Toilet Paper Tube Tricks
by Martin Gardner in
Games Magazine February 2007
When your toilet paper rolls run out of paper,
don't throw away the cardboard tubes.
Here are seven amusiing things you can do with them:
1. A Betcha
Bet someone that he or she can't hold the tube six inches
above a table and drop it so it lands upright and remains
standing on one end. After repeated failures, you show the
only way it can be done: Hold the tube horizontally before
you drop it. You may have to do this more than once, but
after a few tries the tube will balance upright after landing.
2. An Optical Illusion
Believe it or not, the tube's Circumference is longer than its
length. A quick way to prove this is to cut the cylinder apart
lengthwise, then open it into a rectangle. One side of this
rectangle is the tube's circumference. The other side is the
tube's length. A ruler will prove the surprising fact that the
circumference is almost a full inch longer than the length!
3. A Paradox
Place two tubes side by side, then balance a yardstick
across them. If you rotate the tubes
inward in opposite directions,
the yardstick will stay balanced. Now try rotating the
tubes the other way. The yardstick will slowly travel to
one side until it falls off the tubes. Why does the
direction of rotation make such a big difference?
4. Hole in Your Hand
Hold up your left hand, palm toward you. With your other hand,
place the tube alongside your palm. Peek through the
tube with your right eye, keeping both eyes open, and stare at
a distant spot. You'll be looking through a large hole in your
left hand.
5. A Mysterious Force
Two tubes are alongside each other on a table. Rub your
hands vigorously together to generate a psychic force. Place
your hands palms down fingers pointing toward the tubes. Lower
your head slightly. Move your hands slowly away from the tubes,
and at the same time secretly blow on them.
They will roll toward your hands as if drawn by a mysterious
attractive force. You'll be suprised at how many people will
be totally mystified by this simple trick.
6. Unbreakable Tissue
With a rubber band, attach a piece of tissue paper over one
end of the tube. With the tube vertical, fill it to the top
with uncooked rice.
Using a thumb or finger, press as hard as you can on top
of the rice. Amazingly, you'll fmd it impossible to break the
tissue!
7. A Kazoo
Attach a piece of wax paper over one end of the tube,
using a rubber band. Near the other end make a small hole
in the tube's side. With your lips around the
hole, hum a tune. You've made a kazoo!