query: who was the first scientist who produce electromagnetic waves in a laboratory

pos: Heinrich Hertz by his life's work, on its home page. Heinrich Hertz Heinrich Rudolf Hertz (; ; 22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves theorized by James Clerk Maxwell's electromagnetic theory of light. The unit of frequencycycle per secondwas named the "hertz" in his honor. Heinrich Rudolf Hertz was born in 1857 in Hamburg, then a sovereign state of the German Confederation, into a prosperous and cultured Hanseatic family. His father Gustav Ferdinand Hertz (originally named David Gustav Hertz) (1827–1914) was a barrister and later a senator. His

pos: Invention of radio it was written off as electromagnetic induction at the time. The discovery of electromagnetic waves, including radio waves, by Heinrich Rudolf Hertz in the 1880s came about after over a half century theoretical development on the connection between electricity and magnetism starting in the early 1800s and culminated in a theory of electromagnetism developed by James Clerk Maxwell by 1873, which Hertz finally proved. The development of radio waves into a communication medium did not follow immediately afterwards. After their discovery Hertz considered them of little practical value and other experimenters who explored the physical properties of the new phenomenon,

pos: History of radio could propagate through free space. It is likely that the first intentional transmission of a signal by means of electromagnetic waves was performed in an experiment by David Edward Hughes around 1880, although this was considered to be induction at the time. In 1888 Heinrich Rudolf Hertz was able to conclusively prove transmitted airborne electromagnetic waves in an experiment confirming Maxwell's theory of electromagnetism. After the discovery of these "Hertzian waves" (it would take almost 20 years for the term "radio" to be universally adopted for this type of electromagnetic radiation) many scientists and inventors experimented with wireless transmission, some

pos: Heinrich Hertz Heinrich Hertz Heinrich Rudolf Hertz (; ; 22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves theorized by James Clerk Maxwell's electromagnetic theory of light. The unit of frequencycycle per secondwas named the "hertz" in his honor. Heinrich Rudolf Hertz was born in 1857 in Hamburg, then a sovereign state of the German Confederation, into a prosperous and cultured Hanseatic family. His father Gustav Ferdinand Hertz (originally named David Gustav Hertz) (1827–1914) was a barrister and later a senator. His mother was Anna Elisabeth Pfefferkorn. Hertz's father converted

pos: Heinrich Hertz by his life's work, on its home page. Heinrich Hertz Heinrich Rudolf Hertz (; ; 22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves theorized by James Clerk Maxwell's electromagnetic theory of light. The unit of frequencycycle per secondwas named the "hertz" in his honor. Heinrich Rudolf Hertz was born in 1857 in Hamburg, then a sovereign state of the German Confederation, into a prosperous and cultured Hanseatic family. His father Gustav Ferdinand Hertz (originally named David Gustav Hertz) (1827–1914) was a barrister and later a senator. His

neg: Radio wave light and similarities in electrical and magnetic observations. His mathematical theory, now called Maxwell's equations, described light waves and radio waves as waves of electromagnetism that travel in space, radiated by a charged particle as it undergoes acceleration. In 1887, Heinrich Hertz demonstrated the reality of Maxwell's electromagnetic waves by experimentally generating radio waves in his laboratory, showing that they exhibited the same wave properties as light: standing waves, refraction, diffraction, and polarization. Radio waves, originally called "Hertzian waves", were first used for communication in the mid 1890s by Guglielmo Marconi, who developed the first practical radio transmitters and receivers.

neg: Irish Radio Transmitters Society Ireland in the International Amateur Radio Union. Radio in Ireland can be traced back to the 1800s with Professor George Francis Fitzgerald of TCD who in conjunction with Heinrich Hertz clarified and confirmed James Clerk Maxwell's mathematical theories of the electromagnetic field. This work led Fitzgerald to conclude in 1883 that an oscillating electric current would produce electromagnetic waves, which was experimentally confirmed by Heinrich Hertz in 1888 and used in the development of wireless telegraphy. Fitzgerald was the first to suggest a method of producing radio frequency waves which forms the basis for modern radio. An early pioneer of

neg: Mary Taylor Slow in 1926 for a thesis on aspects of electromagnetic waves that she wrote in German. Taylor was awarded a Yarrow Research Fellowship which enabled her to remain at Göttingen and continue her work on electromagnetic waves with Professor Richard Courant. In 1929 Taylor returned to the UK and took up a post as Scientific Officer at the Radio Research Station in Slough, Berkshire (part of the UK Department of Scientific and Industrial Research and the UK National Physics Laboratory, now the National Physical Laboratory). Here she continued to carry out research into the theory of electromagnetic waves, specialising in the

neg: Nathan Marcuvitz Heinrich Hertz Medal (Gold Medal and Monetary Award, IEEE highest recognition for electromagnetic waves), (He was the first recipient, 1989) Microwave Career Award from the IEEE Microwave Theory and Techniques Society in 1985 Son of Samuel and Rebecca M.(Feiner); Married Muriel Spanier, June 30, 1946; children – Andrew, Karen (Levy). Nathan Marcuvitz Nathan Marcuvitz (born December 29, 1913 in Brooklyn, New York, d. February 14, 2010 in Naples, FL), was an American electrical engineer, physicist, and educator who worked in the fields of microwave and electromagnetic theory. He was head of the experimental group of the Radiation Laboratory (MIT). He

neg: Guglielmo Marconi the transmission of telegraph messages without connecting wires as used by the electric telegraph. This was not a new idea; numerous investigators and inventors had been exploring wireless telegraph technologies and even building systems using electric conduction, electromagnetic induction and optical (light) signalling for over 50 years, but none had proven technically and commercially successful. A relatively new development came from Heinrich Hertz, who, in 1888, demonstrated that one could produce and detect electromagnetic radiation. At the time, this radiation was commonly called "Hertzian" waves, and is now generally referred to as radio waves. There was a great deal of

neg: Sergei Tretyakov (scientist) on modelling and applications of thin composite layers with engineered electromagnetic properties (metasurfaces), in particular, developing approaches to full control of reflected and transmitted waves. Sergei Tretyakov (scientist) Sergei Tretyakov () (born in 1956) is a Russian-Finnish scientist, focused in electromagnetic field theory, complex media electromagnetics and microwave engineering. He is currently a professor at Department of Electronics and Nanoengineering, Aalto University (former Helsinki University of Technology), Finland. His main research area in recent years is metamaterials and metasurfaces from fundamentals to applications. He was the president of the European Virtual Institute for Artificial Electromagnetic Materials and Metamaterials (”Metamorphose VI”)

neg: Nathan Marcuvitz Nathan Marcuvitz Nathan Marcuvitz (born December 29, 1913 in Brooklyn, New York, d. February 14, 2010 in Naples, FL), was an American electrical engineer, physicist, and educator who worked in the fields of microwave and electromagnetic theory. He was head of the experimental group of the Radiation Laboratory (MIT). He was a member of the National Academy of Engineering. He had a PhD in electrical engineering from Polytechnic Institute of Brooklyn. "Dr. Nathan Marcuvitz stands out clearly as the leading figure in the field of electromagnetic waves for the period of at least two decades following World War II. He

