The round cells were reproducibly positioned in the light beam which entered the thermostated mineral oil-bath through a window.

The light beam from the lamp was filtered through a half-standard thickness Corning 1840 filter.

The sighting procedure includes the use of a fixture for the transit to project a beam of light, which is darkened by crossed hairs, on the accelerometer mirror.

At the instant of any observation of an object, the apparent position of the object is displaced from its true position by an amount which depends solely upon the transverse component of the velocity of the observer, with respect to the vector of the incoming beam of light ( i. e., the line actually taken by the light on its path to the observer ).

Another way to state this is that the emitting object may have a transverse velocity with respect to the observer, but any light beam emitted from it which reaches the observer, cannot, for it must have been previously emitted in such a direction that its transverse component has been " corrected " for.

Such a beam must come " straight " to the observer along a line which connects the observer with the position of the object when it emitted the light.

For the simple case where the direction of the light beam along the line SE is perpendicular to the motion of the observer then only light emitted at an angle equal to the arc cosine of the ratio of the observer's speed to the speed of light will reach the telescope.

According to the special theory of relativity, the aberration looks as a transform of the celestial sphere due to different frames of reference and is virtually a special case of velocity addition, namely one of the light beam and frames ' relative velocity v. The formula from relativistic aberration can be simplified to

Laser Doppler anemometers use a beam of light from a laser that is divided into two beams, with one propagated out of the anemometer.

Particulates ( or deliberately introduced seed material ) flowing along with air molecules near where the beam exits reflect, or backscatter, the light back into a detector, where it is measured relative to the original laser beam.

At the regional cable television headend | headend, the TV channels are sent multiplexed on a light beam which travels through optical fiber trunklines, which fan out from distribution hubs to optical nodes in local communities.

At the headend the radio frequency electrical signal carrying all the channels is modulated on a light beam and sent through the fiber.

At the optical node, the light beam from the fiber is translated back to an electrical signal and carried by coaxial cable distribution lines on utility poles, from which cables branch out to subscriber residences.

The length over which the phase in a beam of light is correlated, is called the coherence length.

When looking at a cross section of a beam of light, the length over which the phase is correlated is called the transverse coherence length.

#* An infrared curtain or beam which shines invisible light onto sensors ; if someone or something blocks the beam the door is triggered open.

In the basic version of the experiment, a coherent light source such as a laser beam illuminates a thin plate pierced by two parallel slits, and the light passing through the slits is observed on a screen behind the plate.

However, one of the consequences of Einstein's theory is that there is no possible physical test that can distinguish between a beam of light as a model of a geometrical line and any other physical model.

The two horses broke from the yard, from the circle of light cast by the lamp still burning in the house, into the darkness.

A lantern hung from a peg, giving light.

It was, I felt, possible that they were men who, having received no tickets for that day, had remained in the hall, to sleep perhaps, in the corners farthest removed from the counter with its overhead light.

A match flared, and he reached above his head to light a lantern which hung from a wire loop.

They whirled and saw him, standing there dim in the slatted light from the boarded freight wall.

The distances of these points of light is a problem he cannot master, beyond crude conjectures as to the orderings of the planetary orbits viewed outward from earth.

In light of the scholarly reappraisals engendered by the higher criticism this is a most remarkable statement, particularly coming from one who was well known for his antifundamentalist views.

Far from being irrelevant to the ecumenical task, the Pontiff believes that a revivified Church is required in order that the whole world may see Catholicism in the best possible light.

But it also looked like a toad, hopping away from the light.

from the early evening lights of them which had first startled Izaak to look at her in an uncousinly way, they had faded to a near-absence of color which had, possibly from her constant looking at the water, something of the light of the sea in them.

At that time consideration will be given to whether in the light of the United States supplies of rice available for Title 1, disposal, India's production, consumption and stocks of food grains, other imports from the United States and countries friendly to the United States, India's storage capacity, and other related factors, any increase would be possible in the portion of the total rice programmed which is currently planned for procurement during the first year.

