Take this quad, for example.

And also, for me, biking is a matter of empowerment.

Fifth Man ... from my childhood, Fifth Man we were having fun, biking.

For example, that's how we can make the quad hover.

It naturally doesn't spill, no matter what the quad does.

Mountain biking in Israel is something that I do with great passion and commitment.

I don't care if it's mountain biking or reading a book or playing a game.

So they believe you should not just wear helmets for biking, but also for walking around.

So they believe you should not just wear helmets for biking, but also for walking around.

We added the mathematical model of the pole to that of the quad.

Here, the quad is behaving as if it were in a viscous fluid.

Twenty milliseconds later, the whole process is repeated until the quad strikes the ball.

You can notice that this quad is making fine adjustments to keep the pole balanced.

Notice how the quad lost altitude when I put this glass of water on it.

We can use mathematical models to estimate the force that I'm applying to the quad.

You know, perspective is one of these critically important life coping strategies that mountain biking can really teach you.

Suppose that we want this quad to not only hover but to also balance this pole.

We can also augment the model to include where we want the quad to be in space.

And I would go biking up to the end of the beach and buy all the comics from the poor kids.

We then manipulate these equations with the help of control theory to create algorithms that stabilize the quad.

I can point to where I want the quad to be in space a fixed distance away from me.

Like before, I could use the pointer to tell the quad where I want it to be in space.

Third, a trajectory is planned that carries the quad from its current state to the impact point with the ball.

We then next calculate how the quad should hit the ball so that it flies to where it was thrown from.

The algorithms to do this are very similar to what the single quad used to hit the ball back to me.

Once we have a model of the combined quad pole system, we can use control theory to create algorithms for controlling it.

Suppose we want this quad here to perform a triple flip and finish off at the exact same spot that it started.

Once we know this force, we can also change the laws of physics, as far as the quad is concerned, of course.

But there is a continuous world from walking, biking, driving, flying there are people on all levels, and most people tend to be somewhere in the middle.

This quad has a racket strapped onto its head with a sweet spot roughly the size of an apple, so not too large.

I will use this new capability to position this camera carrying quad to the appropriate location for filming the remainder of this demonstration.

I told the warden that I wanted to start a mountain biking club in this place and that basically I wanted to take the kids from here to there.

This data is then sent to another laptop that is running estimation and control algorithms, which in turn sends commands to the quad, which is also running estimation and control algorithms.

Let's tell the quad to come back here and let the pole drop, and I will next demonstrate the importance of understanding physical models and the workings of the physical world.

Instead, what the quad can do is perform the maneuver blindly, observe how it finishes the maneuver, and then use that information to modify its behavior so that the next flip is better.

Instead, if your friend's idea of recreation is physical activity, bowling, or playing hockey, biking or gardening, if your friends drink a little, but not too much, and they eat right, and they're engaged, and they're trusting and trustworthy, that is going to have the biggest impact over time.

Love to the country, to the uphill and the downhill, to all the incredible creatures that surround us the animals, the plants, the insects love and respect to other fellow members in your team, in your biking team, and most importantly, love and respect to yourself, which is something that they badly miss.

Or a girl who decides that she is going to leave love letters around her campus in Dubuque, Iowa, only to find her efforts ripple effected the next day when she walks out onto the quad and finds love letters hanging from the trees, tucked in the bushes and the benches.