>> SCIENTISTS ARE INTERESTED
IN GLASSES.
NOT DRINKING GLASSES.
GLASSES ARE A STATE OF
MATTER THAT SHARE PROPERTIES
WITH BOTH LIQUIDS
AND SOLIDS.
WHILE SOLIDS TEND TO
ORGANIZE THEMSELVES IN NEAT,
TIDY CRYSTALLINE STRUCTURES,
GLASSES ORGANIZE THEMSELVES
RANDOMLY IN UNIQUE
AND LIQUID-LIKE WAYS.
NASA GLENN RESEARCH CENTER
IN CLEVELAND, OHIO,
TOGETHER WITH ITS PARTNERS
AT THE NEW JERSEY
INSTITUTE OF TECHNOLOGY
AND NEW YORK UNIVERSITY,
ARE PROBING THIS REDISCOVERED
STATE OF MATTER ON
THE INTERNATIONAL SPACE STATION
AND REWRITING THE TEXTBOOKS OF
SOFT MATTER COLLOIDAL PHYSICS.
WHILE MANY STILL LABOR
UNDER THE MYTH THAT GLASS
IS A LIQUID, MOVEMENT EVEN
ON GEOLOGICAL TIMESCALES
WOULD BE HARD TO MEASURE.
WHAT GLASS DOES SEEM TO BE
IS AN AMORPHOUS SOLID,
OTHER EXAMPLES OF WHICH
INCLUDE PLASTICS,
GELS, AND RUBBER.
WE HAVE, OF COURSE,
USED GLASSES IN BOTTLES,
WINDOW PANES, AND CELL PHONE
SCREENS FOR MANY YEARS.
BUT EVEN AS WE HAVE
TAMED THE STRUCTURAL
USE OF THIS MATERIAL,
HOW IT FORMS
STILL HOLDS MYSTERIES.
TO UNRAVEL THESE MYSTERIES,
NASA RESEARCHERS
TRIED SOMETHING NEW
AND QUITE INTERESTING.
THEY CHANGED THE PARAMETERS
OF THIS EXPERIMENT
BY USING OBLONG SHAPED
MICRON SIZED PLASTIC PARTICLES
MIXED IN A COLLOIDAL SUSPENSION.
THEY CHANGED THE SHAPE
OF THE PARTICLES
BY STRETCHING THE SPHERES
INTO ELLIPSOIDS.
THIS ENABLED MEASUREMENT
OF MOTION IN NEW WAYS,
BOTH ROTATIONAL MOTION
OF THE PARTICLES, AS WELL AS
TRANSLATIONAL MOTION
OF THE PARTICLES.
SIDE TO SIDE MOTION
COULD ALSO BE DETECTED
AS THE CRYSTALLINE STRUCTURES
RANDOMLY FORMED.
TO THIS POINT,
ONLY TEXTBOOK PARTICLES
HAD BEEN USED IN EXPERIMENTS,
OR PARTICLES UNIFORM
IN SIZE AND SHAPE.
THE OBLONG SHAPED PARTICLES
BETTER RESEMBLE
THE NATURAL WORLD.
ON EARTH, PARTICLES OF THIS
SIZE WOULD BE INVISIBLE.
AND IF YOU COULD SEE THEM
THEY'D SINK DUE TO GRAVITY.
MICROGRAVITY ABOARD THE ISS
OFFERED THE OPPORTUNITY
TO OBSERVE THESE CHANGES
IN REAL TIME IN THE LIGHT
MICROSCOPY MODULE USING
EASILY OBSERVABLE PARTICLE
SIZES IN REAL TIME.
WHAT THE RESEARCHERS FOUND
WAS THAT WHEN A CERTAIN DENSITY
OF THESE ELLIPSOIDAL PARTICLES
WERE SUSPENDED IN A SOLVENT
THEY FORMED A GLASS.
THE ELLIPSOIDAL PARTICLES
IN THESE RIGID STRUCTURES
COULD ROTATE,
MAKING THE SOLUTION
APPEAR TO BE A SOLID,
BUT STRANGELY THEY COULD
TRANSLATE SIDE TO SIDE,
ACTING AS IF IN A LIQUID.
A LITERATURE REVIEW REVEALED
A DECADES OLD PAPER THAT
PREDICTED THIS PHENOMENON.
THE PAPER DID MISS
SOME ELEMENTS OF
THE RECENT DISCOVERIES,
SUCH AS LIKE PARTICLES
BUNCHING TOGETHER
AND OTHERS INTERSECTING
AND GROWING AT RANDOM ANGLES.
MAYBE THAT'S WHY GLASS FORMS
RANDOM SHAPES AS IT COOLS.
THESE DISCOVERIES
AND NASA PARTNERSHIPS
ARE SEEDING NEW CHAPTERS
IN FUTURE TEXTBOOKS.