I'm sure there is a simple explanation as to why this wouldn't work, please enlighten me. Take a computer, which generates a random number. When the number is generated, a positron gun shoots out that exact number of positrons into a vacuum with a magnetic field. On the other end of the vacuum, a detector waits to read the number of positrons, then display that number. I'm torn on what would actually happen here. According to Feynman, anti mater moves backwards in time. However, under the same hypothesis, a PET scanner would return an image before the positrons were ever emitted, and that obviously doesn't happen.