gyroscopic

A unicycle is a one-wheeled human powered vehicle. Unicycles are similar to, but less complex than, bicycles. Unicycle - Construction. Unicycles are comprised of a few key parts: the wheel, which includes the tire, tube, rim, spokes, hub and axle; the cranks and pedals; the frame; the seatpost; and the saddle. The wheel is the main part of the unicycle; it is basically a bicycle wheel with a special hub that doesn't freewheel, which means the axle can't turn independently of the hub. This makes it so the ro ...

Including:

• Unicycle - Construction
• Unicycle - Riding
• Unicycle - History
• Unicycle - Theory
• Unicycle - Recent developments
• Unicycle - Unicycle hockey Unihoki
• Unicycle - Variations

Read more here: » Unicycle: Encyclopedia - Unicycle

Uranium is a chemical element in the periodic table that has the symbol U and atomic number 92. Heavy, silvery-white, toxic, metallic, naturally radioactive, pyrophoric, and teratogenic uranium belongs to the actinide series and its isotope 235U is used as the fuel for nuclear reactors and the explosive material for nuclear weapons. Depleted uranium is used in incindiary projectile weapons. Uranium is commonly found in very small amounts in rocks, soil, water, plants, and animals (including humans). Uranium - ...

Including:

• Uranium - Notable characteristics
• Uranium - Applications
• Uranium - History
• Uranium - Military applications
• Uranium - Uranium exploration and mining
• Uranium - Rise stagnation and possible renaissance of uranium mining
• Uranium - Risks of uranium mining
• Uranium - Codenames tuballoy and oralloy
• Uranium - Compounds
• Uranium - Occurrence
• Uranium - Production and distribution
• Uranium - Isotopes
• Uranium - Precautions

Read more here: » Uranium: Encyclopedia - Uranium

The yo-yo is a toy consisting of two equally-sized discs of plastic, wood, or metal, connected with an axle, around which a string is wound. There is a slip knot at the free end of the string, and, on a properly strung yo-yo, an uncut loop around the axle end which allows it to spin freely, or "sleep" upon reaching the string's end. It is played by tying the string's free end around the middle finger, grasping the yo-yo, and then throwing it with a smooth motion. As the axle spins within the loop, a gyroscopic effect occurs, pe ...

Including:

• Yo-yo - History of the yo-yo
• Yo-yo - Ancient origins
• Yo-yo - The yo-yo in modern times
• Yo-yo - Commercial success
• Yo-yo - Contemporary yo-yo culture
• Yo-yo - Yo-yo contests
• Yo-yo - Yo-yo club sport

Read more here: » Yo-yo: Encyclopedia - Yo-yo

A helicopter is an aircraft which is lifted and propelled by one or more horizontal rotors (propellers). Helicopters are classified as rotary-wing aircraft to distinguish them from conventional fixed-wing aircraft. The word helicopter is derived from the Greek words helix (spiral) and pteron (wing). The engine-driven helicopter was invented by the Slovak inventor Jan Bahyl. The first stable, fully-controllable helicopter pl ...

Including:

• Helicopter - Applications
• Helicopter - History
• Helicopter - Generating lift
• Helicopter - Conventional layout
• Helicopter - Alternative layouts
• Helicopter - Controlling flight
• Helicopter - Stability
• Helicopter - Limitations
• Helicopter - Landing
• Helicopter - On a ship
• Helicopter - Hazards of helicopter flight
• Helicopter - Helicopter models and identification

Read more here: » Helicopter: Encyclopedia - Helicopter

An autopilot is a mechanical, electrical, or hydraulic system used to guide a vehicle without assistance from a human being. Most people understand an autopilot to refer specifically to aircraft, but autopilots for boats and ships are called by the same name and serve the same purpose. In the early days of transport aircraft, aircraft required the continuous attention of a pilot in order to fly in a safe manner. This created very high demands on crew attention and high fatigue. The autopilot is des ...

