Jo Ann Caplin

is a senior fellow at the University of Pennsylvania and is producing a limited series for PBS called Science+Art

He was born out of wedlock. He was a vegetarian. He loved practical jokes. He didn't have a university education. He was talented, however, in many ways. He understood that aesthetics served science and technology. He designed beautiful machines. He lived in a time of extraordinary change and growth. He created incredible works that moved forward that change and growth.

If you have been reading Walter Issacson's book on Steve Jobs, you may think that I am referring to him. I'm not. I'm talking about Leonardo da Vinci.

As a professor who teaches a course called "DaVinci: Scientist and Artist," I always ask my students: "What would Leonardo be doing if he were alive today?"

The answers are many.

Because of his beautifully detailed anatomical drawings and his love of animals, some answer that he would be a veterinary surgeon.

Because he designed cities with waste management and health issues in mind, some say he would be a famous architect, helping us understand how to live more healthy lives.

Because he made extravagant theatrical stage performances for the ruler of Milan, many say he would be a great director of theater and film.

Because he did research on flight and designed a glider that worked, and helicopter concept that in his time did not work, students say he would be a great aviator and designer of flying machines of all kinds, or be a rocket scientist working for NASA.

Because he studied astronomy and, 100 years before Galileo, wrote, "The sun does not move," students say he would be an astronaut.

Because he studied light in depth, both to help in his painting, and because, according to Leonardo scholars, he was "the most curious man alive," he came up with the dual nature of light both as waves and particles, students say he would be a physicist.

Because he studied water flow and what we now call fluid dynamics, some suggest he would be the mathematical wunderkind who discovered fractal math.

When asked, I always say: "He would be Steve Jobs."

Because Leonardo hid his scientific works, mostly for fear of being charged with heresy by the Catholic Church, his science was not well-known during his lifetime. And then the scientific Notebooks were lost for more than 200 years. We think we now have only about a fifth of them.

Since the Notebooks were found, each generation since has marveled at them, found something new in them. Martin Kemp, one of the most important Leonardo scholars today, started his academic career in the natural sciences, as a botanist, which led him to Leonardo's drawings of nature, trees, flowers, and grasses. Fritjof Capra, the physicist and systems analyst who wrote about the science of Leonardo, was attracted by Leonardo's thinking the Earth was a living organism with everything interconnected, which mirrors today's Gaia theory.

Others just marvel at his drawings and paintings, which changed the course of Renaissance art with the delicately wrought sfumato and aerial perspective and backgrounds of flora and fauna and rock formations so accurately portrayed. And of course, the smile of the most famous painting of all, the Mona Lisa, still intrigues.

But why would I say today Leonardo da Vinci would have been Steve Jobs?

It's not just that they were both born out of wedlock, that they were both vegetarian, that they both enjoyed practical jokes. It's not just that they both did not attend the university. It's not just that they both mixed aesthetics with science, but that's important. For Leonardo drawing was a way of "knowing." And they were different, too. Leonardo used all of his charm to stay employed during the turbulent times of the early Italy Renaissance. Steve Jobs we know was difficult and brash, but we are lucky that he understood how to market and did it well. Very well! Leonardo, except for his art and engineering plans, kept the rest of his work hidden, only to be revealed hundreds of years later to stun us.

But both Jobs and Leonardo followed their own paths, their own way. They lived in times of extraordinary change and were in the right place to make change happen. Both men were able see further than others; they were able to understand that there were things society wanted or needed that society didn't know it wanted or needed. But that is not enough. They both were able to affect our world in such a way that we can call them genius.

E-mail Jo Ann Caplin at jocaplin@sas.upenn.edu.