Recent content by kgreen

Could somebody please explain this excerpt to me from Feynman's Lectures on Physics on perpetual motion? I don't completely understand his definition of perpetual motion. Thanks! "We must be careful to define perpetual motion...If, when we have lifted and lowered a lot of weights and restored...

That's what I thought. Thank you.

Thanks!

I'm new to studying physics. Are the laws of nature and the laws of physics synonymous with each other? Thanks!

That does answer my question. Thank you! Could someone give me a simple example of how distance is relative when moving relative to one another?

In reference to a person who's stationary. I want to understand how distance is relative.

I'm currently reading Brian Greene's The Fabric of the Cosmos. I have a question about Special Relativity. I understand that time slows down when there's relative motion. I wanted to ask something about distance/space. When time slows down, does that mean that, e.g. the speed of a car, slows...