twice of the speed of light???

[Tim_Lou]

nothing can be faster than the speed of light as we know. photons are traveling at that speed.

when a person is driving a car, the person is moving at the view point of the earth.
but to the car, the person is actually staying.

if this is true, to a photon, we all are moving at the speed of light and that photon is not moving.

but to two photon moving at opposite direction, to one of the photon, the speed is twice of the speed of light??? but isnt it like nothing can go faster than light speed???

when we say a photon is moving at the speed of light, what are we talking about? to what???
movement is base on the view point of an object.

is this right? or???

[Tormod]

I think you need to read up on Einstein's theory of relativity.

According to him, the speed of light is finite. Thus, if two objects move away from each other at the speed of light, both will perceive the other object as moving away at the speed of light. From someone observing these objects from a distance, both are moving at the speed of light (which is correct).

It's like the question, "what happens if I drive at the speed of light and turn on the headlights of my car?". The light from the car will leave you at the speed of light. They will NOT leave at the speed of light plus the speed of light. this is rather counterintuitive, but that's what the theory says! But the entire question is meaningless, because objects such as cars cannot move at the speed of light.

Check out this page: http://www.weburbia.demon.co.uk/physics/headlights.html

Saying that the person inside the car is staying relative to the car is actually irrelevant. It does not matter whether an object is moving or the world around it - the speed of light is the same.

Now, an interesting phenomenon is entanglement. When two entangled photons move away from each other at the speed of light, they STILL react instantly to events affecting one of them. This seems to be communication at a faster-than-light speed, and has been at the heart of many raging debates in particle physics (and still is, I think).

Tormod

[lessthanadam]

http://science.howstuffworks.com/relativity.htm

Einstein's theory of Relativity^

[Tim_Lou]

i know what you are talking about. but there is one thing really confuse me.

when a person is driving a car and a photon comes opposite, he should oberser the photon traveling at the sped of light. but if car goes the same direction of the photon travels, would it still be the speed of light?? if so, would the speed be slower to the first moving car???

one car is chasing the photon and one car is going oppisite way to the photon. would they observe the photon traveling at the speed of light????maybe the difference is too little. how about both cars moving at 99% of the speed of light??

if the speed is the same. to the photons, both cars stop??? whats the speed of the car to the photons???

[Roberto]

It doesn´t matter the relative velocity of the two cars, both will see the photon with the same speed. What happens is that each car will perceive the space and time of the other distorted such that the light have always the same speed. This constancy of the speed of light is the origin of the time dilation and space contraction effects.

[Razorofoccam]

The photon has a velocity of 'C' [ 299,792,458 m/s (metres per second) ]

The CAR has an indeterminaye delta V

What WE 'see' is irrellevent. What IS... is what IS

The SOL and the car continue on there paths as does EVERYTHING.
FOR EVERYTHING..is in motion.
motion is time...

humans think that our descriptioms of observed reality..
define it.
rubbish.
WE interpret it. And NO more

What we experience of Einstienian theory[fact]
IS ALL that matters..

It says that humans [or any mass]who experience near SOL velocities will experience
motion at a different rate to those who do not.
WILL be subject to a different 'time' rate.

That is, when we stop moving at near the SOL.
the only resulting objective effect is that we have experienced LESS
time/motion than the rest of reality.

Observations while at near SOL velocity..interesting...
but temporary.

InUnity><
Occam

[special j]

i'm not at all a mathematical person. so excuse me if i've misunderstood.. but is that then to say that if traveling at the speed of light, time would essentially cease for that in travel?

[deamonstar]

precisely, special j.

[Roberto]

The only observation is that you cannot travel at the speed of light. Only massless particles can (and in fact, they always do).

[maddog]

In answer to everyone on this post, find a book on Einstein's Special Theory of Relativity and
read it !

Originally Posted by Tormod

Now, an interesting phenomenon is entanglement. When two entangled photons move away from each other at the speed of light, they STILL react instantly to events affecting one of them. This seems to be communication at a faster-than-light speed, and has been at the heart of many raging debates in particle physics (and still is, I think).
Tormod

Tormod: Yes. However, this means two photons had interacted at some point in their
communative past to become entangled. This is where things get really weird. Information
can now pass from one photon to the other instantaneously (no time). There have been a
few Scientific American articles describing the latest findings in this branch of Physics (say
last two years). Neat stuff!

Maddog