The New Hampshire filmmaker's latest is a gorgeous portrait of Renaissance genius: "The man of the last millennium," Burns says.

Ken Burns has told me time and again, in various interviews about his various films, that all his films are about the same thing: "us" lowercase and "U.S." capitalized.

But his latest film, for the first time, looks "at just the two lowercase letters," the 17-time Emmy winner told me from his Walpole, New Hampshire, home this week. "Just us."

And how.

I was gripped watching "Leonardo da Vinci," a two-part four-hour documentary directed by Burns, his daughter Sarah Burns and her husband David McMahon. It airs Monday and Tuesday on PBS. Stream it via PBS.org, the PBS App, and PBS Passport.

This is what Burns and company do best. They take a subject most of us think we know something about -- from country music to baseball -- and blow your mind.

We all know the 15th-century Italian Renaissance man. Heck, there's a Teenage Mutant Ninja Turtle named after him. But if you remember only school-days key terms -- Mona Lisa, flying machine, Vitruvian Man, Last Supper -- "Leonardo" is jaw-dropping.

This is us.

This is what it means to be human, to wonder about this world, to understand the intertwined relationship between the macro and the micro. He saw the human body relating directly to how the earth works. Human veins like tree branches. A river flowing from the ocean blood to the head.

He theorized why the sky was blue. He saw marine fossils and concluded the earth was ancient and must've been underwater at some point -- not created in seven days, as was the current thought.

A century before Galileo, Leonardo mused on the force of gravity, and filled a jar with sand to calculate the earth's gravitational constant. He helped one church with their water system, and another with bell tower construction.

You almost sense he invented film -- from his notes about how to paint a realistic battle scene, how he takes the storyline of the Last Supper and brings it to cinematic life -- each person at the table reacting viscerally to the news that one is a traitor.

His analysis of the mathematics of birds in flight, how a human-made machine could replicate the physics.

He painted human emotion by studying anatomy. He opened up cadavers to study the heart, and studied the human skull to see how the brain fit. He dissected to study nerves and blood vessels, and how a face flushed. He looked at the liver, bladder, kidneys, and colon.

He opened up the heart and discovered there were four chambers, not two as previously thought -- and there was no such thing as surgery in the 1500s.

"In some ways, we're all still living within Leonardo's dreams," Burns, 71, tells me. "He is, arguably, the man of the last millennium."

"Leonardo is the most curious man who's ever lived," the Hampshire College alum tells me. "As Guillermo del Toro says [in the film], his job was to interrogate the universe and ask: What is the nature of the universe? What is the nature of man? Why am I here? What is my purpose? Where am I going? These are things our own siloed society doesn't do anymore."

What I love most about this film is how little we're told about da Vinci's personal life.

We get the skeleton sketch -- born out of wedlock in 1452 to a peasant mother and notary dad. Couldn't go to university because of his status, so he became proudly self-taught, hyper-curious about the world around him. Experts tell us he was probably gay -- then we quickly move on to his genius.

"You think about Oppenheimer: Nobody made an attempt to try to explain physics or fission to you -- but we did know that he cheated on his wife. And we do know he had political problems," Burns tells me. "Don't you want to know how he figured out how to create an atom bomb? I mean, it's a great film, but it's still a slave to the idea that it has to be juicy."

Spot on.

This is no "Oppenheimer." This is simply a riveting portrait of a beautiful mind.

It may be Burns's most emotional film to date. I had goosebumps at the end.

In an era where so many humans are obsessed with the hyper-personal on Instagram or TikTok, content to passively take in information from influencers, get your facts from Siri and Wikipedia and podcasts, walk past a dragonfly or blackbird without a second glance -- this is an urgent reminder to never cease wondering. Of what can happen when one is endlessly curious.

I had to call New England's Television Academy Hall of Famer to unpack the Italian polymath.

So why Leonardo? Your first non-American subject.

I was dragged kicking and screaming into it. Years ago, I was working on "Benjamin Franklin," having dinner in Washington with Franklin's biographer [Harvard alum] Walter Isaacson, an old friend. He spent almost the entire dinner trying to convince me to do a film on Leonardo.

I was like, "Walter, Walter, I only do American topics." He kept pushing, I kept pushing back. Later, I talked to Sarah and David, and they said, "Why not?" So this old dog decided he could learn new tricks.

[laughs] You've got some new techniques here, too. It's your first time using a split-screen, videos from different eras.

It was a risk, because I take an old photograph or a painting and I treat it as if it's a motion picture.

Right, the Ken Burns Effect.

If I do a split-screen, I'm returning it to its two-dimensionality, its plasticity. This was a risk. But there's an exuberance and joy to Leonardo. He's all about this joyous exploration. So it demanded a different grammar.

