According to Plancks quantum theory, light is explained by discrete energy packet that is quanta. Quanta is considered to show the nature that it has mass but originally didn’t belongs to any mass

You can't apply Newton's gravitational equation in the extreme case of a black whole. Also photons have other than zero energy regardless of their zero mass. Use Einstein's field equations instead.

Dear Sudipto,

The mass does not increase according to the speed, the relativistic mass is a way of relating the relativistic moment and the speed, but that, in my opinion, causes confusion, what increases with the speed is the relativistic moment.

Gravity does not attract masses (Newton was replaced by Einstein), gravity is the curvature of space-time that causes light and matter to follow geodesic routes.

The photon has no rest mass and it cannot be found resting.

But it has a mass according to h*ny=m*c² when moving!

And a black hole is not exactly an object with much gravity, it is a singularity, a division between 0, we can measure curvatures as long as we have a differentiable surface, discontinuities in space-time we can not measure them, it would be like a "hole" in space-time

Dear Sudipto,

Your question is a paradox. But it is so only in our head, but not in nature. Photons have mass. "Without mass" means "without energy", means "does not exist." You talk formally. But you have to look at the essence of the phenomena. And here it is better to talk about inertness. The longitudinal inertness of the photon is zero. But the transverse inertness is equal to the longitudinal inertness of the electron. Read more about the structure of the photon in the book "Electromagnetic Gravity. Part 1" in my profile.

Yours

Valeriy Pakulin

Thanks.

The photon has longitudinal inertia corresponding to mc2 when moving, but only transverse inertia mc2/2

Ref: https://doi.org/10.4172/2090-0902.1000153

According to Plancks quantum theory, light is explained by discrete energy packet that is quanta. Quanta is considered to show the nature that it has mass but originally didn’t belongs to any mass

Sudipto, the mass of any particle is related to its energy and momentum by:

E2 = m2 + |p|2

where E is the energy, m is the mass, p is the momentum vector and |p| indicates the norm of the vector. For a photon, E = |p| so m=0. That mass is independent of speed for all particles so is sometimes called "invariant mass", the comment by Sergio is correct.

1，Insert a basic physical problem

***

The system is isothermal and exchanges heat with a large heat source to keep the temperature constant. Only volume changes are discussed.

The problem here is that the actual system is balanced and the second law of thermodynamics judges it to be unbalanced.

Dear George,

If in E2 = m2 + |p|2 you set m to zero, then p also goes down to zero, because m is embedded in the definition of p (p=γmv). So this equation (E2 = m2 + |p|2) can in no way be applied to localized EM photons, contrary to the general incorrect assertion.

Best Regards,André

photon has no mass to make m0/sqrt(1-v²/c²) operation impossible... maybe

Photons have no mass, they must obey E = pc and therefore get all of their energy from their momentum. Now there is an interesting additional effect contained in the general equation. If a particle has no mass (m = 0) and is at rest (p = 0), then the total energy is zero.

Dear Paul,

The gamma factor (1sqrt(1-v²/c²)) cannot be involved in defining the mass component of localized moving photons because their velocity is invariant at c in vacuum.

Best regards, André

dear Andre, in my opinion speed of light is not constant

Dear Supito,

you wrote: " they must obey E = pc and therefore get all of their energy from their momentum."

They do not obey E=pc, but E=hν, and their momentum accounts for only half of their energy. The other half is provided by their transversely oscillating electromagnetic other half-quantum:

Ref: https://www.omicsonline.org/open-access/on-de-broglies-doubleparticle-photon-hypothesis-2090-0902-1000153.pdf

Best Regards, André

For some reason, this question gets asked all the time. Its answer can be found in all the textbooks on electromagnetism and general relativity.

Photons are massless due to the gauge invariance of electromagnetism.

They are affected by gravitational fields--that describe spacetime curvature--because the motion of any form of matter, in curved spacetime, is described by its energy-momentum tensor. The energy-momentum tensor of the electromagnetic field doesn't vanish identically in curved spacetime. Like all particles, photons follow geodesics in spacetime and the geodesics in curved spacetime aren't, globally, straight lines. That's what ``bending'' means. Once more, it's not useful to confuse space and spacetime.

Interesting: Two well documented mutually exclusive assertions that apparently can be found in all the textbooks on electromagnetism and general relativity:

If one is conform to physical reality, then the other is an illogical and axiomatic pronouncement disconnected from reality:

"Photons are massless " and "They are affected by gravitational fields"

Sudipto Datta

Following top relativists and physicists Kip Thorne and Wolfgang Rindler, light or electromagnetic radiation behaves like a wave and like a particle called photon, based on Einstein’s discovery of wave-particle duality of light.

As a particle, a photon has zero rest mass. On the other hand, a photon as a wave, according to Albert Einstein, has a mass which is equal to the photon’s energy, given by Einstein-Planck relation E = hv, divided by the square of the speed of light.

Much more details can enjoyably be read in Thorne’s extraordinary book “ Black Holes And Time Warps-Einstein’s Outrageous Legacy” and Rindler’s great book “Relativity: Special, General, and Cosmological”.

It is unquestionably experimentally confirmed that gravity as spacetime curvature affects light whose quanta are photons in such a way that light gets bent when it passes near heavy objects such as black holes as correctly described by Einstein’s general relativity.

I think photons exist only at emissions and absorptions. The energy of light can be seen as the mass part of gravitational field where it is bent. If light managed bent 360 degrees it would be considered as a unstable bounded state for some observers - if bent two times 360 degrees (720 degrees) it's quantum spin state and bent multiple times 720 degrees it is part of a stable particle structure...

Good

It's very important

As I understand it, light in empty space simply follows the curvature of space (a null geodesic), hence it's path appears to be distorted when the path is approached by a very massive object (as in Eddington's confirmation of General Relativity: https://www.wired.com/2009/05/dayintech-0529/ ). The photon's energy or momentum has no effect, whether it's a very long-wavelength photon or a highly energetic gamma ray. https://en.wikipedia.org/wiki/Geodesics_in_general_relativity

Incidentally, and in reply to Esa Säkkinen, I got somethng of a 'pasting' when I argued on Stack Exchange Physics for photons only existing at emission and absorption, a couple of years ago. Some upvoted, some downvoted, and last time I looked the balance was -1 for my contribution to that thread.

https://physics.stackexchange.com/questions/273032/what-exactly-is-a-photon/273538#273538