theory of everything

@wolfgang59 said
You wrote
... The photon already knows the future ....

You call that an explanation?

Yes, I do.

https://www.universetoday.com/111603/does-light-experience-time/

@sonhouse said
Hard to understand how you would say it has infinite mass, relativistic or otherwise. Photons impart momentum to mass it hits and that is the only relevance to mass, which is the ability to impart momentum when hitting something of mass.

https://www.forbes.com/sites/startswithabang/2016/09/30/how-do-photons-experience-time/#10f69f7c278d

@metal-brain said
Yes, I do.

https://www.universetoday.com/111603/does-light-experience-time/

I would differ with that assessment. For instance, there is well known the ability of photons to turn into mass when they collide at sufficient energy. That would mean they would HAVE to experience time because there would be a time slot for the conversion where in a few attoseconds or whatever, the process is underway for the photon to convert to an actual particle.
They also undergo a change in frequency when two photons mix properly, one taking energy from the other ending up with a shorter wavelength and that process involves time. It does not happen in zero time because the photon is a wave which means fundamentally it propagates which also involves time.

@sonhouse said
I would differ with that assessment. For instance, there is well known the ability of photons to turn into mass when they collide at sufficient energy. That would mean they would HAVE to experience time because there would be a time slot for the conversion where in a few attoseconds or whatever, the process is underway for the photon to convert to an actual particle.
They ...[text shortened]... time because the photon is a wave which means fundamentally it propagates which also involves time.

You're describing what an outside observer might see.

But if you were the photon (not an outside observer, but an actual photon) you would not experience any passage of time. You couldn't, because at light speed the passage of time is zero.
Distances would also effectively be zero, because any distance traveled (from the photon's POV) is experienced in zero time.

@ogb said
The correct theory of everything must not include time. TIME is a human invention and not "real" in our universe.

The cosmic arrow does indeed exist, from the planck epoch ( <10−43s ) to the 1st picosecond (<10−12s). We just gave it a name, like any newborn, we had to call this dimension something. It shares it's name with the dimension we physically move through because they are intertwined. Einstein said 'spacetime' is actually one dimension. We cannot separate time from space anymore than Schrödinger can be separated from his cat.

@metal-brain said
Yes, I do.

https://www.universetoday.com/111603/does-light-experience-time/

That article does not support "a photon knowing the future".
In fact on the contrary - there is no elapsed time for a photon.
No past.
No future.

@wolfgang59 said
That article does not support "a photon knowing the future".
In fact on the contrary - there is no elapsed time for a photon.
No past.
No future.

You are taking my words too literally. A photon knows nothing. I was trying to explain a hypothetical point of view so you would understand. It went over your head.

From the link below:

"You absolutely cannot have a mass; if you did, you’d carry an infinite amount of energy at the speed of light. You must be massless.
You will not experience any of your travels through space. All the distances along your direction of motion will be contracted down to a single point.
And you will not experience the passage of time; you entire journey will appear to you to be instantaneous."


https://www.forbes.com/sites/startswithabang/2016/09/30/how-do-photons-experience-time/#7e18888b278d

"All the distances along your direction of motion will be contracted down to a single point."

@metal-brain said
You are taking my words too literally.

So we both agree that what you wrote isn't true.

Glad we cleared that up.

@sonhouse said
I would differ with that assessment. For instance, there is well known the ability of photons to turn into mass when they collide at sufficient energy. That would mean they would HAVE to experience time because there would be a time slot for the conversion where in a few attoseconds or whatever, the process is underway for the photon to convert to an actual particle.
They ...[text shortened]... time because the photon is a wave which means fundamentally it propagates which also involves time.

I've got a few issues with this. The first is the notion that the photon "turns into" another particle as the result of a collision. The way this is described in quantum field theory involves creation and annihilation operators. Taking the description seriously the photon is destroyed (or absorbed) and a new particle is created (or emitted). What does happen is that in describing the physical photon propagator (Green's function for Maxwell's equations) in terms of the bare photon propagator one has to include terms where the photon splits into an electron and anti-electron which then mutually annihilate and emit a bare photon indistinguishable from the original one. However, this does not generate a mass term in the physical propagator, what is more the electron and anti-electron are off mass shell (are not required to obey the normal rule relating energy, momentum and mass) so I don't think there is any way of slowing a photon down so it "experiences" the passage of time.

The thing with photons is that there is no comoving frame of reference. Basically no observer exists (even an idealized one) which moves at the speed of light. So the photon is ruled out from being an observer. In any frame of reference, sure time passes, but that is irrelevant as far as the photon is concerned.

@metal-brain said
Relativistic mass.

I noticed that some physicists reject relativistic mass altogether though. Maybe I should create a thread about it.

It's not a useful quantity. The formula relating energy, momentum and mass is:

E^2 = p^2c^2 + m^2c^4.

Now, suppose we insist that there is a relativistic mass I'll call M, we then have:

E = M c^2

Let's use Planck units where the speed of light is set to 1. Then we can write:

E^2 = p^2 + m^2.

and

E = M

so all "relativistic" mass is is a synonym for energy. It doesn't really add anything other than confusion, so is a deprecated quantity.

@wolfgang59 said
So we both agree that what you wrote isn't true.

Glad we cleared that up.

You are being bull headed. Here is the title to an article I posted.

"How Do Photons Experience Time?"

We all know a photon cannot experience anything. It is just a thought experiment that is hypothetical. Reasonable people know not to take that title literally, but you have a grudge against me because I proved you wrong too many times on the debates thread. In other words, you are "pulling a humy".

You have failed.

@metal-brain said
You are being bull headed. Here is the title to an article I posted.

"How Do Photons Experience Time?"

We all know a photon cannot experience anything. It is just a thought experiment that is hypothetical. Reasonable people know not to take that title literally, but you have a grudge against me because I proved you wrong too many times on the debates thread. In other words, you are "pulling a humy".

You have failed.

YOUR OWN ARTICLE SAYS THAT THERE IS NO PASSAGE OF TIME FOR A PHOTON

NO PAST
NO FUTURE

@metal-brain said
but you have a grudge against me because I proved you wrong too many times on the debates thread. In other words, you are "pulling a humy".

You have failed.

A grudge? I can't even remember debating you.
I'm sure you can demonstrate an instance.

@wolfgang59 said
YOUR OWN ARTICLE SAYS THAT THERE IS NO PASSAGE OF TIME FOR A PHOTON

NO PAST
NO FUTURE

That is exactly my point.
Lemon lime understands. Why can't you see that you are only an observer? The thought experiment is intended to help the observer to think from the POV of the photon.

I thought about writing a story called "if a photon could talk", but you would just become captain obvious and point out a photon can't talk and even if it could it would take time to talk and photons do not experience time. You know, the obvious!

If you are dead set on sabotaging the thought experiment before you even consider it, all I can say is you are hopelessly biased against the entire idea of the thought experiment to begin with.

@wolfgang59 said
YOUR OWN ARTICLE SAYS THAT THERE IS NO PASSAGE OF TIME FOR A PHOTON

NO PAST
NO FUTURE

Think about it this way. The photon experiences the past and the future instantaneously.

Imagine a long florescent light that stretches 8 light years long. To the photon it lights up all at once. To you (the observer) it starts lighting up on one end and takes 8 years for it to reach the other end.
Saying there is no past and no future is like saying it didn't start on the far end at the left and it didn't arrive at the far end of the right. The photon is at both ends from it's POV.

Both past and future to the photon.