When the first atomic bombs went off in 1945, people witnessed the awesome power of the atom. It was so small that even microscopes failed to detect it, and yet it could cause the largest of any man-made explosions. But it was suspected even in antiquity that the world is made up of tiny particles. The word “atom” is itself of very ancient origin, and originally meant “indivisible.” But as any high school chemistry student knows, atoms are divided into much smaller parts. These include protons, neutrons, and electrons (among other things).
It is only in recent centuries that we’ve made any real breakthroughs in understanding this strange world, and harnessing its power to both good and bad ends – with the good ends including many medical applications to cells and germs. Atomic theory owed much to other subfields of physics (and also chemistry), such as electricity, magnetism, and light. Thus, problems in these other fields would also create complications for atomic theory. For example, is light more like a wave or a particle? Isaac Newton certainly believed that light was more like a particle, but the idea was challenged even in his own time. Thus, wave theory instead became the predominant way of viewing light for some centuries. But, strangely enough, Newton’s particle theory was resurrected in the early twentieth century. In some ways, it may actually make more sense to think of light as a particle. In other ways, it may instead make more sense to think of it as a wave. But both theories have some problems, as physicists have acknowledged for decades now – even though each is borne out by data in some circumstances.
Erwin Schrödinger
Some of the major breakthroughs in this area came back in the nineteenth century. This included the discovery of subatomic particles, such as electrons. This era’s work on electricity became important here, because electrons had been shown to have a negative charge. But the atoms as a whole usually had a balance of positive and negative charges – or, in other words, an overall neutral charge. Thus, people wondered where the corresponding positive charge was coming from. Scientists eventually discovered that there were protons that had a positive charge, and that the protons and neutrons (which were neutrally charged) existed in the nucleus of an atom. Electrons, by contrast, were believed to orbit around this nucleus. This aspect of atomic theory is still taught in physical science classes today, although some scientists have since questioned this basic assumption. Thus, there is ongoing debate about this in the scientific community today.
Werner Heisenberg, the namesake of the “Heisenberg uncertainty principle”
One of the major scientists covered here is Niels Bohr. By most accounts, he is one of the greatest scientists in history – and deserves this great reputation. He had a friendly dispute with Albert Einstein over various aspects of atomic theory. Each of them had some good points to make, but neither of them seemed to believe that his own theory was “superior” to that of the other. Rather, they just believed that we’re stuck with some of the apparent deficiencies of this theory, at least for the time being. It is still the best theory that we have for atomic science, so it is still well that we teach it anyway. But many developments in atomic theory came from the realm of quantum theory. And quantum mechanics has a number of strange aspects, which seem to contradict our ordinary “common sense” notions of reality. Indeed, this is one of the most intellectually difficult audiobooks that I have ever listened to. Given that it covers both atomic and quantum physics, this came as no surprise to me, but listeners should still be warned of its difficulty before listening to it.
Ernest Rutherford
Niels Bohr
Nonetheless, this is the best introduction to atomic chemistry and physics that I have ever heard, and makes a good argument for the relevance of quantum mechanics to these debates about the atom. One hopes that some of the difficulties in these theories will eventually be sorted out, and that future generations will eventually be able to fill in some of the gaps in our current knowledge of the subject.
If you liked this post, you might also like:
Part of an audiobook series
Science & Discovery
A New Understanding of the Atom
Others to be covered later
See also the audiobook series
The Giants of Philosophy
Others to be covered later
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