Where the extra energy comes from?

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Discussion Overview

The discussion revolves around a hypothetical scenario involving a balloon filled with a lighter-than-air gas, which is used to generate electricity as it descends in a vacuum tube. Participants explore the feasibility of this setup, particularly focusing on the mechanics of placing the balloon in a vacuum and the implications for energy generation.

Discussion Character

  • Exploratory
  • Debate/contested

Main Points Raised

  • One participant proposes a scenario where a balloon descends in a vacuum tube to generate electricity, raising the question of where the energy comes from.
  • Several participants question the practicality of getting the balloon in and out of the vacuum without allowing air to enter the chamber.
  • There is a suggestion that two airtight compartments could be used to facilitate the balloon's entry into the vacuum, but this raises concerns about energy expenditure.
  • Another participant argues that displacing air to insert the balloon would require energy, potentially negating any energy gained from the balloon's descent.
  • A later reply emphasizes that even with an airtight seal, the need to displace air when extracting the balloon means that the energy gained would not be free, as it involves lifting the atmosphere.

Areas of Agreement / Disagreement

Participants generally express skepticism about the feasibility of the proposed energy generation method, with multiple competing views on the mechanics and energy implications involved. The discussion remains unresolved regarding the viability of the initial concept.

Contextual Notes

Limitations include assumptions about airtight seals, the mechanics of balloon insertion, and the energy costs associated with displacing air. The discussion does not resolve these complexities.

habiler
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Let's say you've created a very large balloon that doesn't explode in a vacuum and filled it with a gas lighter than air. Next, attach the balloon to a basic electric generator with a very light rope and place the balloon in a vacuum tube. Due to the balloon's weight, it will descend in the tube, generating some electricity. After that, remove the balloon from the tube and allow it to rise in the atmosphere to the upper end of the tube. Now, the balloon is back at the starting position with the same potential energy, and you have generated some electricity. Where does the electricity come from?
 
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:welcome:

How do you get the balloon in and out of the vacuum?
 
PeroK said:
:welcome:

How are you getting the balloon in and out of the vacuum?
I hadn't considered that part; perhaps there could be two airtight compartments at each end of the tube. Place the balloon in the tube and then seal it shut.
 
habiler said:
I hadn't considered that part; perhaps there could be two airtight compartments at each end of the tube. Place the balloon in the tube and then seal it shut.
Do you think that might take some energy?
 
PeroK said:
Do you think that might take some energy?
Why? If you make compartments just enough size to fit the balloon inside and tube will not get any air inside.
 
habiler said:
Why? If you make compartments just enough size to fit the balloon inside and tube will not get any air inside.
I don't see how you can get a balloon into a vacuum chamber without the air getting in. The balloon is, by your own design, lighter than air. I would say that the chamber would fill with air unless you forced the balloon in. I don't think you've thought this through!
 
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PeroK said:
I don't see how you can get a balloon into a vacuum chamber without the air getting in. The balloon is, by your own design, lighter than air. I would say that the chamber would fill with air unless you forced the balloon in. I don't think you've thought this through!
Makes sense. So you're saying there is no way to put the balloon inside without air getting in and created electricity comes from using force to put the balloon in vacuum.
 
habiler said:
Makes sense. So you're saying there is no way to put the balloon inside without air getting in and created electricity comes from using force to put the balloon in vacuum.
That's one problem. Attaching the balloon to an external generator is another.
 
PeroK said:
That's one problem. Attaching the balloon to an external generator is another.
Ok i got it thanks for the help.
 
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We don’t discuss perpetual motion machines here, so I have closed the thread.

habiler said:
So you're saying there is no way to put the balloon inside without air getting in
Even if you could form an airtight seal and never get any leaking, you still would not get free energy. To extract the balloon itself requires you to displace the air. Essentially you have to lift the atmosphere. This is more than the energy extracted on the way down. All buoyancy based perpetual motion machines that I have seen neglect that. They neglect the fact that at some point you have to lift or displace the external fluid.
 
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