Why does squinting sharpen vision?
In this week's show, recorded before the Euro 2021 final, Dr Chris explains why Inuits survive on polar fare with impunity but Shackleton's crew developed nutritional deficiency when they were stuck in the Antarctic. Also, why laser beams are bad for goalkeepers, if energy drinks are dangerous, why squinting sharpens vision, if there humans with better senses than average, and where all the water came from on Earth? Also, how many senses does a human have? What is meant by the percentage chance of rain? Why does day-length not change uniformly over the year?