Now a staple of planetariums and major concert events, the laser light show has wowed audiences for nearly half of a century. In this week’s Throwback Thursday, we take a look at the development of lasers for the sake of entertainment and the worldwide phenomenon that was and continues to be, the laser light show.

In the late 1960’s, artists and scientists collaborated on the use of lasers for art and entertainment. Similar to the invention of the laser itself, it is hard to pinpoint the “first” laser light show, as so many were fascinated with experimenting with the new medium for artistic or practical applications.

Much of the “wow factor” associated with laser light shows rely on very simple optical principles. A low powered laser, mirrors, and the “persistence of vision” (the afterimage seen by the human eye when light moves faster than the eye can perceive) are all that is needed to create a basic laser light show.

Advanced shows used mirrored prisms, galvanometers (electrical signals that shake mirrors at a fast enough rate that the lasers “trace” an image) and “chopping,” which refers to the rapid shutting on and off of the laser to create the illusion of movement. These, combined with simplistic, cartoonish designs make laser light shows a reality.

In the 1970s, major touring acts such as Led Zeppelin, Blue Oyster Cult, The Who, and Pink Floyd made the laser light show a central part of their live performances. Contributing heavily to the world’s fascination with laser technology, the integration of lasers into popular musical performances rewrote the expectations of a live concert event. Today, you’ll be hard pressed to find a planetarium that does not hold “tribute shows” to these acts on a regular basis.

Comparatively, laser light shows are much easier and efficient than in their early heyday. Argon and krypton ion lasers were bulky and required a significant amount of power to put on the show. These days, the type and power of the laser required is based more on venue size. A small auditorium or theater can use standard electrical power and low-powered beams to put on a decent show. Larger venues, such as outdoor amphitheaters, require more power and still often use gas-based lasers for a greater variety in visuals. That being said, outside of better control of images through the use of computer-based controls, the laser light show has not evolved all that much since the turn of the century.

That is not, of course, to say that advancements in laser technology will not also be applied for entertainment purposes. Seeing as the use of lasers in entertainment has only become more standardized, it will likely not be long before someone decides to re-invent this long standing performance staple.