- Hi, it's Ken Burns for our series of Unum chats focused on Leonardo da Vinci.

I am thrilled to speak today with Dr. Attu Gowane, a renowned surgeon, writer, and public health leader.

He currently serves as the assistant administrator for global health at U-S-A-I-D.

Prior to that, he was a practicing general and endocrin surgeon at Brigham and William Women's Hospital in Boston, and professor at Harvard Medical School.

As if that wasn't enough, you might also be familiar with his four count, them four New York Times bestselling books, particularly the incredible to me being mortal.

Welcome Dr. Gwane to our Unum Chat.

It's such a pleasure and honor to have you.

- Great pleasure to, to meet you and, and talk to you.

- Great.

Well, we're gonna start off by watching a short clip from our film on Leonardo da Vinci.

This clip is from the second part of our two part film later in Leonardo's Life, and to sort of set the scene, his workshop is now in a villa outside of Milan.

He's been in Florence, he's been in Milan.

He's been forced outta Milan, he's been to Rome.

He is been various places there.

He continues his research into a variety of his interests, particularly in human anatomy, which has fascinated him for years and years.

So let's play the clip and I'll get your reaction to it on the other side.

- At Villa Meze, Leonardo had also returned to his anatomical studies, dissecting ox hearts to determine how blood flows through their chambers and valves.

He now recognized that rather than having two chambers as anatomists had believed since the second century, the human heart had four marvelous instrument invented by the supreme master.

He had written below a drawing.

- He came up with this totally accurate idea that the valves begin to close while a blood still flowing through them, and he translates that along with other knowledge to saying, well, look, that's what must happen to the blood.

It must form these vortices and the vortex, which is forming as the blood is still flowing outta the heart, is actually unfurling the leaflets so they can close in perfect harmony.

And then he challenges himself, well, what if I'm wrong?

What happens there?

He then designed an experiment to demonstrate how this happens.

- He writes notes to himself that how to actually pour hot wax inside the calf heart and then use that wax model to make a glass model out of it and buy some silk fabrics and cut it to the shape of the leaflets of the heart of the calf, and, you know, sew it together and then put together perhaps the first, you know, synthetic heart valve ever.

Then he uses water and hand pump and use grass seeds to do visualization, basically watching how the flow pattern forms every time the heart valve opened or closed, - The first ever drawing of a synthetic heart valve, which is exactly like heart valves we use today, tissue valves.

But he didn't stop there.

He went on and he described why the aortic valve, pulmonary valve had to have three leafs, not two, not four, through geometric proof, beautiful geometric proof.

- It would be more than 450 years before scientists using modern imaging techniques proved Leonardo's theory.

Correct.

- Why, why did you, why did you do this?

First of all, there's no use for it.

There's no cardiac surgery, there's no cardiology.

You couldn't do anything with it.

So it wasn't of any use to anybody.

It was purely understanding for understanding sake.

- Well, thank you for watching that.

I just, what, what did you think?

I'd love to just start off with your reaction to that short clip.

He - Was such an incredible scientist.

He was someone who just thought unlike people in his time, you know, in that era, people were not probing at this level of depth, this level of curiosity and this level of fearlessness.

I mean, he's dissecting not just a calf heart.

He's dissecting people's bodies and unpacking a, a deep understanding of what is happening.

That example is just one of many, many examples.

He discovers the structures of the brain and the, and the ventricles of the brain and the spinal system.

I mean, the over and over and over again, he's doing this at, at, at extraordinary depth.

- Dr. Wells in the film described Leonardo's research into heart valves, is understanding for understanding's sake, and since cardiology didn't even exist as he points out at the time, you know, how would you describe what's going on right now?

Are we so imprisoned by specialism?

Are we able to get to the place where we're working purely at a theoretical or investigative or just sheer curiosity sake rather than the physical or the practical or the applied?

What's, what's happening now in the cutting edge of medical research today?

Are, are people, do we have anybody that approaches the kind of free thinker that, that Leonardo was?

Of course, without the benefit of a telescope with, of course, without the benefit of a microscope, but his own eyes and received wisdom that has been incorrect for millennia and suddenly is able to, to do something, which only 500 years later do we realize he was absolutely right.

- We, we do, I mean, there, the incredible thing about our current era is that you don't just have to just rely on rich philanthropists.

We have our version of those today who are benefactors to the arts and the sciences and allow for wide ranging free thinking out of just curiosity.

