What do you do when all the fields are full of skyscrapers?
Getting up there is relatively easy. But staying in orbit needs enormous sideways velocity; you need to be going so fast that rather than falling into the earth you miss it. There is an excellent way to think about this involving a really tall tower, and throwing a ball from it faster and faster – the ball lands further and further away, and…[Read more]
active 3 months, 2 weeks ago