http://www.nature.com/nature/journal/v248/n5443/abs/248028a0.html http://www.nature.com/nature/journal/v248/n5443/abs/248028a0... I forget the source, but they

http://www.nature.com/nature/journal/v248/n5443/abs/248028a0.html http://www.nature.com/nature/journal/v248/n5443/abs/248028a0... I forget the source, but they later tested their setup with random input and found it predicted tachyons from that as well.