ray

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A narrow stream of radiant energy, especially visible light, traveling in a straight or nearly straight line.
• noun A narrow stream of particles such as protons traveling in a straight or nearly straight line.
• noun A rapidly moving particle traveling in a straight or nearly straight line.
• noun Sunshine.
• noun A small amount; a trace.
• noun Mathematics A straight line extending from a point.
• noun A structure or part having the form of a straight line extending from a point, such as.
• noun Any of the bright streaks that are seen radiating from some craters on the moon.
• noun A ray flower or the strap-shaped portion of the corolla of a ray flower.
• noun A branch of an umbel.
• noun One of the bony spines supporting the membrane of a fish's fin.
• noun One of the arms of a starfish or other radiate animal.
• transitive verb To send out as rays; emit.
• transitive verb To supply with rays or radiating lines.
• transitive verb To cast rays on; irradiate.
• noun Any of various cartilaginous fishes of the superorder Batoidea, having ventral gill slits, enlarged pelvic fins that are fused to the sides of the head, and a flattened body, and including the stingrays, skates, and guitarfishes.
• noun Any of various members of this superorder having a whiplike tail usually with a stinging spine, such as a stingray, considered in contrast to a guitarfish, sawfish, or skate.

from The Century Dictionary.

• noun A kind of dance.
• noun Same as roy.
• To array.
• To beray with dirt or filth; daub; defile.
• noun A certain disease of sheep, also called scab, shab, or rubbers.
• noun Light emitted in a given direction from a luminous body; a line of light, or, more generally, of radiant energy; technically, the straight line perpendicular to the wave-front in the propagation of a light- or heat-wave.
• noun A beam of intellectual light.
• noun A stripe; streak; line.
• noun In geometry, an unlimited straight line.
• noun In botany:
• noun One of the branches or pedicels in an umbel.
• noun The marginal part as opposed to the central part or disk in a head, umbel, or other flower-cluster, when there is a difference of structure, as in many Compositæ and in wild hydrangeas.
• noun A ray-flower.
• noun A radius. See medullary rays, under medullary.
• noun One of the ray-like processes or arms of the Radiata, as of a starfish; a radiated or radiating part or organ; an actinomere. See cuts under Asterias and Asteriidæ.
• noun One of the hard spinous or soft jointed processes which support and serve to extend the fin of a fish; a part of the skeleton of the fin; specifically, one which is articulated, thus contradistinguished from a hard or inarticulated one called specifically a spine; a fin-ray.
• noun In entomology, one of the longitudinal nervures or veins of an insect's wing.
• noun plural In heraldry:
• noun Long indentations or dents by which a heraldic line is broken, whether dividing two parts of the escutcheon or bounding any ordinary. Compare radiant, 3 .
• noun A representation of rays, whether issuing from the sun or from a corner of the escutcheon, a cloud, or an ordinary.
• noun Bundles of straight or collecting tubules of the kidney contained in the cortex; the pyramids of Ferrein. See tubule.
• To mark with long lines; form rays of or in.
• To shoot forth or emit; cause to shine out.
• To stripe.
• To shine forth or out as in rays.
• noun Array; order; arrangement; rank; dress.
• noun A kind of striped cloth.
• noun In geometry: The aggregate of all points of the straight a situated on one and the same side of a point O of adjective
• noun One of the two parts of a straightest (great circle) determined by a point of it O with its opposite O′ .
• noun See obscure rays, radiation, and radioactivity.
• noun plural Emblems of light and glory embroidered around monograms of the holy name and sacred personages.
• noun The cathode rays, the X- or Röntgen rays, and the various types of radiation discovered in the study of the electric discharge in gases (see cathode rays) and of radioactivity. See radioactivity. Obscure rays are detected by their action on the photographic plate, their heating effect, their power of exciting luminescence or of producing other rays, and their electrical effects. Owing to the recent and very rapid development of this branch of physics the nomenclature of obscure radiation is somewhat confused. The term Hittorf rays is applied indiscriminately to all rays observed when the electric discharge passes through a tube with two terminals, a Hittorf tube, at high vacuum. When in a vacuum-tube the cathode is perforated, or consists of a tube, portions of the stream of positively charged ions from the anode pass through the opening. These form rays which enter the tube behind the cathode and which are known as canal rays or, after