Essentially, the question presented for decision in the present Daytime Skywave proceeding is whether our decision ( in 1938-1939 ) to assign stations on the basis of daytime conditions from sunrise to sunset, is sound as a basis for AM allocations, or whether, in the light of later developments and new understanding, skywave transmission is of such significance during the hours immediately before sunset and after sunrise that this condition should be taken into account, and some stations required to afford protection to other stations during these hours.

It is a simple task to haul a boat fifty or one hundred miles to a lake or reservoir on the new, light, strong, easy-to-operate trailers which are built to accommodate almost any kind of small boat and retail from $100 to $2,000.

Then pour water or light oil from a graduated beaker into the chamber to fill the chamber to its gasket surface.

Just after sunset is a good time to record the city lights in color since you get a `` fill-in '' light from the sky.

( Note: Because of light leakage from one ultraviolet source to another, the lights are switched by a commutator-like assembly rotated by a synchronous motor.

Also, the light sources are shielded from dirt and weather exposure and cannot obstruct the view of the sign.

Changes of intensity on the cell were achieved by use of a wire screen and by varying the distance of the light source from the cell.

Some 80 reaction tubes from 13 manifold fillings were illuminated in the temperature range from 40 to 85-degrees in a further endeavor to determine the cause of the irreproducibility and to obtain information on the activation energy and the effect of light intensity.

By comparing reaction cells sealed from the same manifold temperature dependency corresponding to activation energies ranging from 11 to 18 Af was observed while dependence on the first power of the light intensity seemed to be indicated in most cases.

In series 1, the relative light intensity was varied by varying the distance of the lamp from the reaction cell over the range from 14.7 to 29.2 cm..

Let us suppose ( as is the practical case ) that the star is sufficiently distant that all light from the star travels in parallel paths to the Earth observer, regardless of where the Earth is in its orbit.

Eta Bootis, or Muphrid, is only 3. 3 light years distant from Arcturus, and would have a visual magnitude-2½, whereas an observer on the former system would find Arcturus as bright as Venus as seen from Earth.

Conversely, because space is expanding, and more distant objects are receding ever more quickly, light emitted by us today may never " catch up " to very distant objects.

* The Lyman alpha forest, which allows cosmologists to measure the distribution of neutral atomic hydrogen gas in the early universe, by measuring the absorption of light from distant quasars by the gas.

While this might suggest that the Earth is at the center of the Universe, the Copernican principle requires us to interpret it as evidence for the evolution of the Universe with time: this distant light has taken most of the age of the Universe to reach and shows us the Universe when it was young.

The most distant light of all, cosmic microwave background radiation, is isotropic to at least one part in a thousand.

For instance, dark bands in the light emitted by a distant star are due to the atoms in the star's atmosphere.

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

In 2010, fullerenes ( C < sub > 60 </ sub >) have been discovered in a cloud of cosmic dust surrounding a distant star 6500 light years away.

On the other hand, what some physicists refer to as " apparent " or " effective " FTL depends on the hypothesis that unusually distorted regions of spacetime might permit matter to reach distant locations in less time than light could in normal or undistorted spacetime.

If a laser is swept across a distant object, the spot of laser light can easily be made to move across the object at a speed greater than c. Similarly, a shadow projected onto a distant object can be made to move across the object faster than c. In neither case does the light travel from the source to the object faster than c, nor does any information travel faster than light.

Although the theory of special relativity forbids objects to have a relative velocity greater than light speed, and general relativity reduces to special relativity in a local sense ( in small regions of spacetime where curvature is negligible ), general relativity does allow the space between distant objects to expand in such a way that they have a " recession velocity " which exceeds the speed of light, and it is thought that galaxies which are at a distance of more than about 14 billion light-years from us today have a recession velocity which is faster than light.

Miguel Alcubierre theorized that it would be possible to create an Alcubierre drive, in which a ship would be enclosed in a " warp bubble " where the space at the front of the bubble is rapidly contracting and the space at the back is rapidly expanding, with the result that the bubble can reach a distant destination much faster than a light beam moving outside the bubble, but without objects inside the bubble locally traveling faster than light.

However, it permits distortions in spacetime that allow an object to move faster than light from the point of view of a distant observer.

The bending of light by gravity can lead to the phenomenon of gravitational lensing, in which multiple images of the same distant astronomical object are visible in the sky.