Professor Saiful Islam, a Guinness World Record holder and battery technology expert, reveals the shocking truth about fruit-powered batteries. Despite using 3,000 lemons, they barely produced 2 Watts—far from what’s needed for space travel! Randall Munroe pitches zany ideas for extracting energy from these fruits while discussing the potential of a lemon-based diet. Professor Paul Shearing weighs in on the future of energy sources for planes, hinting at solar power and innovative battery materials as the way forward in aviation.