Perpetual Motion - Is It Possible?

AI Thread Summary
Perpetual motion is considered impossible in our universe, particularly regarding machines that generate excess energy without fuel, as this violates the 2nd Law of Thermodynamics. While perfectly elastic collisions between gas particles are not classified as perpetual motion, they do illustrate continuous motion. Similar examples include planets in orbit and particles moving in space. The challenge lies in harnessing energy from these elastic collisions, which would necessitate inelastic processes. Overall, while perpetual motion in certain contexts exists, creating a self-sustaining machine remains unattainable.
Ryan H
Messages
15
Reaction score
0
Perpetual motion has been deemed "impossible", at least in the world we live in. Why aren't the perfectly elastic collisions between gas particles considered perpetual motion?
 
Physics news on Phys.org
There are several different characterizations of "perpetual motion" and the one you picked is physically real. There are plenty of similar examples, like a planet in orbit or a particle in motion in space.

What is impossible are perpetual motion machines - self-powering devices that never need fuel and give off excess energy.
 
Yes, you would violate the 2nd Law of Thermodynamics. Elastic collisions happen, but to control them for energy harnessing purposes...that would require inelastic processes, I suppose.
 

Thread 'Is calling fictitious forces "not real" just about terminology?'

Hi there, im studying nanoscience at the university in Basel. Today I looked at the topic of intertial and non-inertial reference frames and the existence of fictitious forces. I understand that you call forces real in physics if they appear in interplay. Meaning that a force is real when there is the "actio" partner to the "reactio" partner. If this condition is not satisfied the force is not real. I also understand that if you specifically look at non-inertial reference frames you can...
View full post »

Thread 'Derivation of Hamilton's Principle: Questions'

I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...
View full post »

Similar threads

Can we mimic a perpetual motion machien?
Replies
9
Views
2K
Is a Superfluid Perpetual Motion Machine Theoretically Possible?
Replies
1
Views
2K
What are the top toys that can run almost perpetually?
Replies
16
Views
2K
Perpetual Motion: Is it Possible?
Replies
2
Views
2K
When can we have perpetual motion?
Replies
5
Views
2K
B Extracting electrical energy from Orbital motion
Replies
10
Views
1K
Atoms and the law of perpetual motion
Replies
1
Views
2K
What's the trick to this "perpetual" marble device?
Replies
9
Views
1K
Perpetual Motion: Particle Spin & Earth's Role
Replies
4
Views
2K
Why Is Perpetual Motion Impossible?
Replies
42
Views
19K

Hot Threads

Recent Insights

Back
Top