h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Right. This is an old question, but it needs a new and proper answer. If, say, Rover built a car that could go by the speed of light (I know, it's a VERY theoretical question), would it be sensible, or useful even, to put lamps on it?

...and what happens if you're in the car travelling at the speed of light, and you downshift into first??

Doesn't it depend on whether your going to drive it at night?

If you are driving at the speed of light, is it light or always night? Would the light accompany you or are you just always ahead of it?

I don't think you need bother about headlights.

According to Einstein's theories, at the speed of light your car would have acquired an infinite mass and it must surely follow that you would therefore have an infinitely powerful gravitational pull on each and everything in the universe at the same time. Indeed, every single particle in the universe would be compelled to accelerate itself near to the speed of light and start heading directly for you.

So its not your headlamps that need worry you but your side impact bars amd airbags. And, as to whether or not it's day or night - the emd result is goodnight Vienna.

BTW all the above is off the top of my head, non researched amd probably best taken with small portion of NaCl

Whouldn't sodium clhoride (NaCl the stuff used in r/c car batteries) be harmful to your health. And if the car had infinate mass it would become a black hole and crush everthing to the smallest possible point (point refering to synthetic geometry stating that a point is an exact location) therefore you would be spegheitified (scientific term meaning when you get near a black hole all your atoms get streached acrosed millions of miles) and you would be dead before you know it. Also down shifting would be hard because the gear shift would also be streached acrosed millions of miles. ohh thats also without reasearch and I'm only 15 years old so hah

First would be what? The speed of sound?

If you're really interested, there are some good video clips of how things would look at relativistic speeds at the 'Backlight' site http://www.anu.edu.au/Physics/Searle/

Is it perhaps a little obvious to point out that it would fail Type Approval if it had no lights, because it failed to conform to the Vehicle Lighting Regulations?

I guess brakes would be superfluous as well, since if it is moving, and has infinite mass, then it also has infinite inertia and is unstoppable...?

Actually brakes would work as nothing can ever be described as infinite. Any friction would reduce the velocity no matter how infinite it's mass and inertia was but to get any sort of measurable reults they,d have to be bloody big. Anyone feel upto calculating the size of disks that would be needed to stop a one ton car from the speed of light???

If you downshifted to 1st...I'd be thinking about a service.

I'd do a bit more research in science class mate. sodium chloride is table salt...the stuff you throw on yer chips.

At the speed of light, downshifting to first would probably drop both you and the theoretical auto into the nearest black hole [which are no longer theoretical].

A slightly easier question for you all. Asuming that the laws of physicis have been thrown out of the window for the time being. How long would it take a car traveling at the speed of light to go from London to Grimsby, park in Tesco's, let the driver pick up a blottle of vintage vinegar and then back to London?

Asuming a sensible pair of trousers of course.

N.B. The driver can't move at light speed around Tescos as that would just be silly.

...to quote your earlier posting...

OK, there ARE differing degrees of infinity, in theory (Aleph null, Aleph one etc. - try a web search for "Cantor's Diagonal Slash"...), but the one thing they all have in common is... well... they are limitless. Einstein and his contemporaries showed that any mass increases as an object is accellerated, and as a result of this, if the object were ever to reach the speed of light, its mass would be infinite (Aleph null). Infinity isn't just "a very big number" - it's a specific mathematical concept, such that phrases like "...no matter how infinite ..." are meaningless.

How infinite... Heh heh... Isn't that a bit like asking "How pregnant are you?"

I apologise peet, maybe I should have paid more attention in class instead of drawing faces on the atoms...still, bit late for regrets now hahaha...I bow to your superior knowledge.

Sodium Chloride and batteries are illegal! (Salt and battery)
Another factor to consider in the matter of light speed, is that time slow's down the closer you get, in fact time stands still at the speed of light. so now not only have you gained infinate mass, but the universe is not getting any older, relative to you, (but you are relative to it)

If time stands still at the speed of light, how fast does light travel when time stands still... If it doesn't travel, is it always dark? (I think this was asked before, but I don't recall an answer. )