Maxwell's Demon - Information is power...

[kandrathe]

For the scientific minded among us, who are also big Diablo fans.... An article in the Economist ("Applied Demonology"), that discusses some experiments showing that information can be converted into energy.

I've seen it done with different colored lasers shifting the orbitals of electrons in special crystal materials, but this is a different take. In that case, energy could be stored, creating information, and later destroyed releasing the information.

In Naturenews the article is "Demonic device converts information to energy".

The team's set-up was inspired by a nineteenth-century thought experiment proposed by Scottish physicist James Clerk Maxwell, which — controversially, at the time — suggested that information could be converted into energy. In the thought experiment, a demon guards a door between two rooms, each filled with gas molecules. The demon allows only fast-moving gas particles to pass out of the room on the left and into the room on the right, and only slow-moving particles to pass in the opposite direction.

...

Vlatko Vedral, a quantum physicist at the University of Oxford, UK, says that it will be interesting to see whether the technique can be used to drive nanomotors and artificial molecular machines. "I would also be excited to see whether something like this is already at work in nature," he says. "After all, you could say that all living systems are 'Maxwell's demons', trying to defy the tendency for order to turn back into randomness."

Coolest profession of the year 2020... Nanomechanical engineer.

[NuurAbSaal]

Coolest profession of the year 2020... Nanomechanical engineer.

Coolest profession of the year 2010... Demon!



take care
Tarabulus

P.S.: I'd contribute something meaningful if I understood anything of the subject matter

[ZatarRufus]

... thought experiment proposed by Scottish physicist James Clerk Maxwell ...

$#@&!

I'm not, no, I'm not taking the links. That could (enjoyably) distract me for way too long.

Based on what you posted here (and I as I recall), Maxwell's demon itself required no energy input and the thought experiment was clarifying an aspect of the behaviour of matter by illustrating the opposite of what would transpire if the demon where not directing traffic. With the demon, the collection of the high-energy molecules on the one side and the slow motion ones on the tother causes the temperature to rise in one chamber whilst it decreases in the other. Obviously this could be used to represent binary ones and zeroes.

I believe the point at the time was that the demon still could not violate the 2nd law because it would require some sort of radiation different than what is in the rest of the system in order to see the molecules and the energy level of whatever light source was used would exceed the entrophy lost by the sorting.

[eppie]

... thought experiment proposed by Scottish physicist James Clerk Maxwell ...

I believe the point at the time was that the demon still could not violate the 2nd law because it would require some sort of radiation different than what is in the rest of the system in order to see the molecules and the energy level of whatever light source was used would exceed the entrophy lost by the sorting.

Indeed it was.
@KAndrathe;
read the book 'decoding the universe from Charles Seife
(ISBN 978-0-14-303839-9)
It handles about this topic, of information/energy 'duality'.

[kandrathe]

Thanks eppie. I like Charles Seife's other works.

[--Pete]

Hi,

I believe the point at the time was that the demon still could not violate the 2nd law because it would require some sort of radiation different than what is in the rest of the system in order to see the molecules and the energy level of whatever light source was used would exceed the entrophy lost by the sorting.

Actually, Maxwell published his Demon in order to show what it would take to violate the second law of thermodynamics. The additional analysis that leads to the conclusion that the law is still not violated is a later work. Maxwell's Demon still works if one invokes a supernatural demon that 'just knows' when to open and close the door. Of course, such a hypothesis then says nothing about our natural universe.

--Pete

[ZatarRufus]

The additional analysis that leads to the conclusion that the law is still not violated is a later work.

Ah, well. Goes to show what I thought I knew but didn't.

@kandrathe, I had time today to read the articles and found them quite interesting. Thanks for posting the links.

[--Pete]

Hi,

The additional analysis that leads to the conclusion that the law is still not violated is a later work.

Ah, well. Goes to show what I thought I knew but didn't.

Actually, there are relatively few people who know of the latter work, so the fact that you did is impressive (unless, of course, you're a physicist -- then it's expected )

--Pete