# How well would a car work if the speed of light was 60 MPH?

I asked this in another thread about the hypothetical possibilities of a speed of light of 60 MPH, but nobody answered. How well would a car even function if the speed of light was reduced to that level? My guess is that it would ruin the electrical system(electricity travels at the speed of light!) and the car wouldn’t even start. Even if it did start, the timing of the spark plugs would be way off, causing all kinds of issues.

A change in the definition of a mile and/or of an hour would have no effect on the operation of a car.

Yes, I know that that’s not the question you thought you were asking. But it’s the question you actually were asking. It’s not actually meaningful to speak of c as changing.

Your highway mileage is gonna suck.

Probably wouldn’t work at all, at least internal combustion engines. The explosions that take place in the cylinder probably take place at much higher speeds than 60MPH, and one has to assume that the speed of light is still inviolable.

If you could get the car to move, driving at night would be an issue, as you’d outpace your headlights.

There’s be obviously weird physics effects. I imagine you’d get Doppler shifting at relatively low speeds, so an approaching car would probably fry you with ultraviolet or gamma ray headlights. It would take an infinite amount of energy to get to 60mph, so you’d probably see the effects of relativity much sooner. Driving while coping with the effects of time dilation would be interesting.

The fundamental constants of physics govern everything. If they were different, reality as we know it could not exist.

I think there are many ways to interpret the question.

1. Simplest interpretation: the universal speed limit isn’t changed, but light is a lot slower than that limit. In fact, it’s even slower than sound. This will cause some strange phenomena! Explore!

2. Next-simplest (?) interpretation: c is the speed limit, but it’s value is set to x instead of y. Nothing else changes. As all of the laws of the universe follow this change, nothing has really changed. From within, everything will be percieved exactly as before.

3. Complex interpretation: c changes, while some other constants remain… constant? Let’s say, while c=inv(sqrt(epsilon0*mu0)) still holds, the relative values of epsilon0 and mu0 changes… this will lead to …Maxwell, help me!

it would be such an upheaval from what we understand now I don’t know that any plausible answer could be determined, apart from “nothing would be the way it is.”

in fact, I could understand it if the answer turned out to be “Nothing would be.”