neg: Heinrich Hertz effects he was observing were results of Maxwell's predicted electromagnetic waves. Starting in November 1887 with his paper "On Electromagnetic Effects Produced by Electrical Disturbances in Insulators", Hertz would send a series of papers to Helmholtz at the Berlin Academy, including papers in 1888 that showed transverse free space electromagnetic waves traveling at a finite speed over a distance. In the apparatus Hertz used, the electric and magnetic fields would radiate away from the wires as transverse waves. Hertz had positioned the oscillator about 12 meters from a zinc reflecting plate to produce standing waves. Each wave was about 4

neg: Electromagnetic radiation for the electromagnetic field which suggested that waves in the field would travel with a speed that was very close to the known speed of light. Maxwell therefore suggested that visible light (as well as invisible infrared and ultraviolet rays by inference) all consisted of propagating disturbances (or radiation) in the electromagnetic field. Radio waves were first produced deliberately by Heinrich Hertz in 1887, using electrical circuits calculated to produce oscillations at a much lower frequency than that of visible light, following recipes for producing oscillating charges and currents suggested by Maxwell's equations. Hertz also developed ways to detect these

neg: Diffraction a light wave travels through a medium with a varying refractive index, or when a sound wave travels through a medium with varying acoustic impedance. Diffraction has an impact on the acoustic space. Diffraction occurs with all waves, including sound waves, water waves, and electromagnetic waves such as visible light, X-rays and radio waves. Since physical objects have wave-like properties (significantly at the atomic level, invisibly at macro level), diffraction also occurs with matter and can be studied according to the principles of quantum mechanics. Italian scientist Francesco Maria Grimaldi coined the word "diffraction" and was the first to record

neg: Spark-gap transmitter generate or detect electromagnetic waves of other frequencies. By 1883 it was known that accelerated electric charges could produce electromagnetic waves, and George Fitzgerald had calculated the output power of a loop antenna. Fitzgerald in a brief note published in 1883 suggested that electromagnetic waves could be generated practically by discharging a capacitor rapidly; the method used in spark transmitters, however there is no indication that this inspired other inventors. The division of the history of spark transmitters into the different types below follows the organization of the subject used in many wireless textbooks. German physicist Heinrich Hertz in 1887

neg: Extremely high frequency Extremely high frequency Extremely high frequency (EHF) is the International Telecommunication Union (ITU) designation for the band of radio frequencies in the electromagnetic spectrum from 30 to 300 gigahertz (GHz). It lies between the super high frequency band, and the far infrared band, the lower part of which is also referred to as the terahertz gap. Radio waves in this band have wavelengths from ten to one millimetre, giving it the name millimetre band or millimetre wave, sometimes abbreviated MMW or mmW. Millimetre-length electromagnetic waves were first investigated in the 1890s by Indian scientist Jagadish Chandra Bose. Compared to lower

neg: James Clerk Maxwell James Clerk Maxwell James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish scientist in the field of mathematical physics. His most notable achievement was to formulate the classical theory of electromagnetic radiation, bringing together for the first time electricity, magnetism, and light as different manifestations of the same phenomenon. Maxwell's equations for electromagnetism have been called the "second great unification in physics" after the first one realised by Isaac Newton. With the publication of "A Dynamical Theory of the Electromagnetic Field" in 1865, Maxwell demonstrated that electric and magnetic fields travel through space as waves moving

neg: Stephen J. Lukasik thesis was supervised by William Allis and treated a subatomic phenomenon. While a graduate student at MIT, he worked at nearby BBN Technologies security-related wave phenomenon as an acoustical engineer. After graduating from MIT, Lukasik joined Westinghouse Bettis Atomic Laboratory as a scientist, refining criticality codes. In 1957, he went to Stevens Institute of Technology Davidson Laboratory, where he established a Fluid Physics Division which pioneered techniques such as explosive compression of magnetic flux to produce megagauss-level magnetic fields, sweeping pressure sensitive naval mines, and examining energy loss mechanisms acting on shallow water waves. He also taught as an Associate

neg: Elizabeth Rauscher and van Bise, moved to an estate in Devotion, North Carolina, owned by Richard J. Reynolds III, grandson of R. J. Reynolds, the tobacco magnate. Until his death in 1994, Reynolds allowed them to live there to conduct research into the effects of electromagnetic fields on brain waves. A third scientist, physician Andrija Puharich, had been living and conducting research on the estate since 1980. After Reynolds' death, the scientists said he had invited them to remain there as long as they wanted, but they were unable to produce a written agreement. Elizabeth Rauscher Elizabeth A. Rauscher is an American

neg: Seismic metamaterial are body waves and surface waves. Both of these have different modes of wave propagation. Computations showed that seismic waves traveling toward a building, could be directed around the building, leaving the building unscathed, by using "seismic metamaterials". The very long wavelengths of earthquake waves would be shortened as they interact with the metamaterials; the waves would pass around the building so as to arrive in phase as the earthquake wave proceeded, as if the building was not there. The mathematical models produce the regular pattern provided by Metamaterial cloaking. This method was first understood with electromagnetic cloaking metamaterials -

neg: Walter Dieminger Walter Dieminger Walter Dieminger, (July 7, 1907 – September 29, 2000) was a German space scientist and director of Germany's Max Planck Institute for Aeronomy from 1955 to 1975. Dieminger's research was focused on the ionosphere. Dieminger studied physics between 1926 and 1935 at the University of Technology Munich. After receiving his Ph.D. for work on electromagnetic waves and the ionosphere with Jonathan Zenneck, he worked at the Deutsche Versuchsanstalt für Luftfahrt (German Experimental Institute for Aviation). With his focus on research of the ionosphere and electromagnetic waves at his new institute, called the Zentralstelle für Funkberatung (Central Counseling Office

neg: Spark-gap transmitter electric charges when they are accelerated. Radio waves, electromagnetic waves of radio frequency, can be generated by time-varying electric currents, consisting of electrons flowing through a conductor which suddenly change their velocity, thus accelerating. A capacitance discharged through an electric spark across a spark gap between two conductors was the first device known which could generate radio waves. The spark itself doesn't produce the radio waves, it merely serves to excite resonant radio frequency oscillating electric currents in the conductors of the attached circuit. The conductors radiate the energy in this oscillating current as radio waves. Due to the inherent

neg: Radio receiver digital receivers, a related problem is DC offset of the signal. This is corrected by a similar feedback system. Radio waves were first identified in German physicist Heinrich Hertz's 1887 series of experiments to prove James Clerk Maxwell's electromagnetic theory. Hertz used spark-excited dipole antennas to generate the waves and micrometer spark gaps attached to dipole and loop antennas to detect them. These primitive devices are more accurately described as radio wave sensors, not "receivers", as they could only detect radio waves within about 100 feet of the transmitter, and were not used for communication but instead as laboratory instruments

