The return spring on the throttle cable, or...

But you can imagine, if I have just a wall, and then I have a spring attached to some mass right there, and let's say that this is a natural state of the spring, so that the spring would want to be here, so it's been stretched a distance y from its kind of natural where it wants to go.

And I'll say this is a positive rightward direction, so it's that force, and then you have a minus force from the spring.

Watch that hand on the spring.

(Laughter)

So we thought, OK, this must be a spring the saddle could very well be a spring.

And let's say I have some external force right here.

It's not the spring. It's the linkage from the pedal to the carb. See?

The spring slams shut in 38 thousands of a second.

There's a cuff and a spring. They both have teeth.

There needs to be some kind of spring loaded mechanism in order to generate the amount of force that we observe, and the speed that we observe, and the output of the system.

If you look on this, imagine a piano keyboard.

like Richard, or a cockroach, or a crab, or a kangaroo, the relative leg stiffness of that spring is the same for everything we've seen so far.

These molecules, as you saw in the beginning, the building blocks had springs connecting them to each other.

They all work like this kangaroo, they bounce.

We couldn't believe that it could do this.

So if you had no outside force, if this was zero you'd have a homogeneous differential equation.

You push down on the spring, disengage the teeth like that.

A sofa sprouting springs... a 24 hour water supply from the leaking roof

Commonly I rested an hour or two in the shade at noon, after planting, and ate my

The animals, when you look at them running, appear to be self stabilizing like this, using basically springy legs.

You don't think I was right?

Interestingly, what I did with these rollers is, basically, I took them off of these mouses and then put them in one line.

I translate natural mechanics into wooden parts that are operated by strings and springs.

And they can be modeled by a spring mass system that we call the spring mass system because we're biomechanists.

Or I heard the peep of the young when I could not see the parent bird.

Its large eyes appeared young and unhealthy, almost dropsical.

So you put a message into this device and then you roll it on the wall, and it basically has all these solenoids pressing the buttons on spray cans, so you just pull it over a wall and it just writes on the wall all the political messages.

But scientists now know that a traumatic event doesn't doom us to suffer indefinitely.

And then we did a series of calculations, and what we were able to show is that these mantis shrimp have to have a spring.

And all of these are the same principles that apply to the saddle shaped spring in stomatopods.

And again, that brings us back to the importance of that spring in storing up and releasing so much energy in this system.

So, the saddles that saddle shaped spring has actually been well known to biologists for a long time, not as a spring but as a visual signal.

And interestingly, this turns out the stomatopod saddle turns out to be the first described biological hyperbolic paraboloid spring.

And one of the reasons why he designed roofs this way is because it's he found it fascinating that you could build such a strong structure that's made of so few materials and can be supported by so few points.

Now and then he'd come into the club with a kind of cloud on his shining morning face, and I'd know that there had been doings in the home but it wasn't till well on in the spring that he got the thunderbolt just where he had been asking for it in the thorax.

They range from this fluffy toy that is about hugging you because autistic children like to be hugged tight, so it has a spring inside all the way to this doll with a mirror so the child can see him or herself in the mirror and regain a sense of self.

So, we've had very solid evidence showing that that saddle shaped structure actually compresses and extends, and does, in fact, function as a spring.

Since energy density implied by cosmological constant is constant in time, it corresponds roughly to the force that is proportional to the distance, like the elastic force.

And these animals may very well be making use of not only the force and the energy stored with that specialized spring, but the extremes of the fluid dynamics.

A little flock of these titmice came daily to pick a dinner out of my woodpile, or the crumbs at my door, with faint flitting lisping notes, like the tinkling of icicles in the grass, or else with sprightly day day day, or more rarely, in spring like days, a wiry summery phe be from the woodside.