What exactly is your telescope measuring, and what does that tell us about the galaxy?

Yeah, uh, it turns out that one of the easier ways of getting started with radio astronomy is by picking up, uh, what, what I call the heartbeat of the Milky Way.

It's, it, it turns out that, uh, there's a, a physical process- That is really astounding to think about.

We live in a galaxy that is composed of, of stars and gas and dust, and most of that gas is hydrogen.

Uh, that's the most abundant element in the universe.

Once in every 10 million years for an individual atom, there'll be a spontaneous flip of the electron spin axis, and what'll happen is it'll give off a photon of energy, and you can calculate the frequency and the wavelength of that energy, and it turns out it, it falls right in the radio spectrum at, uh, 1,420 plus some little bit of, uh, megahertz.

And you would think that, well, if there's...

Is that how you're able to reconstruct the galaxy's structure?