This image of the Vitruvian Man, taken from Leonardo's sketches, has become one of the most recognizable symbols of the Renaissance.
But why?
It's a simple pen and ink drawing, right?
Wrong!
Let's start to answer this question with a math problem.
I know how to calculate the area of a circle.
I take the value for pi and multiply it by the radius squared.
I also know how to take the area of a square.
I multiply the base by itself.
But how can I take the area of a circle and create a square with an equal area?
This is a problem often called "squaring a circle" that was first proposed in the ancient world.
And like many ideas of the ancient world, it was given new life during the Renaissance.
As it turns out, this problem is impossible to solve because of the nature of pi, but that's another story.
Leonardo's sketch, which is influenced by the writings of the Roman architect, Vitruvius, places a man firmly at the center of a circle and a square.
Vitruvius claimed the navel is the center of the human body and that if one takes a compass and places the fixed point on the navel, a circle can be drawn perfectly around the body.
Additionally, Vitruvius recognized that arm span and height have a nearly perfect correspondence in the human body, thus placing the body perfectly inside a square as well.
Leonardo used the ideas of Vitruvius to solve the problem of squaring a circle metaphorically using mankind as the area for both shapes.
Leonardo wasn't just thinking about Vitruvius, though.
There was an intellectual movement in Italy at the time called Neoplatonism.
This movement took an old concept from the 4th century developed by Plato and Aristotle, called "The Great Chain of Being."
This belief holds that the universe has a hierarchy resembling a chain, and that chain starts at the top with God, then travels down through the angels, planets, stars, and all lifeforms before ending with demons and devils.
Early in this philosophic movement, it was thought that mankind's place in this chain was exactly in the center.
Because humans have a mortal body accompanied by an immortal soul, we divide the universe nicely in half.
Around the time Leonardo sketched the Vitruvian Man, however, a Neoplatonist named Pico Della Mirandola had a different idea.
He pried mankind off the chain and claimed that humans have a unique ability to take any position they want.
Pico claimed that God desired a being capable of comprehending the beautiful and complicated universe he had created.
This led to the creation of mankind, which he placed at the center of the universe with the ability to take whatever form he pleases.
Mankind, according to Pico, could crawl down the chain and behave like an animal or crawl up the chain and behave like a god, it's our choice.
Looking back at the sketch, we can see that by changing the position of the man, he can fill the irreconcilable areas of a circle and a square.
If geometry is the language the universe is written in, then this sketch seems to say we can exist within all its elements.
Mankind can fill whatever shape he pleases geometrically and philosophically as well.
In this one sketch, Leonardo was able to combine the mathematics, religion, philosophy, architecture, and artistic skill of his age.
No wonder it has become such an icon for the entire time period.
This may sound strange, but I'm a big fan of the concrete block.
The first concrete blocks were manufactured in 1868 with a very simple idea: modules made of cement of a fixed measurement that fit together.
Very quickly concrete blocks became the most-used construction unit in the world.
They enabled us to to build things that were larger than us, buildings, bridges, one brick at a time.
Essentially concrete blocks had become the building block of our time.
Almost a hundred years later in 1947, LEGO came up with this.
It was called the Automatic Binding Brick.
And in a few short years, LEGO bricks took place in every household.
It's estimated that over 400 billion bricks have been produced -- or 75 bricks for every person on the planet.
You don't have to be an engineer to make beautiful houses, beautiful bridges, beautiful buildings.
LEGO made it accessible.
LEGO has essentially taken the concrete block, the building block of the world, and made it into the building block of our imagination.
Meanwhile the exact same year, at Bell Labs the next revolution was about to be announced, the next building block.
The transistor was a small plastic unit that would take us from a world of static bricks piled on top of each other to a world where everything was interactive.
Like the concrete block, the transistor allows you to build much larger, more complex circuits, one brick at a time.
But there's a main difference: The transistor was only for experts.
I personally don't accept this, that the building block of our time is reserved for experts, so I decided to change that.
Eight years ago when I was at the Media Lab, I started exploring this idea of how to put the power of engineers in the hands of artists and designers.
A few years ago I started developing littleBits.
Let me show you how they work.
LittleBits are electronic modules with each one specific function.
They're pre-engineered to be light, sound, motors and sensors.
And the best part about it is they snap together with magnets.
So you can't put them the wrong way.
The bricks are color-coded.
Green is output, blue is power, pink is input and orange is wire.
So all you need to do is snap a blue to a green and very quickly you can start making larger circuits.
You put a blue to a green, you can make light.
You can put a knob in between and now you've made a little dimmer.
Switch out the knob for a pulse module, which is here, and now you've made a little blinker.
Add this buzzer for some extra punch and you've created a noise machine.
I'm going to stop that.
So beyond simple play, littleBits are actually pretty powerful.
Instead of having to program, to wire, to solder, littleBits allow you to program using very simple intuitive gestures.
So to make this blink faster or slower, you would just turn this knob and basically make it pulse faster or slower.
The idea behind littleBits is that it's a growing library.
We want to make every single interaction in the world into a ready-to-use brick.
Lights, sounds, solar panels, motors -- everything should be accessible.
We've been giving littleBits to kids and seeing them play with them.
And it's been an incredible experience.
The nicest thing is how they start to understand the electronics around them from everyday that they don't webblaura@example.org.
For example, how a nightlight works, or why an elevator door stays open, or how an iPod responds to touch.
We've also been taking littleBits to design schools.
So for example, we've had designers with no experience with electronics whatsoever start to play with littleBits as a material.
Here you see, with felt and paper water bottles, we have Geordie making ...
(Clanging) (Buzzing) A few weeks ago we took littleBits to RISD and gave them to some designers with no experience in engineering whatsoever -- just cardboard, wood and paper -- and told them "Make something."
Here's an example of a project they made, a motion-activated confetti canon ball.
(Laughter) But wait, this is actually my favorite project.
It's a lobster made of playdough that's afraid of the dark.
(Laughter) To these non-engineers, littleBits became another material, electronics became just another material.
And we want to make this material accessible to everyone.
So littleBits is open-source.
You can go on the website, download all the design files, make them yourself.
We want to encourage a world of creators, of inventors, of contributors, because this world that we live in, this interactive world, is ours.
So go ahead and start inventing.
Thank you.
(Applause)