Read more here: » Autopilot: Encyclopedia - Autopilot

A propeller's efficiency is determined by (thrust × axial speed)/(resistance torque × rotational speed). Changes to a propeller's efficiency are produced by a number of factors, notably adjustments to the helix angle, the angle between the resultant relative velocity and the blade rotation direction, and to blade pitch. Very small pitch and helix angles give a good performance against resistance but provide little thrust, while larger angles have the opposite effect. The best helix angle is when the blade is act ...

See also:

Propeller, Propeller - History, Propeller - Aircraft propellers airscrews, Propeller - Aircraft Fans, Propeller - Ship/Submarine propellers screws

Read more here: » Propeller: Encyclopedia II - Propeller - Aircraft propellers airscrews

Intended as a replacement for the Sopwith Pup, the Sopwith Camel prototype first flew in December 1916. It was known as the "Big Pup" early on in its development. It was armed with two .303 in (7.7 mm) Vickers machine guns mounted in front of the cockpit, firing forward through the propeller disc. A fairing surrounding the gun installation created a hump that led to the aircraft acquiring the name Camel. The Camel entered squadron service in June 1917. ...

See also:

Sopwith Camel, Sopwith Camel - History, Sopwith Camel - Variants, Sopwith Camel - Sopwith Camel F.1, Sopwith Camel - Sopwith Camel 2F.1, Sopwith Camel - Sopwith Camel 'Comic' Nightfighter, Sopwith Camel - F.1/1, Sopwith Camel - Trench Fighter T.F.1, Sopwith Camel - Characteristics, Sopwith Camel - Dimensions, Sopwith Camel - Performance, Sopwith Camel - Trivia, Sopwith Camel - The Camel in Popular Culture, Sopwith Camel - Operators

Read more here: » Sopwith Camel: Encyclopedia II - Sopwith Camel - History

Riding a unicycle typically takes between 5 and 10 hours of practise time to learn to ride forwards with some control, unless one has an inherent natural ability for riding one. Mastery of the skill however takes a lifetime as there are always new things to learn. Compared to a bicycle, although the rider must maintain balance in two dimensions rather than one it is not a great deal harder to learn (although stabilisers are not an option). At slower speeds steering motions need to be exaggerated to achieve the same angle of turn as at higher ...

See also:

Unicycle, Unicycle - Construction, Unicycle - Riding, Unicycle - History, Unicycle - Theory, Unicycle - Recent developments, Unicycle - Unicycle hockey Unihoki, Unicycle - Variations

Read more here: » Unicycle: Encyclopedia II - Unicycle - Riding

Contrary to popular myth, there is no evidence that the yo-yo is derived from, nor even existed in any form intended for use as a weapon. While the impact generated by a yo-yo could indeed be rendered deadly with the addition of sharpened edges, the difficulty of safely retrieving it would render such a device somewhat impractical. This rumor likely originated in the Philippines, where hunters in the 16th century used sharp rocks with strings attached to kill prey from trees. The development of the modern yo-yo began in the Philippines at around this time, which is probably the source of the confusion. ...

See also:

Yo-yo, Yo-yo - History of the yo-yo, Yo-yo - Ancient origins, Yo-yo - The yo-yo in modern times, Yo-yo - Commercial success, Yo-yo - Contemporary yo-yo culture, Yo-yo - Yo-yo contests, Yo-yo - Yo-yo club sport

Read more here: » Yo-yo: Encyclopedia II - Yo-yo - History of the yo-yo

The use of uranium, in its natural oxide form, dates back to at least AD 79, when it was used to add a yellow colour to ceramic glazes (yellow glass with 1% uranium oxide was found near Naples, Italy). The discovery of the element is credited to the German chemist Martin Heinrich Klaproth who in 1789 found uranium as part of the mineral called pitchblende. It was named after the planet Uranus, which had been discovered eight years earlier by William Herschel. It was first isolated as a metal in 1841 by Eugene-Melchior Peligot. In 1850 ...

