Brian Cox tried to teach us about gravity on Monday night, but all we could do was watch Spanish children fall down human towers.
To demonstrate how concentric circles can spread the force of gravity, Brian Cox's Forces Of Nature took us to Catalonia, where different towns compete to form the highest human tower.
Members of the town form concentric circles, pushing to the centre to support the tower.
The lightest and smallest member of the community goes to the top of the tower.
Sometimes that's a child as young as five.
Sometimes the tower collapses.
Yes, that's right.
We watched Carla try to get to the summit.
Luckily she made it.