(Light Amplification by Stimulated Emission of Radiation) was conceived in l958. Its light is unlike sunlight or any previous artificial light - which disperses in all directions. Laser light is coherent organized intense powerful precise. It travels in only one direction with the sides of the beam remaining almost parallel. Simpler solid lasers can produce light in short bursts lasting less than a millionth of a second. Gas-lasers usually emit continous and clearly, visible light. At theperformances of the LaserTheater an equalized colour mixture is provided by a blue-green argon and a red-yellow krypton gas-laser. The power of these two lasers makes possible the presentation of figures "under the stars". These are not holograms, but conjure up images of real three-dimensional pictures. The swinging-mirrored rapid scanner has very similar effects, but draws onto the "sky" of the Planetarium with the help of a computer. However the most fantastic phenomenon is the laser interference! It cannot be compared to anything, it doesn't remind you of anything, yet it evokes fantasy, feelings and transfers certain moods. These delicate pictures cannot be described, You have to see them! The last decade has seen hundreds of sophisticated laser applications in industry, medicine, navigation and communications. Lasers can transmit voice and TV signals and measure distances in space. They are a highly efficient cutting implement for the machine-tool, metal working and apparel industries, Doctors use lasers to treat tumors and optical impairmets. Lasers are also being used in Video Discs, and in the most innovative copy machines to reproduce colour and computer printouts at phenomenal speeds. Yes, we can do a lot of good and - unfortunately - a lot of bad things with the special light of laser.