See also:

Uranium, Uranium - Notable characteristics, Uranium - Applications, Uranium - History, Uranium - Military applications, Uranium - Uranium exploration and mining, Uranium - Rise stagnation and possible renaissance of uranium mining, Uranium - Risks of uranium mining, Uranium - Codenames tuballoy and oralloy, Uranium - Compounds, Uranium - Occurrence, Uranium - Production and distribution, Uranium - Isotopes, Uranium - Precautions

Read more here: » Uranium: Encyclopedia II - Uranium - History

In conventional aircraft, the wing profile (called airfoil) is designed to have a shape where the bottom surface has a shorter path than the top surface. The longer path that the fluid (in this case air) must travel across the top surface equates to a higher speed. The higher the speed of a fluid, the lower the dynamic pressure (as opposed to static pressure) on the surface. Thus, by causing the air to flow faster over the top surface than the bottom, the airfoil causes a pressure difference directed upward. This pressure difference integrat ...

See also:

Helicopter, Helicopter - Applications, Helicopter - History, Helicopter - Generating lift, Helicopter - Conventional layout, Helicopter - Alternative layouts, Helicopter - Controlling flight, Helicopter - Stability, Helicopter - Limitations, Helicopter - Landing, Helicopter - On a ship, Helicopter - Hazards of helicopter flight, Helicopter - Helicopter models and identification

Read more here: » Helicopter: Encyclopedia II - Helicopter - Generating lift

Traditionally, criticism of Marx's law of value has been of three kinds: conceptual logical empirical The conceptual criticism concerns the concept of value itself. For Marx, value was an objective social characteristic of labour-products, exchanged in an economic community, given the physical reality that products took a definite amount of society's labour-time to produce. Critics however argue that economic value is something purely subjective, determined by personal preferences and ma ...

See also:

Law of value, Law of value - Economic value as such, Law of value - Is it an equilibrium theory?, Law of value - Factors counteracting the law of value, Law of value - Law of value in capitalism, Law of value - Smith's hidden hand, Law of value - Modification of the law of value in the world market, Law of value - A comment by Marx on the law of value, Law of value - A comment by Frederick Engels on the law of value, Law of value - The law of value in non-capitalist societies, Law of value - Post-modern thinking about the topic, Law of value - Criticism, Law of value - A Californian perspective: Jim Devine on the LoV, Law of value - Steve Keen and the machine

Read more here: » Law of value: Encyclopedia II - Law of value - Criticism

Mars 1 was a modified Venera-type spacecraft in the shape of a cylinder 3.3 m long and 1.0 m in diameter. The spacecraft measured 4 meters across with the solar panels and radiators deployed. The cylinder was divided into two compartments. The upper 2.7 m, the orbital module, contained guidance and on-board propulsion systems. The experiment module, containing the scientific instrumentation, comprised the bottom 0.6 m of the cylinder. A 1.7 m parabolic high gain antenna was used for communication, along with an omnidirectional antenna and a ...

See also:

Mars 1, Mars 1 - Spacecraft design, Mars 1 - Scientific results

Read more here: » Mars 1: Encyclopedia II - Mars 1 - Spacecraft design

Motocross motorcycles or ATVs are lightweight and powered by highly tuned two-stroke or four-stroke engines (but usually geared for quick acceleration rather than very high speeds). They have knobby tires for traction on loose surfaces, a highly absorbent suspension designed to cope with the shock of heavy landings, and short gearing designed for swift acceleration rather than high top speed. They feature hinged footpegs and levers so that they simply fold rather than bend or snap when the machine is inevitably dropped. Also the exhaust may ...

See also:

Motocross, Motocross - Machines, Motocross - Manufacturers, Motocross - Event, Motocross - Physical demands, Motocross - ATVs, Motocross - Sidecars, Motocross - Freestyle, Motocross - Minibikes, Motocross - Supermoto, Motocross - Governing bodies, Motocross - Renowned Motocross Riders

Read more here: » Motocross: Encyclopedia II - Motocross - Machines

The first effective rotaries were built by Stephen Balzer, who was interested in the design for two main reasons: In order to generate 100 hp (75 kW) at the low RPM at which the engines of the day ran, the pulsation resulting from each combustion stroke was quite large. In order to damp out these pulses, engines needed to mount a large flywheel, which added weight. In the rotary design the engine itself doubled as its flywheel, thus rotaries were lighter than similarly sized engines of regular design. The cyli ...

