General Relativity VS Quantum Theory

[pgrmdave]

If matter warps space, and matter is just concentrated energy, why doesn't energy warp space?

[infamous]

If matter warps space, and matter is just concentrated energy, why doesn't energy warp space?

I believe that energy does cause space to warp, consider the photon moving through space as a wave, this wave is basicly space warpage as the energy passes through it. When the photon interacts with matter here on earth it then represents itself as a particle. This is a short explaination of the wave particle duality of the photon.

[lindagarrette]

If matter warps space, and matter is just concentrated energy, why doesn't energy warp space?

I think we use the term "warp" to indicate the geogaphy of space is non-euclidean, not as a verb.

[pgrmdave]

I thought that the degree to which matter warped space determined it's gravitational force, in relativity at least. If warp is just to indicate that space-time is curved, what is gravity in relativity?

[lindagarrette]

I thought that the degree to which matter warped space determined it's gravitational force, in relativity at least. If warp is just to indicate that space-time is curved, what is gravity in relativity?

I agree with your first statement but as to what is gravity? So far, no one knows.

[paultrr]

A few corrections here:

 

1.) The speed of photons is C in a vacuum. They do slow down when they pass through other mediums and certain lab experiments with dispersion mediums from time to time yield slight speed ups. However, all of these cases involve states different from a vacuum itself. The original wording out of SR specifies the speed of light in a vacuum and a lot of people tend to forget that mediums such as air have a different velocity for light. The two values that determine the local velocity of light in a medium stem from the dielectric and dimagnetic properties of the medium in question. All mediums have certain values for this. The vacuum's combined value is 1. Air on the other hand as an example has a different value. Light is slowed down in transparent media such as air, water and glass. The ratio by which it is slowed is called the refractive index of the medium and is always greater than one.* This was discovered by Jean Foucault in 1850.

 

Strictly speaking, the refractive index is not always greater than one. Indeed, it is almost always less than one for X-rays. This is because the phase velocity of X-rays in a medium (i.e. the speed of their wave fronts) is faster than the phase velocity of visible light, and the refractive index is the ratio of phase velocities. The speed of photons is the "group velocity", which is always slower than c, except under certain dispersion medium cases and in a vacuum.(see http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/FTL.html#5 ) for information on the subject of phase velocity. The actual phase velocity can at times exceed C even in the vacuum case. In general, our velocity of light is based upon the group velocity and never the phase velocity.

 

All this might sound confusing. But it is all solid physics inspite of the fact that we always speak of C being constant even though the term constant depends upon a lot of factors. As an example, by theory, if anyone here has heard of Casimir effects, within such a region C should be higher than in a vacuum. This is because the vaccum state between those two plates has less energy density than a normal vacuum. If, and this is a big if, anyone ever proves that say dark energy regions have a different vacuum energy density those regions too ought to display higher values for C. None of this violates relativity which specifies certain values of the vacuum to begin with. What one must always bear in mind is that C is only constant in a certain specific medium. If one varies that medium C can and does vary.

 

 

2.) What photons do is they have a kenetic energy. Its true they have no rest mass(some argument exists on this), even though the term is odd given all photons are in motion at a certain velocity and thus, never are at rest.

 

3.) Energy does curve space-time as well as mass. But, under GR a given amount of energy/mass is required to produce a certain amount of curvature. Its more the volume over which energy is present than anything else that dictates the curvature.

 

4.) All particles have a dual nature, not just photons. It depends upon how one views them or tries to measure them which quality(particle or wave) one derives.

[lindagarrette]

A few corrections here:

 

3.) Energy does curve space-time as well as mass. But, under GR a given amount of energy/mass is required to produce a certain amount of curvature. Its more the volume over which energy is present than anything else that dictates the curvature.

 

 

I sort of get it, again! Now, how does mass take on volume? Anw what does mass look like, anyway? I presume from your last statement that mass doesn't have to be a thing, just a domain of accumulated energy. Right?

[maddog]

paultrr,

 

I found your post to be fascinating. I have found that website in my quest to learn about

Alternative Algebras. It turns out this Baez guy has a similar passion that I do.

 

I do see the arguement about the energy density of X-rays being massive enough to have

to use relativistic equations as reference by the website you cite.

