| slovo | definícia |
refraction
(encz) | refraction,lámání světla n: Zdeněk Brož |
refraction
(encz) | refraction,refrakce n: Zdeněk Brož |
Refraction
(gcide) | Refraction \Re*frac"tion\ (r?*fr?k"sh?n), n. [F. r['e]fraction.]
1. The act of refracting, or the state of being refracted.
[1913 Webster]
2. The change in the direction of ray of light, heat, or the
like, when it enters obliquely a medium of a different
density from that through which it has previously moved.
[1913 Webster]
Refraction out of the rarer medium into the denser,
is made towards the perpendicular. --Sir I.
Newton.
[1913 Webster]
3. (Astron.)
(a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly
body from which it emanates, arising from its passage
through the earth's atmosphere; -- hence distinguished
as atmospheric refraction, or astronomical refraction.
(b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of
atmospheric refraction, in order to obtain the true
altitude.
[1913 Webster]
Angle of refraction (Opt.), the angle which a refracted ray
makes with the perpendicular to the surface separating the
two media traversed by the ray.
Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone.
This occurs when a ray of light is passed through crystals
of some substances, under certain circumstances. Conical
refraction is of two kinds; external conical refraction,
in which the ray issues from the crystal in the form of a
cone, the vertex of which is at the point of emergence;
and internal conical refraction, in which the ray is
changed into the form of a cone on entering the crystal,
from which it issues in the form of a hollow cylinder.
This singular phenomenon was first discovered by Sir W. R.
Hamilton by mathematical reasoning alone, unaided by
experiment.
Differential refraction (Astron.), the change of the
apparent place of one object relative to a second object
near it, due to refraction; also, the correction required
to be made to the observed relative places of the two
bodies.
Double refraction (Opt.), the refraction of light in two
directions, which produces two distinct images. The power
of double refraction is possessed by all crystals except
those of the isometric system. A uniaxial crystal is said
to be optically positive (like quartz), or optically
negative (like calcite), or to have positive, or negative,
double refraction, according as the optic axis is the axis
of least or greatest elasticity for light; a biaxial
crystal is similarly designated when the same relation
holds for the acute bisectrix.
Index of refraction. See under Index.
Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction.
Refraction of latitude, longitude, declination, {right
ascension}, etc., the change in the apparent latitude,
longitude, etc., of a heavenly body, due to the effect of
atmospheric refraction.
Terrestrial refraction, the change in the apparent altitude
of a distant point on or near the earth's surface, as the
top of a mountain, arising from the passage of light from
it to the eye through atmospheric strata of varying
density.
[1913 Webster] |
refraction
(gcide) | Angle \An"gle\ ([a^][ng]"g'l), n. [F. angle, L. angulus angle,
corner; akin to uncus hook, Gr. 'agky`los bent, crooked,
angular, 'a`gkos a bend or hollow, AS. angel hook, fish-hook,
G. angel, and F. anchor.]
1. The inclosed space near the point where two lines meet; a
corner; a nook.
[1913 Webster]
Into the utmost angle of the world. --Spenser.
[1913 Webster]
To search the tenderest angles of the heart.
--Milton.
[1913 Webster]
2. (Geom.)
(a) The figure made by. two lines which meet.
(b) The difference of direction of two lines. In the lines
meet, the point of meeting is the vertex of the angle.
[1913 Webster]
3. A projecting or sharp corner; an angular fragment.
[1913 Webster]
Though but an angle reached him of the stone.
--Dryden.
[1913 Webster]
4. (Astrol.) A name given to four of the twelve astrological
"houses." [Obs.] --Chaucer.
[1913 Webster]
5. [AS. angel.] A fishhook; tackle for catching fish,
consisting of a line, hook, and bait, with or without a
rod.
[1913 Webster]
Give me mine angle: we 'll to the river there.
--Shak.
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A fisher next his trembling angle bears. --Pope.
[1913 Webster]
Acute angle, one less than a right angle, or less than
90[deg].
Adjacent or Contiguous angles, such as have one leg
common to both angles.
Alternate angles. See Alternate.
Angle bar.
(a) (Carp.) An upright bar at the angle where two faces of
a polygonal or bay window meet. --Knight.
(b) (Mach.) Same as Angle iron.
Angle bead (Arch.), a bead worked on or fixed to the angle
of any architectural work, esp. for protecting an angle of
a wall.
Angle brace, Angle tie (Carp.), a brace across an
interior angle of a wooden frame, forming the hypothenuse
and securing the two side pieces together. --Knight.
Angle iron (Mach.), a rolled bar or plate of iron having
one or more angles, used for forming the corners, or
connecting or sustaining the sides of an iron structure to
which it is riveted.
Angle leaf (Arch.), a detail in the form of a leaf, more or
less conventionalized, used to decorate and sometimes to
strengthen an angle.
Angle meter, an instrument for measuring angles, esp. for
ascertaining the dip of strata.
Angle shaft (Arch.), an enriched angle bead, often having a
capital or base, or both.
Curvilineal angle, one formed by two curved lines.
External angles, angles formed by the sides of any
right-lined figure, when the sides are produced or
lengthened.
Facial angle. See under Facial.
Internal angles, those which are within any right-lined
figure.
Mixtilineal angle, one formed by a right line with a curved
line.
Oblique angle, one acute or obtuse, in opposition to a
right angle.
Obtuse angle, one greater than a right angle, or more than
90[deg].
