NationMaster - Encyclopedia: Aether theories

The Aether of classical elements is a concept, historically, used in science and in philosophy. Alchemy, natural philosophy, and early modern physics proposed the existence of a medium of the æther (also spelled ether, from the Greek word (αἰθήρ) aether, meaning "upper air" or "pure, fresh air" ^[1]), a space-filling substance or field, thought to be necessary as a transmission medium. The assorted aether theories embody the various conceptions of this "medium" and "substance". Chinese Wood (æœ¨) | Fire (ç«) | Earth (åœŸ) | Metal (é‡‘) | Water (æ°´) Hinduism and Buddhism The Pancha Mahabhuta (The Five Great Elements) Vayu/Pavan (Air/Wind) Agni/Tejas (Fire) Akasha (Aether) Prithvi/Bhumi (Earth) Ap/Jala (Water) Aether (also spelled ether) is a concept used in ancient and medieval science as a substance. ... This article or section includes a list of works cited or a list of external links, but its sources remain unclear because it lacks in-text citations. ... Natural philosophy or the philosophy of nature, known in Latin as philosophia naturalis, is a term applied to the objective study of nature and the physical universe that was regnant before the development of modern science. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... A transmission medium is any material substance, such as fiber-optic cable, twisted-wire pair, coaxial cable, dielectric-slab waveguide, water, or air, that can be used for the propagation of signals, usually in the form of modulated radio, light, or acoustic waves, from one point to another. ... Free space is the most simple and elementary electromagnetic medium. ... Substance theory, or substance attribute theory, is an ontological theory about objecthood, positing that a substance is distinct from its properties. ...

Plato described ether as that which God used in the delineation of the universe.^[1]

Although hypotheses of the Æther vary somewhat in detail they all have certain characteristics in common. Essentially it is considered to be a physical medium occupying every point in Space, including within material bodies. A second essential feature is that its properties gives rise to the electric, magnetic and gravitational potentials and determines the propagation velocity of their effects. Therefore the speed of light and all other propagating effects are determined by the physical properties of the Æther at the relevant location, analogous to how gaseous, liquid and solid media affect the propagation of sound waves.

The Æther is considered the global reference frame for the Universe and thus velocities are all absolute relative to its rest frame. Therefore, in this view, any physical consequences of those velocities are considered as having an absolute, ie real effects.

Recent Æther theories (see section below on protoscience links) of velocity effects, phenomenon of gravitation and planetary motion (i.e. the angular momentum), creation of proton, of stars (neutron stars too) and planets, etc., exist but are not generally accepted by the mainstream scientific community. This article or section does not adequately cite its references or sources. ...

Newtonian æther

Isaac Newton disproved the æther "vortex theory" of planetary motion but later proposed a "new" æther, exceptionally fluid, whose density was affected by the local density of matter and local gravitational field strength (see: Optiks). Newton also said that he did not know whether his new æther should be particulate or not ^[2] - if it were particulate, the particles would have to be incredibly small, even smaller than light-corpuscles. ^[3] Sir Isaac Newton (4 January 1643 â€“ 31 March 1727) [ OS: 25 December 1642 â€“ 20 March 1726][1] was an English physicist, mathematician, astronomer, natural philosopher, and alchemist. ... Opticks or a treatise of the reflections, refractions, inflections and colours of light Opticks is a book written by English physicist Isaac Newton that was released to the public in 1704. ...

