This is CBS I In The World. I'm John Batsow with Govert Schilling, his wonderful new book,

The Elephant in the Universe, 100-year search for dark matter. It also has travels and

his conversations with astronomers and researchers in deep minds in the beautiful

Chile, high desert of Chile, and also back in time, Govert is going to take us to the big

bang and why it is that that's important to make part of the search for dark matter.

What happened in the first moments? How can we imagine it, Govert?

It's an extremely complicated topic, but we see now that space is expanding because all

the galaxies get farther and farther away from each other. So the empty space between

galaxies is expanding. That's something that we have measured over and over again.

So if you try to work that back in time, you must realize that in the past everything,

all the matter in the universe was closer together. And if you go back in time,

then it must have started in a very dense state and a very hot state, and that's what the

storm was called, the big bang, which is actually the birth of our current universe.

Obviously, there are many, many riddles about the big bang. We don't know why it started or how it

started. We don't know the details, but we are pretty sure it must have happened. But now the

problem is that if you start to study the remaining radiation of this hot face, the cosmic background

radiation, this radiation tells you something about the situation back then. And you see that

the universe must have been extremely smooth back then. So maybe a little bit tiny differences

in density, but in general, very smooth, like a well-stored soup. Not much clumps and concentrations

in it. But if we look at the universe today, only 14 billion years later, it's very clumpy. We

have galaxies, we have clusters, we have big dense concentrations, we have empty voids. So somehow,

from this smooth beginnings, we must have evolved towards the current clumpy universe.

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