This is CBSI in the world.

I'm John Batchel with Govert Schilling, an astronomer chronicler, who is taking us into the part of astronomy that is the most confounding and tempting to astronomers, to cosmologists, to people who read Govert's book.

We're looking for something that we can't see.

We've never found.

And we're going to try to imagine how we can certify it exists.

We need theory is wonderful.

But how do we certify it?

Now we come to Jeremiah Osterker, who, thanks to Govert,

I've been led to his book, Heart of Darkness, published just a few years ago. He is an astronomer

with firm ideas, and one of those firm ideas is to picture again what we can't see. It's called

the halo effect around our galaxy, the Milky Way,

around all galaxies. What is that? How should we picture it? Yeah, it was a strange situation because

as we discussed before, Fritz Vicki was the one who really was the main one who realized

there must be a lot of unseen matter in galaxies, but no one paid too

much attention back then. And only in the 1960s, the late 1960s, there were those theorists like

Jerry Osterker who started to calculate how a massive galaxy, like our own Milky Way galaxy,

could be stable because it's all these

rotating stars and gas clouds in a flattened disk. And when he did the calculations using

the first generation of big computers back then, he realized that a flattened disk of stars cannot stay

stable. It can only be stable when there is a big spherical halo around it

filled with some kind of matter. So he proposed that our Milky Way and other galaxies also

would be surrounded by a big halo of unseen matter and it fitted very nicely in with his observations by

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