Luminiferous æther

The basic idea of the æther as a physical transmission medium is simple, and like all media, if it exists, must have fundamental properties including a pressure, mass density, and temperature. Further, if compressible, it will also exhibit a characteristic finite propagation speed, c, at which all transfer of momentum and energy through it can be carried from one physical location to another. Compressibility also means that there will also be a distinct coefficient of compressibility (and its inverse, a distinct modulus), a characteristic impedance, and the ability to create and sustain wave activity. Any other properties, including ponderable matter and the specific characteristics of waves are solely dependent upon specifics arising from these basics. The luminiferous aether: it was hypothesised that the Earth moves through a medium of aether that carries light In the late 19th century luminiferous aether (light-bearing aether) was the term used to describe a medium for the propagation of light. ... A transmission medium is any material substance, such as fiber-optic cable, twisted-wire pair, coaxial cable, dielectric-slab waveguide, water, or air, that can be used for the propagation of signals, usually in the form of modulated radio, light, or acoustic waves, from one point to another. ... The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin in Canberra, Australia. ... This article or section is in need of attention from an expert on the subject. ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: Ï (rho) is the density of the substance, measured in kgÂ·m-3 m is the mass of the substance, measured in kg V is... This article includes a list of works cited or a list of external links, but its sources remain unclear because it lacks in-text citations. ... A line showing the speed of light on a scale model of Earth and the Moon The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning swiftness.[1] It is the speed of all electromagnetic... In classical mechanics, momentum (pl. ... Fluid Dynamics Compressibility (physics) is a measure of the relative volume change of fluid or solid as a response to a pressure (or mean stress) change: . For a gas the magnitude of the compressibility depends strongly on whether the process is adiabatic or isothermal, while this difference is small in... Mathematical meanings Especially in British/European usage, the modulus of a number is its absolute value. ... Electrical impedance, or simply impedance, is a measure of opposition to a sinusoidal alternating electric current. ... A wave is a disturbance that propagates through space or spacetime, transferring energy and momentum and sometimes angular momentum. ... Matter is the substance of which physical objects are composed. ...

As can be seen from historical timelines ^[4] referenced above, up until the early part of the twentieth century æther played a central and dominant role in the development and evolution of all of theoretical physics.

During the 19th century the most basic and fundamental physical characteristics known were those pertaining to electric, magnetic, and luminous (light) phenomena. The focus of theoretical development focused upon these phenomena and integrating them into a single common framework. Based upon Faraday's meticulous findings James Clerk Maxwell succeeded brilliantly in doing so. His model was based upon Helmholtz's æther vortex model and is described in detail in his 1861-62 series of articles titled On the Physical Lines of Force.^[5] Because of this, the aether concept was commonly referred to as luminiferous aether during this period. For the individuals of this time, which included Lord Kelvin, J. J. Thomson, and P. G. Tait, the ether was hypothesized to be a non-compressible, inviscid fluid.^[6] In physics, the faraday (not to be confused with the farad) is a unit of electrical charge; one faraday is equal to the charge of 6. ... James Clerk Maxwell (13 June 1831 â€“ 5 November 1879) was a Scottish mathematician and theoretical physicist. ... Hermann Ludwig Ferdinand von Helmholtz (August 31, 1821 – September 8, 1894) was a German physician and physicist. ... The luminiferous aether: it was hypothesised that the Earth moves through a medium of aether that carries light In the late 19th century luminiferous aether (light-bearing aether) was the term used to describe a medium for the propagation of light. ... William Thomson, 1st Baron Kelvin, OM, GCVO, PC, PRS, FRSE, (26 June 1824 â€“ 17 December 1907) was a mathematical physicist, engineer, and outstanding leader in the physical sciences of the 19th century. ... Sir Joseph John Thomson, OM, FRS (18 December 1856 â€“ 30 August 1940) often known as J. J. Thomson, was a British scientist. ... Peter Tait Peter Guthrie Tait (April 28, 1831 - July 4, 1901) was a Scottish mathematical physicist. ...

the Timeline of Luminiferous Aether begins in the late 19th century with the concept of the aether (light-bearing aether), or ether, as a medium for electromagnetic propagation. ...

Motion and the preferred frame

During the 19th Century attention was also focused on the interaction of electro-magnetic phenomena with matter. It was in this area of late 19th Century physics that certain unresolvable contradictions arose, leading to the emergence of Einstein's Relativity theories. At the time it was commonly assumed by many that ponderable matter (mass having a rest value & inertia) was distinctly different, and was embedded, or enveloped in the all pervasive æther. By logical extension, movement of such objects should require it to plow through this æther, and this in turn, should create a drag reaction in the æther. If the material object is not moving the pressure exerted by æther is equal in all directions (isotropic). This condition is called the rest frame of the æther. The aether drag hypothesis was an early attempt to explain the way experiments such as Aragos experiment showed that the speed of light is constant. ... Matter is the substance of which physical objects are composed. ... This article or section is in need of attention from an expert on the subject. ... Inertia is the property of an object to remain at constant velocity unless acted upon by an outside force. ... An object falling through a gas or liquid experiences a force in direction opposite to its motion. ... Isotropic means independent of direction. Isotropic radiation has the same intensity regardless of the direction of measurement, and an isotropic field exerts the same action regardless of how the test particle is oriented. ...

