Light speed and Astronomical Unit question.

[Theben]

Originally posted by SlowwHand

The beam of light emitting from your headlight structural.

He's saying that your headlight won't be very 'structured'.

[Ben Kenobi]

What about your headlights, if you're going at the speed of light?

A beam of light heading towards you will still be travelling at the speed of light. That's the cool part about it.

[Ben Kenobi]

And how can you even measure something going at that speed?

Good question. If you flash a beam of light from the spaceship, while it is travelling at that speed, it will be shifted in the spectrum, according to the speed relative to the speed of light. You can measure the shift in the spectra and use that to figure out the approximate speed that the object is travelling.

And yes, there are some objects that are travelling at significant enough percentages for this effect to occur.

You can do this with sound waves too, this is why the train has a high pitch as it approaches, and a lower pitch as it travels away from you, the wavelength of the sound is lengthened the faster the train is travelling.

The amount of the shift depends only the wavelength of the object in question, and the speed of the object, so once you know the wavelength, you can find the speed.

[TheStinger]

I know how to go faster than light.

If'm in Slow's car doing nearly the speed of light, I can slip stream behind another car and get a sling shot when I put my foot down.

Einstein never thought of that

[Dauphin]

In Einstein's day it was all about trains. Trying to use a train's slipstream to overtake it with another train is....fraught with dangers.

[TheStinger]

It's a credit to the man he was thinking about health and saftey even when overturning the established order