neg: Microwave ablation Microwave ablation Microwave Ablation (MWA) is a form of thermal ablation used in interventional radiology to treat cancer. MWA uses electromagnetic waves in the microwave energy spectrum (300 MHz to 300 GHz) to produce tissue-heating effects. The oscillation of polar molecules produces frictional heating, ultimately generating tissue necrosis within solid tumors. It is generally used for the treatment and/or palliation of solid tumors in patients who are nonsurgical candidate. The technique for thermal ablation in the lung by using radiofrequency ablation was first described in 1995 for use in animal lung tumor models and then in 2000 in humans. Microwave

neg: X-ray crystallography by Charles Glover Barkla showed that X-rays exhibited phenomena associated with electromagnetic waves, including transverse polarization and spectral lines akin to those observed in the visible wavelengths. Single-slit experiments in the laboratory of Arnold Sommerfeld suggested that X-rays had a wavelength of about 1 angstrom. However, X-rays are composed of photons, and thus are not only waves of electromagnetic radiation but also exhibit particle-like properties. Albert Einstein introduced the photon concept in 1905, but it was not broadly accepted until 1922, when Arthur Compton confirmed it by the scattering of X-rays from electrons. Therefore, these particle-like properties of X-rays, such

neg: Radio modulation (PM). An "antenna" (or "aerial") is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver. In transmission, a radio transmitter supplies an electric current oscillating at radio frequency (i.e. high frequency AC) to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of an electromagnetic wave in order to produce a tiny voltage at its terminals, that is applied to a receiver to be amplified. Some antennas

neg: Maxwell's equations at various wavelengths to produce a spectrum from radio waves to γ-rays. The equations are named after the physicist and mathematician James Clerk Maxwell, who between 1861 and 1862 published an early form of the equations that included the Lorentz force law. He also first used the equations to propose that light is an electromagnetic phenomenon. The equations have two major variants. The microscopic Maxwell equations have universal applicability, but are unwieldy for common calculations. They relate the electric and magnetic fields to total charge and total current, including the complicated charges and currents in materials at the atomic scale.

neg: Light From this, Maxwell concluded that light was a form of electromagnetic radiation: he first stated this result in 1862 in "On Physical Lines of Force". In 1873, he published "A Treatise on Electricity and Magnetism", which contained a full mathematical description of the behaviour of electric and magnetic fields, still known as Maxwell's equations. Soon after, Heinrich Hertz confirmed Maxwell's theory experimentally by generating and detecting radio waves in the laboratory, and demonstrating that these waves behaved exactly like visible light, exhibiting properties such as reflection, refraction, diffraction, and interference. Maxwell's theory and Hertz's experiments led directly to the development

neg: Sergei Tretyakov (scientist) Possibility of existence of a backward wave medium, where electromagnetic waves propagate with anti-parallel phase and group velocities, was suggested by several scientists throughout the twentieth century: Arthur Schuster, Horace Lamb, Leonid Mandelstam, Victor Veselago, and others. However, due to the absence of materials with such properties in nature, wide interest to the backward wave media was generated only in the early 2000s, when the team of David R. Smith experimentally demonstrated first negative-index metamaterial. In 2003, Tretyakov and colleagues suggested an alternative way to achieve backward waves by using bianisotropic chiral materials. In this case, it is not required

neg: Electromagnetic spectrum in the field. Analyzing the speed of these theoretical waves, Maxwell realized that they must travel at a speed that was about the known speed of light. This startling coincidence in value led Maxwell to make the inference that light itself is a type of electromagnetic wave. Maxwell's equations predicted an infinite number of frequencies of electromagnetic waves, all traveling at the speed of light. This was the first indication of the existence of the entire electromagnetic spectrum. Maxwell's predicted waves included waves at very low frequencies compared to infrared, which in theory might be created by oscillating charges in

neg: Edouard Sarasin Edouard Sarasin Edouard Sarasin (20 May 1843 – 22 July 1917) was an independent scientist in Geneva. Born in a wealthy family, he established a private laboratory where he collaborated with other researchers. His studies included those on the properties of waves, resonance, radiowaves, radiation and geophysics. Sarasin came from a family of French descent who had settled in Geneva in the early sixteenth century. Sarasin studied physics at Paris, Heidelberg and Berlin and in 1867 he established a private laboratory on rue de l'Hôtel-de-Ville, and worked with other collaborators including Auguste de la Rive (1801-1873) and his son Lucien

neg: N ray Prosper-René Blondlot was a professor of physics at the University of Nancy studying electromagnetic radiation. Blondlot was a respected member of the scientific community: he was one of eight physicists who were corresponding members of the French Academy of Sciences and was awarded the Academy's Gaston Planté prize in 1893 and the LaCaze prize in 1899. His attempts to measure the speed of electromagnetic waves were commended by Thomson and Henri Poincaré. After the discovery of X rays, Blondlot began investigating the nature of X rays, trying to determine whether they behaved as particles or electromagnetic waves. (This was before

neg: Introduction to electromagnetism are a result of Maxwell's equations which, in part, state that changing electric fields produce magnetic fields and vice versa. Due to this dependence, the fields form an electromagnetic wave, also called electromagnetic radiation (EMR). The electric and magnetic fields are transverse to each other, and transverse to the direction of propagation of the electromagnetic wave. Visible light is a form of electromagnetic radiation. Other forms of electromagnetic radiation include radio waves, X-rays and infrared. Introduction to electromagnetism Electromagnetism is the study of interactions between particles and the electromagnetic field. It includes the study of forces between charged particles, electromagnetic

neg: Anderson localization Anderson localization In condensed matter physics, Anderson localization (also known as strong localization) is the absence of diffusion of waves in a "disordered" medium. This phenomenon is named after the American physicist P. W. Anderson, who was the first to suggest that electron localization is possible in a lattice potential, provided that the degree of randomness (disorder) in the lattice is sufficiently large, as can be realized for example in a semiconductor with impurities or defects. Anderson localization is a general wave phenomenon that applies to the transport of electromagnetic waves, acoustic waves, quantum waves, spin waves, etc. This phenomenon

neg: Sergei Tretyakov (scientist) metal wires, what is now referred as metasurfaces or two-dimensional metamaterials. During the doctoral studies, Tretyakov worked on ferrite-based anisotropic layered structures under supervision of Prof. M.I. Kontorovich. The first research visit to Helsinki University of Technology profoundly influenced his research interest, shifting it towards a novel and very promising direction of complex electromagnetic materials (now called metamaterials). From this time forth Tretyakov actively works in this research direction with the main contributions listed below. Tretyakov made important contributions to research of bianisotropic media. Together with co-authors, he developed the general theory of electromagnetic waves interactions with bianisotropic materials and

neg: Infrasound about 10 times the size. Infrasound is defined by the American National Standards Institute as "sound at frequencies less than 20 Hz." The Allies of World War I first used infrasound to locate artillery. One of the pioneers in infrasonic research was French scientist Vladimir Gavreau. His interest in infrasonic waves first came about in his laboratory during the 1960s, when he and his laboratory assistants experienced shaking laboratory equipment and pain in the eardrums, but his microphones did not detect audible sound. He concluded it was infrasound caused by a large fan and duct system, and soon got to

