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Entangled Particles Break Classical Law of Thermodynamics, Say Physicists
New submitter Zex_Suik writes "Japanese physicists have used one of Maxwell's thought experiments and the ability to turn information into energy to extract more energy from an entangled system than should be possible according to the laws of thermodynamics (abstract). From the article: 'Imagine two boxes of particles with trap door between them. You want to use the trap door to guide the faster particles into one box and the slower particles into the other. In a classical experiment you would have to measure the particles in both boxes to do this experiment. But things are different if the particles in one box are entangled with the particles in the other. In that case, measurements on the particles in one box give you info about both sets of particles. In essence, you're getting information for nothing. And since you can convert that information into energy, there is clear advantage when entanglement plays a role. That's hugely significant. It means that the laws of thermodynamics depend not only on classical phenomenon and information but on quantum effects too.'"
... beforehand to entangle particles? And then put one from each pair into separate boxes?
Something tells me that energy conservation still holds...
Paul B.
doesn't seem to match the rest of the article. TFA talks about how they can extract more usable energy from the system using entanglement, but it doesn't violate any physical laws. The only violation is in the title!
I'm sorry to be such a grammar freak but you misspelled billion in your comment.
a cat somewhere dies to compensate. It all adds up.
Table-ized A.I.
I can create something out of nothing ?
Well God did *that* some 6,000 years ago.
According to classical theology, which is totally unsubstantiated by biblical text. Just because it's been taught for more than a thousand years doesn't make it biblical.
I won't join Slashcott. OTOH, If Beta goes live, I just won't be back until it's fixed. Sorry Dice.
This isn't about antiparticles; it's about information being exchangeable for energy.
This is really fascinating in that they've actually implemented Maxwell's Demon. A bit of backstory: Maxwell's Demon is a thought experiment about there being two chambers with a tiny, atom-sized demon sitting guarding an atom-sized gate between them. If there's a high-energy particle coming, he open's the gate. If there's a low-energy particle, he lowers the gate. Hence, you end up doing work (pumping heat) without a relevant source of energy (since there's no realistic constraints on the mass of the demon or the gate, they can be discounted). Entropy is going in the wrong direction. The question is: would such a thing work, violating the laws of physics, and if not, why?
The solution was that to know when to open the gate, the demon would have to measure the incoming particles. And it turns out that the entropy change involved in the measurement is more than the gain from what the demon is doing. But then later a hole in this argument was pointed out: if you have information on quantum states stored in a "memory", the demon doesn't need to measure the particles. But since memory can't be infinite, at some point you must cause the entropy change that the information storage is hiding. Information is basically acting as a form of energy.
Here, from the sound of it, they've actually implemented that in the real world, which I find just fascinating.
The chloride owes the sodium money.
> monster.com
Job title: Maxwell's demon
Job description: evaluates energy of subluminal particles. Makes time-critical decisions and pass/fail determinations on them. Operates retractable gate assembly. Supervises particle passage through the gate. Maintains the integrity of the gate assembly through preventive maintenance.
Job requirements: Ph.D. in Physics with 15 years of experience specializing in quantum mechanics and entanglement. At least 10 years of industry experience with retractable gates. Minimum 12 years of experience required with FPGA controller development and .NET programming. Must be able to make quick decisions under pressure (23 kPa or higher) and possess excellent interpersonal communication skills. Must be able to repeatedly lift up to 34 ng.
Compensation: 42 kJ/hour
According to my understanding of the article (IANAP), this has nothing to do with memory, and use of memory would not impact the system in any significant way in any case (the initial energy required to take the measurements to store into memory would offset the reduction in entropy during the experiment).
The fundamental issue with the classical scenario of Maxwell's Demon is that in order to know if/when to open/close the gate you need to measure each particle in the system at least once. The number of measurements >= The number of particles. The basic implication is that you introduce entropy via taking measurements at least as much as you reduce it via segregating particles according to energy differential.
If you consider quantum entanglement, however, the rule that number of measurement >= the number of particles is no longer necessarily true. E.g., if each particle in the system is entangled with another particle in the system, the number of measurements could be as low as 1/2 the number of particles since one measurement gives you information about both of the paired particles. It is also possible for more than 2 particles to be entangled, so to generalize, you could have N-way entanglement between sets of particles in the system, and the minimum number of measurements becomes number of particles / N.
The fundamental question I have is if it's possible to determine entanglement relationships between particles in the system for less energy than independently measuring each particle. If not, then you offset the entropy reduction of only measuring one particle from each entangled set by the energy required to identify entanglement relationships.
Creates world 6000 years ago
Spreads lots of clues that something else happened instead (fossils, C14 dating, star light already travelling towards us, etcetera)
Reveals himself only to a dozen or so people
Sends you to hell if you don't believe in him
Troll level: God
My first program:
Hell Segmentation fault