If photons have no mass, how can they have energy?

Abandon all hope of using human experience and classical physics when trying to understand why photons have energy. E=mc2 is only for the static case. It’s how your microwave oven works. Photons have the famous quantum mechanics wave/particle duality and therefore have energy e=pc where p = relativistic momentum. Some describe photons as having as “relativistic mass”.

What’s really cool is some people are thinking about harvesting energy from  the unused waves that permeate our existence.

Photons are just electro-magnetic wave energy, no different from radio waves except in frequency. Unlike particles, waves pass through each other. Imagine what the universe would look like if photons were particles that could collide. Star clusters would look pretty blurry, moreso than from how their dust blurs them.

But waves can still interact with mass. As double-slit experiments show, photon waves even seem to pass through both slits at once, only converging into one defined location when they convert back into a particle. And they are curved by gravity without affecting the gravity mass; as they’re travelling without mass they aren’t tugging on other mass. The big conundrum here is regarding the non-locality of a photon, which becomes even more mysterious when two photons start out entangled with each other and seem to interact instantaneously (i.e. faster than light) over large distances. They act like they’re the same particle, only temporarily split.

tldr, mass and energy are different states of “wavicles“.

Not sure why you’d think energy has mass because sunlight can warm you. Simple analogy here is a microwave oven heating up your soup. The waves interact strongly with mass, making them move faster, so making them hotter. The big question, again, is how and when do waves and matter interact.

And we haven’t even touched on how waves and matter change state from and to each other.

• This reply was modified 7 years, 8 months ago by PopeBeanie.

Thanks for link to article Reg.

That is a cool attempt to explain it but lets say two photons are entangled from one light year away and they are communicating simultaneously is the information about position retrievable  because our understanding of time is incomplete?

Yeah, like love and marriage (space and time) ya can’t have one without the other.  Yes, the information is preserved.  Yes, expansion is or may be relevant to understanding entanglement.

But if we have allowed for or adjusted for time space so that the two photons are one light yr apart and yet they dance together how can we explain it?

Perhaps the implication is that everything that happened continues to happen and everything that will happen continues to happen all at once.  We are stuck in past present and future but maybe the monkey is fooling us?

About 15 years ago I installed a new fiber “backbone” to link 3 factory buildings in the same plant back to the data storage building. It greatly improved network speeds, especially from the furthest away plant (700m).

One of the managers, who was to pay me for the work, asked me if I could speed it up anymore, without replacing any more hardware. I replied that the “ping” rates were so fast that there was no need and explained that it was his old Windows 95 PC that was the bottleneck as the newer PCs were working as I predicted. “So you are telling me that you can’t make the transfer any faster then?” he replied in a condescending tone. This was a ploy to argue for a deduction to my bill. “Correct, I think you will find it difficult to get the fiber to transfer data faster than the speed of light. But feel free to get a second opinion”. I got paid in full 🙂

• This reply was modified 7 years, 8 months ago by PopeBeanie. Reason: condensing -> condescending. What, you can't spell this right?!