Lasers are being used to do many things now: eye correction, speed scaning, cutting, and now even to create iron! Scientists now use lasers to heat up hydrogen so they fuse into helium and all the way up the table into iron, just like stars. I want to know if lasers have mass. I know that they are just photons in a narrow beam, and photons have mass (or do they?), so lasers must have mass too, right?