A what???

The speed of light is constant, but relative.

Consider a car travelling at the speed of light minus 1meter/second, and an observer standing at the side of the road. When the driver turns on his headlights, the observer sees the light come out of the front of the car at 1 metre/second faster than the car. The driver in the car however, sees the lights come on as normal, becasue the speed of light is constant, relative to your viewpoint.
Does that make sense? It is actually a very famous thought experiment that Einstein did.

bludvl_x19 said:

The driver in the car however, sees the lights come on as normal, becasue the speed of light is constant, relative to your viewpoint

Click to expand...

So some fella driving a car traveling at the speed of light minus 1 m/s turns on his lights and the beam of light zooms off into the distance at the speed of light. So the speed of the light beam is the speed of light plus the speed of the car, that equals 2 x the speed of light minus 1 m/s?

But the fella on the footpath watching the car drive by see's the beam of light from the head lights traveling at 1 x the speed of light.

How can the same beam of light be traveling at 2 different speeds? Surely the fella in the car would see the light beam crawl away from him at 1 m/s and not the speed of light because the speed of light is constant(in a vacuum), fixed at 299 792 458 m/s(700 million miles an hour).

Shadeyman is right, the driver of the car would see the lights come on in front of him at 1 m/s.

Russ126 said:

Even if the centres are jointly operated the operater should still know that Sheffield is in the South Riding of Yorkshire and Wakefield is in the West.. over 25miles apart.. (yes not that much...)

But both south and west have seperate call centres.. ironically based in Sheffield and Wakefield...

Click to expand...

Let's face it, there are just too many fields in Yorkshire, Wakefield, Huddersfield, Sheffield, Driffield, Dronfield. I can understand the confusion. It would be a lot easier just to call them, Wake, Hudders, Sheff, Driff and Dron.

johnw. I don't know how you do it. It's not what you know but the uncanny ability you have of popping up to answer queries almost out of the blue.

Anyone ever tried getting hold of BS bike lights? they are like rocking horse manure