their discoverer, as Goldstein rays. They differ from cathode rays in having smaller velocity, and greater mass of the moving particles, in bearing a positive electric charge, and in being deflected in the opposite direction by a magnetic or electrostatic field. If cathode rays are allowed to fall upon a window of aluminium that forms part of the wall of the vacuum-tube within which they are produced, those which penetrate the metal and enter the outer air are called Lenard rays. Lenard showed that such rays suffer diffusion in passing through the air, like light in a turbid medium, and that, like the cathode rays within the tube, they are deflected by a magnet. In 1896 Becquerel discovered the spontaneous emission of obscure rays of the corpuscular type in substances containing uranium, and the name Becquerel rays is now applied to such rays from any radioactive material. These rays are also called uranium, thorium, radium, polonium, or actinium rays respectively, according to the radioactive element to which they are due. See radium, uranium. It was later shown by Rutherford that there are at least three distinct types of such radiation which may be distinguished from each other by their power of penetrating layers of metal and by their behavior in the magnetic field. The first of these, α-rays, have the least power of penetration. They are capable of ionizing gases and thus imparting to them the power of conducting electricity. They are deflected by the magnetic and electrostatic fields, but in the opposite direction from cathode rays, and are supposed to consist of a stream of positively charged particles of comparatively large mass traveling with a speed of about one tenth as great as the velocity of light. The α-rays affect the photographic plate and are capable of producing fluorescence and phosphorescence. The second, the β-rays, have somewhat greater penetrating power and intense photographic action. They are deflected by the magnetic field in the same sense as cathode rays and are supposed to consist of a Stream of negatively charged particles having a mass equal to of an atom of hydrogen with velocities comparable to that of light. β-rays produce fluorescence and phosphorescence, ionize gases, and may be detected by their electrical action. The third type of rays discovered by Villard, the γ-rays, have extraordinary penetrating power, being able to pass through several centimeters of lead. They are not affected by the magnetic field, in which respect they resemble ordinary X-rays. The γ-rays are regarded as electromagnetic disturbances produced by the action of the β-rays, just as the X-rays are produced by the action of cathode rays. Like the other types they produce ionization of gases and fluorescence and phosphorescence. See radioactivity. When X-rays meet an obstacle, as a metal surface, reflection in the ordinary sense of the word does not occur, hut rays differing in certain respects from the incident rays are diffusely emitted from the surfaces upon which the X-rays impinge. These rays were termed secondary rays by Sagnac, who investigated their properties. They are also occasionally called Sagnac rays, after their discoverer. In the same manner, bodies upon which secondary rays, or S-rays, fall emit a further modified type of radiation known as tertiary rays. Aside from the ordinary radiation from wires heated to incandescence by the electric current, rays similar to those emitted by radioactive bodies have been described. Tommasina claims to have distinguished three distinct types of rays, α-, β-, and γ-rays, having different powers of penetration and producing different effects upon a charged body. It is claimed that these socalled pyro-rays produce ionization of gases and excite fluorescence. In 1903, Blondlot announced the discovery of a new type of radiation originally obtained by filtering the rays from an X-ray tube through aluminium or black paper. These rays, which Blondlot terms N-rays (from Nancy, in France, where he discovered them), differ from X-rays in exhibiting the phenomena of polarization, refraction, and reflection. They were subsequently detected in various sources of light, properly screened, such as the Welsbach burner, an ordinary gas flame, a piece of metal heated to incandescence, and even sunlight. The N-rays are said to pass readily through wood, paper, and metal, but to be absorbed by rock-salt, fluorite, and glass, to increase the luminescence of fluorescent substances previously excited, but to be without effect on photographic plates. Their wave-length, according to Sagnac, is about 0.2 millimeters. In spite of the detailed description of the methods of obtaining N-rays and the definite reports concerning their properties, many physicists have failed altogether to reproduce Blondlot's results and the existence of the Blondlot rays is no longer credited.