Bristol physicists break 150-year-old law

University of Bristol ^ | July 19, 2011 | Unknown

[decimon]

A violation of one of the oldest empirical laws of physics has been observed by scientists at the University of Bristol. Their experiments on purple bronze, a metal with unique one-dimensional electronic properties, indicate that it breaks the Wiedemann-Franz Law. This historic discovery is described in a paper published today in Nature Communications. In 1853, two German physicists, Gustav Wiedemann and Rudolf Franz, studied the thermal conductivity (a measure of a system’s ability to transfer heat) of a number of elemental metals and found that the ratio of the thermal to electrical conductivities was approximately the same for different metals at the same temperature.

The origin of this empirical observation did not become clear however until the discovery of the electron and the advent of quantum physics in the early twentieth century. Electrons have a spin and a charge. When they move through a metal they cause an electrical current because of the moving charge. In addition, the moving electrons also carry heat through the metal but now it is via both the charge and the spin. So a moving electron must carry both heat and charge: that is why the ratio does not vary from metal to metal.

For the past 150-plus years, the Wiedemann-Franz law has proved to be remarkably robust, the ratio varying at most by around 50 per cent amongst the thousands of metallic systems studied.

[decimon]

Thermo couple ping.

[MWS]

I hope it carries a hefty jail sentence and/or fine.

[frogjerk]

Not much of a law then.

[BipolarBob]

Arrest them.breaking the law is breaking the law. I don’t care if they are physicists.

[aMorePerfectUnion]

First she’s on Dancing with the Stars
Then she buys a mansion in AZ
Then she has a NYT best selling book
Now, a University is named after her!

Wow! Bristol Palin is on the move!!!

[bvw]

Phonons and Fermi-levels.

[ClearCase_guy]

Perhaps this is connected to the nearby thread — “Men who buy sex commit more crimes, study finds”

[Constitution Day]

This thread needs a Judas Priest soundtrack.

[KarlInOhio]

For the past 150-plus years, the Wiedemann-Franz law has proved to be remarkably robust, the ratio varying at most by around 50 per cent amongst the thousands of metallic systems studied.

50% variance? That's barely a suggestion, much less a law.

186,000 miles per second speed limit ... now that's a law.

[ImJustAnotherOkie]

The new one we'll call Obama's Law.

It only applies to what he says it does.

[farlander]

The really interesting thing here is that the metal is 100,000 more heat conductive than expected. There are serious commercial implications/uses to this.

[thackney]

the electrons split into two distinct components or excitations, one carrying spin but not charge (the spinon), the other carrying charge but not spin (the holon). When the holon encounters an impurity in the chain of atoms it has no choice but for its motion to be reflected.

The technical details for those of us that wanted to know how.

[thackney]

A non-conductive heat sink for power electronics, LEDs, etc.

It has real uses, not just a gee-whiz factor for nerds.

[ImJustAnotherOkie]

I wonder what was expected?

A lot of spin? Or lack of spin?

[Eagle of Liberty]

The really interesting thing here is that the metal is 100,000 more heat conductive than expected. There are serious commercial implications/uses to this.

Wow. That's pretty neat!! So much for the LAW, huh?

[Sgt_Schultze]

If this “law” 150 years old, shouldn’t it be considered “settled science” and thus beyond question?

[Robert A. Cook, PE]

Sounds interesting. As you point out - IF (big “IF” there) it works out in practice, there could be a lot of applications.

(But the “science” was settled” wasn’t it? “Everybody” agrees on the “scientific consensus” involved, right? Where have we heard that recently?)

[decimon]

A non-conductive heat sink for power electronics, LEDs, etc.

Apparently.

Maybe internal combustion engines - get the heat from where you don't want it to where you might want it. Put the waste heat to work.

[aruanan]

Wow. That's pretty neat!! So much for the LAW, huh?

A natural law or physical law is a description of observed regularities of behavior. It's not necessarily the case that it will apply in all situations. And it's certainly not true that there are "laws" that physical systems must obey.

[The Great RJ]

Oh no this can't be true a CONSENSUS of scientists have agreed on the Wiedemann-Franz law so the science is settled and no further research is needed. (global warming sarcasm)

This is why Al Gore and the other global warming hoaxers are not true users of the scientific method. Science is never settled and is always open to new investigation to prove or disprove hypotheses.

[Cyber Liberty]

What’s next? Ice-Nine?

[USMCPOP]

purple bronze = Li 0.9 Mo6 O 17

The paper: http://www.nature.com/ncomms/journal/v2/n7/full/ncomms1406.html

[DManA]

This historic discovery is described in a paper published today in Nature Communications.

I would say it was discovered 15 years ago by Kane and Fisher and finally verified experimentally by this group. Not to take anything away from their achievement.

[agere_contra]

It’s effectively a one dimensional heat sink (and it works better at lower temperatures).

I guess a composite material with trillions of such doped 1D chains ‘baked in’ would act as an effective sink. However: dispersal of waste heat from electronics does seem a better fit than bulk heat transfer from engines.

[Pecos]

And when he says it applies... and only how he says it does....and, by definition, it never violates the laws of physics, even if it actually does.....

[OneWingedShark]

http://en.wikipedia.org/wiki/Ice_IX

[decimon]

Thanks. I did a search on ‘purple bronze’ and came up blank.

It would seem that there is no bronze in purple bronze.

[DeoVindiceSicSemperTyrannis]

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[ml/nj]

I thought this was going to be about opening a bootery on Sunday.

ML/NJ

[Eagle of Liberty]

It's not necessarily the case that it will apply in all situations.

Laws are not descriptions. They are explanations. The LAW predicted that action A would happen under a certain set of conditions. Action A did not happen. Law violated.

[Marie Antoinette]

Interesting.

[antiRepublicrat]

We have plenty of other laws with caveats, they don’t work in this or that situation.

[stuartcr]

alchemy...

[Persevero]

“A natural law or physical law is a description of observed regularities of behavior. It’s not necessarily the case that it will apply in all situations. And it’s certainly not true that there are “laws” that physical systems must obey. “

So true, but when we use the shorthand word “law” most people think of it as a settled, unchangeable thing.

[NonValueAdded]

Unpossible, that was Settled Science^™.

[Hatteras]

Oh no... what’s that poor girl getting into now?....

[Eagle of Liberty]

We have plenty of other laws with caveats, they don’t work in this or that situation.

Then the law changes and that is fine. What I simply stated was that the experiment with the purple bronze violated the existing defined law.

[SunkenCiv]

Thanks decimon. Pooper cares ping.

purple bronze, a metal with unique one-dimensional electronic properties, indicate that it breaks the Wiedemann-Franz Law

Danged nanny-physics laws, anyway.

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[Condor51]

.... the Wiedemann-Franz law has proved to be remarkably robust, the ratio varying at most by around 50 per cent amongst the thousands of metallic systems studied.

Close enough for government work.