New state of matter discovered... in chicken eyes

Between this new discovery and the dinosaur tail experiment, it’s really beginning to look like chickens are the key to the secrets of the planet.

Physicists from Princeton University and Washington University in St. Louis have gazed into chickens’ eyes and found, no, not an abyss of feathery, finger-licking horror, but the first known biological occurrence of a possible new state of matter called “disordered hyperuniformity.”

Admittedly, one of the first things that come to mind when the words “chicken” and “disorder” show up in the same sentence is what happens when Link from The Legend of Zelda decides to go medieval on Hyrule’s poor hens.

However, disordered hyperuniformity is just as chaotic, possibly cooler, and definitely less violent than that.

Hatching an idea

First described in a 2003 research paper by Princeton science buffs Salvatore Torquato (a chemistry professor who also happens to be a co-author of the new study) and Frank Stilinger (a senior scientist of chemistry), the concept of hyperuniformity is a relatively fresh one.

Disordered hyperuniformity describes a unique configuration wherein a system of particles somehow exhibits the properties of both crystals and liquids. Thanks to what Torquato describes as a “hidden order,” matter that exists in a disordered hyperuniform state displays order over large distances and disorder over small distances. Thus, the density of particles across large spatial distances is kept consistently (as in crystals) while simultaneously possessing identical physical properties in all directions (as in liquids).

This unconventional particle system may be unique enough to count as a brand-new state of matter, says Torquato. "We've since discovered that such physical systems are endowed with exotic physical properties and therefore have novel capabilities.”

“The more we learn about these special disordered systems, the more we find that they really should be considered a new distinguishable state of matter.”

While disordered hyperuniformity had already been observed in liquid helium and simple plasmas, this is the first proof that this configuration exists in biological systems as well.



An 'egg-citing' discovery

Perhaps equally as interesting as the presence of disordered hyperuniformity in chicken eyes is the reason why our feathered friends would need such a complex system in the first place. While the answer may have nothing to do with Easter Egg hunts, it is just as colorful, in more ways than one.

Chickens (as well as other birds that are mostly active during daytime) possess four color-specific photoreceptor “cones” - violet, blue, green, and red - as well as a fifth kind for detecting light levels.The cones are crammed into a single layer of tissue on the chicken’s retina; thus, they appear to be in a perpetually chaotic arrangement.

However, the cones actually exist in uniform arrangement. Each individual cone has an exclusion region that keeps other cones of the same type from coming too close; thus, a pattern of each cone type is formed. Each pattern of each cone type is layered on top of one another – essentially, order in chaos.

“Because the cones are of different sizes it's not easy for the system to go into a crystal or ordered state,” explained Torquato.

“The system is frustrated from finding what might be the optimal solution, which would be the typical ordered arrangement. While the pattern must be disordered, it must also be as uniform as possible. Thus, disordered hyperuniformity is an excellent solution.”

The researchers go into more detail about their findings (and present solid proof that they really did not make up this ridiculously awesome new discovery) in a paper published in the journal Physical Review E. – TJD, GMA News