(image via conceptships)
It’s pretty hard to travel around in space because there are very few convenient ways of providing propulsion to a space ship. The most common method used in moving a ship in space are rockets, but they require that astronauts bring their fuel with them into space. As a result, rockets are heavy and expensive. The solution that many physicists propose is a solar sail, which would catch the light of the sun much like a canvas sail does with the wind, propelling a ship forward.
Conventional solar sails provide thrust by reflecting light off of their surfaces. This reflection generates a pressure on the sail which moves the ship forward. The trouble is that this makes it impossible to steer the sail. You are forced to move wherever the light takes you.
Scientists at my old alma mater: Rochester Institute of Technology (www.rit.edu) have a solution to this problem. A refractive sail could, conceivably, be used to steer a space craft. As the light passes through the refractive material, it is deflected at an angle due to Snell’s Law, precisely like the light bouncing off the bottom of a swimming pool.
Because of this angled flight, the light provides directional thrust when it impacts the other edge of the sail. By forming a sail from super-light refractive lenses, the astronauts of tomorrow could sail between the planets on a wind of light.
(submitted to itsfullofstars)