A light question.

[psynapse]

I am sorry if this seems obvious because it just came to mind.

AFAIK an object that reverses direction has to stop momentarilly. Eg. a pendulum. How does a photon maintain a constant velocity when reflecting off a surface, lets say perfectly bouncing back along the same path it traveled towards the mirror? Does it stop and then speed up again? This sounds ridiculous, I know.

[Klaynos]

It's a different photon. The first one gets absorbed and then another one identical but traveling in the opposite direction of emmited.

[psynapse]

Thanks for the well explained reply. I was thinking along the lines of wave sounds, and the transfer of energy.

What do you think of the idea that light is an energy vibrating in the fifth dimension?

[Edtharan]

Well .light is just an electromagnetic wave. It is an electric and magnetic field oscillating back and forth perpendicular to each other and to the direction of travel. there does not need to be any other dimension other then the normal 3 involved.

[Klaynos]

Well .light is just an electromagnetic wave. It is an electric and magnetic field oscillating back and forth perpendicular to each other and to the direction of travel. there does not need to be any other dimension other then the normal 3 involved.

 

4, don't forget time...

[Ragib]

well in elementary physics, 4 is fine, but in relativity advanced theories, new diemensions are introduced in the desire to explain all things as distortions of spacetime.

[Klaynos]

well in elementary physics, 4 is fine, but in relativity advanced theories, new diemensions are introduced in the desire to explain all things as distortions of spacetime.

 

But the number is theory specific, and there is currently little to no experimental evidence, so, let's stick with 4 shall we.

[psynapse]

How do the electromagnetic waves travel? Doesn't a wave need a medium, if not then it isn't a wave then, or is it?

[Klaynos]

How do the electromagnetic waves travel? Doesn't a wave need a medium, if not then it isn't a wave then, or is it?

 

EM waves are indeed waves, and they do not need a medium. They are bootstraping (self propergating) waves in the electric and magnetic fields.

[psynapse]

Can you elaborate on that answer? How does a wave "self propagate"?

[swansont]

Can you elaborate on that answer? How does a wave "self propagate"?

 

A changing magnetic field induces an electric field. A changing electric field induces a magnetic field. Do it properly and they keep oscillating.

[Ragib]

You could choose to think of as a particle and a wave. Physicists will tell you that they are only one at a time, choosing on how we observe it, but i find a good analogy is that it is both at the same time. A photon isa particle attracted by both a magnetic and electric field, just an analogy. Now, an electric field is created, athe photon goes there, the magnetic field is now induced, and the photon goes there, and keeps going so the photon, the light, has travelled 'through' a medium it has created.

[Sequence]

That's an excellent explantion. I've been trying to learn more about physics latly but my brain is so geared toward thinking like the observed world that it's hard. I should just stick with biology.........