It was logical therefore to attempt to measure the speed of matter through the æther. The motion of the Earth was considered to be of sufficient magnitude that its speed could be determined. The expected difference was calculated based upon the assumptions that; 1) light speed was independent of Earth's motion (or matter in general), and, 2) the matter in the measuring equipment is independent and unaffected this movement. When these assumptions are valid it was also demonstrated that this rest frame would have preferential properties making it physically different from all others. Thus this condition is also known as the preferred frame. The resulting geometrical calculation formed the basis for the expectation of a positive result, and expected lower bound value that should be seen. In theoretical physics, a preferred or privileged frame is usually a special hypothetical frame of reference in which the laws of physics might appear to be identifiably different from those in other frames. ...

Empirical falsification

An experiment testing this hypothesis was first performed by Albert Michelson in 1881. It produced a null result. It was repeated in 1887 in collaboration with Edward Morley and is known today as the Michelson-Morley experiment. To date all such experiments have failed to demonstrate the expected positive result. Albert Abraham Michelson. ... Generally, a null result is a result which is null (nothing): that is, the absence of an observable result. ... Edward Morley (1887). ... The Michelson-Morley experiment, one of the most important and famous experiments in the history of physics, was performed in 1887 by Albert Michelson and Edward Morley at what is now Case Western Reserve University, and is considered by some to be the first strong evidence against the theory of...

Since it is improbable that any medium would not itself react to the movement of such a foreign embedded body, the idea of a stationary æther can be effectively ruled out. However, like swirling your hand in water, if the medium has any viscosity it will experience drag and form a circulation, which, over time, acts to reduce the relative speed and drag between the body and the medium. The final resulting magnitude is dependent upon the assumption of viscosity, and leads to many variants of the theory, each with slightly different drag coefficients and rules for how matter should interact with light. The number of competing theories of this type made keeping track of all the resulting predictions rather difficult. As with string theory today, there seemed to be too many options, and with the proper ad-hoc choice of coefficient values, it seemed that one could predict almost anything. These, as a group, are known as partially dragged æther theories. Viscosity is a measure of the resistance of a fluid to deform under shear stress. ... An object falling through a gas or liquid experiences a force in direction opposite to its motion. ... Interaction in the subatomic world: world lines of pointlike particles in the Standard Model or a world sheet swept up by closed strings in string theory String theory is a model of fundamental physics whose building blocks are one-dimensional extended objects called strings, rather than the zero-dimensional point...

The Michelson-Gale-Pearson experiment is a modified version of the Michelson-Morley experiment which tests the aether drag along the rotating frame of Earth. ... The Trouton-Noble experiment attempted to detect motion of the Earth through the luminiferous aether, and was conducted in 1901â€“1903 by Frederick Thomas Trouton (who also developed the Troutons ratio) and H. R. Noble. ... The Kennedy-Thorndike experiment (Experimental Establishment of the Relativity of Time), first conducted in 1932, is a modified form of the Michelson-Morley experimental procedure. ...

Lorentz's ether and special relativity

The Lorentz ether theory ("LET") or Lorentzian electrodynamics (1904), made use of the Lorentz-FitzGerald contraction hypothesis - it suggested that an object moving through the aether was contracted in its direction of motion by a special ratio now named after Lorentz: According to this theory, an inertial observer would be incapable of measurng their absolute motion, so that their measurements would comply with the principle of relativity ("PoR"). Nevertheless, in Lorentz's theory, which is completely consistent with Maxwell's theory, the state of a material system is not independent of it motion relative to the medium. In physics, Lorentz ether theory (or LET) proposed that light was transmitted through a light medium in which the motion of objects did not cause dragging effects, but did cause objects to contract in their direction of motion (Fitzgerald-Lorentz contraction). ... The Lorentz-FitzGerald contraction hypothesis was proposed by George FitzGerald and independently proposed and extended by Hendrik Lorentz to explain the negative result of the Michelson-Morley experiment, which attempted to detect Earths motion relative to the luminiferous aether. ... Hendrik Antoon Lorentz (July 18, 1853, Arnhem â€“ February 4, 1928, Haarlem) was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and elucidation of the Zeeman effect. ... Wikisource has original text related to this article: Relativity: The Special and General Theory A principle of relativity is a criterion for judging physical theories, stating that they are inadequate if they do not prescribe the exact same laws of physics in certain similar situations. ...