He's the epitome of the modern man. He's questioning the received wisdom of his time -- I mean, he's looking at how the heart works before surgery existed.

To me, he's a modern person. I think he'd be totally OK now. He'd go, "Oh, OK, you figured that out." "Oh, you got to the moon. What did you do about the gravity thing?"

[laughs] He truly is the quintessential Renaissance man. It's incredible how many fields he was curious about.

He's a thinker, a writer, the greatest scientist of the age, a botanist, and an anatomist. [He] studied water dynamics, aerodynamics and flight, atmosphere, geology, cardiology -- even though it doesn't even exist. And, by the way, he's the greatest painter.

You mention siloes of education. He couldn't go to university, so he had no discipline -- he taught himself everything through observing nature.

He's a guy born out of wedlock who, therefore, cannot go to traditional university, so he's liberated from the tyranny of that. By the end of his life, he knows more than any scholar in any one branch -- whether it's mathematics, philosophy, theories of painting or water-dynamics -- it's just spectacularly inspiring.

Because he doesn't have any silos, disconnecting disciplines from one another, it's all one discipline, asking one big question: Who are we? What is our purpose?

I was stunned that he noticed how dragonflies fly -- that they have two sets of wings, and one goes up while the other goes down.

And Lauren, he doesn't have a microscope.

It's unreal. His observations about fossils, how rain gets to mountains, how the chambers of the heart work -- it's a beautiful mind.

He's got 4,000 pages filled with observation and experiments. There's no diary saying: Oh, I hate this person. I love this. I feel this.

So we get the luxury of not having to do the TikTok personal stuff, and instead do what he's all about. We were liberated from the tabloid sensibilities that inform our present day.

I loved that it didn't get too personal, or guess at his love life. It let you really dive into his mind. Experts briefly mentioned Giacomo Caprotti, [also called Salaì] who lived with him. They say: Leonardo was probably gay, then you move on.

It seems quite probable he was gay, [but] we don't know. He never wrote, "I made love to Salaì." His notes are straightforward, grocery lists, in his mirror script.

That's another thing that surprised me: He wrote everything backward because he was left-handed.

I'm a leftie; I smudged papers all my life.

[laughs] You always get this question, but what do you want people to take from this film?

For 50 years my answer to that has been: "I just want to tell a good story. Whatever you want to get out of it, you can get out of it." But now, I think I want people to want to be more like Leonardo.

To focus, to concentrate, to be aware of nature, to observe, to see the way light strikes objects, to see how everything is connected -- there are no separate disciplines. He was a cartographer and drawing master and inventor and designer and architect. It all becomes one unified pursuit. The Mona Lisa is a great work of science, and his anatomies are great works of art.

I love that.

So I'd want people to be more like him. The other thing is I want people to stop making jokes about Mona Lisa smiles.

[laughs] Right.

I understand why. But when you understand that this painting is the apotheosis of his understanding of how the universe works, she is the embodiment of the entire human project -- it's exquisite beyond belief.

Our film scholar says, Google the Mona Lisa. Look at her right cheek and try to see where the divisions are between the cheek to the nostrils, to the eye, down to the lips -- you just can't find it. It's just an imperceptibly perfectly rendered human being. He's taken inanimate objects -- pigment, poplar panel -- and turned them into a human being. He wanted to understand the intentions of [his subjects] minds: What are they thinking? What are they feeling? What's the story here? Everything is wrapped up in that smile.

You mentioned the intention of the mind -- I found that so powerful in the film. That he wondered about the nerves in the eyes, how that reflected the brain, the way the brain interpreted emotion. One example is The Last Supper. Ross King said it's more than a snapshot.

A painting represents a frozen moment -- but his represents a whole series of moments [by capturing subjects'] emotional and spiritual and mental life. I think today he'd be a filmmaker and put us all out of business [laughs] because he'd have figured out how to capture narratives with such extraordinary compassion.

Or the way his interest in emotions was tied in with his interest in anatomy.

He's experimenting with heart valves and how blood flows. He's building, for no practical reason, a model of the heart using silk as the valves, pumping in grass-seed and water. And he's understanding the mechanics of how they open and close. You just go, "OK, Leonardo, what's this for?" But 450, 475 years later, we find out that that's exactly the way a heart works.

Why do you think he matters now, at this moment?

He's so modern. I have a friend who's a foot doctor who says he only uses Leonardo's drawings of the foot.

I think also, like you were saying, we don't have that sense of connection to nature anymore. We don't have that curiosity anymore. It seems a critical time to bring that back.

We've lost that connection. I have a wish that people would want to be more like him. He's inspirational.