Eureka!

How can someone lift a very heavy load? If one could slice the load into pieces, that would trade increased distance for decreased effort. But since one can't break things because they are so heavy, the inclined plane comes into play.

A teeter-totter is the perfect demonstration of the lever, particularly if you are trying to ride a teeter-totter with someone heavier than you. Such is the Principle of the Lever.

Two professors compete to see who can lift a book with a lesser amount of force. The professor who uses a lever is more efficient than the inclined plane, once we factor in a basic double-edged sword called friction.

All machines in the world can be traced to just two: the inclined plane and the lever. Even the wheel is just a circular lever whose fulcrum has become an axle. The screw? It's just a spiraling inclined plane.

Jack and Jill went up the hill and found a problem: how can they pull a pail of water from the bottom of a well? In this expanded nursery story, we find there is more to a pulley–and its mechanical advantage–than meets the eye.

The first of six shows on heat and temperature, introduces molecules. Even though a solid object looks motionless, its molecules move back and forth in a lattice-work dance.

This episode sacrifices a chocolate rabbit on a hot day to illustrate the movement of molecules in liquids.

No end of problems await the man who keeps fish for pets. Evaporation forces one to refill the tank. And he who thinks he can outsmart water vapor by keeping his fish in a refrigerated water tank, falls prey to Nature's countermeasure: condensation.

This lecture-packed show compares a balloon to a bunch of angry wasps to explain why gases expand and contract. It goes further than that. The expansion process also affects matter when it changes from one state to another.

Given three bathtubs of varying temperature, the star of the show ""blunts"" his feet so that they can't tell temperature. Sure they can't. The human body can only tell changes in temperature in comparison to what it had been used to. It's up to an independent device: a thermometer and the scale devised by Anders Celsius.

What is better to warm up a kiddie pool: a teacup of boiling water (100° Celsius) or a bucket of water at 50° Celsius? The answer tells you the difference between temperature and heat.

There's more to matter than the molecules we had spent discussing in the previous six shows. This fourth unit produces that first look at atoms.

An atom is made of mostly empty space. The electrons in an atom zoom around at fantastic speeds to create existence out of something that is mostly nothingness (at the atomic level).