A bomb whose creation would tip the scales of global power.

A nuclear physicist who sought to redress the balance.

The bomb, a podcast from the BBC World Service.

Season 2 available now.

Welcome to More or Less, the programme that apprauds the good numbers

and disqualifies the bad ones. I'm Ben Carter.

This week, the greatest athletes in the world have gathered in Eugene, Oregon,

in the United States to run around a track and do a bit of throwing and jumping

at the World Athletics Championship.

On Sunday, July of 17th, the big men's race was the 110-meter hurdles final

where the two favourites were the Americans' Grant Holloway and Devon Allen.

A lot of attention was on Allen because this was meant to be his last race.

His main sport is actually American football and his plan was to give up athletics

after the championship. And he had a really good chance of leaving the sport

with a goal medal as he's the fastest herdler in the world this year.

If that wasn't enough, Devon Allen was also the local favourite,

as he'd made his name at the University of Oregon,

so the atmosphere in the stadium was electric as the fastest men in the world

got into position to start the race.

So ready, set,

two shots means a false start,

but there was no obvious early movement from any of the athletes.

...