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🔗 Technology 🔗 Physics 🔗 Telecommunications 🔗 Radio 🔗 Electronics 🔗 Engineering

In antenna theory, a phased array usually means an electronically scanned array, a computer-controlled array of antennas which creates a beam of radio waves that can be electronically steered to point in different directions without moving the antennas. The general theory of an electromagnetic phased array also finds applications in ultrasonic and medical imaging application (phased array ultrasonics) and in optics optical phased array.

In a simple array antenna, the radio frequency current from the transmitter is fed to multiple individual antenna elements with the proper phase relationship so that the radio waves from the separate elements combine (superpose) to form beams, to increase power radiated in desired directions and suppress radiation in undesired directions. In a phased array, the power from the transmitter is fed to the radiating elements through devices called phase shifters, controlled by a computer system, which can alter the phase or signal delay electronically, thus steering the beam of radio waves to a different direction. Since the size of an antenna array must extend many wavelengths to achieve the high gain needed for narrow beamwidth, phased arrays are mainly practical at the high frequency end of the radio spectrum, in the UHF and microwave bands, in which the operating wavelengths are conveniently small.

Phased arrays were originally conceived for use in military radar systems, to steer a beam of radio waves quickly across the sky to detect planes and missiles. These systems are now widely used and have spread to civilian applications such as 5G MIMO for cell phones. The phased array principle is also used in acoustics, and phased arrays of acoustic transducers are used in medical ultrasound imaging scanners (phased array ultrasonics), oil and gas prospecting (reflection seismology), and military sonar systems.

The term "phased array" is also used to a lesser extent for unsteered array antennas in which the phase of the feed power and thus the radiation pattern of the antenna array is fixed. For example, AM broadcast radio antennas consisting of multiple mast radiators fed so as to create a specific radiation pattern are also called "phased arrays".

🔗 London 🔗 Philately 🔗 Trains 🔗 Trains/UK Railways 🔗 London Transport

The London Pneumatic Despatch Company (also known as the London Pneumatic Dispatch Company) was formed on 30 June 1859, to design, build and operate an underground railway system for the carrying of mail, parcels and light freight between locations in London. The system was used between 1863 and 1874.

🔗 Economics 🔗 Politics 🔗 Energy

The technocracy movement is a social and ideological movement which arose in the early 20th century. Technocracy was popular in the United States and Canada for a brief period in the early 1930s, before it was overshadowed by other proposals for dealing with the crisis of the Great Depression. The technocracy movement proposed replacing politicians and businesspeople with scientists and engineers who had the technical expertise to manage the economy.

The movement was committed to abstaining from all revolutionary and political activities. It gained strength in the 1930s but in 1940, due to an alleged initial opposition to the Second World War, was banned in Canada. The ban was lifted in 1943 when it was apparent that 'Technocracy Inc. was committed to the war effort, proposing a program of total conscription.' The movement continued to expand during the remainder of the war and new sections were formed in Ontario and the Maritime Provinces.

In the post-war years, perhaps due to the growing distrust of socialism in the cold war, membership and interest in technocracy decreased. Though now relatively insignificant, the Technocracy movement survives into the present day, and as of 2013, was continuing to publish a newsletter, maintain a website, and hold member meetings. Smaller groups included the Technical Alliance, The New Machine and the Utopian Society of America, though Bellamy had the most success due to his nationalistic stances, and Veblen's rhetoric, removing the current pricing system and his blueprint for a national directorate to reorganize all produced goods and supply, and ultimately to radically increase all industrial output.

🔗 Classical Greece and Rome 🔗 Greece 🔗 Theatre

In the theatre of ancient Greece, the eirôn (Ancient Greek: εἴρων) was one of three stock characters in comedy. The eirôn usually succeeded in bringing down his braggart opponent (the alazôn) by understating his own abilities.

🔗 Physics 🔗 Electronics 🔗 Professional sound production

Pink noise or ​¹⁄_f noise is a signal or process with a frequency spectrum such that the power spectral density (energy or power per frequency interval) is inversely proportional to the frequency of the signal. In pink noise, each octave (halving or doubling in frequency) carries an equal amount of noise energy.

Pink noise is one of the most common signals in biological systems.

The name arises from the pink appearance of visible light with this power spectrum. This is in contrast with white noise which has equal intensity per frequency interval.

Graffiti is an essentially single-stroke shorthand handwriting recognition system used in PDAs based on the Palm OS. Graffiti was originally written by Palm, Inc. as the recognition system for GEOS-based devices such as HP's OmniGo 100 and 120 or the Magic Cap-line and was available as an alternate recognition system for the Apple Newton MessagePad, when NewtonOS 1.0 could not recognize handwriting very well. Graffiti also runs on the Windows Mobile platform, where it is called "Block Recognizer", and on the Symbian UIQ platform as the default recognizer and was available for Casio's Zoomer PDA.

