Despite these many important differences, there is one common thread
running through the solving of all the problems we have chosen. The men
who have been working on them had to know some basic principles of
classical physics—principles that most of them first learned in their
high school physics classes. You can’t, for example, calculate a
satellite’s orbit without knowing Newton’s Laws of Motion. You can’t
make optical measurements on a satellite without knowing the law of
reflection of light. You can’t decide what color a satellite should be
without knowing the law of heat exchange.
To emphasize the importance of a solid grounding in basic physical
principles, we have tried to have our problems touch on most of the
general areas of physics: mechanics, heat, sound, light, electricity and
magnetism, electronics, the properties of matter, atomic physics,
physics of the solid state. But most of them, of course, are not limited
to just one of these—they cross the lines of a number of areas. For
instance, the problem of keeping solar cell power plants working in
space involves laws of heat, mechanics, and atomic physics, as well as
physics of the solid state. And, in studying the perception of time
delay, we even branch out into experimental psychology.