Search results

...Air resistance experiments were performed by investigators throughout the 18th and 19th centuries, aided by the construction of the first [[wind tunnel]] Aerodynamics work throughout the 19th century sought to achieve [[heavier-than-air]] flight. [[George Cayley]] developed ...

...h centuries, [[Russia]] produced many notable [[List of Russian scientists|scientists]], making important contributions in [[physics]], [[astronomy]], [[mathemat ...eduction of state support for science and technology, leading many Russian scientists and university graduates to move to Western Europe or the United States. In ...

...eld emerged in the [[Hellenistic period|Hellenistic world]] during the 3rd century BC from applications of [[geometry]] to [[Astronomy|astronomical studies]]. ...PA235 235–236]|loc="Appendix 1: Hipparchus's Table of Chords"}} In the 2nd century AD, the Greco-Egyptian astronomer [[Ptolemy]] (from Alexandria, Egypt) cons ...

...actions. The system became the standard of France and Europe within half a century. Other measures with unity ratios<ref group="Note">ratios of 1 between mag ...ts for length, mass and time. Advances in [[electromagnetism]] in the 19th century necessitated additional units to be defined, and multiple incompatible syst ...

...ermodynamic work, the caloric theory was, around the end of the eighteenth century, replaced by the "mechanical" theory of heat, which is accepted today. === 17th century–early 18th century === ...

...lestium]]}} in 1543. Increasingly accurate measurements were required, and scientists looked for measures that were universal and could be based on natural pheno ...the [[seconds pendulum]] (a pendulum with a half-period of one second) one century earlier, but this was rejected as it had been discovered that this length v ...

Twentieth-century French philosopher [[Alain Badiou]] claimed that [[ontology]] is mathematic In many cases, natural philosophers and other scientists who have made extensive use of mathematics have made leaps of inference bet ...

...of matter occurs between the liquid and plasma states,<ref>This early 20th century discussion infers what is regarded as the plasma state. See page 137 of Ame The word ''gas'' was first used by the early 17th-century [[Flemish people|Flemish]] chemist [[Jan Baptist van Helmont]].<ref>{{Cite ...

...enturies when a rigorous symbolic formalism was developed. In the mid-19th century, the scope of algebra broadened beyond a [[theory of equations]] to cover d ...[[polynomial equations]] in view of solving them. This changed in the 19th century{{efn|These changes were in part triggered by discoveries that solved many o ...

...the human population will begin to decline in the second half of the 21st century.<ref>{{Cite news |last1=Cave |first1=Damien |last2=Bubola |first2=Emma |las ...s, broken down by continents, were published in the first half of the 19th century, at 600 million to 1&nbsp;billion in the early 1800s and 800&nbsp;million t ...

...ysics)|period]] of [[Cepheid]] [[variable stars]] at the beginning of 20th century. ...chemistry: their changing roles from alchemical times to the mid-twentieth century|last=F.|first=Rayner-Canham, Marelene|date=1998|publisher=American Chemical ...

...2004-02/ignorance-maglev-bliss/ Ignorance = Maglev = Bliss ''For 150 years scientists believed that stable magnetic levitation was impossible. Then Roy Harrigan ...lectromagnetic levitation''' (EML), patented by Muck in 1923,<ref>Muck, O. German patent no. 42204 (Oct. 30, 1923)</ref> is one of the oldest levitation tech ...

..., who made extensive use of this special case of Taylor series in the 18th century.}} ...'''[[Mass number]]'''}}{{defn|defn=The mass number (symbol ''A'', from the German word ''Atomgewicht'' [atomic weight]),<ref>[[Jensen, William B.]] (2005). T ...