What If the Earth Were Hollow?

What if the Earth were hollow? You'd weigh about as much as a bottle of water, the Moon would fly away, and a normal jump would keep you in the air for over a minute. We drill down through a hollow Earth made of real rock, then follow the clues (a twisting wire in a garden shed, the deepest hole ever dug, and earthquakes) to what's really under your feet. 0:00 What if the Earth were hollow? 0:36 The rules 1:08 Half a kilogram 1:46 Losing the Moon and the sky 2:23 Falling inside 3:03 Why it can't exist 3:40 Halley's hollow Earth 4:19 Weighing the Earth 4:53 The deepest hole 5:25 Listening to earthquakes 6:00 The real center 6:42 So, is it hollow? 7:11 Next If you could jump sixty meters high, where would you go first? Tell me in the comments. Subscribe for more big what-if questions. Next: what if the Sun went dark for one day? Notes: the hollow-Earth numbers assume a rock shell 35 km thick (density 2,700 kg per cubic meter) with Earth's radius. That gives 0.8% of Earth's mass, so surface gravity of about 0.08 m/s², escape speed of about 1 km/s, and a Moon (orbiting at about 1,018 m/s) that would no longer be bound. Sources: Newton's shell theorem (Principia, 1687): https://en.wikipedia.org/wiki/Shell_t... Edmond Halley's hollow Earth (1692): https://en.wikipedia.org/wiki/Hollow_... John Cleves Symmes Jr.: https://en.wikipedia.org/wiki/John_Cl.... Cavendish experiment (1798): https://en.wikipedia.org/wiki/Cavendi... Kola Superdeep Borehole: https://en.wikipedia.org/wiki/Kola_Su... Inge Lehmann and the inner core (1936): https://en.wikipedia.org/wiki/Inge_Le... Earth's internal structure: https://en.wikipedia.org/wiki/Interna... Earth's inner core: https://en.wikipedia.org/wiki/Earth%2... Asteroid Bennu (OSIRIS-REx): https://science.nasa.gov/solar-system... #science #space #earth