light (redirected from lights up)

light (lit) electromagnetic radiation with a range of wavelength between 3900 (violet) and 7700 (red) angstroms, capable of stimulating the subjective sensation of sight; sometimes considered to include ultraviolet and infrared radiation as well.

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idioretinal light  the sensation of light in the complete absence of external stimuli.

intrinsic light  the dim light always present in the visual field.

polarized light  light of which the vibrations are made over one plane or in circles or ellipses.

Wood's light  ultraviolet radiation from a mercury vapor source, transmitted through a nickel-oxide filter (Wood's filter, or glass), which holds back all but a few violet rays and passes ultraviolet wavelengths of about 365 nm.

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light (lt)

n.

1. Electromagnetic radiation that has a wavelength in the range from about 4,000 (violet) to about 7,700 (red) angstroms and may be perceived by the normal unaided human eye.

2. Electromagnetic radiation of any wavelength.

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light,

n 1. the electromagnetic radiation of the wavelength and frequency that stimulate visual receptor cells in the retina to produce nerve impulses that are perceived as vision.
2. visible light ranges from 400 to 800 nm.

light box,

n See illuminator.

light, chemiluminescent,

n light produced by the conversion of chemical energy into light energy.

light fog,

n See film fault, fogged.

light leaks,

n.pl See film fault, dark.

light, operating,

n a light with a strong beam that may be directed for concentrated illumination of a part being operated on.

light pen,

n a pointerlike device available with some computer terminals. A light pen selects data displayed on the screen by being pointed at any desired item.

light touch,

n See touch, light.

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light

electromagnetic radiation with a range of wavelength between about 390 nm (violet) and 770 nm (red), capable of stimulating the subjective sensation of sight; sometimes considered to include ultraviolet and infrared radiation as well.

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light beam diaphragm

adjustable lead shutters at the aperture of an x-ray tube. Usually includes a light bulb which delimits the area covered by the beam at the cassette level.

light cattle

store class cattle off range and destined for movement onto irrigated pasture or into feedlot for fattening.

light-dark cycles

an important environmental factor in proper housing of laboratory animals for optimal health and reproductive cycling. Most species do well on a 12:12 light-dark cycle but in rabbits more light for females and less for males is recommended.

polarized light

light of which the vibrations are made over one plane or in circles or ellipses.

light sensitization

see photosensitization.

light sheep

sheep light in condition off subsistence range and destined to go to irrigated pasture or into a feedlot for fattening.

light stimulus

see electroretinograph.

Wood's light

see wood's light.