Sean Ulm

And it reminded me very much of doing a degree in botany, where you were looking not just at the mountain, but these sections.

only about, you know, a square metre of terrain.

What's the soil like?

What are the other little plants like?

Not just what are the trees like, but you've got detail there, which is in the soil itself, you've got thousands of organisms.

And similarly, on a tree, you've got another...

a couple of who knows how many different organisms.

And the indigenous people knew this, and they also knew which plants you could actually light up for a white smoke.

In other words, a cool fire rather than a black smoke.

They were looking at segments, sections, in the same way as I used to, being trained in modern science, so-called.

Sean, we're talking about your book, written, of course, with two other authors, Billy Griffiths and Larissa Berendt, who presents a program on ABC Radio National.

But what about the fish traps, the thing that startled me reading your book?

I knew about fish traps.

Most listeners do, vaguely.

But some of them were gigantic.

Distinguished Professor and archaeologist Sean Alm, such a scale.

As seen from the sky, some of these fish traps are clearly monumental.

So what about the scale of the indigenous population before Europeans arrived?

Billy Griffiths is another main author of the first inventors.

One of the most astonishing things in this amazing book