neg: Le Sage's theory of gravitation particles with longitudinal waves of the aether. After these attempts, other authors in the early 20th century substituted electromagnetic radiation for Le Sage’s particles. This was in connection with Lorentz ether theory and the electron theory of that time, in which the electrical constitution of matter was assumed. In 1900 Hendrik Lorentz wrote that Le Sage's particle model is not consistent with the electron theory of his time. But the realization that trains of electromagnetic waves could produce some pressure, in combination with the penetrating power of Röntgen rays (now called x-rays), led him to conclude that nothing argues against

neg: Eleanor R. Adair 1970s, Adair conducted physiology studies as a fellow at the John B. Pierce Laboratory in New Haven to learn how humans and animals react to heat. This work led her to focus on the controversial area of microwaves and their effect on human health. Experimenting on first on squirrel monkeys and then on human volunteers, she concluded that microwave radiation from microwave ovens, cells phones, and power lines is harmless to humans and animals. In 1996, she joined the U.S. Air Force Research Laboratory at Brooks Air Force Base, Texas as a senior scientist studying electromagnetic radiation effects. Adair was

neg: History of the Tesla coil and low frequency alternating current (AC), but not much was known about frequencies above 20 kHz, what are now called radio frequencies. In 1887, four years previously, Heinrich Hertz had discovered Hertzian waves (radio waves), electromagnetic waves which oscillated at very high frequencies. This attracted much attention, and a number of researchers began experimenting with high frequency currents. Tesla's background was in the new field of alternating current power systems, so he understood transformers and resonance. In 1888 he decided that high frequencies were the most promising field for research, and set up a laboratory at 33 South Fifth Avenue,

neg: Invention of radio such as Oliver Lodge and Jagadish Chandra Bose, while transmitting radio waves some distance, did not seem to see any value in developing a communication system based on them. In their experiments they did develop electronic components and methods to improve the transmission and detection of electromagnetic waves. In the mid 1890s, building on techniques physicists were using to study electromagnetic waves, Guglielmo Marconi developed the first apparatus for long distance radio communication. On 23 December 1900, the Canadian inventor Reginald A. Fessenden became the first person to send audio (wireless telephony) by means of electromagnetic waves, successfully transmitting over

neg: Volta Laboratory and Bureau indent the sound waves on a piece of tin-foil while Bell and Tainter's invention called for cutting or "engraving" the sound waves into an ozokerite wax record with a sharp recording stylus. At each step of their inventive process the Associates also sought out the best type of materials available in order to produce the clearest and most audible sound reproduction. The strength of the Bell and Tainter patent was noted in an excerpt from a letter written by Washington patent attorney S. T. Cameron, who was a member of the law firm conducting litigation for the American Graphophone Company.

neg: Adrianus de Hoop Laboratory of Electromagnetic Research, which has developed into a world-class center for electro-magnetics, having a huge impact on the world's electromagnetic community and on electromagnetic research and education in the Netherlands. Dr. De Hoop's research interests are in the broad area of wavefield modeling in acoustics, electromagnetics and elastodynamics. His interdisciplinary insights and methods in this field can be found in his seminal Handbook of Radiation and Scattering of Waves (1995), with wavefield reciprocity serving as one of the unifying principles governing direct and inverse scattering problems and wave propagation in complex (anisotropic and dispersive) media. He spent a year

neg: Gravitational wave to 10 Hz. The possibility of gravitational waves was discussed in 1893 by Oliver Heaviside using the analogy between the inverse-square law in gravitation and electricity. In 1905, Henri Poincaré proposed gravitational waves ("ondes gravifiques"), emanating from a body and propagating at the speed of light, as being required by the Lorentz transformations and suggested that, in analogy to an accelerating electrical charge producing electromagnetic waves, accelerated masses in a relativistic field theory of gravity should produce gravitational waves. When Einstein published his general theory of relativity in 1915, he was skeptical of Poincaré's idea since the theory implied there

neg: Joan Curran Curran made an even greater contribution to victory, in 1945, than Sam." In early 1944 the Currans were part of a group of British scientists invited to go to the US to take part in the Manhattan Project – the Allied project to develop an atomic bomb. They joined the British Mission at the Berkeley Radiation Laboratory in California, headed by Mark Oliphant, a distinguished Australian scientist that Joan knew from the Cavendish Laboratory. Oliphant also acted as "de facto" deputy to Ernest Lawrence, the director of the Radiation Laboratory. The mission of the laboratory was to develop the electromagnetic

neg: George Francis FitzGerald Natural and Experimental Philosophy in 1881. Along with Oliver Lodge, Oliver Heaviside and Heinrich Hertz, FitzGerald was a leading figure among the group of "Maxwellians" who revised, extended, clarified, and confirmed James Clerk Maxwell's mathematical theories of the electromagnetic field during the late 1870s and the 1880s. In 1883, following from Maxwell's equations, FitzGerald was the first to suggest a device for producing rapidly oscillating electric currents to generate electromagnetic waves, a phenomenon which was first shown to exist experimentally by the German physicist Heinrich Hertz in 1888. In 1883, he was elected Fellow of the Royal Society. In 1899,

neg: History of radio trying to develop a system of communication, some intentionally using these new Hertzian waves, some not. Maxwell's theory showing that light and Hertzian electromagnetic waves were the same phenomenon at different wavelengths led "Maxwellian" scientist such as John Perry, Frederick Thomas Trouton and Alexander Trotter to assume they would be analogous to optical signaling and the Serbian American engineer Nikola Tesla to consider them relatively useless for communication since "light" could not transmit further than line of sight. In 1892 the physicist William Crookes wrote on the possibilities of wireless telegraphy based on Hertzian waves and in 1893 Tesla proposed

neg: Sea interferometry Sea interferometry Sea interferometry, also known as Sea-cliff interferometry, is a form of radio astronomy that uses radio waves reflected off the sea to produce an interference pattern. It is the radio wave analogue to Lloyd's mirror. The technique was invented and exploited in Australia between 1945 and 1948. A radio detecting aerial is placed on top of a cliff, which detects electromagnetic waves coming directly from the source and waves reflected off the water surface. The two sets of waves are then combined to form an interference pattern such as that produced by two separate aerials. The reflected wavefront

neg: Invention of radio out up to the end of the year 1886 and the beginning of 1887. For the first time, electromagnetic radio waves ("Hertzian waves") were intentionally and unequivocally proven to have been transmitted through free space by a spark-gap device, and detected over a short distance. Hertz was able to have some control over the frequencies of his radiated waves by altering the inductance and capacitance of his transmitting and receiving antennas. He focused the electromagnetic waves using a corner reflector and a parabolic reflector, to demonstrate that radio behaved the same as light, as Maxwell's electromagnetic theory had predicted more

