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History[edit] In the early 1700s, Francis Hauksbee and French chemist Charles François de Fay independently discovered what they believed were two kinds of frictional electricity—one generated from rubbing glass, the other from rubbing resin. From this, Du Fay theorized that electricity consists of two electrical fluids, vitreous and resinous, that are separated by friction, and that neutralize each other when combined.[17] A decade later Benjamin Franklin proposed that electricity was not from different types of electrical fluid, but the same electrical fluid under different pressures. He gave them the modern charge nomenclature of positive and negative respectively.[18] Franklin thought of the charge carrier as being positive, but he did not correctly identify which situation was a surplus of the charge carrier, and which situation was a deficit.[19] Discovery[edit] A beam of electrons deflected in a circle by a magnetic field[25] Robert Millikan Atomic theory[edit]

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J. J. Thomson In 1897 Thomson showed that cathode rays were composed of a previously unknown negatively charged particle, and thus he is credited with the discovery and identification of the electron; and, in a broader sense, with the discovery of the first subatomic particle. Thomson is also credited with finding the first evidence for isotopes of a stable (non-radioactive) element in 1913, as part of his exploration into the composition of canal rays (positive ions). He invented the mass spectrometer. Thomson was awarded the 1906 Nobel Prize in Physics for the discovery of the electron and for his work on the conduction of electricity in gases.

History of electromagnetic theory For a chronological guide to this subject, see Timeline of electromagnetic theory. The history of electromagnetic theory begins with ancient measures to deal with atmospheric electricity, in particular lightning.[1] People then had little understanding of electricity, and were unable to scientifically explain the phenomena.[2] In the 19th century there was a unification of the history of electric theory with the history of magnetic theory. It became clear that electricity should be treated jointly with magnetism, because wherever charges are in motion electric current results and, magnetism is due to electric current.[3] The source term for electric field is electric charge where as that for magnetic field is electric current( charges in motion). Magnetism was not fully explained until the idea of magnetic induction was developed.[4] Electricity was not fully explained until the idea of electric charge was developed. Ancient and classical history[edit]

Henri Becquerel Antoine Henri Becquerel (15 December 1852 – 25 August 1908) was a French physicist, Nobel laureate, and the discoverer of radioactivity along with Marie Skłodowska-Curie and Pierre Curie,[1] for which all three won the 1903 Nobel Prize in Physics. Biography[edit] Early life[edit] Becquerel was born in Paris into a family which produced four generations of scientists: Becquerel's grandfather (Antoine César Becquerel), father (Alexandre-Edmond Becquerel), and son (Jean Becquerel). He studied engineering at the École Polytechnique and the École des Ponts et Chaussées. In 1890 he married Louise Désirée Lorieux.

NASA - Sun-Earth Day - Technology Through Time - #50 Ancient Sunlight The 8-minute travel time to Earth by sunlight hides a thousand-year journey that actually began in the core. Sunrises are seen with light created thousands of years ago in the core of the sun. Sunlight is produced through nuclear reactions in the sun's core. Originally born as energetic gamma rays, after billions of collisions with matter, this radiation reaches the surface and escapes into space. How old is sunlight by the time it reaches the surface? Black-body radiation As the temperature decreases, the peak of the black-body radiation curve moves to lower intensities and longer wavelengths. The black-body radiation graph is also compared with the classical model of Rayleigh and Jeans. Black-body radiation is the type of electromagnetic radiation within or surrounding a body in thermodynamic equilibrium with its environment, or emitted by a black body (an opaque and non-reflective body) held at constant, uniform temperature. The radiation has a specific spectrum and intensity that depends only on the temperature of the body.[1][2][3][4]

Carbon-14 Carbon-14, 14C, or radiocarbon, is a radioactive isotope of carbon with a nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples. Carbon-14 was discovered on 27 February 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley. Its existence had been suggested by Franz Kurie in 1934.[2]

Photoelectric effect The photoelectric effect is the observation that many metals emit electrons when light shines upon them. Electrons emitted in this manner may be called photoelectrons. According to classical electromagnetic theory, this effect can be attributed to the transfer of energy from the light to an electron in the metal. From this perspective, an alteration in either the amplitude or wavelength of light would induce changes in the rate of emission of electrons from the metal.

Thomas Young (scientist) Thomas Young (13 June 1773 – 10 May 1829) was an English polymath. Young made notable scientific contributions to the fields of vision, light, solid mechanics, energy, physiology, language, musical harmony, and Egyptology. He "made a number of original and insightful innovations"[1] in the decipherment of Egyptian hieroglyphs (specifically the Rosetta Stone) before Jean-François Champollion eventually expanded on his work. He was mentioned by, among others, William Herschel, Hermann von Helmholtz, James Clerk Maxwell, and Albert Einstein. Young belonged to a Quaker family of Milverton, Somerset, where he was born in 1773, the eldest of ten children.

Proton The proton is a subatomic particle, symbol p or p+, with a positive electric charge of +1e elementary charge and mass slightly less than that of a neutron. Protons and neutrons, each with mass approximately one atomic mass unit, are collectively referred to as "nucleons". One or more protons are present in the nucleus of an atom. The number of protons in the nucleus is referred to as its atomic number. Since each element has a unique number of protons, each element has its own unique atomic number. The word proton is Greek for "first", and this name was given to the hydrogen nucleus by Ernest Rutherford in 1920. Radioactive decay Alpha decay is one example type of radioactive decay, in which an atomic nucleus emits an alpha particle, and thereby transforms (or 'decays') into an atom with a mass number decreased by 4 and atomic number decreased by 2. Many other types of decays are possible. Radioactive decay, also known as nuclear decay or radioactivity, is the process by which a nucleus of an unstable atom loses energy by emitting particles of ionizing radiation.