Question about Galileo's principle of relativity

[vmtgomes]

Hello guys, this is my first post. I'm not sure if it is supposed to be in this section.

But, if Galileo's principle of relativity says we can't do any experiments which would tell whether we are moving or stationary, why can't we say, for example, that if a vehicle with constant velocity relative to Earth is in fact moving as we notice that there is no fuel available after some time?

 

[Janus]

Because you could equally argue that the car is stationary and the Earth was moving and that since friction between the Earth and car would tend to drag the car with the Earth, the car must use up fuel in order to overcome this friction and "stay in place".

All the car burning fuel tells us is that there is a velocity difference between car and Earth, it tells us nothing about the absolute velocity of either.

 

[vmtgomes]

Oh, I see!

Thank you.