It's a big universe out there and if we have any neighbors, it might be better if they left us alone, and one pair of scientists has a plan for that.
Researchers have found that under certain conditions, a laser beam can act like an opaque object and cast a shadow, opening new possibilities for technologies that could use a laser beam to control ...
For the experiment, a high-power green laser was directed through ruby cube and illuminated with a blue laser from the side. The green laser increases the optical absorption of the blue illuminating ...