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### Wiffleball size

Posted: **Sat Apr 03, 2010 6:47 pm**

by **Indrek**

Something I threw up for fun, following from the previous electron count estimates in the "significance of electron recirculation revisited" thread.

http://www.mare.ee/indrek/ephi/wbsize.pdf

Posted: **Sat Apr 03, 2010 10:18 pm**

by **rcain**

thats useful, thanks Indrek. just re-reading over your

http://www.mare.ee/indrek/ephi/images.pdf also.

as I asked MSimon, on separate thread, shouldnt we be trying to derive this using gyro-radius?

### Re: Wiffleball size

Posted: **Sat Apr 03, 2010 11:14 pm**

by **MSimon**

That comes amazingly close to my BOE calculation for a .5 m radius coil 10T coil.

Posted: **Sat Apr 03, 2010 11:21 pm**

by **MSimon**

rcain wrote:thats useful, thanks Indrek. just re-reading over your

http://www.mare.ee/indrek/ephi/images.pdf also.

as I asked MSimon, on separate thread, shouldnt we be trying to derive this using gyro-radius?

It may help but it is not obvious to me how to do it.

I just took the simplistic approach that the currents have to be equal.

Of course that is only a sanity check approach.

Posted: **Sun Apr 04, 2010 10:24 pm**

by **TallDave**

Very interesting and easy to follow, thanks for sharing Indrek!

Posted: **Mon Apr 05, 2010 7:24 am**

by **BenTC**

That link

http://en.wikipedia.org/wiki/Inversive_geometry in the PDF doesn't work, the colon has been included.

Posted: **Mon Apr 05, 2010 10:51 am**

by **icarus**

More specifically it is a

http://en.wikipedia.org/wiki/Kelvin_transform
for the magnetic field of the coils. The transform produces the spherical inclusion (ideal wiffle ball) containing the interior potential field solutions that are merely the exterior potential field solutions mirrored (internally) under a spherical inversion.

Posted: **Fri Apr 09, 2010 8:19 pm**

by **rcain**

... still trying to understand the formation/physics of the Wiffleball ... have come up with a bit of background-and-around reading some might find of interest.

http://www.tkk.fi/Units/AES/courses/crs ... _Jamsa.pdf - nice little intro pp.

http://arxiv.org/PS_cache/physics/pdf/0 ... 0139v2.pdf - 'Is PLasma Diamagnetic?' - very interesting read - '...It seems that the Lorentz force is a test-particle approximation which is not suitable to describe the interaction of moving particles in agreement with the conservation of energy....'

http://media.iupac.org/publications/pac ... 3x0389.pdf - 'Electromagnetic Induction in Plasma' - ancient paper, but consise.

http://people.physics.anu.edu.au/~jnh11 ... chap06.pdf - diamagnetics in MHD. good general read.

http://books.google.co.uk/books?id=ToAt ... ma&f=false - good background even without the missing pages.

http://www2.warwick.ac.uk/fac/sci/physi ... cture4.pdf - quick pp on mag pinches and stability.

Posted: **Fri Apr 09, 2010 10:11 pm**

by **Giorgio**

rcain wrote: http://arxiv.org/PS_cache/physics/pdf/0 ... 0139v2.pdf - 'Is PLasma Diamagnetic?' - very interesting read - '...It seems that the Lorentz force is a test-particle approximation which is not suitable to describe the interaction of moving particles in agreement with the conservation of energy....'

If you liked that you will love also his 2006 and 2008 papers:

http://arxiv.org/PS_cache/physics/pdf/0 ... 4037v1.pdf
http://arxiv.org/PS_cache/arxiv/pdf/080 ... 1243v1.pdf
The Discussion and Conclusion sections are even more interesting than the 2005 paper you mentioned.

Posted: **Sat Apr 10, 2010 12:50 am**

by **rcain**

Thanks Giorgio, certainly is.

i found another paper by W. Engelhardt here

http://redshift.vif.com/JournalFiles/V1 ... 1N2ENG.pdf - 'On the Relativistic Transformation of Electromagnetic Fields'. - 2004.

he is a dude.

tearing great holes in 'accepted'physics without breaking into a sweat.

i hadn't realised that this subject would be so littered with gaps and paradoxes at such a fundamental level.

Posted: **Sat Apr 10, 2010 5:52 am**

by **MSimon**

i hadn't realised that this subject would be so littered with gaps and paradoxes at such a fundamental level.

Feynman has two routes to "mass/inertia is at least 1/2 electrodynamic."

1. Maxwell

2. Quantum Electrodynamics

He may be passe' by now though.

Posted: **Sat Apr 10, 2010 9:49 am**

by **Art Carlson**

rcain wrote:Thanks Giorgio, certainly is.

i found another paper by W. Engelhardt here

http://redshift.vif.com/JournalFiles/V1 ... 1N2ENG.pdf - 'On the Relativistic Transformation of Electromagnetic Fields'. - 2004.

he is a dude.

tearing great holes in 'accepted' physics without breaking into a sweat.

i hadn't realised that this subject would be so littered with gaps and paradoxes at such a fundamental level.

I never expected to run across Wolfgang Engelhardt again. I spent untold hours at IPP arguing with him and finding flaws in his mathematics, so much so that it probably hurt my career. Nobody else cared much, but I was fascinated by the man. He had a good reputation as a spectroscopist, and I still remember being impressed by the talk where he argued for making the first wall of tokamaks out of tungsten. (At the time, all the machines in the world (with one exception) had a first wall of graphite. Now, everyone agrees that at least part of the first wall of ITER and any reactor will have to be tungsten.) In my naivety I thought it must be possible to eventually come to a rational meeting of minds with such an intelligent and well-read physicist. But every time I pointed out a flaw in his logic or mathematics, instead of admitting he was wrong, [h]e constructed a different gedanken experiment o[r] mathematical proof, and the whole story would start over again. I don't know if these papers (none of which are peer reviewed, I point out) have the old errors I know or new ones, but I don't intend to find out. Do enjoy yourselves.

(edited [typos])

Posted: **Sat Apr 10, 2010 12:32 pm**

by **Giorgio**

Art Carlson wrote:But every time I pointed out a flaw in his logic or mathematics, instead of admitting he was wrong, we constructed a different gedanken experiment of mathematical proof, and the whole story would start over again. I don't know if these papers (none of which are peer reviewed, I point out) have the old errors I know or new ones, but I don't intend to find out. Do enjoy yourselves.

The beauty of mathematical proofs without experimental supports (especially at this level of complexity) is that you can prove and disprove almost anything simply by adding or changing an hypothesis here and there.

And as there are no experimental data to support an hypothesis or the other, you can most of the time hypothise what you like more.

Is Engelhardt right or wrong? We won't know until some eperiments wil be done to check his ideas, but is mathematic does not look too weak to me.

Let's remember that also Einstein General Relativity Theory was controversial and proved wrong in 2 different observations until finally proved right at the third observation.

And Einstein himself was not perfect, he also made lot of mathematical mistake in works, but his best idea was proved correct in the end.

There is really nothing new under the sun.

Posted: **Sat Apr 10, 2010 12:34 pm**

by **Giorgio**

rcain wrote:i hadn't realised that this subject would be so littered with gaps and paradoxes at such a fundamental level.

That's becouse there are too many scientists spending their time on the desk instead that in the lab