how fast does light think light travels?(physics question)

[hitech]

That is correct mosgood, because the term moving i.e. (speed) implies a distance over some time interval. We have not gone any distance and no time has elasped.
HiTech

[mosgood]

So why do I hear ppl say that the light you see from a star today, happened xmillion years ago?  Does it just take that long for the light particle to appear ??

[icemaw]

The speed of light is way over modeled. Its just another example of the total bias towards Einstien and all his uber theories.

[airguard]

Originally posted by AdmRose
Einstein is wrong - Time is something that is perceived, not something that can be measured with the exception of temporal distance (i.e. something happened two weeks ago - temporal distance). Time is universally constant regardless of the speed of the perceiver.
Let me put it this way, if time stopped at the speed of light, we'd never see sunlight, or starlight, or moonlight, or anything having anything to do with light, because it would never move. Remember, distance = rate X time. If time is 0, then rate is meaningless, and distance would equal 0 then as well.
Unfortunately, since humanity will never reach the speed of light in any significant sense, this will all just remain a theory.

Oboy you knoe something we dont, speed of light is still 300000/m pr sec.
That cannot be resolved any other way. you might be knowing somthing anyone else dont.
As you said time is meaningless if time did not existed but time do exist and there youre wrong.

[mietla]

Originally posted by mosgood
So does that mean you really aren't "moving" through space but just appearing at the destination?

It' relative and depends on a frame of reference.

Say you are on the ground and watch a two ship flight. They fly out, go through the waypoints and land somewhere else.

The leader of the flight obviously moved some distance, hasn't he? He was here, and now he is over there.

But, if you are his wingman, how far did he moved? Hasn't moved at all. You took off 5 meters apart and now you are still 5 meters apart.

Same with a photon. If you observe it, you yourself being stationary, it looks different than it would if you were a photon's wingman, (you moving with a speed of light).

In addittion, I said stationary in order to make it easier to notice a difference. I reality there is not stationary frame of reference, but it does not change the picture. The point is that different observers in  different frames of reference will see the same phenomenon differently.

Events that are simultaneous in one frame of reference, may not be in another.

[lasersailor184]

Remember, perception doesn't change reality.  



If you were to freeze time, you can analyze everything as being somewhere.  Including light.  Assuming that you'd be able to see it (and you yourself were not frozen in time) you could pin point the location of light.

Now jump ahead 1 second and freeze time again.  That same light beam will be 3x10^(6) m away in the direction it was pointing.  This is known as velocity.

Now, assume that you were the light beam.  You are moving at the same speed as other light beams.  Just because you aren't perceiving anything to change, doesn't alter the fact that after 1 second, you are 300k meters away in the direction you are pointed.

[Nash]

I think I understand now that light is made up of photons.

Does a photon exist forever? If not, what happens to it?

[lasersailor184]

Mass energy is conserved always.


Light has kinetic energy.  If it hits something of a dark color, some of the light reflects, but some of the light converts kinetic energy into Heat energy.

[Nash]

Thanks laser.

Unfortunately it raises yet another dumb question.

My kitchen is around the corner from where I sit. It's mostly white.

The walls of the rooms are all white.

If some of those photons reflect, why can't I at least partially see my kitchen from where I sit?

It's stupid, I know....

[Nash]

Cool...

So one photon that may contain information about a small part of the handle of my refridgerator door comes back to me, but it just looks like light in general since it was just a tiny peice of the puzzle.

Another photon with information about a portion of my stove has reflected off in a different direction and flew out my window.

Do I have it right?

[Holden McGroin]

A try at an answer...

Due to the phenomenon of time dilation, time slows as one approaches the speed of light.  As a photon is travelling the speed of light, time does not pass for a photon: everything happens simultaneously.

So from the reference of the photon, the photon would have to leave the surface of the sun bounce of the bikini babe and hit my retina simultaneously, as by definition time cannot pass in its frame of reference.

So the photon would percieve itself on the surface of the sun, on the babe and in my eye at the same time while I would realize about eight minutes to achieve the same journey.

As it is started and finished simultaneously, it would therefore not be travelling at any speed as it would already be finished with the trip.

I think this would be an explanation for the related light speed length dilation phenomenon as well.

[Nash]

Good example!

So all of these photons get reflected in all sorts of different directions that they become, like, ambient light.... diffused.

The only final thing I'm curious about is the reflected photons themselves. The photon that got bounced off my refridgerator handle, what eventually happens to it?

[MrCoffee]

Originally posted by NUTTZ
Then traveling at the speed of light with a flashlight in your hand would be a moot point. Could you shine it backwards to see where you been???? Or would that be some sort of Physic masturbation??


NUTTZ

If you were in a spaceship traveling near the speed of light and you flicked your flash light on. You would be able to see its light reflect upon some surface within your local space/time which would be everything within your spaceship that is traveling near the speed of light. This is because time slows down for the occupants of the vessel. An observer on earth would not somehow able to observe the spaceship at that perfect instant in absolute time because if he could that would be breaking the rules of time/covariance.

Heres an analogy. Its like standing in one room and looking into another room when the room has walls. In this case the walls represent time. Everytime you go into the other room time slows down in your room and speeds up in the original room so if you return to the original room, much more time has passed. The sum of all of the rooms is the perspective of all of the moments in time. Its just an analogy to my first paragraph, how I view it.

[Udie]

Originally posted by Nash
I think I understand now that light is made up of photons.

Does a photon exist forever? If not, what happens to it?

 They did some test (according to Hawking's book) and determined that a photon last for something like 10 trillion million million years or some nonsense.  And thank y'all for not getting in to the whole particle/wave thing.  That's where I lose it bigtime on this physics stuff.

 Now let's take this to a new level and get small. Quatum mechanics!!!!!   How do you see something that's smaller than a light wave?!?!?!   quarks! Blueons! Spin 1, Spin 2 and Spin 1/2 particles!!

[Udie]

Originally posted by Nash
Good example!

So all of these photons get reflected in all sorts of different directions that they become, like, ambient light.... diffused.

The only final thing I'm curious about is the reflected photons themselves. The photon that got bounced off my refridgerator handle, what eventually happens to it?

 I'd imagine it would keep on reflecting/refracting off of stuff until it hit something black and was absorbed and converted into heat energy.