neg: Interfacial thermal resistance roughness, which is not accounted for in the acoustic mismatch model. For a more detailed theoretical model of this aspect see the paper by A. Khater and J. Szeftel. Like electromagnetic waves which produce surface plasmons on rough surfaces, phonons can also induce surface waves. When these waves eventually scatter, they provide another mechanism for heat to transfer across the interface. Similarly, phonons are also capable of producing evanescent waves in a total internal reflection geometry. As a result, when these waves are scattered in the solid, additional heat is transferred from the helium beyond the prediction of the acoustic

neg: Medical Scientist Training Program Medical Scientist Training Program The Medical Scientist Training Programs (MSTPs) are MD-PhD training programs that streamline the education towards MD and PhD graduate degrees. MSTPs are offered by a small number of United States medical schools with financial support from the National Institute of General Medical Sciences (NIGMS), a branch of the National Institutes of Health (NIH). The goal of these training programs is to produce physician scientists who can translate laboratory discoveries into effective treatments for patients. In 2018, there were 48 MSTP programs in the US, supporting about 900 students at all stages of the program. The program

neg: Medical Scientist Training Program provide MD–PhD training. Medical Scientist Training Program The Medical Scientist Training Programs (MSTPs) are MD-PhD training programs that streamline the education towards MD and PhD graduate degrees. MSTPs are offered by a small number of United States medical schools with financial support from the National Institute of General Medical Sciences (NIGMS), a branch of the National Institutes of Health (NIH). The goal of these training programs is to produce physician scientists who can translate laboratory discoveries into effective treatments for patients. In 2018, there were 48 MSTP programs in the US, supporting about 900 students at all stages of the

neg: Varian Associates Varian Associates Varian Associates was one of the first high-tech companies in Silicon Valley. It was founded in 1948 by Russell H. and Sigurd F. Varian, William Webster Hansen, and Edward Ginzton to sell the klystron, the first vacuum tube which could amplify electromagnetic waves at microwave frequencies, and other electromagnetic equipment. Varian Associates split into three companies in 1999: Varian Medical Systems, Varian, Inc. and Varian Semiconductor. On April 20, 1948, the Articles of Incorporation were filed, signed by nine directors: Edward Ginzton, who had worked with the Varian brothers since his days as a doctoral student; William Webster

neg: Radar display Radar display A radar display is an electronic device to present radar data to the operator. The radar system transmits pulses or continuous waves of electromagnetic radiation, a small portion of which backscatter off targets (intended or otherwise) and return to the radar system. The receiver converts all received electromagnetic radiation into a continuous electronic analog signal of varying (or oscillating) voltage that can be converted then to a screen display. Modern systems typically use some sort of raster scan display to produce a map-like image. Early in radar development, however, numerous circumstances made such displays difficult to produce. People

neg: Electromagnetic radiation a transverse wave. The wavefront of electromagnetic waves emitted from a point source (such as a light bulb) is a sphere. The position of an electromagnetic wave within the electromagnetic spectrum can be characterized by either its frequency of oscillation or its wavelength. Electromagnetic waves of different frequency are called by different names since they have different sources and effects on matter. In order of increasing frequency and decreasing wavelength these are: radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. Electromagnetic waves are emitted by electrically charged particles undergoing acceleration, and these waves can subsequently

neg: Tor Hagfors Tor Hagfors Tor Hagfors (18 December 1930 – 17 January 2007) was a Norwegian scientist, radio astronomer, radar expert and a pioneer in the studies of the interactions between electromagnetic waves and plasma. In the early 1960s he was one of a handful of pioneering theorists that independently developed a theory that explained the scattering of radio waves by the free electrons in a plasma and applied the result to the ionosphere. He became founding director of the new EISCAT facilities that were then under construction in 1975, by which time he already been director at most of the other

neg: Continuous wave method from damped wave signals produced by earlier "spark gap" type transmitters. Very early radio transmitters used a spark gap to produce radio-frequency oscillations in the transmitting antenna. The signals produced by these spark-gap transmitters consisted of strings of brief pulses of sinusoidal radio frequency oscillations which died out rapidly to zero, called damped waves. The disadvantage of damped waves was that their energy was spread over an extremely wide band of frequencies; they had wide bandwidth. As a result, they produced electromagnetic interference (RFI) that spread over the transmissions of stations at other frequencies. This motivated efforts to produce

neg: Jagadish Chandra Bose physicist Heinrich Hertz published the results of his experiments on electromagnetism, which showed the existence of electromagnetic waves in free space. Subsequently, British physicist Oliver Lodge, who had also been researching electromagnetism, conducted a commemorative lecture in August 1894 (after Hertz's death) on the quasi-optical nature of "Hertzian waves" (radio waves) and demonstrated their similarity to light and vision including reflection and transmission at distances up to 50 metres. Lodge's work was published in book form and caught the attention of scientists in different countries, including Bose in India. The first remarkable aspect of Bose's follow-up microwave research was that

neg: The Borderland of Sol disappearing. Ausfaller agrees that Carlos and Bey can go to Forward Station; he did not reveal himself during the conversation and the small ship would not give away the fact that there was a third crewmember. After equipping for potential combat, Bey and Carlos ferry to the station to meet with Forward. He shows them his prize possession, the "Grabber", an electromagnetic assembly that lets him shake masses of neutronium to produce polarized gravitational waves, which he is attempting to use to establish communications with alien races who may not have discovered hyperwave. When Forward asks Carlos what he thinks

neg: Jim Thomas (computer scientist) the Pacific Northwest Laboratory (later renamed Pacific Northwest National Laboratory) as a computer scientist in 1976. He rose through the ranks from senior scientist, staff scientist, chief scientist, to laboratory fellow. In the 1980s, he was a member of the founding team who conceptualized and developed the core concepts for what is today’s William R. Wiley Environmental and Molecular Sciences Laboratory, a DOE scientific user facility located at PNNL. In the early 1990s, to address the problem of information overload, Thomas headed a team of information technology researchers to develop the SPIRE document Visualization (computer graphics) visualization and analytics system.

neg: History of metamaterials induce a changing electric field and vice versa—the two are linked. These changing fields form electromagnetic waves. Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space. The ""history of metamaterials"" can have a variety starting points depending on the properties of interest. Related early wave studies started in 1904 and progressed through more than half of the first part of the twentieth century. This early research included the relationship of the phase

neg: Edouard Sarasin He also studied circular polarization in quartz with Jacques-Louis Soret from 1875. After Soret's death, Sarasin became director of the Archive of Geneva. He received an honorary doctorate from the Universities of Basel in 1885 and Geneva in 1909. Edouard Sarasin Edouard Sarasin (20 May 1843 – 22 July 1917) was an independent scientist in Geneva. Born in a wealthy family, he established a private laboratory where he collaborated with other researchers. His studies included those on the properties of waves, resonance, radiowaves, radiation and geophysics. Sarasin came from a family of French descent who had settled in Geneva in

neg: Electromagnetic spectrum Electromagnetic spectrum The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies. The electromagnetic spectrum covers electromagnetic waves with frequencies ranging from below one hertz to above 10 hertz, corresponding to wavelengths from thousands of kilometers down to a fraction of the size of an atomic nucleus. This frequency range is divided into separate bands, and the electromagnetic waves within each frequency band are called by different names; beginning at the low frequency (long wavelength) end of the spectrum these are: radio waves, microwaves, terahertz waves, infrared, visible light, ultraviolet,

