Free Energy Thought Experiment Question

In summary, there is a thought experiment involving a grain of salt above a pool of water on a piece of flimsy material. Using Newton's 2nd law and assuming a force of 1*10^-4 Newtons is needed to break the material, it is calculated that an extra 3*10^-5 Newtons is needed to break the material. However, this does not take into account the elastic properties of the material. The question is raised whether in the real world, the material would break spontaneously due to the increase in entropy. It is determined that the entropy increase will not play a role in breaking the material, as it must break before the salt comes into contact with the water.
  • #1
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I have a thought experiment I don't understand.
Imagine there's a grain of salt that weighs 5 mg and it's 1mm above above a pool of water and it's on a very thing piece of flimsy material that takes about 1*10^-5 Newtons of force to break. Using Newton's 2nd law, I get the grain of salt is pushing downwards at a force of ~4*10^-5 Newtons. So it needs another 3*10^-5 Newtons to break the material. Since it is 1mm above the water, the work needed is 3*10^-8 Joules. ( Correct me if my math/formulas are wrong).
Using the ∆G= ∆H-T∆S. ∆H is 3*10^-8 let's say the temperature is 330 K. Assume that T∆S>3*10^-8. The entropy would be increased, I think, b/c the breaking of salt into Na and Cl- ions increases the possible microstates of the solution.

My question is, in the real world would the material break spontaneously? It seems counterintuitive. Thanks
 
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  • #2
Your numbers make no sense to me. 5 mg would be pushing down with 5*10^-5 N, which is already 5 times as big as the force you said was needed to break the flimsy material.
The number you give for work needed makes no sense at all. You would need the elastic properties of the object to compute the work needed to break it.

The problems is that the flimsy object must break before any of the salt comes into contact with the water, so the entropy increase will play no role in breaking the material.
 
  • #3
Ok Thanks. Yeah I meant 1*10^-4 for the force needed to break it. I don't know about elastic properties so I just invented a number.
But you answered my question. I guess events in the future can't affect the past.
 

What is free energy?

Free energy is a theoretical concept in physics that refers to the energy that can be extracted from a system without any input. It is often associated with perpetual motion and is not currently achievable with our current technological capabilities.

What is a thought experiment?

A thought experiment is a mental exercise or hypothetical scenario used by scientists to explore and test theories and concepts. It involves imagining a situation or experiment and using logical reasoning to draw conclusions.

How does the free energy thought experiment work?

The free energy thought experiment is a hypothetical scenario in which a system is able to produce more energy than it consumes without any external input. It is used to explore the potential implications and limitations of the concept of free energy.

What is the purpose of the free energy thought experiment?

The purpose of the free energy thought experiment is to challenge our understanding of energy and explore the potential implications of a system that can produce more energy than it consumes. It also helps scientists to identify any flaws or limitations in the concept of free energy.

Is free energy possible?

Currently, free energy is not possible. The laws of thermodynamics state that energy cannot be created or destroyed, only converted from one form to another. However, the free energy thought experiment allows scientists to explore and push the boundaries of our understanding and potentially discover new ways of harnessing energy in the future.

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