It is not often that one has the chance to pass along plans to explore another star system. The idea written up in the Science Times section of the New York Times today is to send small satellite robots the sizes of cell phones to the nearest star to us, Alpha-Centauri.
Alpha-Centauri is more than 4 light years away. With current technology Alpha-Centauri would seem completely out of reach. Although it is the nearest star system to us, it will take 100,000 years for a satellite to reach this neighbor of the Sun. There are a few ways we can dream up on how to cut down this incredibly long travel time.
One way is to launch the cell phone robots into space just above Earth, and then to focus powerful lasers on them. In this case Einstein tells us what will happen. He discovered that light bounces off of objects like little ping-pong balls, and in doing do will impart a little bit of momentum each time. This action will accelerate these tiny satellites until they reach a comfortable cruising speed of 20% the speed of light (which equates to 135 million miles per hour)!
After about 40 years, and with a bit of luck, they will reach their destination and start taking pictures for us. Because Alpha-Centauri is so far away, each picture they snap will take a bit more than 4 years to arrive to Earth. There is just one problem with this idea, well okay, two problems.
First, we are unable to produce lasers powerful enough to accelerate any object up to relativistic speeds. The most powerful lasers are produced in Japan, and those those deliver beams for only a tiny fraction of the power needed and for a very short amount of time compared to the minimum requirements. Second of all, this project is neither started nor even close to being fully funded. Having said that, are we not lucky to live at a time in which we can have such dreams and start to make such bold plans of exploration?