Can Energy Be Created from Compressing Air?

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Discussion Overview

The discussion revolves around the possibility of creating energy from compressing air, specifically using examples like a ziplock bag filled with air. Participants explore whether energy can be harnessed from this process and the efficiency of such a system, touching on concepts related to oscillating pressure and mechanical devices.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants wonder if energy can be created from compressing air and if it can be practically applied.
  • One participant suggests that you cannot extract more energy than what is invested in compressing the air, but mentions the potential of using a source of oscillating pressure to create an engine.
  • Another participant relates the concept to how an internal combustion engine operates.
  • Concerns are raised about the idea of creating a closed-system mechanical device that generates oscillating pressure, which leads to a discussion about "over-unity" machines and their classification as pseudoscience.
  • Participants clarify that "over-unity" refers to devices that supposedly output more energy than input, which is deemed impossible.
  • One participant questions if gravity could be used as a natural force to compress air, but another participant asserts that energy cannot be drawn from a static field like gravity.

Areas of Agreement / Disagreement

Participants express disagreement regarding the feasibility of creating energy from compressing air, particularly in the context of over-unity machines. While some acknowledge the potential of oscillating pressure, others firmly reject the idea of extracting energy from static forces like gravity. The discussion remains unresolved regarding the practical application of these concepts.

Contextual Notes

Limitations include the dependence on definitions of energy extraction and the assumptions about the nature of forces involved. The discussion also highlights the boundaries set by the forum regarding pseudoscience and perpetual motion machines.

thunderfan97
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Hey guys!

I was just wondering if it is possible to create energy from compressing air? For example, a ziplock bag filled with air. If you sit on the bag, the air tries to escape. Is there any way to harness this energy? If so, would it be an efficient enough to be a practically applied system?
 
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thunderfan97 said:
Hey guys!

I was just wondering if it is possible to create energy from compressing air? For example, a ziplock bag filled with air. If you sit on the bag, the air tries to escape. Is there any way to harness this energy? If so, would it be an efficient enough to be a practically applied system?

You don't get out any more energy than you invested in compressing the air. If you have a source of oscillating pressure, you can make an engine that cycles with the pressure. But you would need to find a source of oscillating air pressure someplace...
 
So say there was a source of oscillating pressure. Would it be possible then?
 
Yeah, sure. That's basically how an internal combustion engine (ICE) works.
 
Oh ok! thanks!
 
If you are thinking of a closed-system mechanical device that creates a system of oscillating pressure that you would then harness for energy, you are talking about over-unity machines and that's a no-no here, since this site is dedicated to science, not crackpottedness.

If you are simply curious, yes, there are ways of harnessing this type of power, look at IC engines and (in a similar sense) hydroelectric turbines.
 
Would you explain the "over-unity" machine? I'm not sure I know what that is.
 
thunderfan97 said:
Would you explain the "over-unity" machine? I'm not sure I know what that is.

It's the classic perpetual motion machine (PMM) that people try to dream up. To be able to create free energy from some gadget. Those are closed topics here at the PF. From the Rules link at the top of the page:

PF Forbidden Topics said:
Pseudoscience, such as (but not limited to):

Perpetual motion and "free energy" discussions
http://wiki.4hv.org/index.php/Free_Energy_Debunking
http://en.wikipedia.org/wiki/Perpetual_motion
http://www.skepdic.com/freeenergy.html
http://www.skepdic.com/perpetual.html

You can follow those links to learn more. But we don't discuss PMMs or over-uinty, free energy topics here. They are a waste of time.
 
Over unity is an expression used to describe mythical devices or processes that output more energy than you put in. It therefore refers to a mechanical effiiciency of greater than one or unity, since efficiency = output/input.
 
  • #10
Oh ok, I see where I went wrong. Instead of a source of oscilating pressure, could you use a natural force, such as gravity, to compress the air?
 
  • #11
thunderfan97 said:
Oh ok, I see where I went wrong. Instead of a source of oscilating pressure, could you use a natural force, such as gravity, to compress the air?

No. You are not going to be able to draw energy out of a static field like gravity.

Please read the links that I quoted above. This thread is closed.
 

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