A caption reads "Best of That TVO Kids Show."

The announcer says WE NEED TO KNOW!

The loud voice makes the tree fort shake.

Laura says WHOA!

Lucas says HEY!
(RUMBLING)
YES, WE DO NEED TO KNOW.
AND WE GOT AN EMAIL,
CHECK IT OUT.
THIS IS FROM MUSTAFA, AGE 8.

Laura says TOTALLY.
AND MUSTAFA NEEDS TO KNOW...
"IF METAL SINKS,
HOW DO BOATS FLOAT?"

Lucas says I'VE NEVER THOUGH
ABOUT THIS BEFORE.

Laura says THAT'S A REALLY GOOD POINT.

Lucas says YEAH, IT'S CRAZY THAT THEY CAN
JUST FLOAT ACROSS WATER.
I GUESS WE'RE GONNA FIND OUT.
LET'S CHECK IN WITH
OUT EXPERT.

Walter is in his thirties, with very short curly brown hair and wears glasses and a white lab coat.

He stands behind a table full of objects like metal balls and rocks.

He says IT'S A GREAT QUESTION.
WHY DO THINGS SINK OR FLOAT?
WELL, LET'S START WITH A
THOUGHT EXPERIMENT.
WHAT DO YOU THINK ABOUT THESE
OBJECT IN FRONT OF ME, HERE?
WHICH ONES DO YOU
THINK WILL FLOAT,
AND WHICH ONES DO YOU
THINK WILL SINK
WHEN I DROP THEM
IN THE WATER?
LET'S START WITH OUR BOAT.

He puts a tinfoil boat in a tank and says MADE OUT OF TINFOIL,
SO THIS IS A METAL BOAT,
AND IT FLOATS.
NOT JUST BECAUSE IT'S LIGHT,
BUT BECAUSE IT'S
NOT VERY DENSE.
IT'S SPREAD OUT.
IF WE TAKE THE SAME
AMOUNT OF TINFOIL
AND PACK IT TIGHT TOGETHER,
WELL, IT SINKS TO THE BOTTOM.
AND THE SAME THING'S TRUE IF WE
HAVE SOME VERY DENSE OBJECT...

He puts a tiny solid metal ball in the tank and it sinks.

He says OR SOMETHING THAT'S NOT
SO DENSE AND SPREAD OUT.

He puts a big but hollow metal ball in the water and it floats.

He says IT'S ABOUT HAVING
THE DENSITY OF THE WATER.
IF IT'S LESS DENSE
THAN THE WATER,
IT'LL FLOAT.

He puts a small but dense rock in the water and it sinks. He then puts a much bigger but less dense rock in and it floats.

He says IF IT'S MORE DENSE, WELL,
WE SAW WHAT HAPPENED,
IT SINKS TO THE BOTTOM.