The software is based primarily on a neography of upper-case characters that can be drawn blindly with a stylus on a touch-sensitive panel. Since the user typically cannot see the character as it is being drawn, complexities have been removed from four of the most difficult letters. "A" "F", "K" and "T" all are drawn without any need to match up a cross-stroke.

Some letters can be drawn with strokes other than the "official" ones. Two examples of these alternative strokes are the letters "V" (drawn the same only from right to left) and "X" (drawn the same as the letter "K" except reversed from right to left). These alternative strokes are frequently recognized with greater reliability.

🔗 Biography 🔗 Aviation 🔗 Spaceflight 🔗 Military history 🔗 Military history/Military aviation 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Biography/science and academia 🔗 Military history/Military biography 🔗 Biography/military biography 🔗 Aviation/aerospace biography 🔗 Military history/Cold War 🔗 Pritzker Military Library 🔗 Scouting 🔗 Ohio 🔗 Project-independent assessment 🔗 Spaceflight/adopt an astronaut 🔗 Cleveland

James Arthur Lovell Jr. ( LUV-əl; March 25, 1928 – August 7, 2025) was an American astronaut, naval aviator, test pilot and mechanical engineer. In 1968, as command module pilot of Apollo 8, he became, with Frank Borman and William Anders, one of the first three astronauts to fly to and orbit the Moon. He then commanded the Apollo 13 lunar mission in 1970 which, after a critical failure en route, looped around the Moon and returned safely to Earth. He acted in a few movies, such as The Man Who Fell to Earth (1976) and Apollo 13 (1995; uncredited).

A graduate of the United States Naval Academy in Annapolis, Maryland, in the class of 1952, Lovell flew F2H Banshee night fighters. This included a Western Pacific deployment aboard the aircraft carrier USS Shangri-La. In January 1958, he entered a six-month test pilot training course at the Naval Air Test Center at Naval Air Station Patuxent River, Maryland, with Class 20 and graduated at the top of the class. He was then assigned to Electronics Test, working with radar, and in 1960 he became the Navy's McDonnell Douglas F-4 Phantom II program manager. The following year he became a flight instructor and safety engineering officer at Naval Air Station Oceana in Virginia Beach, Virginia, and completed Aviation Safety School at the University of Southern California.

Lovell was not selected by NASA as one of the Mercury Seven astronauts due to a temporarily high bilirubin count. He was accepted in September 1962 as one of the second group of astronauts needed for the Gemini and Apollo programs. Prior to Apollo, Lovell flew in space on two Gemini missions, Gemini 7 (with Borman) in 1965 and Gemini 12 in 1966. He was the first person to fly into space four times. One of 24 people to have flown to the Moon, Lovell was the first to fly to the moon twice, and the only human to have done so without landing. He was a recipient of the Congressional Space Medal of Honor and the Presidential Medal of Freedom. He co-authored the 1994 book Lost Moon, on which the 1995 film Apollo 13 was based. Lovell was featured in a cameo appearance in the film.

🔗 United States 🔗 Germany 🔗 Ethnic groups 🔗 United States/Texas

The Texas Wends or Wends of Texas are a group of people descended from a congregation of 558 Sorbian/Wendish people under the leadership and pastoral care of John Kilian (Sorbian languages: Jan Kilian, German: Johann Killian) who emigrated from Lusatia (part of modern-day Germany) to Texas in 1854. The term also refers to the other emigrations (and all descendants) occurring before and after this group. However, none came close to the size or importance of the Wendish culture in Texas.

The Berlin key (also known as, German, Schließzwangschlüssel, or, in English, forced-locking key) is a key for a type of door lock. It was designed to force people to close and lock their doors, usually a main entrance door or gate leading into a common yard or tenement block. The key was a solution to the problem of access via communal doors of such blocks (Mietskaserne) as early as the 19th century.

🔗 United States/U.S. Government 🔗 Internet culture 🔗 Telecommunications 🔗 Law 🔗 Politics 🔗 Popular Culture 🔗 Donald Trump

The Communications Over Various Feeds Electronically for Engagement Act (COVFEFE Act) is a bill introduced into the United States House of Representatives in 2017 (on June 12), during the 115th United States Congress.

The bill would amend the Presidential Records Act to preserve Twitter posts and other social media interactions of the President of the United States, and to require the National Archives to store such items.

U.S. Representative Mike Quigley, Democrat of Illinois, introduced the legislation in the wake of Donald Trump's routine use of Twitter, stating "In order to maintain public trust in government, elected officials must answer for what they do and say; this includes 140-character tweets. If the president is going to take to social media to make sudden public policy proclamations, we must ensure that these statements are documented and preserved for future reference." If enacted, the bill "would bar the prolifically tweeting president from deleting his posts, as he has sometimes done."

If the bill were enacted, it would see US law treat US presidents' personal social media accounts (such as Trump's "@realDonaldTrump" Twitter account) the same as "official" social media accounts (such as the "@POTUS" Twitter account).