China has successfully tested a real-life weapon that evokes the Star Wars Death Star laser. China’s government-imposed secrecy allegedly prevented the project scientists from sharing key details, ...
IN a recent letter 1 under this title, Dr. A. H. Rosenthal describes an optical illusion produced by the rotating beam from a lighthouse. We studied this phenomenon last year 2, and we think that both ...
Schematic illustration of a cholesteric liquid crystal device with lens functionality (left) and photos of reflected beam spots (right). The parabolic profile of the helix phase converts the incident ...