Six Easy Pieces: Essentials of Physics Explained by Its Most Brilliant Teacher

by Richard P. Feynman

First figure out why you want the students to learn the subject and what you want them to know, and the method will result more or less by common sense.

all things are made of atoms—little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another.

Another way to remember their size is this: if an apple is magnified to the size of the earth, then the atoms in the apple are approximately the size of the original apple.

Helium, even at absolute zero, does not freeze, unless the pressure is made so great as to make the atoms squash together. If we increase the pressure, we can make it solidify.

An ion is an atom which either has a few extra electrons or has lost a few electrons.

In their study of nerves, the biologists have come to the conclusion that nerves are very fine tubes with a complex wall which is very thin; through this wall the cell pumps ions, so that there are positive ions on the outside and negative ions on the inside, like a capacitor.

the most remarkable discovery in all of astronomy is that the stars are made of atoms of the same kind as those on the earth.

A poet once said, “The whole universe is in a glass of wine.” We will probably never know in what sense he meant that, for poets do not write to be understood.

Although energy is conserved, nature does not seem to be interested in it; she liberates a lot of energy from the sun, but only one part in two billion falls on the earth.