See also:

Rotary engine, Rotary engine - History in aircraft, Rotary engine - Use in cars and motorcycles

Read more here: » Rotary engine: Encyclopedia II - Rotary engine - History in aircraft

Inertial guidance system - Laser gyros. Laser gyroscopes were supposed to eliminate the bearings in the gyroscopes, and thus the last bastion of precision machining and moving parts. A laser gyro moves laser light in the two opposite directions around a circular path. As the vehicle rotates through some angle, the distance traveled around the loop by the two beams becomes different in the two directions. The interferometric phase-shift between the two beams is proportional to the angle of rotation (Sagnac effect). In more sensitive gyros (see ring laser) the interfer ...

See also:

Inertial guidance system, Inertial guidance system - Overview, Inertial guidance system - Inertial navigation systems in detail, Inertial guidance system - Basic schemes, Inertial guidance system - Gimbaled Gyrostabilized platforms, Inertial guidance system - Fluidically Suspended Gyrostabilized Platforms, Inertial guidance system - Strapdown systems, Inertial guidance system - Types of sensors, Inertial guidance system - Laser gyros, Inertial guidance system - Vibrating gyros, Inertial guidance system - Brandy snifter gyros, Inertial guidance system - Quartz rate sensors, Inertial guidance system - MHD sensor, Inertial guidance system - Pendular accelerometers, Inertial guidance system - Accelerometer-only systems

Read more here: » Inertial guidance system: Encyclopedia II - Inertial guidance system - Types of sensors

Prior to the 1970s, air transport operations were not considered sufficiently demanding to require advanced equipment like electronic flight displays. As well, computer technology was not at a level where sufficiently light and powerful circuits were available. The increasing complexity of transport aircraft, the advent of digital systems and the growing air traffic congestion around airports began to change that. The average transport aircraft in the mid-1970s had more than 100 cockpit instruments and controls, and the primary flight ...

See also:

Glass cockpit, Glass cockpit - History, Glass cockpit - Future Developments

Read more here: » Glass cockpit: Encyclopedia II - Glass cockpit - History

Chinese yo-yos were traditionally made of wood. Modern models, however, are usually made of plastic, though the sticks continue to be made of wood. Some Chinese yo-yos have grooves inset in the rim of the discs. This causes them to make a whistling sound when spinning at high speed. ...

See also:

Chinese yo-yo, Chinese yo-yo - Design, Chinese yo-yo - Chinese name, Chinese yo-yo - Diabolo

Read more here: » Chinese yo-yo: Encyclopedia II - Chinese yo-yo - Design

Some modern devil sticks have soft ends for safety - it is actually quite possible to knock oneself unconscious with some of the faster, harder, heavier 'unpadded' batons. These are often colorfully decorated and are known variously as Quick Stix, Crystal Stix, Hippie Sticks, Equilibristicks (a play on the word 'equilibristics'), Trick Sticks and many other names. Despite the plethora of names, s ...

See also:

Devil sticks, Devil sticks - Description, Devil sticks - Basic manipulation, Devil sticks - History, Devil sticks - Modern sticks, Devil sticks - Group activities, Devil sticks - Passing, Devil sticks - Juggle till you drop, Devil sticks - Half-sticking, Devil sticks - Combat sticks, Devil sticks - Fire Devil sticking

Read more here: » Devil sticks: Encyclopedia II - Devil sticks - Modern sticks

In the story, Christopher Columbus attends a dinner which a Spanish gentleman had given in his honor. Columbus asks the gentlemen in attendance to make an egg stand on end. After the gentlemen successively tried to and failed, they stated that it was impossible. Columbus then placed the egg's small end on the table, breaking the shell a bit, so that it could stand upright. Columbus then stated that it was "the simplest thing in the ...

See also:

Egg of Columbus, Egg of Columbus - Christopher Columbus story, Egg of Columbus - Tesla's Egg of Columbus, Egg of Columbus - Further readings, Egg of Columbus - Other uses

Read more here: » Egg of Columbus: Encyclopedia II - Egg of Columbus - Christopher Columbus story