neg: Microwave research by exposing herself, animals and humans to microwave levels that made them feel warm or even start to sweat and feel quite uncomfortable. She found no adverse health effects other than heat. Microwaves were first generated in the 1880s and 1890s in some of the earliest radio experiments by physicists who thought of them as a form of "invisible light". James Clerk Maxwell in his 1873 theory of electromagnetism, now called Maxwell's equations, had predicted the existence of electromagnetic waves and proposed that light was composed of these waves. In 1888, German physicist Heinrich Hertz was the first to

neg: Resonator Resonator A resonator is a device or system that exhibits resonance or resonant behavior, that is, it naturally oscillates at some frequencies, called its resonant frequencies, with greater amplitude than at others. The oscillations in a resonator can be either electromagnetic or mechanical (including acoustic). Resonators are used to either generate waves of specific frequencies or to select specific frequencies from a signal. Musical instruments use acoustic resonators that produce sound waves of specific tones. Another example is quartz crystals used in electronic devices such as radio transmitters and quartz watches to produce oscillations of very precise frequency. A cavity

neg: 19th century in science of that prediction with Helmholtz student Heinrich Hertz's 1888 detection of electromagnetic radiation, was a major triumph for physical theory and raised the possibility that even more fundamental theories based on the field could soon be developed. Experimental confirmation of Maxwell's theory was provided by Hertz, who generated and detected electric waves in 1886 and verified their properties, at the same time foreshadowing their application in radio, television, and other devices. In 1887, Heinrich Hertz discovered the photoelectric effect. Research on the electromagnetic waves began soon after, with many scientists and inventors conducting experiments on their properties. In the mid

neg: Second Industrial Revolution advancements in all of history was the unification of light, electricity and magnetism through Maxwell's electromagnetic theory. A scientific understanding of electricity was necessary for the development of efficient electric generators, motors and transformers. David Edward Hughes and Heinrich Hertz both demonstrated and confirmed the phenomenon of electromagnetic waves that had been predicted by Maxwell. It was Italian inventor Guglielmo Marconi who successfully commercialized radio at the turn of the century. He founded The Wireless Telegraph & Signal Company in Britain in 1897 and in the same year transmitted Morse code across Salisbury Plain, sent the first ever wireless communication

neg: DNA teleportation and established science does not support this theory, or provide any plausible mechanism by which it might work. In 2015, Montagnier's team published another finding similar to the original one, but using bacterial and viral DNA. Here they claim that the electromagnetic waves could be explained in terms of quantum effect. In 2009, Montagnier and his collaborators published a paper titled "Electromagnetic signals are produced by aqueous nanostructures derived from bacterial DNA sequences" in which they showed that bacterial DNA can produce electromagnetic signal (EMS) that is transferred through the cell culture medium. They used the DNA of bacteria "Micoplasma

neg: Solar flare ejection and electromagnetic radiation) barely missed Earth. According to NASA, there may be as much as a 12% chance of a similar event occurring between 2012 and 2022. Solar flares affect all layers of the solar atmosphere (photosphere, chromosphere, and corona). The plasma medium is heated to tens of millions of Kelvin, while electrons, protons, and heavier ions are accelerated to near the speed of light. Flares produce electromagnetic radiation across the electromagnetic spectrum at all wavelengths, from radio waves to gamma rays. Most of the energy is spread over frequencies outside the visual range and so the majority of

neg: Hans Hollmann the incoming aircraft while the "Würzburg" calculated the distance and height. In 1935, Hollmann wrote two books on microwaves, "Physics and Technique of Ultra-short Waves" and "Seeing with Electromagnetic Waves", which were the inspiration for the development of centimetre radar in other countries despite some censorship of their contents. During the war he supervised many research institutes in occupied countries and saved many scientists from being deported to Germany. His home and his laboratory in Berlin were destroyed during the war. After the war he was not allowed to work on microwaves but he turned his attention to a wide

neg: Technological and industrial history of 20th-century Canada to Winnipeg was completed in 1938. The section from Winnipeg to Toronto and Montreal was inaugurated in 1939 and the extensions to Moncton, Halifax and St. John's completed in 1940, 1941 and 1942 respectively. In 1901, Guglielmo Marconi sent radio signals across the Atlantic Ocean. He established a machine to produce electromagnetic waves at Cornwall in England and a machine to detect these waves at Signal Hill in St. John's Newfoundland. On 12 December 1901 he announced that he had received the transmission of waves sent by the transmitter in England at the station in St John’s. In Montreal, in

neg: Medical laboratory scientist Medical laboratory scientist A medical laboratory scientist (MLS), also traditionally referred to as a clinical laboratory scientist (CLS), is a healthcare professional who performs chemical, hematological, immunologic, histopathological, cytopathological, microscopic, and bacteriological diagnostic analyses on body fluids such as blood, urine, sputum, stool, cerebrospinal fluid (CSF), peritoneal fluid, pericardial fluid, and synovial fluid, as well as other specimens. Medical laboratory scientists work in clinical laboratories at hospitals, reference labs, biotechnology labs and non-clinical industrial labs. Educational and licensing requirements vary by country due to differing scopes of practice and legislative differences. In Australia, medical laboratory scientists complete a four-year undergraduate

neg: Radiation properties supposedly fills all evacuated or non evacuated spaces. The transmission of light or of radiant heat are allowed by the propagation of electromagnetic waves in the ether. Electromagnetic waves have similar characteristics to television and radio broadcasting waves they only differ in wavelength. All electromagnetic waves travel at the same speed; therefore, shorter wavelengths are associated with high frequencies. Since every body or fluid is submerged in the ether, due to the vibration of the molecules, any body or fluid can potentially initiate an electromagnetic wave. All bodies generate and receive electromagnetic waves at the expense of its stored energy

neg: Non-ionizing radiation that there is no consistent and convincing scientific evidence of adverse health effects caused by RF radiation at powers sufficiently low that no thermal health effects are produced. Non-ionizing radiation can produce non-mutagenic effects such as inciting thermal energy in biological tissue that can lead to burns. In 2011, the International Agency for Research on Cancer (IARC) from the World Health Organization (WHO) released a statement adding radiofrequency electromagnetic fields (including microwave and millimeter waves) to their list of things which are possibly carcinogenic to humans. In terms of potential biological effects, the non-ionizing portion of the spectrum can be

neg: Allan Carswell Allan Carswell Allan Ian Carswell, CM, FRSC (born 1933) is an internationally recognized leader in the field of laser radar (lidar) applications since the technology's beginning in the early 1960s. Carswell has been actively engaged in the study of the properties and applications of lasers and coherent optical frequency radiation since 1963. He was a member of the Plasma Physics Laboratory at the RCA Victor Research Laboratories in Montreal, Quebec, Canada, studying electromagnetic waves with ionized gas systems. In 1965 Carswell was appointed Director of the RCA Optical and Microwave Research Laboratory, and led the group there that developed the

