Transcript: Ice Clouds | Apr 06, 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 and a plant on it.

She says THIS IS LIQUID NITROGEN.
AND WE ARE GOING TO USE IT TO
TALK ABOUT VERY COLD THINGS.
LIQUID NITROGEN IS ABOUT
MINUS 200 DEGREES CELSIUS.
IT'S VERY COLD.
AND RIGHT NOW,
IT'S BOILING.
IT'S BOILING AT A
VERY COLD TEMPERATURE.
SO IT'S EVAPORATING FROM
A LIQUID INTO A GAS.

She takes some nitrogen out of the tank with a ladle and pours it on the table.

She says IF WE POUR IT ON THE TABLE
HERE, WE CAN SEE THAT
IT'S ACTUALLY EVAPORATING.
AND THE REASON YOU CAN SEE THE
LITTLE BEADS IS BECAUSE
THE LIQUID NITROGEN IS IN
CONTACT WITH A WARM SURFACE.
SO UNDERNEATH THAT LITTLE
DROPLET OF LIQUID,
THERE'S A GAS LAYER.
AND IT ALLOWS THE LIQUID
NITROGEN TO ROLL AROUND
LIKE AN AIR HOCKEY PUCK.
AND IT MOVES VERY,
VERY QUICKLY.
NOW, LIQUID NITROGEN TAKES
UP A LOT MORE ROOM AS A GAS
THAN IT DOES AS A LIQUID.
LET'S FIND OUT EXACTLY HOW
MUCH ROOM IT TAKES UP.
I'M GOING TO PUT SOME OF THIS
LIQUID NITROGEN INTO A FLASK.
YOU DON'T HAVE TO BE VERY
ACCURATE WHEN YOU POUR THIS.
WE'RE GOING TO TRY AND CAPTURE
THE NITROGEN AS IT TURNS FROM
A LIQUID INTO A GAS.

She covers the mouth of the flask with a balloon. The balloon starts to expand.

She says SO WE'LL LET IT EXPAND AND SEE
HOW LARGE THE BALLOON GETS.
IT ACTUALLY TAKES UP 700
TIMES MORE ROOM AS A GAS
THAN IT DOES AS A LIQUID.

The balloon pops.

[popping sound]

She says NOW, THE REASON THE BALLOON
POPPED WAS BECAUSE THE LIQUID
NITROGEN IS
TURNING INTO A GAS.
IT'S EXPANDING, AND ALL THE
MOLECULES ARE MOVING FURTHER
AND FURTHER APART.
THEY PUSH OUT AGAINST THE
SIDE OF THE BALLOON, AND
EVENTUALLY THE BALLOON CAN'T
HANDLE IT ANYMORE, AND IT POPS.
ALL RIGHT, NOW WE'RE GOING
TO DO SOMETHING A LITTLE BIT
DIFFERENT NOW WITH
THE LIQUID NITROGEN.
I'M GOING TO ADD IT TO THIS
FLASK WITH HOT WATER IN IT.
WHAT WE'RE MAKING
HERE IS A CLOUD.
A CLOUD IS JUST FROZEN WATER
VAPOUR, AND THIS IS EXACTLY
WHAT YOU SEE WHEN YOU LOOK
OUT A WINDOW FROM A PLANE.
AND THIS IS WHAT'S USED IN
THEATRICS, AS WELL, TO MAKE
A MIST OR FOG.
AND THAT'S WITH LIQUID
NITROGEN, OR SOMETIMES WITH
DRY ICE, WHICH IS FROZEN
SOLID CARBON DIOXIDE.

A white fog comes out of the flask.

(music plays)

A slate appears with the caption “For more information read: Application of Cryogenic Technology: Proceedings Volume 9. Cryogenic Society of America. Copyright. 1979. New York. Scholium Institution. Encyclopaedia Britannica. Micropaedia, 15th edition. Look under cryogenics.”

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

Watch: Ice Clouds