The Breakthrough Starshot program aims to cross the immense distances to the nearest star in just decades. Using a high-powered laser to propel a reflective sail technology to relativistic speeds is their mission. The selection of sail material is key to its success as it must be lightweight while being able to withstand acceleration and … Continue reading "What Should Light Sails Be Made Out Of?"
Interesting problem. Kinetic energy is Ek = kv2, where k = 1/2 for Newtonian physics. To double your speed, you need to apply four times the energy. Momentum is p = mv, so doubling your speed doubles your momentum. When you’re in a vehicle collision, it’s your momentum that hurts you as you collide with the car frame around you. Small particles don’t have much mass, but at relativistic speeds they have a lot of momentum.