[kansando]

As a lapsed superconductivity physicist, I hate to burst the bubble. In the community there has been a long-standing joke about USOs, Unidentified Superconducting Objects, and it is well known that just because you see "Signs of Superconductivity" does not prove that something is superconducting.

There are really three questions at hand: 1> Does the sample show the Meissner effect, 2> Does it show zero resistance, and 3> Is it stable under addition of impurities. It turns out that for most ceramic compounds, even if 1 is true, 2 and 3 are often not true. For example, the Cuprates (the first to cross the 77K mark) actually have a higher resistance close to the critical temperature than copper. Point 3 is especially damning as sensitivity to impurities also means you can't draw these things into wires (certainly not wires you can bend) as the very act of bending may introduce defects that change local concentration of ingredients and hurt the superconductivity.

So the burden of proof remains very high, and the small blurb is very underwhelming.

[dannyb]

I agree and I remember the days of being a grad student and scouring the pages of High Tc Update looking for the next super-material. It seemed like every other quarter there was a hint of room T superconductivity and it was always dashed by the next quarter.

[igravious]

I have no idea why you are getting upvoted. You're not bursting any bubble, you're just parading your cynicism and knowledge of a specialized field before a technical audience. The post http://www.superconductors.org/276K.htm contains a whole bunch of data which may answer your 3 points. How about you go through it, or email the author who has "released [the details] into the public domain without patent protection in order to encourage additional research" and get back to us? You ask, "Does the sample show the Meissner effect" and I ask you does the information provided supply you with the answer? In which case you should write, "the published research information does not provide any information regarding the Meissner effect" because otherwise it sounds like you didn't even look closely at the article. And 10 out of 10 for not explaining what the Meissner effect is by the way. The top graph on the linked to page has a portion of the plotted function circled and labelled Meissner transition, is this what you mean? From Wiki P: "The Meissner effect is the expulsion of a magnetic field from a superconductor during its transition to the superconducting state. Walther Meissner and Robert Ochsenfeld discovered the phenomenon in 1933 by measuring the magnetic field distribution outside superconducting tin and lead samples."

Is (Tl4Pb)Ba2MgCu8O13+ a ceramic compound? If not, why mention them? They are claiming superconductivity, so this implies zero resistance doesn't it? We can worry about impurities when we make enough of the stuff to extrude and bend it.

[gnosis]

I for one am grateful he commented on this at all.

He has professional experience in this field, and his hunches are worth a thousand completely uninformed responses such as yours.

If you want him to dig through data, email the author, and look up stuff on Wikipedia for you, then how about you pay him before indignantly demanding that he do it?

After receiving backbiting chastisements from the popcorn gallery, I wouldn't be surprised if he refrained from commenting at all next time some similar announcement in his field of expertise came up.

That would be a pity, as his expertise, insight, and any time he cares to spend explaining his field to us are certainly valued.

[ewjordan]

You're not bursting any bubble, you're just parading your cynicism and knowledge of a specialized field before a technical audience.

In this case, I'd have to say that it's probably well deserved cynicism, though. An extremely effective first filter when any scientific or mathematical discovery is announced is to ask, "Does it look like science?", where "it" refers to whatever materials have been released.

In this case, the announcement does not look much like most science, and in fact the design reminds me more of all of those "Einstein was wrong, here's the real special theory of relativity!" sites than anything else.

This might not be a 100% correct filter, but I can't think of the last scientific breakthrough where the author didn't bother to at least set the paper in LaTeX and throw up a preprint somewhere. These days, even most incorrect proofs and discoveries look more like science than this does.

That said, as I know nothing about this field, I'd definitely be curious to hear what an expert had to say in about the specifics of these claims, as well as the other stuff at http://www.superconductors.org - it looks very crank-y to me, but then again I have known legit scientists that suck quite badly at web design, so who knows...

[pygy_]

The Meisner transition is the transition to a state where the Meisner effect is observed.

The author also reports a "resistive transition", 1°C lower than the Meisner transition. He claims that this signs the superconductivity of the material and confirms the origin of the magnetic transition.

> Is (Tl4Pb)Ba2MgCu8O13+ a ceramic compound?

Most probably, yes. See http://www.superconductors.org/type2.htm.