Transcript: Heavy Air | Dec 06, 1989

(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. Heavy Air. Presented by Kim Humphreys. Producer and director: Michael Kushner. Researcher: Lisa-Ann Dunley.”

A caption reads “Kim Humphreys. Ontario Science Centre.”

Kim is in his late thirties, clean-shaving and with short receding light brown hair. He wears a blue polo T-shirt.

He stands next to a table with a bell jar connected to a tube. Inside the bell jar, an odd looking dummy with a ball for a head appears.

He says HI THERE.
TODAY I THOUGHT WE'D TRY
A COUPLE OF EXPERIMENTS
HAVING TO DO
WITH PRESSURE.
SO, I'VE BROUGHT ALONG
AN OLD FRIEND OF MINE,
HIS NAME IS,
MISTER ODDBALL.
AND RIGHT NOW, HE'S LIVING
INSIDE THIS BELL JAR.
THE BELL JAR IS CONNECTED
UP TO A VACUUM PUMP.
AND WHAT I'VE DONE IS PUT
A LITTLE BIT - ACTUALLY,
JUST ABOUT THAT
MUCH SHAVING CREAM
INSIDE OF HIS HEAD.

He pumps a golf ball size of cream in his palm.

He says WHAT I'M GOING TO
DO RIGHT NOW IS
TO REMOVE ALL THE AIR
FROM INSIDE THIS BELL JAR
AND DRAMATICALLY
LOWER THE PRESSURE.
AND NOW, WE'LL
SEE WHAT HAPPENS.
[motor buzzing]

A large amount of shaving cream comes out through the dummy’s nostrils and eyeholes.

He says OKAY, SO I GUESS
YOU GET THE IDEA
ABOUT WHAT'S
HAPPENING.
THIS TINY LITTLE BIT OF
SHAVING CREAM TURNED
INTO AN ENORMOUS
VOLUME INSIDE THERE.
NOW, YOU MIGHT BE
WONDERING WHY THAT HAPPENS.
SHAVING CREAM IS
COMPOSED OF THOUSANDS
UPON THOUSANDS OF
TINY LITTLE BUBBLES.
AND EACH BUBBLE HAS A
LITTLE BIT OF AIR INSIDE IT.
NOW, THAT LITTLE BIT
OF AIR HAS PRESSURE,
NOT ENOUGH TO MAKE THE
BUBBLE GROW VERY LARGE,
BUT IF YOU TAKE THE
PRESSURE AWAY FROM
THE OUTSIDE OF THE
BUBBLE, THEN THAT BUBBLE
IS FREE TO EXPAND
AND IT WILL EXPAND
TO AN ENORMOUS
VOLUME.

A caption reads “Standard sea level air pressure: 14.70 pounds per square inch. 1013.25 by 10 cubed per square centimetre.”

He says WHAT I CAN DO RIGHT NOW
TO SHOW THAT TO YOU,
IS LOOSEN THE VALVE
UNDERNEATH THIS BELL JAR.
LET ALL THE ATMOSPHERIC
PRESSURE RUSH BACK IN
AND WE'LL SEE THE
CHANGE IN THE SIZE
OF ALL THESE
AIR BUBBLES.
[air hissing]

The mass of shaving cream starts to shrink.

He says AND YOU CAN SEE,
THAT WHEN THE AIR
RUSHES BACK INSIDE, THE
VOLUME OF THE BUBBLES
GETS A LOT SMALLER AND THE
LITTLE BIT OF PRESSURE
THAT'S INSIDE EACH
BUBBLE IS NOT VERY MUCH
COMPARED TO THIS
ATMOSPHERIC PRESSURE.
AND THE BUBBLE GETS
SQUEEZED BACK
INTO ITS SMALLER,
ORIGINAL VOLUME.
SO THAT WE'RE NOT LEFT
WITH THAT SAME AMOUNT
OF BUBBLES AGAIN.

(music plays)

A slate appears with the caption “For more information read: Clouds in a Glass of Beer. Simple Experiments in Atmospheric Physics by Craig F. Bohren. Copyright. 1987. New York Wiley. Flying Circus of Physics by Jearl Walker. Copyright. 1977 Wiley. The History of the Barometer. W.W Knowles Middleton. Copyright. 1964. John Hopkins.”

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

Watch: Heavy Air