Einstein's special theory of relativity ("SR", 1905) rederived Lorentz' relationships by declaring that all observers could claim that lightspeed was absolutely fixed in their own inertial frame. Where LET said that constant velocity through the aether was undetectable, SR used this undetectability to reject the concept of an underlying aether as superfluous, and replaced a notional state of aether motion with it with the concept of the inertial frame. SR is now generally considered to be the modern replacement for LET. â€œEinsteinâ€ redirects here. ... Special relativity (SR) or the special theory of relativity is the physical theory published in 1905 by Albert Einstein. ... In physics, an inertial frame of reference, or inertial frame for short (also descibed as absolute frame of reference), is a frame of reference in which the observers move without the influence of any accelerating or decelerating force. ... In physics, an inertial frame of reference, or inertial frame for short (also descibed as absolute frame of reference), is a frame of reference in which the observers move without the influence of any accelerating or decelerating force. ...

Acceleration effects still implied the existence of some physical property to spacetime, and if (like Mach), one decided that acceleration and rotation effects should be the result of interactions between distant masses, acceleration and rotation also had to be capable of distorting light-beam geometry, and, by implication, distorting spacetime itself. If these properties were absolute, then the properties of spacetime forced behaviours onto matter without accepting any back-reaction (like a form of "absolute" aether), a behaviour that Einstein referred to as "an inherent epistemological defect". But if the effects were purely relative, then forcing matter to move in a way that spacetime did not like should cause a distortion in spacetime ("space tells matter how to move, matter tells space how to bend"). Ernst Mach Ernst Mach (February 18, 1838 â€“ February 19, 1916) was an Austrian-Czech physicist and philosopher and is the namesake for the Mach number and the optical illusion known as Mach bands. ... Kinship is a biological and/or familial relationship between two organisms. ... According to Albert Einsteins theory of general relativity, space and time get pulled out of shape near a rotating body in a phenomenon referred to as frame-dragging. ...

See also: History of special relativity To meet Wikipedias quality standards, this article or section may require cleanup. ...

Gravitational aether

Main article: Mechanical explanations of gravitation The mechanical theories or explanations of gravitation are attempts to explain the law of gravity by aid of basic mechanical processes, such as pushes, and without the use of any action at a distance. ...

From the 16th until the late 19th century, gravitational phenomena had also been modeled utilizing an aetherial concept. The most well-known concept is Le Sage's theory of gravitation. Other concepts were made by Isaac Newton, Bernhard Riemann, Lord Kelvin etc. Le Sages theory of gravitation is the most common name for the kinetic theory of gravity originally proposed by Nicolas Fatio de Duillier in 1690 and later by Georges-Louis Le Sage in 1748. ... Sir Isaac Newton (4 January 1643 â€“ 31 March 1727) [ OS: 25 December 1642 â€“ 20 March 1726][1] was an English physicist, mathematician, astronomer, natural philosopher, and alchemist. ... Bernhard Riemann. ... William Thomson, Archbishop of York, has the same name as this man. ...

According to Rughede [7] physical space is the universal aether space, and gravity is a process of enduring exchange of radiant energy between all astrophysical bodies.

Aether and general relativity

"Aether and the theory of relativity"[8] was a title used by Einstein in a lecture on general relativity and aether theory. Einstein said that general relativity's gravitational field parameters could be said to have all the usual properties of an aether except one: it was not composed of particulate bodies that could be tracked over time, and so it could not be said to have the property of motion. ^[9] The general attitude to this amongst physicists today seems to be that Einstein's comments don't count because they stretch the idea of aether theory too far: it is argued that a "non-particulate" aether theory is not really an aether theory, or at least, it doesn't correspond to the idea of "historical" aether theory that is currently taught.^{[citation needed]}

Such a view, however, contradicts the continuum concept of space-time and fields and Einstein's statements in "Aether and the Theory of Relativity", May 5th, 1920:

"More careful reflection teaches us, however, that the special theory of relativity does not compel us to deny ether." and "To deny the ether is ultimately to assume that empty space has no physical qualities whatever".

As to the idea of "historical" aether theories it has to be decided, which "historical" theory out of many may adequately be currently taught?

