Time and the Speed of Light

[KUSA]

Does anyone actually know what a photon or time is? That may sound like a stupid question but I can't seem to get a satisfying answer looking it up.

[archangle]

traveling at the speed of light "time" slows down. I dont think It stops.
So if you fly away for 25 years at the speed of light and come back. you only age 25 years but the world aged 500.

The numbers are off, but itis something like that.

the photon, regular ones, are emitted when electrons jump down levels. I dont think the ending point is meaningful at this time. For now any, that seems to be the case.

[Anomalocaris]

traveling at the speed of light "time" slows down. I dont think It stops.
So if you fly away for 25 years at the speed of light and come back. you only age 25 years but the world aged 500.

The numbers are off, but itis something like that.

the photon, regular ones, are emitted when electrons jump down levels. I dont think the ending point is meaningful at this time. For now any, that seems to be the case.

Uh, no. If you travel closer to speed of light, time slows down. If you travel at speed of light, time stops. Speed of light is an asymtote that can't ever truely be reached by a classical object.

Also, it is perhaps more accurate to say when a electron field and photon field interacts in the right way, an electron appears to change energy state and a photon appears to be created and speeds away at speed of light.

[archangle]

Does anyone actually know what a photon or time is? That may sound like a stupid question but I can't seem to get a satisfying answer looking it up.

no body knows either really. Photon is described by properties, Not what it is really.

We call time by "ticks" between states. If something goes between states (starting -final) at a regular interval we can call the interval "a second" or something. But really it is just changing states at regular intervals.

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traveling at the speed of light "time" slows down. I dont think It stops.
So if you fly away for 25 years at the speed of light and come back. you only age 25 years but the world aged 500.

The numbers are off, but itis something like that.

the photon, regular ones, are emitted when electrons jump down levels. I dont think the ending point is meaningful at this time. For now any, that seems to be the case.

Uh, no. If you travel closer to speed of light, time slows down. If you travel at speed of light, time stops. Speed of light is an asymtote that can't ever truely be reached by a classical object.

Also, it is perhaps more accurate to say when a electron field and photon field interacts in the right way, an electron appears to change energy state and a photon appears to be created and speeds away at speed of light.

thanks for the clarification. on light

and yes, its more of fields. but I kept it simple.

[KUSA]

Time, gravity, photons, magnetism, dark matter, dark energy, ect. We haven't got a clue what they are only the effects they have on things.

Imagine what things will be like when someone figures this shit out.

[Mudhammam]

Can something independent of time experience changes? Doesn't a sequence of changes preclude cause and effect, which precludes time?

I think you are considering photon as a discrete object that travels through time and space, and so it must feel the effects of agents of change acting upon it as a sequential cause and effect. But photon is not like that, and thinking about it this way is bound to lead you to make unsupported conclusions about what is happening.

Think of a photon as a field that is mostly unobserved but spans the entire universe for all time. The interaction of between the field and local conditions give rise to the observed photon. The rule governing the behavior of the field is such that the observed photon appears to be localized and to move at the speed of light. But there are experiments that can tease out the simultaenous presence of the what is underpinning a photon at any location away from where you think the photon actually is at a specific time.

If you tack a clock to the location of the observed photon, that clock would move at the speed of light through space and would appear to stop to a person in a different frame.

But the photon "field" itself does not experience this motion, and is not subjected to this frame. This is no object that is actually following this frame.

Thanks for fleshing it out simply and concisely!

[MindForgedManacle]

Does anyone actually know what a photon or time is? That may sound like a stupid question but I can't seem to get a satisfying answer looking it up.

Hard to say. Ontology is, as ancient thinkers repeatedly discovered, utterly mysterious. Our fundamental concepts like time and space are notions which just break down at the level of language. It's sort of like a mathematician trying to explain more complex parts of number theory through natural language alone. At some point, we just conclude we need a better way of talking about certain things without the bother (at least in strictly science) of discerning what, if anything is "actually" the case, what things really are in themselves. In the case of mathematics and quantum mechanics, it's often good recourse to follow the advice of "Just do the math." Of course, trying to "really" understand things could have benefit, but it is by no means the sole (or most efficient) path.

...Now that I've likely bored you, a partial answer is that time can be conceptualized as really being the same as space, in that the universe tends to be thought of as an unbounded 4-dimensional "block" of spacetime. There is no "present" moment under this B-theory of time, events are simply earlier than or later than another.

Time, gravity, photons, magnetism, dark matter, dark energy, ect. We haven't got a clue what they are only the effects they have on things.

Imagine what things will be like when someone figures this shit out.

Well, saying we haven't got ANY clue about ANY of those things might be pushing it a little. Though, I'm not convinced that things will necessarily be radically different if we ever do "really" understand those things. We humans have a nasty habit of normalizing to our conditions and resurrecting (or worsening) problems we'd hope to have vanquished.

/occasional pessimist

[KUSA]

Well, saying we haven't got ANY clue about ANY of those things might be pushing it a little.

Not really. Explain what magnetism is. I'm not interested in the effects it has on things as I already know that. Tell me what it actually is. What actually is in that space in between one magnet and another that pulls them together?

[Anomalocaris]

I am not sure what you mean by understanding a thing without caring about how the thing interacts with other things.

At the fundamental level, interaction between a thing and it's surrounding is the only way we can ever access reality. Understanding is nothing more than an ability to predict these interactions.

[psychoslice]

Don't worry about it, nobody really knows.