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[BeefontheBone]

First off, a car can't travel at lightspeed since it has mass, but a theoretical massless light source could. the answer is that the beam would travel at the speed of light relative to any observer in an inertial frame, but in the frame in which the source is moving at c the source will move forward as fast as the light it emits - if it were heading toward the observer it would arrive at the same time - he wouldn't "see it coming".

[Playbahnosh]

Just a simple question: WHAT?

[BeefontheBone]

Erm, they both travel at 300 km/s, so the light emitted by the headlights doesn't go in front of the car like normal.

[Playbahnosh]

Oh! Now I understand. So the first theory was right THANKS! k:
This seems unbleiavable to me, bu you know better

And I know a car cannot travel with lightspeed, that was just an example k:

[Indignus IV]

Forgive me if what I say is old news to you all, but here it is from a 14 year old:

Think of the universe and everything as a flat, flexable black cloth. All the planets and stellar bodies have different amounts of gravity, right?
So if the stellar bodies (sb's) all have gravity they make dents in the "fabric" of space time. The sun makes a big dent, and the Earth makes a much smaller dent, see? And a black hole is bottomless so it breaks through the fabric, but we'll talk about that later.
Now: if you throw a small planet like the earth into the "dent" of the sun (the gravity field), it will roll around the dent closer and closer in spirals until it hits the sun. This simulates the effect a big planet like the sun has on a smaller body.
In our solar system, the big sun dent is in the middle and the planets circle around.

Now: you all are familiar with Newton's theory of gravity? he says that gravity has infinite speed.

Einstein, however, with his theory of relativity, says that gravity can move no faster than the speed of light.

So Einstein and Newton are at odds, see?

What if the sun were to suddenly disappear?

According to Newton, at the exact second the sun disappears, the dent caused by the suns gravity would disappear and the planets would immediately begin to float away into the endlessness of space.....

Einstein says: the dent of the sun would spring up slowly and a "wave" of space time fabric would zoom at the speed of light towards the planets. The earth would continue on its elliptical orbit until the wave hits it, which would be about eight minutes.

Like I said, I only have an elemental grasp of the concept, but this "mental picture" is the cornerstone of the theory of relativity, but until Einstein came everybody believed Newton. But something didnt make sense, and Einstein fixed it. His theory is more widely believed because it is more realistic and explains other unexplainable factors like "tachyons" (infinite speed particles). His theory is more concrete. At least it was, until string theory came.....

There was this program on NOVA called "The Elegant Universe" a few years ago. It explains relativity, gravity and string theory so beautifully. You can buy it on the nova website if you want.....I highly recommend it.

[Evad]

sounds inforative at the least.

[Indignus IV]

Did you mean: sounds INFORMATIVE at the least? :blink:

Its been so long since I read about the TOR. I can't barely remember a thing about it.

Is E=MC^2 part of that theory? I have no idea. :blink: :blink: :blink:

[BeefontheBone]

Yup, the Special Relativity includes the equivalence of mass and energy, via the formula E=mc^2

[Indignus IV]

You know, when I was little I used to have so much fun calculating the amount of energy in say, a pencil and comparing that to the amount in an atomic bomb blast.
Good times, good times. :angel:

Edit: I wasn't sure cause I thought E=MC^2 was a different theory of einsteins, he has so many.....

[Quintopotere]

Originally posted by BeefontheBone@Jun 21 2005, 12:42 PM
Yup, the Special Relativity includes the equivalence of mass and energy, via the formula E=mc^2

Someone (and i'm one of them) use this formula to say that matter doesn't exist, cause it's all energy... and this should be clear...