scienceillustrated.com.au | 23Laser 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 infraredlaser, 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
NANOCRYSTALLASERGLASSHEATWATERGLOW