Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thedoc on 06/08/2015 11:50:01

Title: What is perpetual motion and how does it work?
Post by: thedoc on 06/08/2015 11:50:01
Griffin asked the Naked Scientists:
   
What is perpetual motion and how does it work?
What do you think?
Title: Re: What is perpetual motion and how does it work?
Post by: chiralSPO on 06/08/2015 13:12:20
What is perpetual motion? Perpetual motion comes in two flavors: either it is a device that runs forever unless energy is removed from it, or it can still run indefinitely  as energy is removed from it.

How does it work? It doesn't. The two examples above are only thought experiments--both types are actually impossible.
Title: Re: What is perpetual motion and how does it work?
Post by: scotty stull on 06/08/2015 16:14:44
Perpetual motion is pure motion that is transferred from mass to mass, motion in it's self is perpetual! Motion must have mass to be able to travel.
Title: Re: What is perpetual motion and how does it work?
Post by: PmbPhy on 06/08/2015 21:24:33
Griffin asked the Naked Scientists:
   
What is perpetual motion and how does it work?
What do you think?
As chiralSPO said, there are two types of perpetual motion. I disagree with him regarding the definitions of the two though. chiralSPO was describing a perpetual motion machine, not perpetual motion itself. No worries ChiralSPO. People confuse the two all the time.

From Oxford Dictionariess; See:
http://www.oxforddictionaries.com/us/definition/american_english/perpetual-motion
Quote
1. A state in which movement or action is or appears to be continuous and unceasing.

2. The motion of a hypothetical machine that, once activated, would run forever unless subject to an external force or to wear.
Title: Re: What is perpetual motion and how does it work?
Post by: yamo on 07/08/2015 13:30:20
Inertia is perpetual motion unless acted upon by a force.
Title: Re: What is perpetual motion and how does it work?
Post by: Bill S on 07/08/2015 13:39:07
Quote from: Yamo
Inertia is perpetual motion unless acted upon by a force.

Does this mean that one could construct a perpetual motion machine that would work in space where there is no friction?  If so, I guess there would no work one could do with it.
Title: Re: What is perpetual motion and how does it work?
Post by: yamo on 07/08/2015 16:16:56
But gravity is everywhere.