Light bulb in the context of Electric arc

A coronal mass ejection (CME) is a significant ejection of plasma mass from the Sun's corona into the heliosphere. CMEs are often associated with solar flares and other forms of solar activity, but a broadly accepted theoretical understanding of these relationships has not been established.

If a CME enters interplanetary space, it is sometimes referred to as an interplanetary coronal mass ejection (ICME). ICMEs are capable of reaching and colliding with Earth's magnetosphere, where they can cause geomagnetic storms, aurorae, and in rare cases damage to electrical power grids. The largest recorded geomagnetic perturbation, resulting presumably from a CME, was the solar storm of 1859. Also known as the Carrington Event, it disabled parts of the newly created United States telegraph network, starting fires and electrically shocking some telegraph operators.

A bayonet mount (mainly as a method of mechanical attachment, such as fitting a lens to a camera using a matching lens mount) or bayonet connector (for electrical use) is a fastening mechanism consisting of a cylindrical male side with one or more radial pegs, and a female receptor with matching L-shaped slot(s) and with spring(s) to keep the two parts locked together. The slots are shaped like a capital letter L with serif (a short upward segment at the end of the horizontal arm); the peg slides into the vertical arm of the L, rotates across the horizontal arm, then is pushed slightly upwards into the short vertical "serif" by the spring; the connector is no longer free to rotate unless pushed down against the spring until the peg is out of the "serif".

The bayonet mount is the standard light bulb fitting in the United Kingdom and in many countries that were members of the British Empire including Australia, Hong Kong, Fiji, India, Pakistan, Sri Lanka, Ireland and New Zealand, parts of the Middle East and Africa and, historically, in France and Greece.

A lightbulb joke is a joke cycle that asks how many people of a certain group are needed to change, replace, or screw in a light bulb. Generally, the punch line answer highlights a stereotype of the target group. There are numerous versions of the lightbulb joke satirizing a wide range of cultures, beliefs, and occupations.

Early versions of the joke, popular in the late 1960s and the 1970s, were used to insult the intelligence of people, especially Poles ("Polish jokes"). Such jokes generally take the form of:

William David Coolidge (/ˈkuːlɪdʒ/; October 23, 1873 – February 3, 1975) was an American physicist and engineer, who made major contributions to X-ray machines. He was the director of the General Electric Research Laboratory and a vice-president of the corporation. He was also famous for the development of "ductile tungsten", which is important for the incandescent light bulb.

The second millennium of the Anno Domini or Common Era was a millennium spanning the years 1001 to 2000. It began on January 1, 1001 (MI) and ended on December 31, 2000 (MM), (11th to 20th centuries; in astronomy: JD 2086667.5 – 2451909.5).

It encompassed the High and Late Middle Ages of the Old World, the Islamic Golden Age and the period of Renaissance, followed by the early modern period, characterized by the European wars of religion, the Age of Enlightenment, the Age of Discovery and the colonial period. Its final two centuries coincide with modern history, characterized by industrialization, the rise of nation states, the rapid development of science, widespread education, and universal health care and vaccinations in the developed world. The 20th century saw increasing globalization, most notably the two World Wars and the subsequent formation of the United Nations. 20th-century technology includes powered flight, television and semiconductor technology, including integrated circuits. The term "Great Divergence" was coined to refer the unprecedented cultural and political ascent of the Western world in the second half of the millennium, emerging by the 18th century as the most powerful and wealthy world civilization, having eclipsed Qing China, Edo Japan, the Islamic world and India. This allowed the colonization by European countries of much of the world during this millennium, including the Americas, Africa, Oceania, and South and Southeast Asia.

The HP 200A Audio Oscillator, first built in 1938, was the first product made by Hewlett-Packard and was manufactured in David Packard's garage in Palo Alto, California.

It was a low-distortion audio oscillator used for testing sound equipment. It used the Wien bridge oscillator circuit, that had been the subject of Bill Hewlett's masters thesis. It was also the first such commercial oscillator to use a simple light bulb as the temperature-dependent resistor in its feedback network. The light bulb was an inexpensive and effective automatic gain control that not only kept the oscillator output amplitude constant, but it also kept the oscillator's loop gain near unity. The latter is a key technique for achieving a low distortion oscillator. Earlier, Larned Meacham had used light bulbs in bridge circuits to stabilize and linearize oscillators in 1938.

Carl Auer von Welsbach (1 September 1858 – 4 August 1929), who received the Austrian noble title of Freiherr Auer von Welsbach in 1901, was an Austrian scientist and inventor, who separated didymium into the elements neodymium and praseodymium in 1885. He was also one of three scientists to independently discover the element lutetium (which he named cassiopeium), separating it from ytterbium in 1907, setting off the longest priority dispute in the history of chemistry.

He had a talent not only for making scientific advances, but also for turning them into commercially successful products. His work on rare-earth elements led to the development of the ferrocerium "flints" used in modern lighters, the gas mantle that brought light to the streets of Europe in the late 19th century, and the metal-filament light bulb. He took the phrase plus lucis, meaning "more light", as his motto.