The discovery of the neutron in 1932 was a breakthrough in atomic physics.

But it was a subtle discovery. Only specialists understood what it meant. To the average member of the general public, it was just an intellectual curiosity, like a duck-billed platypus.

Interesting that scientists discovered this, but it doesn't actually change our daily lives.

Not yet.

Welcome to the history of the 20th century. Episode 278, chain reaction.

Back in the early days of this podcast, we talked about radioactivity, which was one of the biggest

scientific mysteries at the beginning of the 20th century.

In the first two decades of the century, the physicist Ernest Rutherford determined that

the emissions from radioactive materials consisted of what he dubbed alpha rays and beta rays.

Later investigation would add gamma rays to the mix.

Upon further investigation still, alpha rays proved to be helium nuclei, beta rays electrons,

and gamma rays high-energy electromagnetic radiation, comparable to x-rays.

We talked about atomic physics most recently in episode 246, in which I told you how

physicists bombarded matter with these rays as a means of investigating the structure of the atom.

By 1921, Rutherford had sketched out his

famous model of the structure of an atom, a small, dense central nucleus with a positive

electric charge, surrounded by a large volume of empty space in which electrons orbited that nucleus.

This is basically how we still think about atoms today, although the Rutherford model is way oversimplified. It does have the advantage of offering a basic understanding of how subatomic

particles come together to form an atom, but it doesn't take

into account the peculiarities of quantum mechanics. Electrons are particles, but they also behave

like waves, or they are waves that also behave like particles, take your pick. But in 1926, the Austrian

physicist Ervin Schrodinger worked out the electron wave function,

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