Disco Balls

A disco ball, mirror ball, glitter ball, or ball mirror is a roughly spherical object that reflects light directed at it in many directions, producing a complex display. Its surface consists of hundreds or thousands of facets, nearly all of approximately the same shape and size, and each having a mirrored surface. Usually it is mounted well above the heads of the people present, suspended from a device that causes it to rotate steadily on a vertical axis so that stationary viewers experience beams of light flashing over them.

What are now called "disco balls" were first used in nightclubs in the 1920s. An early example can be seen in the nightclub sequence of Berlin: Die Sinfonie der Großstadt, a German silent film from 1927. In the 1970s, these devices were a standard accompaniment to disco music, and by the end of the 20th century, the name "disco ball" had largely eclipsed the earlier names that had been applied to the object. Miniature disco balls are sold as novelties and used for a number of decorative purposes, including dangling from the rear-view mirror of an automobile. With the appearance of infrared networks, disco balls have found a new application, as a method of dispersing the infrared signals.

Mirrored Disco Ball

The world's largest rotating disco ball is situated in the ABC Nightclub in Glasgow, Scotland.

Pink Floyd used a disco ball on their 1987 and 1994 world tours. The disco ball used on the 1987 tour was somewhat larger than normal but nowhere near as large as the disco ball used on the 1994 tour. This particular disco ball is one of the largest in the world. 4.9 metres in diameter, it rises to a height of 21.3 metres before opening to a width of 7.3 metres, revealing a 12 kilowatt Phobeus HMI lamp. Both can be seen on the video of each tour: "Delicate Sound of Thunder and "P*U*L*S*E" during the song "Comfortably Numb".

Madonna used a 2-ton disco ball that was embellished by 2 million dollars worth of Swarovski crystals for her Confessions Tour in 2006.

( information Source: Wikipedia )

Strobe Lights

Strobe light or stroboscopic lamp, commonly called a strobe, is a device used to produce regular flashes of light. It is one of a number of devices that can be used as a stroboscope.

Strobe lights have many uses, including scientific and industrial applications, but are particularly popular in clubs where they are used to give an illusion of slow motion (cf. temporal aliasing). Other well-known applications are in alarm systems, theatrical lighting (most notably to simulate lightning), and as high-visibility running lights. They are still widely used in law enforcement and other emergency vehicles, though they are slowly being replaced by LED technology in this application, as they themselves largely replaced halogen lighting. Strobe lighting has also been used to see the movements of the vocal cords in slow motion during speech, a procedure known as video-stroboscopy. Special calibrated strobe lights, capable of flashing up to hundreds of times per second, are used in industry to stop the motion of rotating and other repetitively-operating machinery and to measure the rotation speeds or cycle times. Strobelights are often used in nightclubs and raves, and are available for home use for special effects or entertainment.

A typical commercial strobe light has a flash energy in the region of 10 to 150 joules, and discharge times as short as a few milliseconds, often resulting in a flash power of several kilowatts. Larger strobe lights can be used in “continuous” mode, producing extremely intense illumination.

The light source is commonly a xenon flash lamp, which has a complex spectrum and a color temperature of approximately 5,600 kelvins. In order to obtain colored light, colored gels must be used.

Strobe Light History

The origin of strobe lighting dates to 1931, when Harold Eugene "Doc" Edgerton employed a flashing lamp to make an improved stroboscope for the study of moving objects, eventually resulting in dramatic photographs of objects such as bullets in flight.

EG&G [now a division of URS] was founded by Harold E. Edgerton, Kenneth J. Germeshausen and Herbert E. Grier in 1947 as Edgerton, Germeshausen and Grier, Inc. and today bears their initials. In 1931, Edgerton and Germeshausen had formed a partnership to study high-speed photographic and stroboscopic techniques and their applications. Mr. Grier joined them in 1934, and in 1947, EG&G was incorporated. During World War II, the government's Manhattan Project made use of Edgerton's discoveries to photograph atomic explosions; it was a natural evolution that the company would support the Atomic Energy Commission in its weapons research and development after the war. This work for the Commission provided the historic foundation to the Company's present-day technology base.

( Information Source: Wikipedia )