Martin Gardner

The jumping pencil

This trick uses a plastic bottle with a hole punched hear the bottom, a balloon, and a pencil.

A slinky problem

If you hold one end of a SlinkyTM, letting it hang down and then dop it, what happens? Students are not likely to come up with the answer and will be surprised by a demonstration.

The twirled ring

As all physicists know, when an ice skater spins with outstretched arms then quickly lowers her arms, her rotation speed increases enormously. This effect can be neatly demonstrated with a finger ring and a piece of string.

The floating vase

This remarkable optical illusion illustrates how our minds make the best bet in interpreting a picture in the light of experience.

More or Less than Half Full

Physics Trick of the Month problem is to ask why a capped bottle that seems to be about half full of water is hard to measure. The bottle has a long neck, making it difficult to know for sure exactly whether the water fills more than half of the bottle’s volume, less than half, or exactly half.

A Paper Pistol

In his diary, Lewis Carroll speaks of making what he called paper pistols for his child friends. The pistol is best folded from a single sheet of newspaper as shown in the illustration. When held at one corner and swung rapidly through the air, a portion of the paper pops out with a loud bang.

A Newspaper Trick

Here is a physics trick using a sheet of newspaper you hold in your hands and try to poke your index finger through. It is easier than you think thanks to air resistance and inertia.

A Playing‐Card Soliton

A soliton is a wave that maintain itself by means of external restraints that prevent its collapse. You can model a soliton with a deck of playing cards.

A spooky rotation

A new and amazing optical illusion has come to light.A new and amazing optical illusion has come to light.

The unbroken tissue

Using a rubber band, attach a square of tissue paper across one end of a cardboard tube. Hold the tube vertically, open end up, and fill the tube with uncooked rice.