neg: Alraune root itself was used in love philtres and potions while its fruit was supposed to facilitate pregnancy. Witches who "made love" to the Mandrake root were said to produce offspring that had no feelings of real love and had no soul. The novel deviates from the myth by concentrating on the issues of artificial insemination and individuality: genetics versus environment. A scientist, Professor Jakob ten Brinken, interested in the laws of heredity, impregnates a prostitute in a laboratory with the semen of a hanged murderer. The prostitute conceives a female child who has no concept of love, whom the professor

neg: Atomic theory positive charge of the atom must be concentrated in a very tiny volume to produce an electric field sufficiently intense to deflect the alpha particles so strongly. This led Rutherford to propose a planetary model in which a cloud of electrons surrounded a small, compact nucleus of positive charge. Only such a concentration of charge could produce the electric field strong enough to cause the heavy deflection. The planetary model of the atom had two significant shortcomings. The first is that, unlike planets orbiting a sun, electrons are charged particles. An accelerating electric charge is known to emit electromagnetic waves

neg: Vitaly Shafranov headed by Mikhail Aleksandrovich Leontovich at LIPAN (Laboratory of Measuring Instruments of the USSR Academy of Sciences) as today's Russian Research Centre "Kurchatov Institute" was known at the time. He examined tokamaks stability and gave some parameter estimation for Soviet tokamak experiments. He also dealt with shock waves in plasmas and interaction of electromagnetic waves with plasmas. Later, he worked intensively on stellarators. In 1981 he became the successor of Leontovich as head of the Theory Department of Nuclear Fusion at the Kurchatov Institute. Concepts such as the Shafranov shift (1959), the Kruskal-Shafranov stability criterion and limit value and the

neg: Sergei Tretyakov (scientist) to engineer negative permittivity and permeability, instead, one should just ensure proper chiral response of the material. In the extreme case of so-called chiral nihility (when both relative permittivity and permeability are much smaller than the chirality parameter), two eigenwaves represent "forward" and "backward" circularly polarized waves with equal phase velocities. The existence of backward waves in chiral media was independently suggested by John Pendry in 2004. Inspired by the idea of transformation-optics based electromagnetic cloaking, Tretyakov's team developed an alternative realization of the same effect for cylindrical objects. In contrast to the previous designs, Tretyakov's cloaking device exhibits significantly

neg: Electromagnetic radiation Electromagnetic radiation In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space, carrying electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays. Classically, electromagnetic radiation consists of electromagnetic waves, which are synchronized oscillations of electric and magnetic fields that propagate at the speed of light, which, in a vacuum, is commonly denoted "c". In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming

neg: Charles Glover Barkla Sir Oliver Lodge. During the absence of Oliver Lodge due to ill health, Barkla would replace him in lectures. In 1899 Barkla was admitted to Trinity College, Cambridge, with an 1851 Research Fellowship from the Royal Commission for the Exhibition of 1851, to work in the Cavendish Laboratory under the physicist J. J. Thomson (discoverer of the electron). During his first two years at Cambridge, Barkla would, under the directions of Thomson, study the velocity of electromagnetic waves along wires of different widths and materials. After a year and a half at Trinity College, Cambridge, his love of music led

neg: Medical laboratory scientist doctors, due to the sometimes complex nature of the role. Medical laboratory scientist A medical laboratory scientist (MLS), also traditionally referred to as a clinical laboratory scientist (CLS), is a healthcare professional who performs chemical, hematological, immunologic, histopathological, cytopathological, microscopic, and bacteriological diagnostic analyses on body fluids such as blood, urine, sputum, stool, cerebrospinal fluid (CSF), peritoneal fluid, pericardial fluid, and synovial fluid, as well as other specimens. Medical laboratory scientists work in clinical laboratories at hospitals, reference labs, biotechnology labs and non-clinical industrial labs. Educational and licensing requirements vary by country due to differing scopes of practice and legislative

neg: Gravity Probe A for microwave amplification by stimulated emission of radiation, and is similar to a laser, as it produces coherent electromagnetic waves in the microwave region of the electromagnetic spectrum (as opposed to lasers which produce light in the visible or ultraviolet region). The probe was launched nearly vertically upward to cause a large change in the gravitational potential seen by the maser, reaching a height of . At this height, relativity predicted a clock should run 4.5 parts in 10 faster than one on the Earth. Along with the hydrogen maser, a microwave repeater was also included in the probe in

neg: Antenna (radio) Antenna (radio) In radio, an antenna is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an electric current to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves (radio waves). In reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be amplified. Antennas are essential components of all radio equipment, and are used in radio

neg: Neutrino is scattered by dense and turbulent gases, and thus delayed. The neutrino burst is expected to reach Earth before any electromagnetic waves, including visible light, gamma rays, or radio waves. The exact time delay of the electromagnetic waves' arrivals depends on the velocity of the shock wave and on the thickness of the outer layer of the star. For a Type II supernova, astronomers expect the neutrino flood to be released seconds after the stellar core collapse, while the first electromagnetic signal may emerge hours later, after the explosion shock wave has had time to reach the surface of the

neg: Waveguide (electromagnetism) non-radiative dielectric waveguides and the Goubau line, use both metal walls and dielectric surfaces to confine the wave. During the 1890s theorists did the first analyses of electromagnetic waves in ducts. Around 1893 J. J. Thomson derived the electromagnetic modes inside a cylindrical metal cavity. In 1897 Lord Rayleigh did a definitive analysis of waveguides; he solved the boundary-value problem of electromagnetic waves propagating through both conducting tubes and dielectric rods of arbitrary shape. He showed that the waves could travel without attenuation only in specific normal modes with either the electric field (TE modes) or magnetic field (TM modes),

neg: Microwave to produce millimeter waves, generating 60 GHz (5 millimeter) microwaves using a 3 mm metal ball spark oscillator. Bose also invented waveguide and horn antennas for use in his experiments. Russian physicist Pyotr Lebedev in 1895 generated 50 GHz millimeter waves. In 1897 Lord Rayleigh solved the mathematical boundary-value problem of electromagnetic waves propagating through conducting tubes and dielectric rods of arbitrary shape. which gave the modes and cutoff frequency of microwaves propagating through a waveguide. However, since microwaves were limited to line of sight paths, they could not communicate beyond the visual horizon. The subsequent development of radio communication

neg: Radar radars, except when their detection is intended. Radar relies on its own transmissions rather than light from the Sun or the Moon, or from electromagnetic waves emitted by the objects themselves, such as infrared wavelengths (heat). This process of directing artificial radio waves towards objects is called "illumination", although radio waves are invisible to the human eye or optical cameras. If electromagnetic waves travelling through one material meet another material, having a different dielectric constant or diamagnetic constant from the first, the waves will reflect or scatter from the boundary between the materials. This means that a solid object in

