Why Size Matters, BBC4, 9pm
WHY are things the size they are? In this new series Hannah Fry sets out to explain why it is so important. She begins by asking how life would be different if we inhabited a bigger planet and finds that scaling the earth up would have a big effect on gravity – meaning lying down would become the new standing up. She also learns more about Gigantopithecus, the biggest ape to ever exist.

Eamonn & Ruth: How the Other Half Lives, C5, 9pm
TO many viewers, it may seem like Eamonn Holmes and Ruth Langsford already lead the lifestyles of the rich and famous. But if there’s anywhere that can make them feel like the poor relations, it’s probably Monaco, which has more millionaires per capita than any place on Earth. Here, the presenters find out what life is really like in the playground of the super-rich as multi-millionaire former Formula 1 boss Flavio Briatore invites them into his exclusive club to learn more about the tastes of Monaco’s celebrity residents. The couple are also let loose in a wine cellar worth an estimated $80 million and discover how little $30m will get you in the property market.

Ramsay’s 24 Hours to Hell and Back, C4, 10pm
NEW series. Gordon Ramsay travels across the United States in search of restaurants in dire need of renovation – and after analysing their situation, he has just 24 hours to bring them back from the brink of disaster. His first stop is the New York community of Congers, where he hopes to save family-run Italian restaurant Bella Gianna’s. Ramsay and his team work round the clock to clean the premises, remodel the interior and revamp the menu, while also teaching the staff to work together.

George Clarke’s Old House, New Home, C4, 8pm
NEW series. Architect George Clarke returns to unlock the potential of old houses. He meets teachers Simon and Sofie, whose 1930s Liverpool semi has lost its way thanks to a small kitchen squeezed into what would have been the wash house and some dodgy interior design choices made by the previous owner. Can he come up with a structural redesign and interior scheme with just £15,000?