Bad Astronomy: Misconceptions and Misuses Revealed, from ...

34 BAD ASTRONOMY BEGINS AT HOME
people were not as smart as we are now, the ancient Greeks theorized
about the existence of atoms. The thinker Democritus deduced
that if you split a rock in half, then do it again, and again,
and again, eventually you might come to a point where you simply
cannot split it any more. That tiniest part he called an atom, meaning
“indivisible.”
This knowledge was interesting but of no fundamental meaning
until thousands of years later. The advent of better technology
let us investigate these tiny atoms. At first, it was thought that the
atom looked like a solid little ball, but experiments soon showed
that there were two separate parts—a nucleus in the middle made
of particles called protons and neutrons, and an outer part containing
particles called electrons. One model had the atom looking
like a miniature solar system, with the nucleus acting like the Sun
and the electrons orbiting like little planets.
This model sparked a flurry of science-fiction stories in which
the solar system itself was just an atom in a greater universe of
matter. This concept was really just a model, not designed to be a
true picture of reality. Nevertheless, the idea still persists today in
much of the public’s mind.
However, the model turned out to be incorrect. At the very
beginning of the twentieth century, a new physics was born. It was
called quantum mechanics, and it postulated a horde of weird
theories. One of them is that electrons are not free to orbit as they
wish but instead are confined to specific distances from the nucleus.
These distances are like steps in a staircase. You can be on the bottom
step, or on the second or third step, but you can’t be on the
second-and-a-half step; there isn’t any such place. If you are on the
bottom step and try to get to the second, either you have enough
energy to get there or you stay put.
So it goes for electrons. They stick to their specific orbit unless
they get enough energy to jump to the next one. If even 99 percent
of the energy needed to jump comes their way, they cannot do it.
They need exactly the right amount to move to that next step, that
next level. This jump became known as a quantum leap.
In reality, a quantum leap is a teeny-tiny jump. The distances
are fantastically small, measured as billionths of a centimeter or less.