scienceillustrated.com.au | 23
Laser steals heat
By illuminating a nanocrystal with an
infrared laser, American scientists
have made the crystal pull heat
from the water surrounding it.
In the 1997 film Batman & Robin,
supercriminal Mr. Freeze attacks his
enemies with a “freeze gun”. Can
this be done in the real world?
Scientists have not yet invented a
weapon like Mr. Freeze’s, which can
freeze humans, but researchers from
the University of Washington have
come a little closer. Using an infrared
laser, they have managed to cool tiny
quantities of water by 10 degrees.
In a laser, crystals normally produce
a focused light beam, which carries
energy and heats things. The American
scientists turned the principle upside
down, taking advantage of the fact that
when a nanocrystal is illuminated by
infrared laser, it can “steal” energy from
its surroundings and cool them.
Arnold Schwarzenegger, aka Mr.
Freeze in Batman & Robin from 1997,
freezes his enemies while delivering
terrible ice-based puns.
3
The energy difference between the reddish
green glow and the crystal steals heat from
both the crystal and the surrounding water. So
the crystal and the water have been cooled.
2
The laser beam
produces a reddish
green glow around the
crystal. The glow
includes more energy
than the laser leaves in
the crystal.
1
An yttrium lithium
fluo ride nanocrystal
is placed in an aqueous
solution on a glass disc
and lit from below with
an infrared laser.
Could We Really
Build a Freeze-Ray
That Works?
SPECIAL EFFECTS
REX FEATURES/ALL OVER
NANOCRYSTAL
LASER
GLASS
HEAT
WATER
GLOW