Transcript: Boiling Cold | Apr 28, 1990

(music plays)

Outside a diner, a man reads the paper, another man juggles and a magician plays tricks. The name “The science Café” appears in neon lights on one of the windows. Inside, the waitress shows a menu that reads “The Science Café proudly offers food for thought. Science demonstration from Ontario Science Centre. Ice clouds. Presented by Allisa Ritchie. Producer and director: Michael Kushner. Researcher: Wally Longul.”

A caption reads “Allisa Ritchie. Ontario Science Centre.”

Allisa is in her mid-forties, with short wavy brown hair. She wears a blue lab coat and safety goggles. She stands by a table with a tank of nitrogen, a plant and some inflated balloons on it.

She says THIS IS LIQUID
NITROGEN AND TODAY,
WE'RE GOING TO USE
IT TO TALK ABOUT
REALLY COLD THINGS.
THIS LIQUID IS MINUS 196 DEGREES CELSIUS
THAT'S PRETTY COLD.
AND ITS BOILING,
BELIEVE IT OR NOT.
YOU CAN SEE IT JUMPING
RIGHT OUT OF THE LADLE
AND THAT'S BECAUSE IT'S TURNING
FROM A LIQUID TO A GAS.
AND WE BREATHE
NITROGEN EVERY DAY,
SO THERE'S NO PROBLEM
WITH ALL THIS VAPOR
AROUND THE ROOM.
WELL, LET'S SEE WHAT
LIQUID NITROGEN CAN DO.
WE'RE GOING TO PUT SOME
THINGS INSIDE THIS DEWAR,
THAT'S WHAT THIS
CONTAINER IS CALLED,
AND WE'RE GOING TO SEE
WHAT HAPPENS TO THEM.
NOW, THIS IS A
REGULAR BALLOON
AND IT'S FULL OF AIR.
WHEN AIR GETS COLD,
SOMETHING HAPPENS TO IT.
[hissing sound]
THIS BALLOON IS SHRINKING
BECAUSE ALL THE MOLECULES
OF AIR ARE MOVING
REALLY CLOSE TOGETHER.
WHEN THEY MOVE REALLY
CLOSE TOGETHER,
WE CAN MAKE LIQUID AIR.
NOW THE MOLECULES OF
AIR ARE GETTING COLD,
THEY'RE SLOWING DOWN AND
BECAUSE THEY'RE SLOWING DOWN,
THEY MOVE CLOSER AND CLOSER
TOGETHER UNTIL EVENTUALLY,
THE MOLECULES TOUCH AND
THEY MAKE THE LIQUID
INSIDE THE BALLOON.

She pushes 4 balloons inside the dewar. They all shrink.

[crackling sound]

She says YOU CAN HEAR THE
BRITTLENESS OF THE BALLOON.
THE RUBBER IS ALSO
FREEZING AND THAT'S WHY
IT BECOMES VERY
HARD AND BRITTLE.
WE'RE GOING TO PULL
THE BALLOONS OUT NOW
AND WE'RE GOING TO
LET THEM WARM UP.
[crackling sound]
NOW WHEN THE MOLECULES
ARE WARMING UP,
THEY START TO MOVE
AROUND REALLY FAST AND
THEY'RE MOVING AGAINST THE
SIDES OF THE BALLOON PUSHING,
FORCING THAT
RUBBER TO WARM UP.
AND SOMETIMES, THE
RUBBER ISN'T READY.

The balloon pops. She takes another balloon out. It starts expanding.

She says OKAY, LET'S TRY ANOTHER ONE
AND SEE WHAT HAPPENS TO THAT.
[crackling sound]
THE REASON THE BALLOON POPPED
WAS BECAUSE THE MOLECULES
ARE WARMING UP AND
THEY'RE PUSHING VERY HARD
AGAINST THE BRITTLE
SIDES OF THE BALLOON.
SOMETIMES THE BALLOON ISN'T
WARM ENOUGH AND IT POPS.
[crackling sound]
I'M GOING TO TRY AND WARM
THIS ONE UP A LITTLE BETTER.
MY BREATH IS VERY WARM.
SO IT WARMS THE BALLOON
UP SO IT DOESN'T POP.
[blowing sounds]
[crackling sound]
BALLOONS DON'T USUALLY
LOOK THE SAME SHAPE
AFTER THEY'VE WARMED UP.
SOMETIMES THE RUBBER HAS
BEEN CHANGED A LITTLE BIT
BECAUSE OF THE
FREEZING PROCESS.
[crackling sound]
NOW, RUBBER IS WHAT
WE CALL A POLYMER;
THAT JUST MEANS THE MOLECULES
ARE JOINED TOGETHER
AND THEY CAN SLIDE
PAST EACH OTHER.
THAT GIVES RUBBER THE
ELASTICITY YOU SEE HERE.

She stretches a rubber band.

She says NOW THAT ONLY HAPPENS
WHEN THE RUBBER IS WARM.
IF WE COOL OFF THE RUBBER,
SOMETHING HAPPENS.

She puts the rubber band inside the dewar.

She says THE MOLECULES CAN'T
MOVE AROUND AS MUCH
AND SO WHAT WE GET IS A
FROZEN PIECE OF TUBING.
IT'S VERY, VERY HARD
BECAUSE THOSE MOLECULES
ARE FROZEN IN PLACE.
THEY CAN'T MOVE AT ALL.

She takes the band out, tries to stretch it but can’t.

(music plays)

Fast clips show images of the process of frozen food making.

A female voice says CRYOGENIC TECHNIQUES PLAY
IMPORTANT ROLES IN INDUSTRY.
COOKED FOOD IS PRESERVED
IN CRYOGENIC FREEZERS
WHICH INSTANTLY
LOCK IN FRESHNESS.
OTHER THAN BEING
FROZEN SOLID,
THE QUALITY OF THE FOOD HAS
NOT CHANGED IN ANY WAY.
SURGEONS AND VETERINARIANS
SOMETIMES USE LIQUID NITROGEN
TO LOCALLY FREEZE
DISEASED TISSUES.
THE RESULTING DEAD CELLS ARE
LATER ELIMINATED BY THE BODY.
THE ANIMAL IS COMPLETELY
UNHARMED BY THE EXPERIENCE.

A fast clip shows images of a veterinarian healing a horse’s wound with cryogenic liquid nitrogen.

(music plays)

The woman says SUPERCONDUCTIVITY
RESEARCH INVESTIGATES METAL'S
RESISTANCE TO ELECTRICITY
AT LOW TEMPERATURES.
AS THE MATERIAL IS COOLED,
RESISTANCE DROPS
AND VOLTAGE INCREASES.

(music plays)

A slate appears with the caption “For more information read: Microbiology of Frozen Foods by R.K Robinson. Copyright. 1985. New York. Elseivier. Superconductors. The Long Road Ahead. Technology Review. February 1988. S. Foner, T.P Orlando. See pages 36 to 47.”

Another caption reads “A production of TV Ontario. The Ontario Educational Communications Authority. Copyright. 1989.”

Watch: Boiling Cold