The only available field that could be used near flood-ravaged Montpelier was on the Towne farm off upper Main Street, a narrow hillside where takeoffs and landings could be safely made only under light wind conditions.

* Angle-sensitive pixels are CMOS devices that relate angle information about the incident light field

Objects whose gravity field is too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace.

In air and other ordinary gases below the breakdown field, the dominant source of electrical conduction is via relatively few mobile ions produced by radioactive gases, ultraviolet light, or cosmic rays.

A charge in a uniform electric field moves along a catenary ( which tends to a parabola if the charge velocity is much less than the speed of light c ).

# Telstar Gemini ( 1978 ): Four pinball games and two light-gun games in color, light gun, two flipper buttons on left and right sides of case, pinball launch button and field adjustment sliders on top, light gun, uses a MOS Technology MPS 7600-004 chip.

Diatomaceous earth as viewed under Bright field microscopy | bright field lighting | illumination on a light microscope.

In light of the physical interpretation, a vector field with constant zero divergence is called incompressible or solenoidal – in this case, no net flow can occur across any closed surface.

Two slits are illuminated by a plane waveGeometry for far field fringesMuch of the behaviour of light can be modelled using classical wave theory.

It should be noted that only the intensity of a light field can be measured – this is proportional to the square of the amplitude.

The term “ far from sources ” refers to how far from the source ( moving at the speed of light ) any portion of the outward-moving EM field is located, by the time that source currents are changed by the varying source potential, and the source has therefore begun to generate an outwardly moving EM field of a different phase.

Accurate treatment thus incorporates a concept known as retarded time ( as opposed to advanced time, which is not physically possible in light of causality ), which adds to the expressions for the electrodynamic electric field and magnetic field.

While the particles themselves can move quite slowly, sometimes with an average drift velocity only fractions of a millimetre per second, the electric field that drives them itself propagates at close to the speed of light, enabling electrical signals to pass rapidly along wires.

In the field of high-energy particle physics, the fundamental velocity unit is the speed of light c. Thus, dividing energy in eV by the speed of light in vacuum, one can describe the momentum of an electron in units of eV / c.

: Microlensing occurs when the gravitational field of a star acts like a lens, magnifying the light of a distant background star.

The gravitational redshift of a light wave as it moves upwards against a gravitational field ( caused by the yellow star below ).

The changing rates of clocks allowed Einstein to conclude that light waves change frequency as they move, and the frequency / energy relationship for photons allowed him to see that this was best interpreted as the effect of the gravitational field on the mass – energy of the photon.

The system, along with new sod, was installed to prevent the field from becoming too wet to play on during light to medium rains, and to reduce the time needed to dry the field adequately.

The British defence of Ruweisat Ridge relied on an improvised formation called " Robcol ", comprising a regiment each of field artillery and light anti-aircraft artillery and a company of infantry.

The level of armour protection between AFVs varies greatly-a main battle tank will normally be designed to take hits from other tank guns and anti-tank missiles, whilst light reconnaissance vehicles are often only armoured " just in case ".

Their answers to the problem were similar, with the United States developing the M56 Scorpion and the Soviet Union developing the ASU-57, both essentially air-droppable light anti-tank guns.

The cars were primarily armed with light machine guns.

Later the British also developed a version of the Mk. VI light tank armed with 4 machine guns that was known as Light Tank AA Mk. I.

The British developed their own SPAAGs throughout the war mounting multiple machine guns and light cannon on various tank and armoured car chassis and by 1943, the Crusader AA tanks, which mounted the Bofors 40 mm gun or two-three Oerlikon 20 mm cannon.

** M1918 Browning Automatic Rifle, an American family of automatic rifles and light machine guns

* Allows the use of light guns / pens

Moreover, the Polish cavalry brigade order of battle of 1939 included, apart from the mounted soldiers themselves, light and heavy machine guns ( wheeled ), Anti-tank rifle, model 35, anti-aircraft weapon, artillery like Bofors 37 mm anti tank gun or light and scout tanks, etc.

Instead, this effort evolved into the SAGE system for the US Air Force, which used large screens and light guns to allow operators to interact with radar data stored in the computer.

They were fitted with new anti-aircraft guns, radar, and forward-launched ASW weapons, in addition to their existing light guns, depth charges, and torpedoes.

The significance of the railways to the Civil War of the Finns is well symbolized by the most modern and frightening weapon used in the turmoil: armoured train, carrying light cannons and heavy machine guns.

In contrast, modern light machine guns such as the FN Minimi are often wielded by a single infantryman.

* Cannot be used with light guns / pens.

Although subdivided into " light ", " medium ", " heavy " or " general-purpose ", even the lightest machine guns tend to be substantially larger and heavier than other automatic weapons.

The majority of machine guns are belt-fed, although some light machine guns are fed from drum or box magazines, and some vehicle-mounted machine guns are hopper-fed.

Recoil-operated machine guns were light enough to be moved by one man, were easier to move through rough terrain, and could be fired from a lower, protected position.

