the particle and Planck level, and as I said somewhere above, the ultra-complexity is a result of the Non-unification of GR and QFT, just like on the macro level, it is just much harder to identify where the problems really are.


[If neutrinos have mass then they are indistinguishable from anti-neutrinos in other reference frames.]

trinitree88 said this in the primordial neutrino thread in Q&A, which would indicate, that if they do have Planck mass, and still 'go through baryonic matter', that they could be the bottom Planck level base element.


The neutrino is the only 'particle' that I know of that actually goes through baryonic matter (and therefore does not interact), and so it is the one most likely to be miscategorized.

It should be very interesting to see which camp, Higgs boson/field, graviton, iteron, LQG, or String/"M" Theory, just to name a few, comes out the winner.
I am almost certain it will be "M" Theory as GR is inherent in it.

[RussT]

The title of this thread is..."is gravity energy"? and we have been dancing all around this!

The answer is NO!

Everyone is trying to 'make' or explain gravity with energy.

There are 3 forces...EM, Strong nuclear, Weak nuclear (all baryonic matter related)...then there is Gravity, considered the 4th force. BUT, gravity is not a force, as Einstein shows, it is a space/time curvature.

[czeslaw]

The title of this thread is..."is gravity energy"? and we have been dancing all around this!

The answer is NO!

Everyone is trying to 'make' or explain gravity with energy.

There are 3 forces...EM, Strong nuclear, Weak nuclear (all baryonic matter related)...then there is Gravity, considered the 4th force. BUT, gravity is not a force, as Einstein shows, it is a space/time curvature.

What causes the space curvature if not an energy (matter) ?

[gzhpcu]

What causes the space curvature if not an energy (matter) ?
According to Einstein, the presence of matter in space causes a geometric distortion of space.

[czeslaw]

According to Einstein, the presence of matter in space causes a geometric distortion of space.

How the space knows that there is a matter presence ?

[RussT]

How the space knows that there is a matter presence ?

Because it has MASS, which is the only thing that 'counts' for gravity.

[czeslaw]

Because it has MASS, which is the only thing that 'counts' for gravity.

Do you think, the space knows there is mass and it warps then ?

[RussT]

Quote:
Originally Posted by czeslaw
What causes the space curvature if not an energy (matter) ?

Quote:
Orihinally Posted by gzhpcu
According to Einstein, the presence of matter in space causes a geometric distortion of space.

czslaw quote;
[Do you think, the space knows there is mass and it warps then ?]


Yes, that is what gzhpcu just explained.

[czeslaw]

czslaw quote;
[Do you think, the space knows there is mass and it warps then ?]


Yes, that is what gzhpcu just explained.

An electron curves its orbit around a proton because there are particles mediating between electron and proton. Are there any particles mediating between mass particles (gravitons or something else) and warping the space ? How such a graviton causes a dragging frame ?
Does exists a space without an energy ?
Isn't there something like a Vacuum Energy ?
Does the energy oscillate according to its energy (mass) ?
Do you perceive a gravitational field ?

[RussT]

An electron curves its orbit around a proton because there are particles mediating between electron and proton. Are there any particles mediating between mass particles (gravitons or something else) and warping the space ? How such a graviton causes a dragging frame ?
Does exists a space without an energy ?
Isn't there something like a Vacuum Energy ?
Does the energy oscillate according to its energy (mass) ?
Do you perceive a gravitational field ?

[An electron curves its orbit around a proton because there are particles mediating between electron and proton.]

This is NOT gravitational force. This is the Strong, Weak, EM.

[Are there any particles mediating between mass particles (gravitons or something else) and warping the space]

Not the way they are being thought of here.

[Do you perceive a gravitational field?]

Yes

[Does exists a space without an energy ?]

Definitely. All the DM, that does not interact with baryonic matter. That is Planck size/mass DM traveling at "C", has very tiny mass but no energy (the energy is 'locked in' and takes a TEV or very high GEV event to unlock it). So, there is gravity with no energy. All of that DM, makes up 'all' of space and doesn't interact with baryonic matter, so it is its own background gravity field, that warps in the presence of large bodies of baryonic matter.

[Isn't there something like a Vacuum Energy ?]

No. all the energy is EM in nature.

[czeslaw]

Definitely. All the DM, that does not interact with baryonic matter. That is Planck size/mass DM traveling at "C", has very tiny mass but no energy (the energy is 'locked in' and takes a TEV or very high GEV event to unlock it). So, there is gravity with no energy. All of that DM, makes up 'all' of space and doesn't interact with baryonic matter, so it is its own background gravity field, that warps in the presence of large bodies of baryonic matter.

[Isn't there something like a Vacuum Energy ?]

No. all the energy is EM in nature.

Neutrinos do not interact with baryons but they have their positive energy.
I did not hear about an idea that Dark Matter could be without an energy. In String Theory every particles (even hipothetic neutralino) have an energy - it could be other then Electromagnetic Energy of course.

We observe an energy transfer in binaries stars via the gravitational field.
The space may be dragged.
An object emits X-rays if it moves fast relatively to its space not relatively to us.
Gravity causes pressure and emision of the energy.

[Celestial Mechanic]

Neutrinos do not interact with baryons but they have their positive energy. [Snip!]
That's news to me. Ever hear of inverse beta decay?

Beta decay of neutron: n0 --> p+ + e- + nu-bar0

Inverse beta decay of neutron: n0 + nu0 --> p+ + e-

Looks like an interaction of a neutrino with a baryon to me.

[czeslaw]

That's news to me. Ever hear of inverse beta decay?

Beta decay of neutron: n0 --> p+ + e- + nu-bar0

Inverse beta decay of neutron: n0 + nu0 --> p+ + e-

Looks like an interaction of a neutrino with a baryon to me.
Your right about beta decay but it is so rare that relatively to EM interaction it does not interact with baryon matter. That way most ideas construct DM of neutrinos or neutralinos because they have some energy and mass but because rare interaction we can not detect them.
http://www.windows.ucar.edu/tour/link=/sun/Solar_interior/Nuclear_Reactions/Neutrinos/neutrinos.html

[grav]

The title of this thread is..."is gravity energy"? and we have been dancing all around this!

The answer is NO!

Everyone is trying to 'make' or explain gravity with energy.

There are 3 forces...EM, Strong nuclear, Weak nuclear (all baryonic matter related)...then there is Gravity, considered the 4th force. BUT, gravity is not a force, as Einstein shows, it is a space/time curvature.
In the model I propose, the "fabric" of space-time is the energy density. Mass absorbs this, and so a negative energy density is created locally in comparison to the overall background pressure (it is really still positive, but a miniscule portion has been absorbed, making it negative in relation to the average). This is how a mass "warps" space-time in the first place. By simply creating an energy density differential between the mass and that of free space. Another mass is affected by this difference in pressure, and will be pushed from the greater pressure from the direction of space to the lesser pressure in the vicinity of the mass.

[czeslaw]

In the model I propose, the "fabric" of space-time is the energy density. Mass absorbs this, and so a negative energy density is created locally in comparison to the overall background pressure (it is really still positiv