Inventor in the context of Lee De Forest

The siege of Syracuse by the Roman Republic took place in 213–212 BC. The Romans successfully stormed the Hellenistic city of Syracuse after a protracted siege, giving them control of the entire island of Sicily. During the siege, the city was protected by weapons developed by the prominent inventor and polymath Archimedes, who was slain at the conclusion of the siege by a Roman soldier, in contravention of the Roman proconsul Marcellus's instructions to spare his life.

Christiaan Huygens, Lord of Zeelhem, FRS (/ˈhaɪɡənz/ HY-gənz, US also /ˈhɔɪɡənz/ HOY-gənz; Dutch: [ˈkrɪstijaːn ˈɦœyɣə(n)s] ; also spelled Huyghens; Latin: Hugenius; 14 April 1629 – 8 July 1695) was a Dutch mathematician, physicist, engineer, astronomer, and inventor who is regarded as a key figure in the Scientific Revolution. In physics, Huygens made seminal contributions to optics and mechanics, while as an astronomer he studied the rings of Saturn and discovered its largest moon, Titan. As an engineer and inventor, he improved the design of telescopes and invented the pendulum clock, the most accurate timekeeper for almost 300 years. A talented mathematician and physicist, his works contain the first idealization of a physical problem by a set of mathematical parameters, and the first mathematical and mechanistic explanation of an unobservable physical phenomenon.

Huygens first identified the correct laws of elastic collision in his work De Motu Corporum ex Percussione, completed in 1656 but published posthumously in 1703. In 1659, Huygens derived geometrically the formula in classical mechanics for the centrifugal force in his work De vi Centrifuga, a decade before Isaac Newton. In optics, he is best known for his wave theory of light, which he described in his Traité de la Lumière (1690). His theory of light was initially rejected in favour of Newton's corpuscular theory of light, until Augustin-Jean Fresnel adapted Huygens's principle to give a complete explanation of the rectilinear propagation and diffraction effects of light in 1821. Today this principle is known as the Huygens–Fresnel principle.

Béla Barényi (1 March 1907, Hirtenberg, Austro-Hungarian Monarchy – 30 May 1997, Böblingen, Germany) was an ethnic Hungarian engineer from Austria-Hungary, who was a prolific inventor, sometimes even compared to Thomas Edison. Barényi made numerous crash protection inventions, and is therefore regarded as the father of passive safety in automotive design. "The lives of thousands of people have probably been saved thanks to Barényi's work."

Barényi is also credited with first conceiving the original design for the German people's car (the Volkswagen Beetle) in 1925, – notably by Mercedes-Benz, on their website, including his original technical drawing, – five years before Ferdinand Porsche claimed to have made his initial version.

The timeline of historic inventions is a chronological list of particularly significant technological inventions and their inventors, where known. This page lists nonincremental inventions that are widely recognized by reliable sources as having had a direct impact on the course of history that was profound, global, and enduring. The dates in this article make frequent use of the units mya and kya, which refer to millions and thousands of years ago, respectively.

Nicolas-Joseph Cugnot (26 February 1725 – 2 October 1804) was a French inventor who built the world's first full-size and working self-propelled mechanical land-vehicle, the "Fardier à vapeur" – effectively the world's first automobile.

François Isaac de Rivaz (December 19, 1752, in Paris – July 30, 1828, in Sion) was a French-born Swiss inventor and a politician. He invented a hydrogen-powered internal combustion engine with electric ignition and described it in a French patent published in 1807. In 1808 he fitted it into a primitive working vehicle – "the world's first internal combustion powered automobile".

Lee de Forest (August 26, 1873 – June 30, 1961) was an American inventor, electrical engineer and an early pioneer in electronics of fundamental importance. He invented the first practical electronic amplifier,the three-element "Audion" triode vacuum tube in 1908. This helped start the Electronic Age, and enabled the development of the electronic oscillator. These made radio broadcasting and long distance telephone lines possible, and led to the development of talking motion pictures, among countless other applications.

He had over 300 patents worldwide, but also a tumultuous career – he boasted that he made, then lost, four fortunes. He was also involved in several major patent lawsuits, spent a substantial part of his income on legal bills, and was even tried (and acquitted) for mail fraud.

The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m⋅s. It is used to quantify the rate of energy transfer. The watt is named in honor of James Watt (1736–1819), an 18th-century Scottish inventor, mechanical engineer, and chemist who improved the Newcomen engine with his own steam engine in 1776, which became fundamental for the Industrial Revolution.

