Quantum Gravity Limit Observed?

Jorrie - I love it when you talk "forrin".

Does it mean that gravity itself may be propagated at C-x? (if confirmed)

Hi Hendrik.

You mean when I write 'Americanese' instead of Oxford (SA) English?

"Does it mean that gravity itself may be propagated at C-x?"

No, gravitational waves sport such a low energy per graviton that they are unlikely to be retarded (delayed) like is postulated for the super-energetic photons.

Jorrie

...other bleeding-edge theories...

What a wonderful typo!

Hi PW, "...other bleeding-edge theories..."? Not me, not me...

I copied and pasted that straight from the SCIAM article. AFAIK, it's the superlative degree of 'cutting-edge'

Jorrie

Is it possible that different light frequencies travel at slightly different velocities but it is so slight that the difference is only now measured for very high energy photons?

Hi halldavidl.

It has been well proven and tested that the speed of photons of all frequencies are the same in free space. I believe that the effect at work here is that when the energy of the photons are high and they are very concentrated (a lot of energy in a very small space, near the Planck scale), there is a quantum gravitational effect that might delay the most energetic photons.

It is similar in concept to the 'Shapiro time delay of light', which does not mean that the photons move slower through space, but they are nevertheless delayed when they pass a massive body.

Jorrie

Jorrie,

Thank you for that information and reference. However, what is the difference between an observed delay and moving slower? I thought that the observed (measured) velocity of light in a vacuum (free space) should always be the same?

David

Hi again halldavidl.

In free space, with no gravitational fields, the observed speed of light is always the same. In the presence of gravitating mass (curved spacetime) it depends on who measures it and how. A free falling observer near a black hole will always get c if measured over a very small region, where the curvature is negligible.

However, a distant observer that times the travel time of light passing the same black hole will get a different average speed for light, due to the curvature of spacetime near the black hole. I discuss this phenomenon more fully in a download from my web page on 'Tests of Relativity', more specifically the 'Shapiro time delay'.

In the case of free space, it is possible that quantum gravity effects caused by very energetic photons can have a similar delaying effect on the travel time. This is however not a proven fact.

Jorrie

Dear Jorrie

Interesting one.

So does the high energy gamma photon behave more like a larger particle with gravity than a universal photon of greater frequency and shorter wavelength packet?

Perhaps this may be a reason for pair production above 1.2MeV and that may be a critical point in photon energy for having this change of slope into new world of high energy photon characteristics. In vacuum this effect is difficult to sense, but in material it is easier to do so.

This is a very nice observation and perhaps may open more avenues in nuclear research. Good.

Hi Shyam, you asked:

"So does the high energy gamma photon behave more like a larger particle with gravity than a universal photon of greater frequency and shorter wavelength packet?"

No, I believe that the effect is on the quantum level, near the Planck limit for energy. If it is indeed a quantum gravity effect, then it apparently operates on light that travels vast distances, almost like the macroscopic Shapiro time delay of light, but in this case a zillion very tiny delays that add up.

Jorrie

Dear Jorrie

Capability of photon to have particle nature becomes significantly localized in particle form and changed spin state when photon converts into electron and positron. Even though this happens in the nuclear field, the property belongs to the photon itself to split and form particle or to show the effect of gravity. Hence, the quantization should be in multiples of that state unless we know more such states where photon converts into much lighter particles like neutrino, quarks etc. Gravity is prominent to conversion of momentum into rest mass or somewhat like a rest mass which takes away velocity from photon velocity into mass-velocity relationship.

Yes, there may be more gravitational quantized states of free space, more discrete than that of high gravity environment in the near by zone. I think the gravity will have limited scope in energy levels when lots of material is near by like in black hole and some what less dense stars. Perhaps infinite hundreds or even more levels in vacuum or near vacuum.