Aether and quantum mechanics

Quantum mechanics can be used to describe spacetime as being "bitty" at extremely small scales, fluctuating and generating particle pairs that appear and disappear incredibly quickly. Instead of being "smooth", the vacuum is described as looking like "quantum foam". It has been suggested that this seething mass of virtual particles may be the equivalent in modern physics of a particulate aether. Fig. ... Pair production refers to the creation of an elementary particle and its antiparticle, usually from a photon (or another neutral boson). ... This article needs to be cleaned up to conform to a higher standard of quality. ... In the description of the interaction between elementary particles in quantum field theory, a virtual particle is a temporary elementary particle, used to describe an intermediate stage in the interaction. ...

Modern derivatives

In physics there is no concept considered exactly analogous to the aether. However, dark energy is sometimes called quintessence due to its similarity to the classical aether. Modern physics is full of concepts such as free space, space foam, Planck particles, quantum wave state (QWS), zero-point energy, quantum foam, and vacuum energy. Image File history File links Information. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... In physical cosmology, dark energy is a hypothetical form of energy that permeates all of space and tends to increase the rate of expansion of the universe. ... In physics, quintessence is a hypothetical form of dark energy postulated as an explanation of observations of an accelerating universe. ... In physics, free space is a concept of electromagnetic theory, corresponding roughly to the vacuum, the baseline state of the electromagnetic field, or the replacement for the electromagnetic aether. ... A Planck particle is a hypothetical subatomic particle, defined as a tiny black hole whose Compton wavelength is the same as its Schwarzschild radius. ... In physics, the zero-point energy is the lowest possible energy that a quantum mechanical physical system may possess; it is the energy of the ground state of the system. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Vacuum energy is an underlying background energy that exists in space even when devoid of matter (known as free space). ...

The Einstein-aether theory

Although it is by no means widely accepted, the most popular aether theory today is the Einstein æther theory, also known as Æ-theory. This theory was pioneered by Ted Jacobson among others. It is a generally covariant theory that comes equipped with a preferred temporal vector field called the æther field, which is the preferred time direction. Christopher Eling, Ted Jacobson and David Mattingly review this theory in their article Einstein Æther Theory. In physics the Einstein-Ã¦ther theory, also called Ã¦-theory is a toy model of violation of local Lorentz invariance in the gravitational sector. ... In physics the Einstein-Ã¦ther theory, also called Ã¦-theory is a toy model of violation of local Lorentz invariance in the gravitational sector. ...

All æther theories break the Lorentz symmetry of the theory down, at least, to the special orthogonal group of rotations. This symmetry breaking implies the existence of an associated Goldstone boson. Some experimental signatures of such a boson were analyzed by Nima Arkani-Hamed, Hsin-Chia Cheng, Markus Luty and Jesse Thaler in Universal Dynamics of Spontaneous Lorentz Violation and a New Spin-Dependent Inverse-Square Law Force. In physics, Lorentz symmetry is the invariance of physical laws under the Lorentz transformations. ... In mathematics, the orthogonal group of degree n over a field F (written as O(n,F)) is the group of n-by-n orthogonal matrices with entries from F, with the group operation that of matrix multiplication. ... A sphere rotating around its axis. ... In particle and condensed matter physics, Goldstone bosons (also known as Nambu-Goldstone bosons) are bosons that appear in models with spontaneously broken symmetry. ... Prof. ...

External articles, references, and further readings

Categories: Articles with unsourced statements since February 2007 | All articles with unsourced statements | Articles in need of internal merging | Aether theories PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... 1861 (MDCCCLXI) was a common year starting on Tuesday (link with display the full calendar) of the Gregorian calendar (or a common year starting on Thursday of the Julian calendar) // January 1 - Benito JuÃ¡rez captures Mexico City January 2 - Friedrich Wilhelm IV of Prussia dies and is succeeded by... Sir Isaac Newton (4 January 1643 â€“ 31 March 1727) [ OS: 25 December 1642 â€“ 20 March 1726][1] was an English physicist, mathematician, astronomer, natural philosopher, and alchemist. ... Vanity Fair cartoon. ... The EncyclopÃ¦dia Britannica is a general encyclopedia published by EncyclopÃ¦dia Britannica, Inc. ... James Clerk Maxwell (13 June 1831 â€“ 5 November 1879) was a Scottish mathematician and theoretical physicist. ... â€œEinsteinâ€ redirects here. ... Leiden University in the city of Leiden, is the oldest university in the Netherlands. ... PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... Edmund Taylor Whittaker (24 October 1873 - 24 March 1956) was an English mathematician, who contributed widely to applied mathematics, mathematical physics and the theory of special functions. ... William Thomson, Archbishop of York, has the same name as this man. ...

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