Society, Politics & Law
Seismograph
...work? To make a seismograph, you need to get one thing to move with the earth as it shakes, and something else to stay as still as possible relative to the earth. Not easy when the whole earth is moving! Ideally, you’d have a pen, suspended in space, not influenced by the earth at all, marking onto paper that is fixed to the earth. But that’s impossible. The fixing of...