Is Electron Motion in Flat Spacetime Perpetual?

  • Context: Graduate 
  • Thread starter Thread starter Cluelessluke
  • Start date Start date
  • Tags Tags
    Motion
Click For Summary

Discussion Overview

The discussion revolves around the concept of electron motion in a hypothetical flat, static spacetime, particularly focusing on the idea of perpetual motion and its implications in physics. Participants explore the nature of motion, reference frames, and the philosophical aspects of observation and reality.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants question whether an electron in flat spacetime could exhibit perpetual motion, with one suggesting that inertial motion could be considered perpetual.
  • Others clarify that perpetual motion typically refers to a device that continues to operate indefinitely without energy input, while distinguishing this from the concept of inertial motion.
  • A participant notes that once in the rest frame of the electron, knowledge of its speed limits knowledge of its position, leading to increased entropy and a lack of perpetual motion in that sense.
  • There is a debate about whether inertial motion can exist without other bodies in the universe, with some arguing that it could be possible while others question how motion could be detected in such a scenario.
  • One participant suggests that the definition of reference frames may become problematic if only one body exists, implying that time might be a secondary phenomenon in such a context.
  • Another participant raises the question of whether the observer's presence complicates the scenario, suggesting that the existence of an observer introduces additional elements to the discussion.

Areas of Agreement / Disagreement

Participants express differing views on the nature of motion and the implications of a single body in the universe. There is no consensus on whether inertial motion can exist independently or how it relates to the concept of perpetual motion.

Contextual Notes

The discussion includes assumptions about the nature of spacetime, the role of observation, and the definitions of motion and reference frames, which remain unresolved and may affect the interpretations presented.

Cluelessluke
Messages
29
Reaction score
0
So I have a somewhat naive question.

Let's pretend that only an electron existed in a flat, static spacetime. That's all. We can boost to the rest frame of this electron to just say it's sitting there...doing nothing...in flat spacetime.

Is there something not perpetual about this?
 
Physics news on Phys.org
A perpetual motion DEVICE is a device, but there is also the concept of just perpetual motion (without a "device"). This is just motion going on indefinitely without the need to introduce new energy (you could also phrase it in the sense that entropy isn't increasing).

However after posting this I realized that the system I setup isn't physical. Once you boost to the rest frame of the electron you know exactly how fast it's going therefore you can't know anything about where it is. This will cause the wavefunction of the electron to spread increasing the entropy. So projected onto what I CAN know (ie the wavefunction) there is a definite passing of time through the increased entropy of my increasing lack of knowledge of where the electron is. Or at least that's my logic at the moment haha
 
There's nothing wrong with "perpetual" motion if what you mean by perpetual motion is "inertial" motion.

The problem is when someone claims to have a machine which continually extracts energy from a system without ever running out.
 
olivermsun said:
The problem is when someone claims to have a machine which continually extracts energy from a system without ever running out.
And the problem with this is that this violates of the law of conservation of energy.
 
olivermsun said:
There's nothing wrong with "perpetual" motion if what you mean by perpetual motion is "inertial" motion.

The problem is when someone claims to have a machine which continually extracts energy from a system without ever running out.


Is inertial motion possible without any other body in the universe?

Moreover, how can motion be detected if there is nothing else in the universe?
 
Why wouldn't it be possible?

If there's nothing else in the universe, then would it care either way?
 
enquirealways said:
Is inertial motion possible without any other body in the universe?

Moreover, how can motion be detected if there is nothing else in the universe?
Are you there to observe it? If so, you can simply define the reference frames.

This scenario is yours so the answer can be pretty much whatever you want -- but that may not be compatible with reality.
 
Cluelessluke said:
Is there something not perpetual about this?
It is perpetual, but it is also not prohibited by the laws of physics.
 
  • #10
russ_watters said:
Are you there to observe it? If so, you can simply define the reference frames.

This scenario is yours so the answer can be pretty much whatever you want -- but that may not be compatible with reality.

A thread of mine has been closed because i didnt respond to a wrong question. So, i am cautios this time.

But i cannot stop asking questions to what you have said.

1. If reference frames can be so simply defined, it means we think of points in space. Then space ceases to be a continuum. Reference frames seem sensible when there are two particles at least.

2. The scenario that u say is not compatible with reality hints that time itself may be a secondary phenomenon. We cannot even think of the passage of time if there is a single body in the universe. If you say that someone is there to observe it, it makes two things.
 
Last edited:
  • #11
what if the single body was you?
 
  • #12
pondzo said:
what if the single body was you?


When i say a single body, it is assumed that it is a body with no internal parts/mechanism.
 

Similar threads

High School Can we mimic a perpetual motion machien?
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad Perpetual motion machine - Intuitive meaning
  • · Replies 35 ·
2
Replies
35
Views
6K
Undergrad Gravitational Field Transformations Under Boosted Velocity
  • · Replies 14 ·
Replies
14
Views
3K
Graduate Feynman Lectures vol.1 Chapter 4 Topic 4-2GravitationalPotentialEnergy
  • · Replies 9 ·
Replies
9
Views
3K
Graduate Overall perturbation for two free-falling particles in flat spacetime
  • · Replies 9 ·
Replies
9
Views
2K
High School How does mechanical motion start at the deepest, smallest level?
  • · Replies 36 ·
2
Replies
36
Views
5K
Undergrad Check for geodesically-followed path in a coordinate-free way
  • · Replies 95 ·
4
Replies
95
Views
7K
Graduate Does the EP imply that a free-falling observer follows a geodesic?
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad How do non-diagonal indices of a metric allow for local flatness?
  • · Replies 22 ·
Replies
22
Views
3K
Undergrad What's the trick to this "perpetual" marble device?
  • · Replies 9 ·
Replies
9
Views
2K