Slashdot Mirror
Manipulating Heat Like Light
An anonymous reader writes "A new technique allows allows 'thermocrystals' to be created that can manipulate heat (a vibration of the atomic lattice of a material). Predicted manipulations include the ability to selectively transmit, reflect or concentrate heat much like light waves can be manipulated by lenses and mirrors. 'Heat differs from sound, he explains, in the frequency of its vibrations: Sound waves consist of lower frequencies (up to the kilohertz range, or thousands of vibrations per second), while heat arises from higher frequencies (in the terahertz range, or trillions of vibrations per second).' Applications range from better thermoelectric devices to switchable heat insulating/transmitting materials (abstract). Perhaps this will result in better cooling/heating mechanisms or more efficient engines."
Maxwell's Demon?
http://science.slashdot.org/story/13/01/05/225256/what-negative-temperature-really-means
Yes
I wonder if you could use this to concentrate low levels of heat and generate electricity from it. Not only would you be able to get energy out of (almost) nothing, (albeit, probably not much), but you could cool an area without producing a lot of waste heat.
Uneducated as I must be, I at first assumed they were talking about infra-red radiation, and so I was duly enlightened.
systemd is Roko's Basilisk.
How did this one get missed? Fusion's biggest problem is heat management.
Thermal Diodes: Hook this to a solar collecting sterling engine for a considerable performance boost.
That sounds like passive Heating & Air conditioning. Maybe society will use technology to reduce its power consumption overall.
Science & open-source build trust from peer review. Learn systems you can trust.
So thinks he's a rocket scientist, explain how space with no atomic lattice can radiate heat at a temperature of 2.7K?
This is just EM radiation that at our temperature and materials just happens to turn into heat easily.
These crystals aren't heat sinks. The MIT lab is creating a "heat" that is actually just really fast sound. This can then be manipulated with their special thermocrystals. Now, if they can create a way to turn normal waste heat into this "fast sound" heat, we'll open up a wealth of practical applications.
Occasionally living proof of the Ballmer peak.
From TFA:
The crystals could also be used to create thermal diodes: materials in which heat can pass in one direction, but not in the reverse direction. Such a one-way heat flow could be useful in energy-efficient buildings in hot and cold climates.
Other variations of the material could be used to focus heat — much like focusing light with a lens — to concentrate it in a small area. Another intriguing possibility is thermal cloaking,
Some of the speculative uses seem pretty interesting. To date it is only 40% efficient at some of these tasks, but that's not bad for starters.
These things sound like beginnings of heat circuitry components. The method involves making alloys of silicon that incorporate nanoparticles of germanium in a particular size range, and layering these thin films. If they can find a dynamically controllable switch structure you could build most of the necessary components for simple circuits.
Then you run into this sentences from TFA:
Heat also spans a wide range of frequencies, he says, while sound spans a single frequency.
Wow. Journalism student I'm guessing?
Sig Battery depleted. Reverting to safe mode.
Sound is pressure waves. Heat, or more accurately, infrared, is electromagnetic radiation.
They are so vastly different, far beyond just frequency, that I'm not sure what the person who wrote the summary is smoking. :)
One of the major problems with creating extremely powerful fan-less processors for mobile devices is heat. Heat problems increase to a square of scale variations when miniaturizing circuitry. If control of heat can be directed to increase the flow of heat away from NEMS and microchips adequately, we could see mobile devices that could compete with the most powerful current desktop processor.
We should learn what we need to know about issues, before we decide what we need to feel about them.
Napolean already gave Fourier the patent on that.
But this version is transformative! And Faster!
I am wondering about this myself
On Slashdot!
Blackbody radiation isn't from exciting electrons and seeing them decay back to ground-state. That would make blackbody radiation far from smooth and continuous. Instead it is due to the acceleration of charged particles which causes them to emit electromagnetic radiation, which works even with plasma or a soup of pure electrons. It also allows blackbody radiation to go to energies much higher or much lower than what you can find atomic transitions for.
That said, IR can be a component of heat, as can any part of the spectrum depending on the temperatures dealing with, as heat is the energy transferred between bodies. In some cases that is done by irradiation, other times it is done by conduction which would be driven by vibration and motion of atoms. Internal energy of most thermal systems, on the other hand, is pretty much all vibration or motion though.
Parent is wrong.
It's only a "law" because we do not yet know how to break it.
I, for one, look forward to the day (year, century...) when we decide that it's an obsolete principle. Until we actually know all the rules of the game, all the interactions, all the api of the universe... we cannot know that anything is truly a "law of physics". We can speculate, postulate, investigate, narrow-in-on, or disprove, but never really affirm.
(Which is not to say that this specific mechanism shows any promise, just that some mechanism might exist in the future.)
I won't join Slashcott. OTOH, If Beta goes live, I just won't be back until it's fixed. Sorry Dice.
Face Palm!
Heat is vibrating atoms. (Or slightly more accurately, banging off each other randomly like billiard balls.) Some of that energy gets converted and emitted as radiation, and radiation can be absorbed and converted to heat, but that does NOT make them the same thing.
I won't join Slashcott. OTOH, If Beta goes live, I just won't be back until it's fixed. Sorry Dice.
That's what I read into the distinction as well. Of course, they could have just said "thermal phonons".
Someone had to do it.
...but is this a step towards a working Thermal Discouragement Beam?
"So after all this, you make my case for me. To end this stalemate, you must die..."
Technically, neither are phonons "heat". Heat is energy in transit, and semantically is not strictly equivalent to any of the mechanisms or consequences of that transfer. However outside of a scientific treatment, this stricture is dropped.
OP is of course incorrect in assume that IR is the only mechanism by which heat can occur.
Someone had to do it.
Usually the main problem with press release science is that it has nothing to do with the real science behind it. Probably, there's an MIT professor embarrassed to show up to colloquia right now.
This press release is talking about acoustic metamaterials. The scientific description in the press release is bad, very bad, but one thing they got dead wrong is that this is not new.
It is ambiguous, though I can't see why a process for controlling female animal breeding behaviour should be "news for nerds".
Very interesting. Dont you think It always sounded weird when you were in class and the teacher claimed Energy is partially converted partially lost as heat. Certanly these thermocrystals should be kept an eye on. For funding, research and peer finding please refer to the non-profit Aging Portfolio.