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Bristol physicists break 150-year-old law
University of Bristol ^ | July 19, 2011 | Unknown

Posted on 07/20/2011 7:59:33 AM PDT by 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.

(Excerpt) Read more at bris.ac.uk ...


TOPICS: Science
KEYWORDS: cooperpairs; purplebronze; stringtheory; superconductivity
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1 posted on 07/20/2011 7:59:34 AM PDT by decimon
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To: SunkenCiv

Thermo couple ping.


2 posted on 07/20/2011 8:00:28 AM PDT by decimon
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To: decimon

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


3 posted on 07/20/2011 8:00:33 AM PDT by MWS
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To: decimon

Not much of a law then.


4 posted on 07/20/2011 8:01:23 AM PDT by frogjerk (Greedo did not shoot first.)
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To: decimon

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


5 posted on 07/20/2011 8:01:29 AM PDT by BipolarBob (Yes I backed over the vampire but I swear I didn't see him in the rearview mirror.)
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To: decimon

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!!!


6 posted on 07/20/2011 8:02:07 AM PDT by aMorePerfectUnion (This message carfully checkd to misteakes by powerful softwhere)
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To: decimon

Phonons and Fermi-levels.


7 posted on 07/20/2011 8:02:58 AM PDT by bvw
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To: decimon

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


8 posted on 07/20/2011 8:03:25 AM PDT by ClearCase_guy (The USSR spent itself into bankruptcy and collapsed -- and aren't we on the same path now?)
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To: decimon
This thread needs a Judas Priest soundtrack.
9 posted on 07/20/2011 8:03:26 AM PDT by Constitution Day
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To: decimon
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.

10 posted on 07/20/2011 8:04:55 AM PDT by KarlInOhio (The Dems demanding shared sacrifice are like Aztec priests doing it while cutting out my heart.)
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To: frogjerk
The new one we'll call Obama's Law.

It only applies to what he says it does.

11 posted on 07/20/2011 8:07:05 AM PDT by ImJustAnotherOkie (zerogottago)
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To: ImJustAnotherOkie; All

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.


12 posted on 07/20/2011 8:09:50 AM PDT by farlander (Sic Semper Tyrannis)
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To: decimon; All
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.

13 posted on 07/20/2011 8:10:04 AM PDT by thackney (life is fragile, handle with prayer)
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To: farlander

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

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


14 posted on 07/20/2011 8:12:06 AM PDT by thackney (life is fragile, handle with prayer)
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To: farlander

I wonder what was expected?

A lot of spin? Or lack of spin?


15 posted on 07/20/2011 8:17:49 AM PDT by ImJustAnotherOkie (zerogottago)
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To: 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.

Wow. That's pretty neat!! So much for the LAW, huh?
16 posted on 07/20/2011 8:18:09 AM PDT by Eagle of Liberty (Shaking My Head on a daily basis)
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To: decimon

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


17 posted on 07/20/2011 8:21:06 AM PDT by Sgt_Schultze (A half-truth is a complete lie)
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To: thackney; neverdem

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?)


18 posted on 07/20/2011 8:21:27 AM PDT by Robert A Cook PE (I can only donate monthly, but socialists' ABBCNNBCBS continue to lie every day!)
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To: thackney
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.

19 posted on 07/20/2011 8:23:21 AM PDT by decimon
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To: Eagle of Liberty
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.
20 posted on 07/20/2011 8:23:31 AM PDT by aruanan
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