But we have entire institutes, right?

We have the National Institutes of Health where people are investigating the structure of, of, of humanity, the structure of biological existence.

We have the National Science Foundation.

So, so through these we have hundreds of thousands of people getting to be Leonardo's really discovering and focusing on, on an incredible range of things.

And, and that has caused the pace of incredible progress.

It's part of the frustration of Leonardo so, so brilliant, so amazing, had all of these insights and he never published them.

They all sat in his codex and he, you know, 450 years of knowledge that could have been unpacked earlier.

It would've been incredible had he had a kind of a menu that someone to turn the discoveries as he is making them in his own code textbooks into something that the rest of the world could have learned from.

- Yeah, I agree.

I I agree with you.

There's something sort of frustrating in that and, and though he might have run afoul of the church, had he published a lot of these things and often the church was the sponsor.

There's something so incredible to me that he saw no distinction between the works that he was doing.

That is to say, I would venture to say that the Mona Lisa is a great work of anatomy.

In fact, one of the exultant reviews that came later on is that someone was in the midst of describing the face, but then dropped down to the neck and said, I'm certain that I can see the pulse and I can see the flow of blood in the veins of, of her neck.

And it, it, it's magnificent.

And so too, these scientific or so-called scientific drawings are, are complete works of art, and it will be centuries before people will do it, but he's way ahead of Galileo and Newton and in sometimes employing things like calculus that didn't exist or, or having to reach conclusions that only calculus would've been able to bring us to.

And that the fact that he didn't have it makes him stunning to me in that regard.

- Yes.

You know, here's the, the part that I wonder if we have today.

He was the artist combined with the scientist who was following his curiosity everywhere, and that refusal to be either or, right?

He was an artist who wanted to understand how the muscles lay on the bones and then the, the capillaries fed into the skin and the, and, and therefore you understand how not only the contours of the skin, but how it colors and how it changes with emotion and then depict that.

And that was to make him a better artist.

But the art helped him be a better scientist, right?

And they fed into each other in a way that, that, you know, you, I don't know that, that I can think of an example of, of people who currently exist can follow that scope.

And really we have the scientists who will follow the curiosity.

We have the artists who will push the boundaries, but the artists, scientists who will make discoveries in both realms, who will shape the standard that way, that extraordinary ability is, I, I bet there are corners that, that exist in that way, but with the kind of impact and influence that he could demonstrate.

I don't know an a modern example of that.

- This is the first time that we've ever pursued a subject outside of the history of the United States.

And one of the reasons is because he is just so sui generous and you realize that he's inheriting A-A-A-A-A, a Western Greek and Roman tradition that's more observational, but he's adding experimentation, which is more from the Muslim world at the time, and he's coming to these conclusions.

I'm, I'm just, you know, fi you know, figuring out that there are four chambers, and not only that, how the valves work and the precision of that.

I, I don't think there's anybody I, I know there, there's great medical exploration, but I don't think we see in one person as you're describing this sort of combination of all of these interests.

And for him, I think the divisions of labor are inseparable.

He would, if he were here, he would not be talking about any difference between an artist and a scientist.

- No.

And, and, and I think we have, you know, we have people who want to aspire to that.

There are incredible scientists who can turn their own scientific work into objects of beauty.

You see it in photography of, of science and cells and molecular observations and in space and from, you know, the, the different telescopes now floating around the universe helping us understand more about the space and yet to have shaped our imagination, our understanding of what's possible through art as well as what's possible through understanding of science.

Credible, - You're a renaissance man yourself, and as a surgeon and an author, and now a government official, an administrator, can you talk about your career and the integration of these seemingly to most of us disparate sort of dialectics and, and where you find inspiration in your pursuits and how they might affect other aspects of your life.

Is there cross pollination?

Are you able to integrate this stuff?

Do you feel in a way as if Leonardo is a source of inspiration and possibility and not just awe that here's somebody using 75% of his brain while the rest of us are, are sort of scraping at along at about 10%?

- Yeah, I mean, it's hard to call him a source of possibility, but he is a source of permission and, and sparks imagination.

I, my career was born, you know, I was born the child of two Indian immigrant doctors, and that pathway was clear possibility for me, and in many ways I resisted it, but I was very at home in the, in the sciences and, and wanting to work with people and solve problems.

But for whatever reason, there was part of me attracted to people in the arts world.

When I got married in my twenties, four outta my six groomsmen were writers and I had never written before.