The trend toward automatic rifles, light machine guns, and more powerful sub-machine guns resulted in a wide variety of firearms that combined characteristics of ordinary rifles and machine guns.

Electronically controlled machine guns with ultrahigh rates of fire may see use in some applications, although current small-caliber weapons of this type have found little use: they are too light for anti-vehicle use, but too heavy ( especially with the need to carry a tactically useful amount of ammunition ) for individual soldiers.

This is common on light machine guns and some medium machine guns.

Ironically, the rise of infantry in the early 16th century coincided with the " golden age " of heavy cavalry ; a French or Spanish army at the beginning of the century could have up to half its numbers made up of various kinds of light and heavy cavalry, whereas in earlier medieval and later 17th century armies the proportion of cavalry was seldom more than a quarter.

Young's experiment, performed in the early 1800s, played a vital part in the acceptance of the wave theory of light, vanquishing the corpuscular theory of light proposed by Isaac Newton, which had been the accepted model of light propagation in the 17th and 18th centuries.

* 1983 October 21The 17th CGPM defines the metre as equal to the length of the path travelled by light in a vacuum during a time interval of of a second.

In the early 17th century Johannes Kepler expanded on geometric optics in his writings, covering lenses, reflection by flat and curved mirrors, the principles of pinhole cameras, inverse-square law governing the intensity of light, and the optical explanations of astronomical phenomena such as lunar and solar eclipses and astronomical parallax.

Alhazen's intromission theory of light was formulated in the 11th century ; Newton's laws of motion and Newton's law of universal gravitation were formulated in the 17th century ; Maxwell's equations, 19th century ; and quantum mechanics, early 20th century.

In the 17th century the word spectrum was introduced into optics, referring to the range of colors observed when white light was dispersed through a prism.

The idea of duality originated in a debate over the nature of light and matter that dates back to the 17th century, when competing theories of light were proposed by Christiaan Huygens and Isaac Newton: light was thought either to consist of waves ( Huygens ) or of particles ( Newton ).

An early example of this type of experiment was the first verification in the 17th century that light does not travel from place to place instantaneously, but instead has a measurable speed.

Units involved in this call-up included: 1st Battalion, 503rd Infantry Regiment ( Air Assault ); 1st Battalion, 506th Infantry Regiment ( Air Assault ); 2d Battalion, 17th Field Artillery Regiment ; 1st Battalion, 9th Infantry Regiment ( Mechanized ); 44th Engineer Battalion ; 2nd Forward Support Battalion ; Company A, 102nd Military Intelligence Battalion ; Company B, 122nd Signal Battalion, elements of the 2d Battalion, 72nd Armor Regiment, a team from the 509th Personnel Services Battalion, and B Battery 5th Battalion 5th Air Defense Artillery Regiment ( Deployed as a combination of mechanized infantry and light infantry with two platoons of Bradley Fighting Vehicles and 1 platoon of armored HMMWVs ).

At an unknown date in the 17th century, the Inner Holsten Gate was replaced by a smaller, simple half-timbered gate — possibly because no point was seen in having a strong inner gate in light of the strong outer fortifications which had been erected in the meantime.

Even in the light of Casaubon's linguistic discovery and typical of many of the self-styled adherents of Hermetic philosophy scattered throughout 16th and 17th Europe, Thomas Browne in his Religio Medici ( 1643 ) confidently stated-" The severe schools shall never laugh me out of the philosophy of Hermes, that this visible world is but a portrait of the invisible ".

He recorded his discovery as follows: " The great light of my forty-foot telescope was so useful that on the 17th of September, 1789, I remarked the seventh satellite, then situated at its greatest western elongation.

Until the 17th century it included a cavalry sabre, lance, long wooden shield and, optionally, light metal armour or simple leather vest.

In the 17th century Pierre de Fermat postulated that " light travels between two given points along the path of shortest time ," which is known as the principle of least time or Fermat's principle.

He led the remainder of the provincials, consisting primarily of Massachusetts, New Jersey, and Connecticut men, north to Fort Edward, where they joined 6, 000 regular troops ( about 2, 000 Royal Highlanders, as well as the 17th, 27th, and 53rd Regiments of Foot, the 1st battalion of the 60th Foot, about 100 Royal Artillery, 700 of Rogers ' Rangers, and 500 light infantry under Thomas Gage ).

In 1983, the 17th Conférence Générale des Poids et Mesures adopted the standard value, 299, 792. 458 km / s for the speed of light.

As the Frisian word biike means beacon, the bonfires may well have derived from light beacons set out for North Frisian whale catchers during the 17th and 18th centuries.

Infantry had 2 basic types, light and heavy, from the ancient classical period until the late 17th century.

In the 17th century, dragoons were the light infantry skirmishers of their day – lightly armed mounted infantrymen who rode into battle but dismounted to fight, giving them a mobility lacking to regular foot soldiers.

Like the foil ( fleuret ), the épée evolved from light civilian weapons such as the smallsword, which since the late 17th century had been the most commonly used dueling sword, replacing the rapier.