In the

in 1930s, the Cavendish Laboratory at Cambridge University is the most prestigious

place in the world for experimental nuclear physics.

The Cavendish is the domain of the Lord Ernest Rutherford,

and Leo Salard has managed to get an appointment to speak with the Nobel Laureate.

Just a few years earlier, standing on a street corner on a soggy day in London,

Leo Salard had a vision that would change the course of human history.

So Lard foresees the possibility of a nuclear chain reaction. What if you could chip away a neutron from the nucleus of an atom,

and that could trigger a similar release in another atom, and another.

This could release a previously unthinkable amount of energy, enough to power a submarine, or fuel a power plant,

or build the world's most destructive bomb. These are powerful possibilities, but still a long way off.

The first step is to split the atom,

and that has never been done.

There's huge skepticism that it is even possible.

Just before Salard's epiphany, Lord Ernest Rutherford,

the man known as the father of nuclear physics,

had publicly dismissed the ideas Salard is proposing as moonshine.

Split the atom to release energy. It's too far-fetched, Rutherford thinks, too difficult with the technology available.

Rutherford isn't alone.

Even the great and famous Albert Einstein, a friend of Salardz, says the idea of breaking down atoms with

neutrons is like trying to shoot birds in the dark, in a country where there aren't many birds.

On June 4th, 1934, Salard walks into the Cavendish Laboratory

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