In fact, one of them was the one who persuaded me to begin to start writing.

I I might have been born in some way to do science and public health and, and, and that line of work and, and do surgery.

That was very natural pathway and, and in the family, so to speak.

I was not a born writer.

I had my, I in college, my worst grade was in writing.

I took writing classes because there was a girl in, in the fiction writing class that I was particularly interested in.

We're now married, we've been together since this will be the 40th year.

And, and the, and and I thought she would've been the one and she became an editor and, and, and is a source of inspiration and connection to the arts for me.

And, you know, I'm, I'm a nonfiction writer.

Creative nonfiction is the closest I get to capturing a little bit of what some artists want to do.

And it's fantastic.

I've found an audience.

But you know, as my editor said, promise me you won't write fiction.

The the ability to get into the imagination of impossible worlds, impossible objects and ideas and, and throw them together.

I, I struggle with the reality of something of the, of what might have happened in the world, A million ways you can tell that story, then thinking about millions of possibilities and, and, and finding a pathway through where you actually get anything done in being creative in a, in a fictional world.

That's what he managed to be.

I mean, the other part of him that's incredibly frustrating is that he didn't get so much done.

He, there were these series of masterpieces that came out.

He could tolerate not being, you know, the productive machine.

- I I agree completely.

I I think it's always interesting, stunning for our audiences to understand that when you say how many paintings does Leonardo have?

It's fewer than 20, and how many of them are finished and it's fewer than 10.

And yet we have all of these thousands and thousands of pages of his diaries, the codex, and with these remarkable drawings and sketches and inventions and, and ideas days - On end, just, just trying to capture the swirl of a, of, of water out of a pipe.

- Any of, Yeah, it's, it's amazing.

And doing this as a lefty who's writing backwards in a mirror script, which begins to tell you that each one of those pages is in itself some extraordinary imposed discipline that none of us would have sort of the ability to, to replicate.

And he's still as open and as curious and as inventive as you could imagine.

But I I, I understand your fiction dilemma.

I'm, I'm in the business of telling true stories as much as I can get at them.

Is there a way in which your scientific training has served you in that regard?

The mysteries, the unknowns, the things that are part of, of our, our systems that aren't binary.

We insist on imposing these binary systems when as nature shows us very few things are, are that way, - Yes.

But what I would be, what I'm struck by is how much the effort at I, I hesitate to call myself an artist, but to create something new every time on the page feeds into my work in science and in medicine and in public health.

So I'm often running into problems in, in, in real world of practicing and, and doing the various things I do, which puzzle me.

It might be, you know, a case of a woman who had such a horrendous itch that as I was reading in a journal she scratched through her own skull and injured her own brain.

Now why, how does that happen?

What, what, what, what is itching?

What's the nature of, of what does that tell us about sensation?

That, that I could go interview her, find out her story, make the connections and have an excuse because I'm a writer, to talk to scientists about the different theories of perception and then write a piece around that that I can also use to make you really itchy.

Like one of my goals in that piece was to make you want to scratch as well.

And, and that now I can take on subjects like that, that probe different kinds of questions, but then other times I might be asking, why does medicine cost so much?

Or, you know, why have we not eliminated polio entirely in the world yet?

And those then that exploration, getting to ask people questions, think about how to tell the story, how to grab people and remove some of my own confusion leads to sometimes my saying, oh, I've laid out a possible pathway here out of the story.

Now let me try to take that in the real world.

Let me test this hypothesis.

I'm running a research center here now running a, a global health bureau where I lead all foreign assistance.

I can take that into the real world and create an experiment and test it out, and then I will learn things and things will be wrong, and I'll be confused again, and then I can explore that creatively and, and try to resolve that, that confusion, that cycle, I find has, has made me much more effective as a writer and a scientist.

I have confusions I run into every day in the practice of being in the world that I then really need that Albert Albert to understand and explore.

- Well, this sounds like very much a mirror of our beloved Leonardo Guillermo del Toro.

The filmmaker said that he had this chance to interrogate the universe.

And that doesn't mean that the question, the answers that the universe gives you back are, are the, are the answers per se.

And so we will liberate you right now to go back and do the things that Leonardo did to try to forge these connections.

And we're so grateful for the time you've given us and the spectacular answers to, to our, our questions about Leonardo and creativity and science.

Thank you so much Dr. Gwane.

- Thank you for your film.