matter

[Evil]

wat r the 6 states of matter?

[ipx`vortex]

liquid/solid/gas = 3??

[Nereid]

plasma? BEC?? that makes 5.

[Monique]

Sixth state of matter: Fermionic condensate (http://news.bbc.co.uk/1/hi/sci/tech/3441643.stm)

The new matter is the sixth known form of matter after solids, liquids, gases, plasma and a Bose-Einstein condensate, created only in 1995. [:D]

[d00dz]

you've also got that state of matter which i forgot what it is called but neutron stars are made from it...where all atoms strip down to a neutron superfluid

[Monique]

Nature articles are always more impressive [6)]
Fermions chill out - New form of quantum matter unveiled. (http://www.nature.com/nsu/040126/040126-12.html)
29 January 2004

[Evil]

sorry but can anyone here explain Bose-Einstein condensate and fermonic condensate to me?
i read it somewhere it rings a bell but it makes no sense to me :p

[KingNothing]

Sorry to barrage with questions, I hope it's not too much trouble. To quote: Superconductors could allow for the development of magnetically levitated trains. Free of friction they could glide along at high speeds using a fraction of the energy trains now use.

Why would that be possible? Is it just saying that they could levitate by using resistance that didn't lose energy? Or something to that effect?

[Nereid]

Originally posted by d00dz
you've also got that state of matter which i forgot what it is called but neutron stars are made from it...where all atoms strip down to a neutron superfluid baryon degerate matter (http://www.herts.ac.uk/astro_ub/a41_ub.html).Evil wrte: sorry but can anyone here explain Bose-Einstein condensate and fermonic condensate to me? Click on the link in Monique's last post; it's a good summary. For further info, google on Bose-Einstein condensate, and chose one of the articles to suit your level.

Seventh: dark matter (may be more than one kind [;)] ).

[Monique]

BEC is a supercooled particles of bosons, which act as a single molecule. The fermionic condensate is made up of the other kind of particles: fermions.

What I don't understand: how do rubidium atoms belong to the bosonic class? I thought fermions are regular particles as we know it and bosons are force-carrying particles?

[russ_watters]

Originally posted by Decker
Why would that be possible? Is it just saying that they could levitate by using resistance that didn't lose energy? Or something to that effect? Its simply a matter of friction. A train that doesn't touch the tracks has only air resistance to worry about.

[KingNothing]

Originally posted by russ_watters
Its simply a matter of friction. A train that doesn't touch the tracks has only air resistance to worry about.

I see...I get that part...but I jsut don't get how a superconductor (to my understanding, something that can carry energy close to 100% efficiency) could make something have no friction.

[Monique]

Well, if that superconductor has magnetic properties..

[Gara]

the train will have no friction because it is not touching the tracks, but floating ABOVE them.

[KingNothing]

I understand that it wouldn't have friction, because it would levitate. What in the world would make it levitate? Sorry if it's a dumb question.

PS: Is that you in your pic Monique? Lookin sharp!

[ahrkron]

Originally posted by Decker
I understand that it wouldn't have friction, because it would levitate. What in the world would make it levitate?

It levitates due to electromagnetic repulsion.

[ahrkron]

Originally posted by Monique
What I don't understand: how do rubidium atoms belong to the bosonic class? I thought fermions are regular particles as we know it and bosons are force-carrying particles?

Bosons are particles that behave according to Bose-Einstein statistics. It turns out that this is equivalent to saying that "bosons are particles with an integer spin" (as opposed to being 1/2, 3/2, etc).

When atoms (which are, in general, fermions) form pairs, they may do so in such a way that their spins are "aligned" and add up to an integer, which makes the system behave as a boson.

[Monique]

This is what I found on the web (http://www.4hv.org/archive/topic.177.html):

A superconductor is perfectly diamagnetic which means it expels a magnetic field (Meissner-Ochsenfeld effect). Earnshaw's theorem does not apply to diamagnetics as they behave like "anti-magnets": they align ANTI-parallel to magnetic lines while the magnets meant in the theorem always try to align in parallel as iron does (paramagnetics). In diamagnetics, electrons adjust their trajectories to compensate the influence of the external magnetic field and this results in an induced magnetic field which is directed in the opposite direction. It means that the induced magnetic moment is antiparallel to the external field. Superconductors are diamagnetics with the macroscopic change in trajectories (screening current at the surface). I wonder what would happen with someone with a pace-maker if they come close to a maglev (magnetic levitation) train?