light speed...

[Gulielmus]

When having a conversation with my physics teacher we came on the topic of light speed, so cut it short; he said that if you were on a bus going the speed of light and you walked forward on the bus you would still be going the speed of light. To me this makes no sense, you should be going faster than light speed. Why is this so???

[Tormod]

Because - as is explained by Einstein's theory of special relativity - nothing can move faster than light.

[Aki]

Well there's a particle called tachyon, and it moves faster than the speed of light. However, tachyons are hypothetical.

[Kent]

The speed of light is more little the definition of limited in calculus. A limited that can never be reach for any object traval faster then, or slower then light to reach the speed of light. Life is a bitch

[maddog]

You see the Lorentz Transformation in SR has a singularity at C for a particle with mass.
Approaching from below diverges to infinity, from above to negative infinity. Particles
with mass do not pass continuously through the speed of light (C).

BTW, Einstein is often misquoted (intent) as to saying "nothing can move faster than light".
In fact a news reporter interviewed him saying this phrase as
"Mr Einstein, I hear as you say nothing can move faster than light. Is this true ?"
Einstein replied, "I can't imagine anything". Whereupon he got in a cab and left.

See the pun, to imagine it would require it's mass to be imaginary. Only a jokster
like Einstein would think this funny ? LOL!

Maddog

[Qfwfq]

Your teacher put the matter in rather loose terms, actually, leading to a contradiction. If you were on a bus going the speed of light you would not be able to walk forward on the bus. So long as the bus was going as fast as light and you with it, no time would be elapsing for you.

Neither could you be travelling any faster, but you could be travelling slightly less fast. The odd thing is that, to you, the same bus would be travelling as fast as light and no less. This is not easy to understand, but at least it doesn't lead to a contradiction. It can be worked out with the Lorentz coordinate transformations; space-time has this rather odd geometry. At low velocities the principle of relativity is almost exactly as Galileo had put it and had been used by Newton etc. Maxwell's equations and the Michelson-Morley results showed that it can't be right for velocities approaching that of electromagnetic wave propagation.