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Comment by 6ren | Hacker News Reader

I thought "metal" exclusively referred to a metal element, but it seems the definition is broader than that: (http://en.wikipedia.org/wiki/Metal)

  Many elements and compounds that are not normally classified as metals
  become metallic under high pressures.

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To most physicists, a metal is something that conducts electricity AND gets more conductive as it gets colder. The second condition is important to distinguish metals from insulators and semiconductors. (This is a good, but not perfect, definition.)

Don't forget the astronomers, for whom a metal is any element that isn't hydrogen or helium.

Add enough pressure and you can even get metallic hydrogen, which has been predicted to be a room temperature superconductor.

Not that you'd want to be in any room with that kind of pressure (250k atm).

But if this is true and can be demonstrated, I guarantee that there are people who will want to try to commercialize it.

Perhaps I'm misreading your phrasing... but why wouldn't they?

It is hard to commercialize a substance that we are unable to create/maintain the conditions to use.

But if someone can demonstrate how to make and hold solid hydrogen in a configuration where superconduction can be demonstrated at room temperature, then you've clearly gone several steps towards addressing feasibility, and you've demonstrated the existence of potential commercial opportunities.

Metal is a substance where the electrons flow "freely" in a lower potential created by the nuclei. That's different from, for example covalent crystals, where electrons are "locked" into a region, and ionic composts, where electrions distribution is quite like the one on free atoms.

Now, I put "free" and "locked" inside quotes because they are not completely so. There is a continuum, and no substance is at the extrema.

Also, at astronomy "metal" has a completely different meaning.

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