neg: Martin A. Uman Center in Princeton, New Jersey and scientist at Elcon Laboratory, Inc. in Cambridge, Massachusetts. From 1961 to 1965 Uman was associate professor of electrical engineering at the University of Arizona in Tucson. At Arizona Uman taught and conducted research in electromagnetics and gaseous electronics and became interested in the physics of lightning. From 1965 to 1971 Uman was fellow physicist at Westinghouse Research Labs in Pittsburgh. There he studied the physical and electromagnetic aspects of lightning and long laboratory sparks. In 1971 Uman became a professor in the Department of Electrical and Computer Engineering at the University of Florida in

neg: Longitudinal wave Royal Society, have used the Proca equation in an attempt to demonstrate photon mass as a longitudinal electromagnetic component of Maxwell's equations, suggesting that longitudinal electromagnetic waves could exist in a Dirac polarized vacuum. After Heaviside's attempts to generalize Maxwell's equations, Heaviside came to the conclusion that electromagnetic waves were not to be found as longitudinal waves in ""free space"" or homogeneous media. But Maxwell's equations do lead to the appearance of longitudinal waves under some circumstances, for example, in plasma waves or guided waves. Basically distinct from the "free-space" waves, such as those studied by Hertz in his UHF

neg: Non-ionizing radiation radio and satellite communications. Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are made by lightning, or by astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, satellite communication, computer networks and innumerable other applications. Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves may cover a part of the Earth very consistently, shorter waves can reflect

neg: Heinrich Hertz the existence of airborne electromagnetic waves led to an explosion of experimentation with this new form of electromagnetic radiation, which was called "Hertzian waves" until around 1910 when the term "radio waves" became current. Within 10 years researchers such as Oliver Lodge, Ferdinand Braun, and Guglielmo Marconi employed radio waves in the first wireless telegraphy radio communication systems, leading to radio broadcasting, and later television. Today radio is an essential technology in global telecommunication networks, and the transmission medium underlying modern wireless devices. In 1892, Hertz began experimenting and demonstrated that cathode rays could penetrate very thin metal foil (such

neg: Baltic Fleet steamships – prevented the British and French Allies from occupying Hangö, Sveaborg, and Saint Petersburg. Despite being greatly outnumbered by the technologically superior Allies, it was the Russian Fleet that introduced into naval warfare such novelties as torpedo mines, invented by Boris Yakobi. Other outstanding inventors who served in the Baltic Fleet were Alexander Stepanovich Popov (who was the first to demonstrate the practical application of electromagnetic (radio) waves), Stepan Makarov (the first to launch torpedoes from a boat), Alexei Krylov (author of the modern ship floodability theory), and Alexander Mozhaiski (co-inventor of aircraft). As early as 1861, the first

neg: X-ray transient three main components: the main ovals, which are bright, narrow (< 1000 km in width) circular features located at approximately 16° from the magnetic poles; the satellite auroral spots, which correspond to the footprints of the magnetic field lines connecting their ionospheres with the ionosphere of Jupiter, and transient polar emissions situated within the main ovals. The auroral emissions were detected in almost all parts of the electromagnetic spectrum from radio waves to X-rays (up to 3 keV). The X-ray monitor of Solwind, designated NRL-608 or XMON, was a collaboration between the Naval Research Laboratory and Los Alamos National Laboratory.

neg: Bo Thidé discovered electromagnetic emissions stimulated by powerful radio waves in the ionosphere during experiments in August 1981 at the EISCAT facility in Tromsø, Norway. For the first time it was shown that the plasma turbulence excited by powerful radio waves in the ionosphere radiates secondary electromagnetic radiation that can be detected and analysed on the ground. These stimulated electromagnetic emissions (SEE) exhibit a rich spectral structure, particularly near harmonics of the ionospheric electron gyro frequency. The SEE technique is now a useful tool in plasma turbulence research. For his discovery, Thidé was awarded the Edlund Prize of the Royal Swedish Academy

neg: Invention of the telephone Company, and the results were covered up by STC's chairman Sir Frank Gill to maintain Bell's reputation. An early voice communicating device was invented around 1854 by Antonio Meucci, who called it a "telettrofono". In 1871 Meucci filed a caveat at the US Patent Office. His caveat describes his invention, but does not mention a diaphragm, electromagnet, conversion of sound into electrical waves, conversion of electrical waves into sound, or other essential features of an electromagnetic telephone. The first American demonstration of Meucci's invention took place in Staten Island, New York in 1854. In 1861, a description of it was

neg: Aleksandr Stoletov Aleksandr Stoletov Alexander Grigorievich Stoletov (; 10 August 1839 – 27 May 1896) was a Russian physicist, founder of electrical engineering, and professor in Moscow University. He was the brother of general Nikolai Stoletov. Alexander Stoletov defended his doctoral dissertation in 1872 and became professor at Moscow University a year later. After defending his dissertation he became a renowned scientist worldwide. He attended the opening ceremony of the physical laboratory in Cambridge in 1874, and represented Russia at the first World Congress of Electricity in Paris in 1881, where he presented his work on links between electrostatic and electromagnetic values.

neg: Cavendish Laboratory of the new Cavendish Laboratory is known for its inscription from the Book of Psalms in the Bible: "The works of the Lord are great, sought out of all them that have pleasure therein." The department is named to commemorate British chemist and physicist Henry Cavendish for contributions to science and his relative William Cavendish, 7th Duke of Devonshire, who served as chancellor of the university and donated money for the construction of the laboratory. Professor James Clerk Maxwell, the developer of electromagnetic theory, was a founder of the lab and became the first Cavendish Professor of Physics. The Duke

neg: Radionics Vibe Technologies had a Class I recall that was completed in 2012 Other ineffectual EMT therapy devices that have been marketed include: Radionics Radionics (also called electromagnetic therapy (EMT)) is a form of alternative medicine that claims disease can be diagnosed and treated by applying electromagnetic radiation (EMR), such as radio waves, to the body from an electrically powered device. It is similar to magnet therapy which also applies EMR to the body, but using a magnet that generates a static electromagnetic field. The concept behind radionics originated in the early 1900s with Albert Abrams (1864–1924), who became a millionaire

neg: Rogue wave Administration compiled a catalogue of more than 50 historical incidents probably associated with rogue waves. In 1826, French scientist and naval officer Captain Jules Dumont d'Urville reported waves as high as in the Indian Ocean with three colleagues as witnesses, yet he was publicly ridiculed by fellow scientist François Arago. In that era it was widely held that no wave could exceed . Author Susan Casey wrote that much of that disbelief came because there were very few people who had seen a rogue wave, and until the advent of steel double-hulled ships of the 20th century "people who encountered

neg: William R. Blair soon realized that this could better be done using electromagnetic waves. In 1917, the Army established the Signal Corps Radio Laboratories at Camp Vail, in eastern New Jersey. After the war, this became Fort Vail, then in 1925, it was renamed Fort Monmouth. In 1926, Blair was assigned as the Chief of Research and Engineering. Coupling capabilities in electronics and meteorology, in 1929 the Laboratory developed and launched the first radio-equipped weather balloon. Going into the 1930s, the Great Depression with declining economic conditions led the Signal Corps to consolidate their widespread laboratories to Fort Monmouth. On June 30, 1930,