Comments on: Controlling heat like light

By: asiwel

asiwel — Sun, 20 Jan 2013 09:36:20 +0000

Yes, this summary is also a good one .. reading the actual PRL paper is even more interesting. This is really good research work, very liable to have all kinds of practical payoffs as well, I’d think .. just the sort of thing MIT is very good at doing.

By: asiwel

asiwel — Sat, 19 Jan 2013 07:26:02 +0000

Sorry, this was a response to @eugene below

By: asiwel

asiwel — Sat, 19 Jan 2013 07:24:59 +0000

Hi, @eugene. Sorry but I seem to have put my reply/response in the wrong place above under @vin.

By: asiwel

asiwel — Sat, 19 Jan 2013 07:22:51 +0000

Look up in the article summary. It says “Heat also spans a wide range of frequencies” .. so, yes, incoherent noise. But then they are “…Reducing the range of frequencies … This ends up concentrating most of the heat phonons within a relatively narrow “window” of frequencies” .. so now we have less incoherence … more of the heat energy concentrated into relatively few vibrational modes .. a heat “chord” if you will. But still another way of thinking about a “coherent heat beam” (without any matter around) is simply an infrared laser.

By: Bob Blackledge

Bob Blackledge — Fri, 18 Jan 2013 21:53:13 +0000

eugene (& others) should read the brief summary of the published article at:
http://www.materials360online.com/newsDetails/33860

By: eugene

eugene — Thu, 17 Jan 2013 11:57:00 +0000

“Coherent heat”? Heat is incoherent intrinsically. Indeed each vibration mode is coherent motion of atoms. Vibration modes may be complex but all different modes are independent/incoherent. If you start to think you can break the second law of thermodynamics by some strange material structure you are on the wrong way.

By: AZryan

AZryan — Wed, 16 Jan 2013 20:26:06 +0000

waste, not waist.

By: Vin

Vin — Wed, 16 Jan 2013 20:03:48 +0000

Good question. Answer is at wikipedia, Heat pump and refrigeration cycle.

By: asiwel

asiwel — Wed, 16 Jan 2013 19:36:48 +0000

Off-hand, I would doubt any conflict with the 2nd law of thermodynamics. After all, air conditioners “move” heat from cold areas to warmer areas … but they do “work” in the process, using at least as much energy (if 100% efficient) from outside the system as represented by the amount of heat “moved”. Here, it probably requires energy to create the meta material in the first place. Then, if some spots in it have, say, higher heat affinity than others, then that is where heat will accumulate. If too much accumulates, then the whole thing would melt. But, yes, on the other hand, there seems no reason with advances in this sort of technology that you could not build a computer or other types of devices such as “coherent heat beams” that work entirely on the basis of thermodynamics rather than electromagnetics. If fact, the mathematics modelling these sorts of systems is amazingly similar if not identical. After all, this article is about similarities between “sound” and “heat” and various kind of “phonons” of all sorts of sizes and wavelengths … duality metaphors pretty familiar these days.

By: Mr. Kirk

Mr. Kirk — Wed, 16 Jan 2013 02:43:04 +0000

When looking for Type II or Type III civilizations (see Kardeshev), we look for an abundance of heat. I’ve always thought an advanced civilization wouldn’t produce the waist heat we expect. Perhaps ultra efficiency means not waisting any energy, heat or otherwise. This is a prime example of such technologies in their infancy.

By: the_system

the_system — Wed, 16 Jan 2013 01:13:09 +0000

I see a contradiction to the 2nd law of thermodynamics, or am I wrong? If you can construct something like a heat lens or beam to focus heat you can create a hotspot of heat out of a material that has had a homogeneous heat distribution before, you make the heat to float from a could spot to a hot spot what contradicts the 2nd LoT. Especially when it is possible to make something like a heat diode! Couldn’t you make a computer that works with heat out of this? This would revolutionize our whole energy problems. So where is my thought fault?

By: donklemencic

donklemencic — Tue, 15 Jan 2013 21:16:50 +0000

The image that comes to mind is of layers of thermocrystals sandwiched between layers of dense heat-generating circuitry, rapidly removing the unwanted heat. Would that be a feasible use?

By: asiwel

asiwel — Tue, 15 Jan 2013 20:10:31 +0000

These were essentially my thoughts too. I tend to think of heat as energy or as thermal vibrational noise. This article about “reorganizing” heat, controlling its vibrational frequency – sort of a “taser” or teraser, rather than a maser or laser, or putting all of the energy in these spots and not in other spots, etc., seems to focus more on the mechanical or displacement aspects rather than the energetic aspects (i.e., treating heat as a wave rather than a phonon.) So, if you put a lot of heat in one spot, doesn’t that spot get awfully hot? If you have coherent heat (which, of course, is no longer “noise”), don’t you have a heat beam? Interesting, what you can do with meta-materials.

By: Chrispium

Chrispium — Tue, 15 Jan 2013 18:35:38 +0000

Insulators for housing and clothing for arctic environments is an option too.

By: Bri

Bri — Tue, 15 Jan 2013 15:56:42 +0000

It’s surprisingly simlar to the coherence of lasers. Heat ray gun anyone? If they can accomplish the same conversion with a less expensive material than germanium, it could be applied to a tremendous number of activities and processes. Just taking the heat loss from server farms and turning it into electricity would represent huge savings in energy.