A question about light speed.

Quote:

---

Originally Posted by Hired_Goon

Irrelevant. It has taken longer to get there, therefore, it has been slowed.

It is of course slowed by something, but the definition of a detour is then up for debate.

A perfect pane of glass will slow light down in a direct line, Therefore not a detour. A detour would be through a series of prism's or mirrors.

It's the same as the term Vacuum loosely used in previous posts. A vacuum doesn't really exist in reality. The term vacuum is used to define a lower pressure area that is created by the higher pressure of matter outside it. The terms of definition can always be argued, as can the interpretation.

But in reality, your simple question of "Can light move slower than the speed of light?" is Yes. It can. But not by itself.

---

If Rota's right, it only really appears to still be travelling in a straight line; the changes in direction would all average out to that result; the changes would be tiny and many. And the fact of a "detour" is important. There's a big distinction between instantaneous speed and average velocity.

Has anyone considered the effects of 'Dark Matter' on light? Im an economics major but i took an astrophysics course last year for the fun of it, and i seem to recall the prof talking about a theroy stating that the mass of the 'dark matter' affects the wavelengths of light. This could be the friction that was mentioned earlier, and could also be responsible for bending light.

Quote:

---

Originally Posted by Bree Fletcher

If Rota's right, it only really appears to still be travelling in a straight line; the changes in direction would all average out to that result; the changes would be tiny and many. And the fact of a "detour" is important. There's a big distinction between instantaneous speed and average velocity.

---

If you drive directly through a pane of glass, you will lose velocity, therefore speed. You are not being detoured from your original direction.

All glass is doing to light is slowing down the velocity of it's travel.

Not detouring.

Quote:

---

Originally Posted by Lucas101

Has anyone considered the effects of 'Dark Matter' on light? Im an economics major but i took an astrophysics course last year for the fun of it, and i seem to recall the prof talking about a theroy stating that the mass of the 'dark matter' affects the wavelengths of light. This could be the friction that was mentioned earlier, and could also be responsible for bending light.

---

Anything with mass will create at least a minor gravitational field. That will bend light, even if it is very slight. Dark matter will bend light, as well as planets, and stars, and asteroids, and comets, and ANYTHING the light might pass by. :)

Quote:

---

Originally Posted by Hired_Goon

If you drive directly through a pane of glass, you will lose velocity, therefore speed. You are not being detoured from your original direction.

All glass is doing to light is slowing down the velocity of it's travel.

Not detouring.

---

That analogy... isn't really valid... for so many reasons...

Quote:

---

Originally Posted by Hired_Goon

If you drive directly through a pane of glass, you will lose velocity, therefore speed. You are not being detoured from your original direction.

All glass is doing to light is slowing down the velocity of it's travel.

Not detouring.

---

LOLWUT??

:duh:

Quote:

---

Originally Posted by Hired_Goon

Irrelevant. It has taken longer to get there, therefore, it has been slowed.

---

Incorrect. Speed = Distance/Time, what you are thinking of is velocity. The distance is how far the light travels, which counts all the little bumps/detours/refractions that the light goes through. Velocity is Displacement/Time, and displacement only counts the distance between the end and beginning points.

So basically, the speed never changes while velocity does.

k i haz 1..
youre in space (a vacuum) straight in front of you theres a mirror, you can see yourself.
then you both start accelerating (at the same rate) up to the speed of light.
what do you see in the mirror?

good luck sleepin tonight rota ;)

Quote:

---

Originally Posted by lkmus

k i haz 1..
youre in space (a vacuum) straight in front of you theres a mirror, you can see yourself.
then you both start accelerating (at the same rate) up to the speed of light.
what do you see in the mirror?

good luck sleepin tonight rota ;)

---

Actually, that one's pretty simple. First, you'd never get to the speed of light. Second, you'd always see yourself in the mirror, so long as you have a light source.

Quote:

---

Originally Posted by Bree Fletcher

That analogy... isn't really valid... for so many reasons...

---

A hell of a lot simpler than quoting passages from the 100 odd wikipedia passages the basicaly say the same thing.

Light is matter, matter can travel at a certain velocity, velocity can be slowed by passing through different matter.

Semantics can be argued to keep a point of debate going, but basically, the question has been answered:).