Can Relativity Help Create a Powerful Energy Generator?

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Discussion Overview

The discussion revolves around the feasibility of using principles of relativity to create a powerful energy generator, specifically through the concept of a rapidly rotating fan. Participants explore the implications of energy differences between the center and the ends of the fan blades as perceived in different frames of reference.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant proposes that a rapidly rotating fan could create energy differences between the center and the ends of the blades, suggesting that they could exchange energy due to relativistic effects.
  • Another participant challenges this idea, stating that the phrase "has less energy than it does" is nonsensical in the context of relativity and asserts that the center of the fan will always have less kinetic energy than the ends in all inertial frames.
  • A participant questions the validity of the claim that energy differences can be interpreted as "less energy" in different frames, seeking clarification on the concept.
  • It is noted that to collect energy from the fan, one would need to slow down the blades, as energy cannot be extracted without a corresponding decrease in their kinetic energy.

Areas of Agreement / Disagreement

Participants express disagreement regarding the interpretation of energy differences in relativistic terms. There is no consensus on the feasibility of the proposed energy generator concept, as some participants challenge the foundational assumptions made in the initial proposal.

Contextual Notes

Limitations include the unclear definitions of energy exchange in relativistic contexts and the assumptions made about the behavior of energy in rotating systems. The discussion does not resolve the mathematical implications of energy extraction from the proposed system.

TinManZin
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I'm thinking that if you had a fan, rotating really really fast, then according to relativity the ends of the fan blades would think that the center of the fan has less energy than they do, and the center would think that the ends have less energy than it does right? So if this fan was made of a conductive material, then both the center and the ends would try to send energy to the other right? And if the center and ends had significant mass you'd be dealing with a huge difference in energy right? So then you could put something between the center and the ends and collect all of the energy they're giving off? Trick matter into giving up it's ridiculously large amount of energy. Possible?
 
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The short answer is no. It's true that the energy of an object depends on the frame of reference you are in. But the statement "has less energy than it does" doesn't make any sense. Things start to go downhill from there.
 
If it's true that energy depends on the frame of reference, than why is it wrong to say "has less energy that it does"?
 
TinManZin said:
according to relativity the ends of the fan blades would think that the center of the fan has less energy than they do, and the center would think that the ends have less energy than it does right?
There is no inertial frame in which the second part (highlighted in bold) is correct according to relativity. In all inertial frames the center has less kinetic energy than the ends. Also, in order to collect that energy you must slow the blades down, they don't just "give off" the energy without a decrease in their energy.
 

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