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Allais Effect
The Allais effect is the alleged anomalous behavior of pendulums or gravimeters which is sometimes purportedly observed during a solar eclipse. The effect was first reported as an anomalous precession of the plane of oscillation of a Foucault pendulum during the solar eclipse of June 30, 1954 by Maurice Allais, a French polymath who went on to win the Nobel Prize in Economics. Allais reported another observation of the effect during the solar eclipse of October 2, 1959 using the paraconical pendulum he invented. This study earned him the 1959 Galabert Prize of the French Astronautical Society and made him a laureate of the U.S. Gravity Research Foundation for his 1959 memoir on gravity. The veracity of the Allais effect remains controversial among the scientific community, as its testing has frequently met with inconsistent or ambiguous results over more than five decades of observation. Experimental observations Maurice Allais emphasized the "dynamic character" of the eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allais Paradox
The Allais paradox is a choice problem designed by to show an inconsistency of actual observed choices with the predictions of expected utility theory. Statement of the problem The Allais paradox arises when comparing participants' choices in two different experiments, each of which consists of a choice between two gambles, A and B. The payoffs for each gamble in each experiment are as follows: Several studies involving hypothetical and small monetary payoffs, and recently involving health outcomes, have supported the assertion that when presented with a choice between 1A and 1B, most people would choose 1A. Likewise, when presented with a choice between 2A and 2B, most people would choose 2B. Allais further asserted that it was reasonable to choose 1A alone or 2B alone. However, that the same person (who chose 1A alone or 2B alone) would choose both 1A and 2B together is inconsistent with expected utility theory. According to expected utility theory, the person should choose e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravity Research Foundation
The Gravity Research Foundation is an organization established in 1948 by businessman Roger Babson (founder of Babson College) to find ways to implement gravitational shielding. Over time, the foundation turned away from trying to block gravity and began trying to understand it. It holds an annual contest rewarding essays by scientific researchers on gravity-related topics. The contest, which awards prizes of up to $4,000, has been won by at least six people who later won the Nobel Prize in physics. The foundation held conferences and conducted operations in New Boston, New Hampshire through the late 1960s, but that aspect of its operation ended following Babson's death in 1967. It is mentioned on stone monuments, donated by Babson, at more than a dozen American universities. History Thomas Edison apparently suggested the creation of the Gravity Research Foundation to Babson, who established it in several scattered buildings in the small town of New Boston, New Hampshire.Mooa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Eclipse Of March 7, 1970
A total solar eclipse occurred on March 7, 1970, visible across most of North America and Central America. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring only 1.3 days after perigee (Perigee on March 6, 1970 at 09:32 UTC), the Moon's apparent diameter was larger than the Sun and thus fulfilled this condition. Totality was visible across southern Mexico and the Gulf of Mexico, the southeast Atlantic coast of the United States, northeast to the Maritimes of eastern Canada, and northern Miquelon-Langlade in the French overseas collectivity of Saint Pierre and Miquelon. Gre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torsion Spring
A torsion spring is a spring that works by twisting its end along its axis; that is, a flexible elastic object that stores mechanical energy when it is twisted. When it is twisted, it exerts a torque in the opposite direction, proportional to the amount (angle) it is twisted. There are various types: *A torsion bar is a straight bar of metal or rubber that is subjected to twisting (shear stress) about its axis by torque applied at its ends. *A more delicate form used in sensitive instruments, called a torsion fiber consists of a fiber of silk, glass, or quartz under tension, that is twisted about its axis. *A helical torsion spring, is a metal rod or wire in the shape of a helix (coil) that is subjected to twisting about the axis of the coil by sideways forces (bending moments) applied to its ends, twisting the coil tighter. *Clocks use a spiral wound torsion spring (a form of helical torsion spring where the coils are around each other instead of piled up) sometimes cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mildred Allen (physicist)
Mildred Allen (March 25, 1894 – November 4, 1990) was an American physicist. Biography Early life and education Mildred Allen was born in Sharon, Massachusetts to MIT professor C. Frank Allen and Caroline Hadley Allen. She had one younger sister, Margaret Allen Anderson. Allen graduated from Vassar College in 1916 with Phi Beta Kappa honors. She completed her doctoral studies in physics in 1922 at Clark University with Arthur Gordon Webster, with thesis research done at Massachusetts Institute of Technology. Career During the 1920s and early 1930s, Allen taught at Mount Holyoke, Wellesley and Oberlin Colleges and undertook post-doctoral work at the University of Chicago and at Yale University. She began working with William Francis Gray Swann at Yale and continued work under his direction with the Bartol Research Foundation between 1927 and 1930. She also did research at Harvard University before becoming a professor at Mount Holyoke, where she taught for 31 years, until he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erwin Saxl
