Modern
Physics
Almost
everything we’ve covered in the previous 15 chapters
was known by the year 1900. Taken as a whole, these 15 chapters
present a comprehensive view of physics. The principles we’ve examined,
with a few elaborations, are remarkably accurate in their predictions
and explanations for the behavior of pretty much every element of our
experience, from a bouncy ball to a radio wave to a thunderstorm.
No surprise, then, that the physicist Albert Michelson should have
claimed in 1894 that all that remained for physics was the filling
in of the sixth decimal place for certain constants.
But as it turns out, the discoveries of the past 100 years
show us that most of our assumptions about the fundamental nature
of time, space, matter, and energy are mistaken. The “modern” physics
of the past century focuses on phenomena so far beyond the scope of
ordinary experience that Newton and friends can hardly be blamed
for failing to notice them. Modern physics looks at the fastest-moving
things in the universe, and at the smallest things in the universe.
One of the remarkable facts about the technological advances of the
past century is that they have brought these outer limits of nature
in touch with palpable experience in very real ways, from the microchip
to the atomic bomb.
One of the tricky things about modern physics questions
on SAT II Physics is that your common sense won’t be of very much
use: one of the defining characteristics of modern physics is that
it goes against all common intuition. There are a few formulas you
are likely to be tested on—E = hf in
particular—but the modern physics questions generally test concepts
rather than math. Doing well on this part of the test requires quite
simply that you know a lot of facts and vocabulary.
