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People usually use nightlights for the sense of security which having a light on provides, or to relieve fear of the dark, especially in young children.Nightlights are also useful to the general public by revealing the general layout of a room without requiring a major light to be switched on, for avoiding tripping over stairs, obstacles, or pets, or to mark an emergency exit.
1962 Nick Holonyak Jr. develops the first practical visible-spectrum (red) light-emitting diode. 1963 Kurt Schmidt invents the first high pressure sodium-vapor lamp. [18] 1972 M. George Craford invents the first yellow light-emitting diode. 1972 Herbert Paul Maruska and Jacques Pankove create the first violet light-emitting diode.
In the US, street lights using sodium vapor were first installed on a rural highway near Port Jervis, New York, in 1933. [1] In 1938, a study of sodium vapor light use at selected intersections in Chicago claimed that the new lighting had helped to reduce the number of accidents in those areas.
In honor of Women’s History Month, we’re giving credit where credit is due, and highlighting 10 products made by women.
In 1993, Ashok Gadgil invented a lightweight, easy-to-use and economical device that used UV light to purify water. It could process four gallons per minute at a cost of 5 cents for every thousand ...
The dishwasher, chocolate-chip cookies, and the first version of the Monopoly board game were all created by women. Skip to main content. Sign in. Mail. 24/7 Help. For premium support please call: ...
Automatically generated playlists known as "YouTube Mix" were first rolled out in April 2013. [151] A year later, the feature was rolled out to the mobile app for Android OS. [152] A similar feature called "YouTube Radio" for continuous music playback in resemblance to radio stations was tested in February 2015. [153]
A moonlight tower or moontower is a lighting structure designed to illuminate areas of a town or city at night. Only the collection of towers in Austin, Texas, have been termed historically "moonlight towers," a term that dates to the mid-20th century. The light from the towers was compared to moonlight, after they were installed in 1895.