Erwin Joseph Saxl (May 7, 1904 – January 28, 1981) was a physicist and inventor. He was born in Vienna in 1904 and received his Ph.D. there in 1927. In the late 1920s he emigrated to the United States. In 1935 he founded the Saxl Instrument Company, which designed and manufactured tension meters for use in the textile industry, and later in other industries. The company, which Saxl ran jointly with his wife, Lucretia Hildreth Saxl, from their home in Harvard, Massachusetts, was renamed Tensitron in 1953. Saxl is reported as having stated that he worked under Albert Einstein.Maccabee, 1996.Sopka, 1979. He died in 1981. Saxl is most well known for a series of controversial experiments in which he measured unexpected changes in the period of a torsion pendulum under various conditions. In one series of experiments, the period of a torsion pendulum situated inside a Faraday cage, with the pendulum and the cage connected by a conducting path, was observed to increase as the v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitational Wave
Gravitational waves are waves of the intensity of gravity generated by the accelerated masses of an orbital binary system that propagate as waves outward from their source at the speed of light. They were first proposed by Oliver Heaviside in 1893 and then later by Henri Poincaré in 1905 as waves similar to electromagnetic waves but the gravitational equivalent. Gravitational waves were later predicted in 1916 by Albert Einstein on the basis of his general theory of relativity as ripples in spacetime. Later he refused to accept gravitational waves. Gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation. Newton's law of universal gravitation, part of classical mechanics, does not provide for their existence, since that law is predicated on the assumption that physical interactions propagate instantaneously (at infinite speed)showing one of the ways the methods of Newtonian physics are unable to explain ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffraction
Diffraction is defined as the interference or bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture. The diffracting object or aperture effectively becomes a secondary source of the propagating wave. Italian scientist Francesco Maria Grimaldi coined the word ''diffraction'' and was the first to record accurate observations of the phenomenon in 1660. In classical physics, the diffraction phenomenon is described by the Huygens–Fresnel principle that treats each point in a propagating wavefront as a collection of individual spherical wavelets. The characteristic bending pattern is most pronounced when a wave from a coherent source (such as a laser) encounters a slit/aperture that is comparable in size to its wavelength, as shown in the inserted image. This is due to the addition, or interference, of different points on the wavefront (or, equivalently, each wavelet) that travel by paths of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravity Of Earth
The gravity of Earth, denoted by , is the net acceleration that is imparted to objects due to the combined effect of gravitation (from mass distribution within Earth) and the centrifugal force (from the Earth's rotation). It is a vector quantity, whose direction coincides with a plumb bob and strength or magnitude is given by the norm g=\, \mathit\, . In SI units this acceleration is expressed in metres per second squared (in symbols, m/ s2 or m·s−2) or equivalently in newtons per kilogram (N/kg or N·kg−1). Near Earth's surface, the gravity acceleration is approximately , which means that, ignoring the effects of air resistance, the speed of an object falling freely will increase by about per second every second. This quantity is sometimes referred to informally as ''little '' (in contrast, the gravitational constant is referred to as ''big ''). The precise strength of Earth's gravity varies depending on location. The nominal "average" value at Earth's surface, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravity, gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or "tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the #Phase and amplitude, phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see ''#Timing, Timing''). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal cycle, diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Eclipse Of February 15, 1961
A total solar eclipse occurred on February 15, 1961. Totality was visible from France, Monaco, Italy, San Marino, SFR Yugoslavia (parts now belonging to Croatia, Bosnia and Herzegovina, Montenegro, Serbia and Kosovo, North Macedonia), Albania, Bulgaria including the capital city Sofia, Romania including the capital city Bucharest, and the Soviet Union (parts now belonging to Ukraine, Russia and Kazakhstan). The maximum eclipse was recorded near Novocherkassk (Russian SFSR). This was the 51st of 55 umbral eclipses in Solar Saros 120. Upcoming 4 umbral eclipses 52. 1979 February 26 53. 1997 March 9 54. 2015 March 20 55. 2033 March 30 In popular culture The crucifixion scene in the 1961 film ''Barabbas Barabbas (; ) was, according to the New Testament, a prisoner who was chosen over Jesus by the crowd in Jerusalem to be pardoned and released by Roman governor Pontius Pilate at the Passover feast. Biblical account According to all four canoni ...'' was shot during th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbra
The umbra, penumbra and antumbra are three distinct parts of a shadow, created by any light source after impinging on an opaque object. Assuming no diffraction, for a collimated beam (such as a point source) of light, only the umbra is cast. These names are most often used for the shadows cast by celestial bodies, though they are sometimes used to describe levels, such as in sunspots. Umbra The umbra (Latin for "shadow") is the innermost and darkest part of a shadow, where the light source is completely blocked by the occluding body. An observer within the umbra experiences a total eclipse. The umbra of a round body occluding a round light source forms a right circular cone. When viewed from the cone's apex, the two bodies appear the same size. The distance from the Moon to the apex of its umbra is roughly equal to that between the Moon and Earth: . Since Earth's diameter is 3.7 times the Moon's, its umbra extends correspondingly farther: roughly . Penumbra The pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
