Season 5 - Episode Guide

Jem makes his own diamond and then proves they aren't forever. Dr Yan explains the science of popcorn, and Dallas investigates why we haven't cured cancer yet, meeting the team that hope to change that.

In the second episode of the science series, Liz hits the beach with the RNLI to experience the power of rip currents; Dr Yan attempts to demonstrate evolution by drawing a couple of lines; and Jem is back in the workshop, turning everyday scrap into gold.

Jem witnesses the awesome power of rockets with the Bloodhound land speed record project, Yan re-enacts an Ancient Greek experiment to measure the earth's circumference with a couple of sticks, and Dallas goes in search of a robot to call his own.

The team puts more science to the test, including new stem-cell research and the Nocebo effect (placebo's evil twin). And Dallas Campbell goes to a memory boot camp.

Liz investigates an increasingly common and unwelcome guest - the bedbug. Meanwhile, Yan explains why statistics are not to be trusted, and Dallas goes stargazing in California.

Dallas downs his toothbrush to discover what causes tooth decay and gum disease, Yan explains why refreezing food is not a great idea, and Jem investigates new research that electric lights can play havoc with the way we sleep.

Dallas investigates a potential global helium shortage, Dr Yan tests shoppers on how much they know about radiation, and Liz tries out the new airport security technology that can see beneath your clothes.

The team examines nuclear power. Jem Stansfield climbs into a reaction chamber to show how a nuclear power station works and looks at the Fukushima radiation scare.