Carlo Rubbia OMRI OMCA (born 31 March 1934) is an Italian particle physicist and inventor who shared the Nobel Prize in Physics in 1984 with Simon van der Meer for work leading to the discovery of the W and Z particles at CERN.

Ctesibius or Ktesibios or Tesibius (Ancient Greek: Κτησίβιος; fl. 285–222 BCE) was an ethnically Greek inventor and mathematician in Alexandria, Ptolemaic Egypt. Very little is known of Ctesibius' life, but his inventions were well known in his lifetime. He was likely the first head of the Museum of Alexandria. He wrote the first treatises on the science of compressed air and its uses in pumps (and even in a kind of cannon). This, in combination with his work On pneumatics on the elasticity of air, earned him the title of "father of pneumatics." None of his written work has survived, including his Memorabilia, a compilation of his research that was cited by Athenaeus. Ctesibius' most commonly known invention today is a pipe organ (hydraulis), a predecessor of the modern church organ. He was married to a woman named Thais, who is not to be confused with Thaïs, the Greek hetaira who travelled with Alexander the Great on his military campaigns.

Elmer Ambrose Sperry Sr. (October 12, 1860 – June 16, 1930) was an American inventor and entrepreneur, most famous for construction, two years after Hermann Anschütz-Kaempfe, of the gyrocompass and as founder of the Sperry Gyroscope Company. He was known as the "father of modern navigation technology".

Sperry's compasses and stabilizers were adopted by the United States Navy and used in both world wars. He also worked closely with Japanese companies and the Japanese government and was honored after his death with a volume of reminiscences published in Japan.

Hanaya Yohei (華屋 与兵衛 or 花屋 與兵衛; 1799–1858) was a Japanese restaurateur and chef who is generally credited as the inventor of Tokyo-style (Edomaezushi; 江戸前寿司) nigiri sushi at the end of the Edo period. He is also regarded as the inventor of modern sushi that is widely recognized around the world.

Poor Richard's Almanack (sometimes Almanac) was a yearly almanac published by Benjamin Franklin, who adopted the pseudonym of "Poor Richard" or "Richard Saunders" for this purpose. The publication appeared continually from 1732 to 1758. It sold exceptionally well for a pamphlet published in the Thirteen Colonies; print runs reached 10,000 per year.

Franklin, the American inventor, statesman, and accomplished publisher and printer, achieved success with Poor Richard's Almanack. Almanacks were very popular books in colonial America, offering a mixture of seasonal weather forecasts, practical household hints, puzzles, and other amusements. Poor Richard's Almanack was also popular for its extensive use of wordplay, and some of the witty phrases coined in the work survive in the contemporary American vernacular.

Manfred Baron von Ardenne (German pronunciation: [ˈmanfʁeːt fɔn aʁˈdɛn]; 20 January 1907 – 26 May 1997) was a German researcher, autodidact in applied physics, and an inventor. He took out approximately 600 patents in fields including electron microscopy, medical technology, nuclear technology, plasma physics, and radio and television technology. From 1928 to 1945, he directed his self-funded and private research laboratory Forschungslaboratorium für Elektronenphysik, where he developed and invented many techniques used in modern physics.

After World War II, von Ardenne was held in Soviet custody and was one of many of the German nuclear physicists in the Soviet program of nuclear weapons, and later honored with the Stalin Prize.

Luis Walter Alvarez (June 13, 1911 – September 1, 1988) was an American experimental physicist, inventor, and professor of Spanish descent who was awarded the Nobel Prize in Physics in 1968 for his discovery of resonance states in particle physics using the hydrogen bubble chamber. In 2007 the American Journal of Physics commented, "Luis Alvarez was one of the most brilliant and productive experimental physicists of the twentieth century."

After receiving his PhD from the University of Chicago in 1936, Alvarez went to work for Ernest Lawrence at the Radiation Laboratory at the University of California, Berkeley. Alvarez devised a set of experiments to observe K-electron capture in radioactive nuclei, predicted by the beta decay theory but never before observed. He produced tritium using the cyclotron and measured its lifetime. In collaboration with Felix Bloch, he measured the magnetic moment of the neutron.

Jacob Perkins (July 9, 1766 – July 30, 1849) was an American inventor, mechanical engineer and physicist based in the United Kingdom. Born in Newburyport, Massachusetts, Perkins was apprenticed to a goldsmith. He soon made himself known with a variety of useful mechanical inventions and eventually had twenty-one American and nineteen English patents. Sometimes known as the father of the refrigerator. He was elected a Fellow of the American Academy of Arts and Sciences in 1813 and a member of the American Philosophical Society in 1819.