Photons, Phonons and Electrons

[Thales]

A recent article in new scienctist illuded to the fact that setting up irregular 'islands' of differing metallic materials was an efficient way of inhibiting the movement of phonons while not hindering the movement of electrons. Thus enabling a temperature gradient to be maintained in metals and produce substantial voltages from what was formerly labelled 'waste heat'.

 

This is a major advancement in physics as it means many reactions from photovoltic to chemical reactions and even convential means of electricity generation will be able to yield higher net power outputs as a result of harnessing this effect to create electricity via heat output.

 

Just thought I would share my excitement, as combining this technique with forms of fuel cells and decentralised power generation may indeed hold the key to solving the looming energy crises.

[ydoaPs]

what is a phonon?

[Thales]

Phonons are hypothetical particles used to aid the modelling of heat flow. They can be considered as particles for all intents and purposes because the vibrational modes of atoms in a solid absorb(and emit) specified discrete energy levels. These 'particles' also obey the Bose-Einstien statistical methods used in thermodynmic analysis.

 

Basically the thermodynamic equivilent of a photon.

[RICHARDBATTY]

Wow. Are there any estimates of out put per area/input. The applications could be endless. Can this material be moulded to any shape or am I getting giddy again.

[Thales]

The materials themselves are metallic alloys so the answer is yes, they can be molded into any shape. The current record for power output is still only around 18% however that is expected to improve substantially as the physical processes that dominate the generation of potential differences have only just been identified.

 

You are indeed right about the endless applications, almost any engineer/scientist is used to calculating heat loss as part of a systems efficiency equations. Utilising waste heat in every facet it occurs by the application of what is a relatively simple idea, will indeed lift the load, so to speak, on the inefficient processes that dominate today's world. Its taken nearly 200 years but finally we may be able to harness the power of heat.

[RICHARDBATTY]

Would this also cool the object as heat energy is transformed. How hard is the the material. I mean could it be incorperated into roads/buildings. What is the melting point of the alloy could it be used in fussion reactors what are the effects of radiation.

[Thales]

So many questions, but I like inquisitive minds.

 

Cooling an object-> Yes. Nasa has already exploited the effect to make miniture refrigorators.

Building materials-> Probably not the most economically viable implementation the effect. Particularly seeing the temperature gradient would not be as drastic and thus the power output would be minimal vs investment.

Fusion-> Unnessercary, such reactions need to retain all their heat in order to maintain the pressures/temperatures required to fuse nuclei together.

[[Tycho?]]

Do you have a link to that article?

[Thales]

Unfortunately the article does not appear to be on the new scienctist webiste. Its in their latest addition though (4th September, pg 34). Well worth a read.

[Sorcerer]

Its taken nearly 200 years but finally we may be able to harness the power of heat.

 

lol...... harness the power of heat, well apart from camp fires and steam engines and etc etc I guess so...... anyway enough sarcasm, I actually do have a question.

 

From the name "phonons" I am guessing they relate to sound, as does heat right?... it travels at the speed of sound in a material because it is vibrational energy. However heat travels across a vaccuum as photons right?..... (there is no speed of sound here), how are photons(heat radiation) absorbed by matter and turned into vibrational energy(heat as I know it). I know that electrons absorb photons and jump to higher energy levels, is this heat? Anyway I'm not a physicist, biologys my major, keep it simple plz .

[swansont]

From the name "phonons" I am guessing they relate to sound, as does heat right?... it travels at the speed of sound in a material because it is vibrational energy. However heat travels across a vaccuum as photons right?..... (there is no speed of sound here), how are photons(heat radiation) absorbed by matter and turned into vibrational energy(heat as I know it). I know that electrons absorb photons and jump to higher energy levels, is this heat? Anyway I'm not a physicist, biologys my major, keep it simple plz .

 

Phonons are vibrational modes, so yes, they relate to sound as well as heat.

 

It's more accurate to say that heat can only travel across a vacuum as photons, since you can't have conduction or convection.