Perpetual Motion using Brownian Motion?

In summary, the conversation discusses the concept of perpetual motion and how it is impossible according to the laws of thermodynamics. The idea of harnessing Brownian motion as a source of perpetual energy is also brought up, and it is explained that this is not possible due to the law of conservation of energy and the concept of entropy. The conversation also mentions the role of textbooks in explaining these concepts.
  • #1
samsracecar
5
0
Let me start off by saying that I very well know that PM is impossible. Thermodynamics aren't just good ideas-they're the law. :)

I have heard that Brownian Motion will go on infinitely, but you can't harness it and it is useless perpetual motion. Is this true?
 
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  • #2
samsracecar said:
Let me start off by saying that I very well know that PM is impossible. Thermodynamics aren't just good ideas-they're the law. :)

I have heard that Brownian Motion will go on infinitely, but you can't harness it and it is useless perpetual motion. Is this true?

I'm not sure where you heard this, Brownian motion will slow down as the medium cools I believe.
 
  • #3
Ordinary Brownian motion will go on indefinitely as long as the medium is in equilibrium. There is no way to harness the energy, since that would be equivalent to cooling the medium.
 
  • #4
Well, to be fair, the motion of all atoms in the universe is perpetual by that logic, since temperature can never reach 0K.
 
  • #5
There is an objective measure of "useful" energy, which is entropy. Energy with high entropy can only be used if you have a sink for the excess entropy. For example, you can use thermal energy of a hot object, only if you have a colder object handy to be used as a sink.

Random movement of pollen particles observed by Brown is not a violation of thermodynamics, because a) total energy is conserved, and b) the motion of pollen has high entropy, same as motion of individual molecules in the medium that the pollen particles are floating in.

This isn't an issue of laws of physics being violated. But I agree, a lot of thermodynamics books do a poor job of explaining all this, so the point on examining textbooks is valid.
 
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Related to Perpetual Motion using Brownian Motion?

1. What is the concept of perpetual motion using Brownian motion?

The concept of perpetual motion using Brownian motion is based on the idea that the random movement of particles in a fluid can be harnessed to create a continuous source of energy. This is possible because Brownian motion, which is the random movement of particles due to collisions with other particles, is always present in any fluid and does not require any external energy input.

2. Is perpetual motion using Brownian motion possible?

Currently, perpetual motion using Brownian motion is not possible. This is because although Brownian motion is a continuous source of energy, it is also a random process and cannot be controlled or harnessed in a predictable manner. Therefore, it cannot be used to generate a continuous and sustainable source of energy.

3. What are the potential applications of perpetual motion using Brownian motion?

The potential applications of perpetual motion using Brownian motion are still being explored. Some scientists have suggested that it could be used to power small devices or sensors that require minimal energy. However, further research and development are needed before any practical applications can be realized.

4. What are the challenges in achieving perpetual motion using Brownian motion?

One of the main challenges in achieving perpetual motion using Brownian motion is the issue of efficiency. While Brownian motion is a continuous source of energy, the energy it produces is very small and difficult to harness. Additionally, the random nature of Brownian motion makes it difficult to control and utilize in a predictable manner.

5. Are there any current attempts to create perpetual motion using Brownian motion?

There have been several attempts to create perpetual motion using Brownian motion, but none have been successful so far. Many of these attempts have been theoretical or based on small-scale experiments, and have not been able to produce a sustainable source of energy. However, research in this area is ongoing and there may be future breakthroughs in harnessing Brownian motion for perpetual motion.

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