An athlete uses physics to shatter world records Asaf BarYosef

In the early 1960s,

Dick Fosbury tried his hand at almost every sport,

but never excelled at anything,

until, at the age of 16, he turned to the high jump.

But when he couldn’t compete against

the strong athletes at his college

using the standard high jump techniques of the time,

Fosbury tried to jump a different way: backwards.

Instead of jumping with his face towards the bar,

bringing each leg over in the

traditional straddle method,

he jumped with his back towards the bar.

Fosbury improved his record by over half a foot,

and left his coaches amazed

by this strange new style of high jumping.

During the next few years,

Fosbury perfected his high jump style,

won the U.S. National trials,

and assured his place in the 1968 Olympics in Mexico.

In the Olympic Games, Fosbury amazed the world

with his new technique, winning a gold metal

with an Olympic record leap of 2.24 meters.

By the next Olympic Games,

almost all of the competing of high jumpers

had adopted what came to be known as

the Fosbury Flop.

What’s the secret behind the technique?

It lies in a physics concept

called the center of mass.

For every object,

we can locate the average position of all of its mass

by taking into account how the mass

is spread around the object.

For instance, the center of mass

of a flat, rectangular object of uniform density

will be in the intersection of both diagonals,

in equal distance from each corner.

We can find the center of mass for other objects

by similar calculations,

or by finding the object’s balancing point,

which lies right underneath its center of mass.

Try balancing a broom by holding it

and slowly bringing your hands together until they meet.

This balancing point lies right underneath

the broom’s center of mass.

We humans also have a center of mass.

When most people stand up,

their center of mass is around the belly,

but what happens to your center of mass

when you lift your hands in the air?

Your center of mass moves upwards.

It moves all the time as you move through the day,

based on how your body is positioned.

It can even move outside of your body.

When you bend forward, your center of mass

is located below your bent belly

in a place where there is no mass at all.

Weird to think about, but that’s the average position

of all your mass.

Many objects' center of mass

are outside their bodies.

Think of doughnuts or boomerangs.

Now look at the Fosbury Flop, and follow the position

of the center of mass of the jumper.

The jumper runs very fast,

so he can divert his horizontal velocity

to vertical velocity, and jumps.

Wait for it…there.

Look at the jumper’s center of mass

as his body bends backward.

It’s below the bar.

That is the secret behind the jump.

With the old, pre-Fosbury techniques,

the jumper had to apply enough force

to lift his center of mass above the bar

by a few inches in order to clear it.

The Fosbury Flopper doesn’t have to do that.

The genius of the Fosbury Flop is that the jumper

can apply the same amount of force,

but raise his body much higher than before.

That means he can raise the bar so high

that even when his center of mass

can’t go any higher, his arching body can.

Fosbury’s technique brought

the high jump to new heights

by splitting the jumper’s body

away from his center of mass,

giving it that much more room

to clear higher and higher bars.

So the Fosbury Flop may be sports history’s

only great leap forward,

that is also a great leap backward.