New state of matter found

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15 Νοε 2013 (πριν από 3 χρόνια και 11 μήνες)

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Title:
New state of matter found




Source:
Current Science
, May 7, 2004 v89 i16 p13(2).



BOULDER, Colo.
--

A team of U.S. scientists has discovered a new phase of matter, brin
ging to six the number of known
phases.


The three basic states of matter are solid, liquid, and gas. The fourth state, plasma, is gas that has become so hot that ele
ctrons
have broken away from its atoms. The fifth state, Bose
-
Einstein condensate, discove
red in 1995, occurs at extremely low
temperatures when subatomic particles, called bosons, merge to form one superparticle.


Bosons are one of two broad groups of subatomic particles. The other group is called fermions. Bosons are sometimes
nicknamed "love
rs" because they are very "sociable" and can be made to come together quite readily. Fermions are called
"loners" because they resist socializing. When researchers finally brought fermions together earlier this year, the result wa
s the
sixth phase of matte
r, a fermionic condensate.


Deborah Jin, a physicist at the University of Colorado, led the group that made the fermionic condensate. The researchers fir
st
chilled a form of potassium to almost absolute zero
--
the lowest possible temperature of matter, at w
hich all molecules stop
moving (
-
273.15 degrees Celsius, or
-
459.67 degrees Fahrenheit). Then they subjected the frigid potassium to a special
magnetic field. The result was not a superparticle like a Bose
-
Einstein condensate but rather pairs of fermions mo
ving together
like dance partners
--
the fermionic condensate.


What promise does the discovery hold? "We've opened a door," Jin stated, "and where it goes is unclear." One of her hopes is
that the study of fermionic condensates might help scientists better
understand superconductivity, the ability of some materials
to conduct electricity with almost no resistance The behavior of paired fermions in a fermionic condensate is similar to the
behavior of particles (electrons) in a superconductor.


The first super
conductors, discovered 20 years ago, operated only near absolute zero. Since then, superconductors have been
made that function at higher, but still very cold, temperatures. A superconductor that works at room temperature could save t
he
world a staggering
amount of electrical energy that is currently lost to resistance.



-----------------------------------------------------------------------------------------------------------------------------
--------------------------


Title:
New state of matter found




Source:
Current Science
, May 7, 2004 v89 i16 p13(2).



BOULDER, Colo.
--

A team of U.S. scientists has discovered a new phase of matter, bringing to six the number of known
pha
ses.


The three basic states of matter are solid, liquid, and gas. The fourth state, plasma, is gas that has become so hot that ele
ctrons
have broken away from its atoms. The fifth state, Bose
-
Einstein condensate, discovered in 1995, occurs at extremely lo
w
temperatures when subatomic particles, called bosons, merge to form one superparticle.


Bosons are one of two broad groups of subatomic particles. The other group is called fermions. Bosons are sometimes
nicknamed "lovers" because they are very "sociable
" and can be made to come together quite readily. Fermions are called
"loners" because they resist socializing. When researchers finally brought fermions together earlier this year, the result wa
s the
sixth phase of matter, a fermionic condensate.


Deborah

Jin, a physicist at the University of Colorado, led the group that made the fermionic condensate. The researchers first
chilled a form of potassium to almost absolute zero
--
the lowest possible temperature of matter, at which all molecules stop
moving (
-
27
3.15 degrees Celsius, or
-
459.67 degrees Fahrenheit). Then they subjected the frigid potassium to a special
magnetic field. The result was not a superparticle like a Bose
-
Einstein condensate but rather pairs of fermions moving together
like dance partners
--
the fermionic condensate.


What promise does the discovery hold? "We've opened a door," Jin stated, "and where it goes is unclear." One of her hopes is
that the study of fermionic condensates might help scientists better understand superconductivity, the a
bility of some materials
to conduct electricity with almost no resistance The behavior of paired fermions in a fermionic condensate is similar to the
behavior of particles (electrons) in a superconductor.


The first superconductors, discovered 20 years ago
, operated only near absolute zero. Since then, superconductors have been
made that function at higher, but still very cold, temperatures. A superconductor that works at room temperature could save t
he
world a staggering amount of electrical energy that is

currently lost to resistance.

1.

What are the 6 states of matter?

2.

Compare and contrast fermions and bosons.

3.

What is absolute zero?

4.

What is the difference between the Bose
-
Einstein condensate and the fermionic condensate?

5.

What are superconductors and why are
they important?