Dr Karl explains how most of the water in the world was created at the moment of the Big Bang. It's still being made across the universe whenever oxygen and hydrogen get together under the right conditions, but none of it's getting to Earth.
As we live our lives, an array of invisible forces are exerting their influence on us. Gravity pulls you into the seat. Light waves hit you from the screen. Sound waves roll in from everywhere. Electromagnetic radiation from around the universe races through your entire being and if it weren't for the nuclear forces holding every sub-atomic particle in your body together you would fall apart. In short you would cease to exist. This show is all about Force. That immutable, invisible thing that makes the world 'go round'.
In this episode, Stefan visits a brand new hospital in London where he learns about measuring and controlling temperature and visits a school that uses data collection to run an energy saving campaign.