April 18 is the 108th day of the year in the Gregorian calendar. 257 days remain until the end of the year.
Absolute magnitude is a measure of the luminosity of a celestial object, on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it were viewed from a distance of exactly 10 parsecs, without extinction of its light due to absorption by interstellar matter and cosmic dust. By hypothetically placing all objects at a standard reference distance from the observer, their luminosities can be directly compared on a magnitude scale.
Dungeons & Dragons is a fantasy tabletop role-playing game (RPG) originally designed by Gary Gygax and Dave Arneson. It was first published in 1974 by Tactical Studies Rules, Inc. (TSR). The game has been published by Wizards of the Coast since 1997. It was derived from miniature wargames, with a variation of the 1971 game Chainmail serving as the initial rule system. D&D's publication is commonly recognized as the beginning of modern role-playing games and the role-playing game industry.
In mathematics, an integral assigns numbers to functions in a way that can describe displacement, area, volume, and other concepts that arise by combining infinitesimal data. Integration is one of the two main operations of calculus, with its inverse operation, differentiation, being the other. Given a function f of a real variable x and an interval [a, b] of the real line, the definite integral
Lysergic acid diethylamide (LSD), also known as acid, is a hallucinogenic drug. Effects typically include altered thoughts, feelings, and awareness of one's surroundings. Many users see or hear things that do not exist. Dilated pupils, increased blood pressure, and increased body temperature are typical. Effects typically begin within half an hour and can last for up to 12 hours. It is used mainly as a recreational drug and for spiritual reasons.
The MD5 message-digest algorithm is a widely used hash function producing a 128-bit hash value. Although MD5 was initially designed to be used as a cryptographic hash function, it has been found to suffer from extensive vulnerabilities. It can still be used as a checksum to verify data integrity, but only against unintentional corruption. It remains suitable for other non-cryptographic purposes, for example for determining the partition for a particular key in a partitioned database.
The periodic table, also known as the periodic table of elements, is a tabular display of the chemical elements, which are arranged by atomic number, electron configuration, and recurring chemical properties. The structure of the table shows periodic trends. The seven rows of the table, called periods, generally have metals on the left and nonmetals on the right. The columns, called groups, contain elements with similar chemical behaviours. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases. Also displayed are four simple rectangular areas or blocks associated with the filling of different atomic orbitals.
Adobe Photoshop is a raster graphics editor developed and published by Adobe Inc. for Windows and macOS. It was originally created in 1988 by Thomas and John Knoll. Since then, the software has become the industry standard not only in raster graphics editing, but in digital art as a whole. The software's name has thus become a generic trademark, leading to its usage as a verb although Adobe discourages such use. Photoshop can edit and compose raster images in multiple layers and supports masks, alpha compositing and several color models including RGB, CMYK, CIELAB, spot color, and duotone. Photoshop uses its own PSD and PSB file formats to support these features. In addition to raster graphics, this software has limited abilities to edit or render text and vector graphics, as well as 3D graphics and video. Its feature set can be expanded by plug-ins; programs developed and distributed independently of Photoshop that run inside it and offer new or enhanced features.
In mathematics, a Taylor series is a representation of a function as an infinite sum of terms that are calculated from the values of the function's derivatives at a single point.
Washington, D.C., formally the District of Columbia and commonly referred to as D.C., Washington, or The District, is the capital of the United States. Founded after the American Revolution as the seat of government of the newly independent country, Washington was named after George Washington, the first president of the United States and a Founding Father. As the seat of the United States federal government and several international organizations, Washington is an important world political capital. The city, located on the Potomac River bordering Maryland and Virginia, is one of the most visited cities in the world, with more than 20 million tourists annually.
Scrubs is an American medical comedy-drama television series created by Bill Lawrence that aired from October 2, 2001, to March 17, 2010, on NBC and later ABC. The series follows the lives of employees at the fictional Sacred Heart Hospital, which is a Teaching Hospital. The title is a play on surgical scrubs and a term for a low-ranking person because at the beginning of the series, most of the main characters are medical interns.
The Normandy landings were the landing operations on Tuesday, 6 June 1944 of the Allied invasion of Normandy in Operation Overlord during World War II. Codenamed Operation Neptune and often referred to as D-Day, it was the largest seaborne invasion in history. The operation began the liberation of German-occupied France and laid the foundations of the Allied victory on the Western Front.
Pound sterling, known in some contexts simply as the pound or sterling, is the official currency of the United Kingdom, Jersey, Guernsey, the Isle of Man, Gibraltar, South Georgia and the South Sandwich Islands, the British Antarctic Territory, and Tristan da Cunha. It is subdivided into 100 pence. The Pound sterling is the oldest currency in continuous use. A number of nations that do not use sterling also have currencies called the pound.
The Douglas C-47 Skytrain or Dakota is a military transport aircraft developed from the civilian Douglas DC-3 airliner. It was used extensively by the Allies during World War II and remained in front-line service with various military operators for many years.
SHA-2 is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle–Damgård structure, from a one-way compression function itself built using the Davies–Meyer structure from a (classified) specialized block cipher.
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and multiple other biological effects. In humans, the most important compounds in this group are vitamin D3 (also known as cholecalciferol) and vitamin D2 (ergocalciferol).
Marvel's Agents of S.H.I.E.L.D., or simply Agents of S.H.I.E.L.D., is an American television series created for ABC by Joss Whedon, Jed Whedon, and Maurissa Tancharoen, based on the Marvel Comics organization S.H.I.E.L.D., a peacekeeping and spy agency in a world of superheroes. It is set in the Marvel Cinematic Universe (MCU) and acknowledges the continuity of the franchise's films and other television series. The series is produced by ABC Studios, Marvel Television, and Mutant Enemy Productions, with Jed Whedon, Tancharoen, and Jeffrey Bell serving as showrunners.
Emmanuel Jean-Michel Frédéric Macron is a French politician who has been President of France and ex officio Co-Prince of Andorra since 14 May 2017.
