Talk:Meissner effect

From Wikipedia, the free encyclopedia

WikiProject Physics This article is within the scope of WikiProject Physics, which collaborates on articles related to physics.
Start This article has been rated as Start-Class on the assessment scale.
Mid This article is on a subject of Mid importance within physics.

Help with this template This article has been rated but has no comments. If appropriate, please review the article and leave comments here to identify the strengths and weaknesses of the article and what work it will need.

Contents

[edit] light

you think maybe you could do kinda the same thing with light. Bend it around somthing that is not affacted by it?

gravity bends light...that's how we know of the existence of black holes. we see where a star's supposed to be, and where we see it as being, and so we know that there's a superdense celestial body somewhere in between. so yeah. the effect is similar with light.

[edit] Article too brief

Much is left to be said about the Meissner effect, including experimental methods for measurement and historical discussion. Overall, the page is lacking in content.

[edit] Page inaccurate

"This active exclusion of magnetic fields is distinct from perfect diamagnetism." This sentence is confusing. From the book High-Temperature Superconductivity by Genrald Burns, it is said that:""Thus in a weak magnetic field, a superconductor has perfect diamagnetism, a phenomenon called the Meissner effect." So Meissner effect is a diamagnetic phenomenon?

chianshin 09:40, 10 April 2007 (UTC)


There is no such thing as the Laplacian of B. That's just incorrect. B is a vector quantity. I don't enough about the actual theory to correct the page, but this page needs to be fixed up.

Mgummess 16:04, 31 March 2007 (UTC)

Yes, there *is* such a thing as the Laplacian of a vector quantity. Since \nabla^2 is a scalar operator, it operates on each component of the vector, i.e.
\nabla^2 \vec{B} = \hat{x} \nabla^2 B_x + \hat{y} \nabla^2 B_y + \hat{z} \nabla^2 B_z —The preceding unsigned comment was added by 24.9.121.240 (talk) 02:53, 28 April 2007 (UTC).

Superconductivity#Meissner_effect is more comprehensive for the most part and integrates the topic into its natural category. This article does contain some information and images not present in the Superconductivity article and should be merged.KF6AUF

  • Do not merge; stand-alone topics are conducive to learning; (online) article length is inversely proportional to information-acquisition.--Sadi Carnot 17:36, 19 February 2006 (UTC)
  • It would be good to have a brief, phenomenological description of the M. effect on the superconductivity page and then a link to a longer article here. Why limit the amount of information on wikipedia or have excessively long articles?

I came to this article looking for a non-technical answer as to why the Meissner effect happens. I left the article still thirsting for knowledge. How about a brief non- (less?) technical description of what's going on? -Mr.Logic 17:40, 22 March 2006 (UTC)

As of 15:40PST on 17 May 2006, this article and the article on perfect diamagnetism are very similar, with the notable difference that this article says "Note that there is a difference between a perfect diamagnet and a superconductor," while the article on perfect diamagnetism says the exact opposite.

[edit] Factual inaccuracy in theory

The meissner effect is distinct from perfect diamagnetism arising from zero resistance. The theory described in the article, as it stands now is wrong. There's no reference to the london equations. I lack the time, so can someone fix it? I'll try editing myself if I have the time siddharth 08:28, 8 June 2006 (UTC)

There, I've showed that the meissner effect is distinct from perfect diamagnetism. siddharth 18:07, 14 June 2006 (UTC)

[edit] History?

How was this discovered? — Omegatron 01:49, 19 June 2007 (UTC)

[edit] Simplified a little?

I was reading this article like someone who doesn't know a thing about it, and well, yes, I had some trouble trying to understand it. Can anyone just explain to me how the liquid nitrogen affects the magnet and makes it a superconductor?

the answer is that a material doesn't attain superconductivity until it's below a certain temperature. The temperature varies for each material. some superconducting materials are lead, mercury and aluminum.

[edit] absorption, or reflection?

from the illustration given, it's unclear whether the Meissner effect can be used to focus a magnetic field (as with a parabolic solar oven focusing light) or if the material used simply stops the magnetic field from going beyond the material's penetration depth. 38.99.84.53 (talk) 17:37, 4 April 2008 (UTC)AI#0

[edit] Apparent contradiction

The article says that "Observation of the Meissner effect is difficult, because the applied fields have to be relatively small (the measurements need to be made far from the phase boundary)." It also shows a refrigerator magnet levitating over a superconductor. I assume that what the original author meant is that measurements of the Meissner effect are difficult because using a particular method of calculation requires a small applied field, but I'm no expert. Wnt (talk) 21:46, 21 May 2008 (UTC)