Ask the Naked Scientists, South Africa 14.07.25 - Why do some wines give you a worse hangover?

Summary: Should my air-conditioning be fresh or recycled air? Is the International Space Station in geostationary orbit? What causes plane vapour trails? Is it alright to drink water on an empty stomach? Why do we have blood groups? Why do we boil our food? Why do some wines give you a worse headache? Plus, why beef is off the menu for a sustainable world...