 

I think I need to bone up my relativity. :)

 

Maddog

[paultrr]

Isaac Newton called mass the quantity of matter. Mass is related to an object's inertia but it also is related to how hard objects are attracted to the earth. In the metric system mass is measured in kilograms and grams. But, it all boils down back to energy being in the form of particle-waves from quantum mechanics.

 

Einstein made the formulation that mass is equivalent to energy in his theory of special relativity. What he really meant is that rest mass is equivalent to energy. There are two known energy concepts accepted before 1905. These are the kinetic and the potential. Kinetic energy is energy of motion. For it to exist, there must be motion. But one also encounters such things as potential energy stemming from quantum fields because they too display motion. Yet, in this case of the Zero Point field, the energy of motion takes the form of what we term virtual particles. These virtual particle-waves, mostly electron-positron pairs, have very short fleeting existance and simple yield a potential background energy to spacetime.

 

To boil it all down we really do not know yet why some energy became realized in the form of particle-waves and some energy in this universe becomes expressed simply as potential energy. We just know from theory, observation and experiment that it does. What we do know is how to measure such and to see the difference between the two.

[paultrr]

Relativity forms the backbone of almst everything we have in modern physics. Yet, if one looks across all the text out there that attempts to explain relativity its interesting to note how few of them actually bother to go back to the original explinations and thoughtlines that its creator, Einstein once used.

 

One reason I brought up the issue of the difference between wave front velocity and the wave packet velocity is a lot of people read articles out there that tend to confuse the two. I also brought up the issue because there is something known as a cutoff frequency for energy under relativity. Yet, from time to time observational evidence would suggest there are natural processess out there that yield particles with energy above this cutoff point. We base this cutoff on the limiting velocity of light. So almost everytime findings about particles with energy higher than the cutoff surface one also hears researchers calling into question that cutoff limit. But, what little of these researchers tend to consider is that perhaps these above cutoff signatures are stemming from events transpiring in regions where the vacuum conditions are altered. If that was the case then one would have no real violation of the principles of relativity at all. Yes, the energy level does signal higher velocities than our normal vacuum would support. But, given all the evidence from experiment that C remains rather constant in a certain type of vacuum those higher energies should be considered a signal that perhaps the vacuum is not all the same in every spot in this universe.

 

We can perform experiments on earth where we alter the vacuum like in the Casimir case. I suspect that nature is far more capable of displaying altered cases also. Throw into this mix the fact that we seem to have matter out there(dark Matter) which gives no photonic signature of its presence and energy that seems to work in reverse of gravity and the fact that the vacuum of spacetime must vary somewhat becomes rather acceptable. That begs then the question of just how constant is our constant. This is where all that modern debate on the subject of a possible variable C has arisen from.

 

No one of the many research articles out there from legit researchers who hold to this idea would actually suggest that Einstein was wrong(with one major exception). The modern media tends to suggest such when they cover such research. But, going back to the original meaning of Einstein's theory all they are suggesting is that perhaps the vacuum isn't always a constant state as we once assumed.

 

My own position on this issue is that lorentz invariance holds in all vacuum states. What may change, and here there is no problem with relativity, is the local velocity of light in one medium or another. Granted if one tried to compare states one would find what seems like a violation of lorentz invariance. But, if you actually compare each frame in its seperate right you find that for that frame C remains a constant irrespective of its actual velocity. The same could be said for say our earth's atmosphere even though C is slower there than in vacuum. No researcher has ever suggested that the speed difference between light in air and light in a vacuum offers proof that relativity is wrong. They always consider the medium itself as the reason for the difference. I suspect that those pesky high energy particle signatures themselves boil down to a vacuum state difference as does dark matter and dark energy.

 

To put this is short format, relativity properly understood supplies an answer from itself.

[lindagarrette]

Isaac Newton called mass the quantity of matter.

 

Einstein made the formulation that mass is equivalent to energy in his theory of special relativity. What he really meant is that rest mass is equivalent to energy.

 

To boil it all down we really do not know yet why some energy became realized in the form of particle-waves and some energy in this universe becomes expressed simply as potential energy.

 

Paultrr, Thanks so much for your posts. You are realy helpful! I still don't quite understand what is mass/matter, even though I do understand the particle-wave duality/distinction. It seems to me that potential energy diesn't really exist (goes without saying) but where does is potential energy from (reside) and does it or how does it get converted to kinetic energy?