Information - Energy equivalence

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SUMMARY

The discussion centers on the claim that information can be converted into energy, as presented in a Physics World article. The article describes an experiment where a molecule in an aqueous solution is manipulated by an electric field, allowing it to gain potential energy without direct energy input. Participants express skepticism about this claim, arguing that the energy gained by the molecule likely originates from interactions with the surrounding solution, thus questioning the validity of stating that information is converted to energy. The conversation also references Szilard's engine, illustrating the relationship between information and work in thermodynamic systems.

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  • Understanding of thermodynamics and entropy
  • Familiarity with Szilard's engine concept
  • Knowledge of molecular interactions in aqueous solutions
  • Basic principles of electric fields and their effects on particles
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  • Research the principles of thermodynamics related to Szilard's engine
  • Explore the relationship between information theory and entropy reduction
  • Study the effects of electric fields on molecular behavior in solutions
  • Investigate the concept of energy distribution in open systems
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Physicists, thermodynamics researchers, and anyone interested in the intersection of information theory and energy conversion will benefit from this discussion.

Routaran
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I was having a discussion with an individual who was claiming that information is a form of energy. I disagreed with that claim. Over the course of the conversation, he provided me with the following article

http://physicsworld.com/cws/article/news/2010/nov/19/information-converted-to-energy

The article says that the molecule was placed in an aqueous solution and then electric field was applied to the solution causing the molecule to spin in a given direction, causing it to fall down the potential energy staircase but every once in a while, buffered by the solution (I read buffered as colliding with the molecules in the solution) it rotated in the other direction causing it to go up the staircase. Then the article says that the researched reversed the phase of the field there by preventing it from falling down the potential energy staircase.

The article then says,
"In this way they could gradually raise the potential of the particle even though they had not imparted any energy to it directly."

That statement seems dubious to me. Energy may not have been added from the outside but what about the collisions that test molecule had with the solution it was sitting in? Couldn't it have simply gained that potential from the molecules in the solution? Is it more correct to say that after collisions with the molecules in the solution, the test molecule had more energy than it did before the collision while the molecules in the solution had less energy but the total energy is still the same, just distributed differently. Why say that information was converted to energy?

Then the article goes on to say,
"In recent years other groups have shown that collections of particles can be rearranged so as to reduce their entropy without providing them with energy directly."

That just sounded like bunk to me. Yes the test molecule gained potential but what about the solution it was sitting in? Why isn't that being discussed as part of the system?

Can someone please shed some light on this for me? The source seems reputable but I'm very skeptical about what they are saying.

Thanks.
 
Science news on Phys.org
The energy comes from the liquid, I agree. The interesting result of the experiment is the entropy reduction in the (not closed) system "fluid+particle"*. You could extract the energy stored in the particle, and perform work. This does not reduce the overall entropy, as image processing and the control of the electric field increases entropy more than it gets reduced by the rotation.

*this leads to the second quote in your post
 
I went back and looked at Szilard's engine, the article made a reference to that.
http://en.wikipedia.org/wiki/Entropy_in_thermodynamics_and_information_theory#Szilard.27s_engine

if I understand it correctly, his thought experiment was:
You have 1 atom of gas in a chamber. When that atom is in the bottom half, we put a shutter in and split the chamber in half. Then the piston can drop unopposed in the empty half. When the shutter is opened, work can be performed by the atom.

I may be way off in my thinking but here's what i got from it.
When the shutter was closed, the volume available to the atom decreased thus increasing the pressure. This pressure increase is what allows for work to be done.

What I don't understand is why it says that information was converted to energy.
 
If you know where the particle is, you can use this to operate the engine - you can use this knowledge to convert thermal energy to mechanical energy.
Information and high-entropy energy (heat) is converted to low-entropy energy.
 
I don't fully understand that article. Did they simply create a tiny heat engine? And what do they mean by "converting information to energy"? They can't mean they destroyed information in order to create energy out of nothing. That would violate two fundamental laws of physics. Maybe they mean they moved information from the particle into the surroundings and moved energy from the surroundings into the particle?
 

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