Tuesday, March 4, 2014

Disordered hyperuniformity: new state of matter

States of matter
There are five main states of matter. Solids, liquids, gases, plasmas, and Bose-Einstein condensates (BEC) are all different states of matter. Each of these states is also known as a phase. Elements and compounds can move from one phase to another when specific physical conditions are present. One example is temperature. When the temperature of a system goes up, the matter in the system becomes more excited and active. Scientists say that it moves to a higher energy state. Generally, as the temperature rises, matter moves to a more active state.
solid
liquid
gas
The plasma state is often misunderstood, but it is actually quite common on Earth, and the majority of people observe it on a regular basis without even realizing it. Fire, lightning, electric sparks, fluorescent lights, neon lights, plasma televisions, and the stars are all examples of illuminated matter in the plasma state.

A gas is usually converted to a plasma in one of two ways, either from a huge voltage difference between two points, or by exposing it to extremely high temperatures.
Heating matter to high temperatures causes electrons to leave the atoms, resulting in the presence of free electrons. At very high temperatures, such as those present in stars, it is assumed that essentially all electrons are "free," and that a very high-energy plasma is essentially bare nuclei swimming in a sea of electrons.

The collapse of the atoms into a single quantum state is known as Bose condensation or Bose-Einstein condensation is now considered a 5th state of matter.
Recently, scientists have discovered the Bose-Einstein condensate, which can be thought of as the opposite of a plasma. It occurs at ultra-low temperature, close to the point that the atoms are not moving at all. A Bose-Einstein condensate is a gaseous superfluid phase formed by atoms cooled to temperatures very near to absolute zero. The first such condensate was produced by Eric Cornell and Carl Wieman in 1995 at the University of Colorado at Boulder, using a gas of rubidium atoms cooled to 170 nanokelvins (nK). --Under such conditions, a large fraction of the atoms collapse into the lowest quantum state, producing a superfluid. This phenomenon was predicted in the 1920s by Satyendra Nath Bose and Albert Einstein, based on Bose's work on the statistical mechanics of photons, which was then formalized and generalized by Einstein. 
(http://en.wikipedia.org/wiki/State_of_matter, http://www.chem4kids.com/files/matter_states.html, http://www.chem.purdue.edu/gchelp/atoms/states.html, http://www.edinformatics.com/math_science/states_of_matter.htm )

A new state of matter
 'disordered hyperuniformity' is an arrangement of particles that allows material to behave like both a crystal and a liquid.
The unusual arrangement of cells in a chicken's eye, shown here, constitutes the first known biological occurrence of a potentially new state of matter known as 'disordered hyperuniformity'
This new state of matter has been discovered in the eye of a chicken.

Gaze deeply into the eye of a chicken, and what do you see? Researchers at Princeton University and Washington University in St. Louis say they see in the bird's eye the first known biological occurrence of a strange state of matter known as "disordered hyperuniformity. 
("http://www.huffingtonpost.com/2014/02/26/chicken-eye-weird-state-of-matter_n_4854897.html)
The breakthrough was made by researchers studying minute light sensitive cells known as cones responsible for the perception of colour.
DISORDERED HYPERUNIFORMITY
Materials in this state are like crystals in the way they keep the density of particles consistent across large spatial distances.
But these systems are also like liquids because they have the same physical properties in all directions.
Researchers say this may be the first time disordered hyperuniformity has been observed in a biological system.
Previously it had only been seen in physical systems like liquid helium and simple plasmas.
For chicken eyes, the researchers speculate this cone arrangement allows the birds to evenly sample incoming light. 
(http://www.dailymail.co.uk/sciencetech/article-2567765/How-chickens-eye-revealed-new-state-matter.html)

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