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Lariat Chain
A Lariat chain is a loop of chain that hangs off, and is spun by a wheel. It is often used as a science exhibit or a toy. The original Lariat Chain was created in 1986 by Norman Tuck, as an Artist-in-Residence project at the Exploratorium in San Francisco. Lariat Chain was developed from an earlier Tuck piece entitled Chain Reaction (1984). Chain Reaction was hand cranked, and utilized a heavy chain attached by magnets onto an iron flywheel. As in Lariat Chain, Chain Reaction used a brush to disrupt the motion of the traveling chain. The speed of the chain is arranged to equal the wave speed of transverse waves, so that waves moving against the motion of the chain appear to be standing still. See also *Belt (mechanical) *Foucault pendulum *Launch loop A launch loop, or Lofstrom loop, is a proposed system for launching objects into orbit using a moving cable-like system situated inside a sheath attached to the Earth at two ends and suspended above the atmosphere in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barcelona
Barcelona ( , , ) is a city on the coast of northeastern Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second most populous municipality of Spain. With a population of 1.6 million within city limits,Barcelona: Población por municipios y sexo – Instituto Nacional de Estadística. (National Statistics Institute) its urban area extends to numerous neighbouring municipalities within the and is home to around 4.8 million people, making it the [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exploratorium
The Exploratorium is a museum of science, technology, and arts in San Francisco, California. Characterized as "a mad scientist's penny arcade, a scientific funhouse, and an experimental laboratory all rolled into one", the participatory nature of its exhibits and its self-identification as a center for informal learning has led to it being cited as the prototype for participatory museums around the world. The Exploratorium was founded by physicist and educator Frank Oppenheimer and opened in 1969 at the Palace of Fine Arts, its home until January 2, 2013. On April 17, 2013, the Exploratorium reopened at Piers 15 and 17 on San Francisco's Embarcadero. The historic interior and exterior of Pier 15 were renovated extensively prior to the move, and are divided into several galleries mainly separated by content, including the physics of seeing and listening (Light and Sound), Human Behavior, Living Systems, Tinkering (including electricity and magnetism), the Outdoor Gallery, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Group Velocity
The group velocity of a wave is the velocity with which the overall envelope shape of the wave's amplitudes—known as the ''modulation'' or ''envelope'' of the wave—propagates through space. For example, if a stone is thrown into the middle of a very still pond, a circular pattern of waves with a quiescent center appears in the water, also known as a capillary wave. The expanding ring of waves is the wave group, within which one can discern individual waves that travel faster than the group as a whole. The amplitudes of the individual waves grow as they emerge from the trailing edge of the group and diminish as they approach the leading edge of the group. Definition and interpretation Definition The group velocity is defined by the equation: :v_ \ \equiv\ \frac\, where is the wave's angular frequency (usually expressed in radians per second), and is the angular wavenumber (usually expressed in radians per meter). The phase velocity is: . The function , which gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transverse Wave
In physics, a transverse wave is a wave whose oscillations are perpendicular to the direction of the wave's advance. This is in contrast to a longitudinal wave which travels in the direction of its oscillations. Water waves are an example of transverse wave. A simple example is given by the waves that can be created on a horizontal length of string by anchoring one end and moving the other end up and down. Another example is the waves that are created on the membrane of a drum. The waves propagate in directions that are parallel to the membrane plane, but each point in the membrane itself gets displaced up and down, perpendicular to that plane. Light is another example of a transverse wave, where the oscillations are the electric and magnetic fields, which point at right angles to the ideal light rays that describe the direction of propagation. Transverse waves commonly occur in elastic solids due to the shear stress generated; the oscillations in this case are the displaceme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belt (mechanical)
A belt is a loop of flexible material used to link two or more rotating Drive shaft, shafts mechanically, most often parallel. Belts may be used as a source of motion, to Transmission (mechanics), transmit power efficiently or to track relative movement. Belts are looped over pulleys and may have a twist between the pulleys, and the shafts need not be parallel. In a two pulley system, the belt can either drive the pulleys normally in one direction (the same if on parallel shafts), or the belt may be crossed, so that the direction of the driven shaft is reversed (the opposite direction to the driver if on parallel shafts). The belt drive can also be used to change the speed of rotation, either up or down, by using different sized pulleys. As a source of motion, a conveyor belt is one application where the belt is adapted to carry a load continuously between two points. History The mechanical belt drive, using a pulley machine, was first mentioned in the text the ''Dictionary of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foucault Pendulum
The Foucault pendulum or Foucault's pendulum is a simple device named after French physicist Léon Foucault, conceived as an experiment to demonstrate the Earth's rotation. A long and heavy pendulum suspended from the high roof above a circular area was monitored over an extended time period, showing that the plane of oscillation rotated. The pendulum was introduced in 1851 and was the first experiment to give simple, direct evidence of the Earth's rotation. Foucault pendulums today are popular displays in science museums and universities. Original Foucault pendulum The first public exhibition of a Foucault pendulum took place in February 1851 in the Meridian of the Paris Observatory. A few weeks later, Foucault made his most famous pendulum when he suspended a brass-coated lead bob (physics), bob with a wire from the dome of the Panthéon, Paris. The proper period of the pendulum was approximately 2\pi\sqrt\approx 16.5 \,\mathrm. Because the latitude of its location was \ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Launch Loop
A launch loop, or Lofstrom loop, is a proposed system for launching objects into orbit using a moving cable-like system situated inside a sheath attached to the Earth at two ends and suspended above the atmosphere in the middle. The design concept was published by Keith Lofstrom and describes an active structure maglev cable transport system that would be around 2,000 km (1,240 mi) long and maintained at an altitude of up to 80 km (50 mi). A launch loop would be held up at this altitude by the momentum of a belt that circulates around the structure. This circulation, in effect, transfers the weight of the structure onto a pair of magnetic bearings, one at each end, which support it. Launch loops are intended to achieve non-rocket spacelaunch of vehicles weighing 5 metric tons by electromagnetically accelerating them so that they are projected into Earth orbit or even beyond. This would be achieved by the flat part of the cable which forms an acceleration tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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