Optic angle. See under Optic.
Rectilineal or Right-lined angle, one formed by two right
lines.
Right angle, one formed by a right line falling on another
perpendicularly, or an angle of 90[deg] (measured by a
quarter circle).
Solid angle, the figure formed by the meeting of three or
more plane angles at one point.
Spherical angle, one made by the meeting of two arcs of
great circles, which mutually cut one another on the
surface of a globe or sphere.
Visual angle, the angle formed by two rays of light, or two
straight lines drawn from the extreme points of an object
to the center of the eye.
For Angles of commutation, draught, incidence,
reflection, refraction, position, repose, fraction,
see Commutation, Draught, Incidence, Reflection,
Refraction, etc.
[1913 Webster] |
refraction
(wn) | refraction
n 1: the change in direction of a propagating wave (light or
sound) when passing from one medium to another
2: the amount by which a propagating wave is bent [syn:
deflection, deflexion, refraction] |
| | podobné slovo | definícia |
double refraction
(encz) | double refraction, n: |
index of refraction
(encz) | index of refraction,index lomu [fyz.] |
refraction
(encz) | refraction,lámání světla n: Zdeněk Brožrefraction,refrakce n: Zdeněk Brož |
x-ray refraction
(encz) | x-ray refraction,rentgenová refrakce n: [fyz.] mamm |
Angle of refraction
(gcide) | Refraction \Re*frac"tion\ (r?*fr?k"sh?n), n. [F. r['e]fraction.]
1. The act of refracting, or the state of being refracted.
[1913 Webster]
2. The change in the direction of ray of light, heat, or the
like, when it enters obliquely a medium of a different
density from that through which it has previously moved.
[1913 Webster]
Refraction out of the rarer medium into the denser,
is made towards the perpendicular. --Sir I.
Newton.
[1913 Webster]
3. (Astron.)
(a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly
body from which it emanates, arising from its passage
through the earth's atmosphere; -- hence distinguished
as atmospheric refraction, or astronomical refraction.
(b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of
atmospheric refraction, in order to obtain the true
altitude.
[1913 Webster]
Angle of refraction (Opt.), the angle which a refracted ray
makes with the perpendicular to the surface separating the
two media traversed by the ray.
Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone.
This occurs when a ray of light is passed through crystals
of some substances, under certain circumstances. Conical
refraction is of two kinds; external conical refraction,
in which the ray issues from the crystal in the form of a
cone, the vertex of which is at the point of emergence;
and internal conical refraction, in which the ray is
changed into the form of a cone on entering the crystal,
from which it issues in the form of a hollow cylinder.
This singular phenomenon was first discovered by Sir W. R.
Hamilton by mathematical reasoning alone, unaided by
experiment.
Differential refraction (Astron.), the change of the
apparent place of one object relative to a second object
near it, due to refraction; also, the correction required
to be made to the observed relative places of the two
bodies.
Double refraction (Opt.), the refraction of light in two
directions, which produces two distinct images. The power
of double refraction is possessed by all crystals except
those of the isometric system. A uniaxial crystal is said
to be optically positive (like quartz), or optically
negative (like calcite), or to have positive, or negative,
double refraction, according as the optic axis is the axis
of least or greatest elasticity for light; a biaxial
crystal is similarly designated when the same relation
holds for the acute bisectrix.
Index of refraction. See under Index.
Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction.
Refraction of latitude, longitude, declination, {right
ascension}, etc., the change in the apparent latitude,
longitude, etc., of a heavenly body, due to the effect of
atmospheric refraction.
Terrestrial refraction, the change in the apparent altitude
of a distant point on or near the earth's surface, as the
top of a mountain, arising from the passage of light from
it to the eye through atmospheric strata of varying
density.
[1913 Webster] |
Conical refraction
(gcide) | Refraction \Re*frac"tion\ (r?*fr?k"sh?n), n. [F. r['e]fraction.]
1. The act of refracting, or the state of being refracted.
[1913 Webster]
2. The change in the direction of ray of light, heat, or the
like, when it enters obliquely a medium of a different
density from that through which it has previously moved.
[1913 Webster]
Refraction out of the rarer medium into the denser,
is made towards the perpendicular. --Sir I.
Newton.
[1913 Webster]
3. (Astron.)
(a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly
body from which it emanates, arising from its passage
through the earth's atmosphere; -- hence distinguished
as atmospheric refraction, or astronomical refraction.
(b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of
atmospheric refraction, in order to obtain the true
altitude.
[1913 Webster]
Angle of refraction (Opt.), the angle which a refracted ray
makes with the perpendicular to the surface separating the
two media traversed by the ray.
Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone.
This occurs when a ray of light is passed through crystals
of some substances, under certain circumstances. Conical
refraction is of two kinds; external conical refraction,
in which the ray issues from the crystal in the form of a
cone, the vertex of which is at the point of emergence;
and internal conical refraction, in which the ray is
changed into the form of a cone on entering the crystal,
from which it issues in the form of a hollow cylinder.
This singular phenomenon was first discovered by Sir W. R.
Hamilton by mathematical reasoning alone, unaided by
experiment.
Differential refraction (Astron.), the change of the
apparent place of one object relative to a second object
near it, due to refraction; also, the correction required
to be made to the observed relative places of the two
bodies.
Double refraction (Opt.), the refraction of light in two
directions, which produces two distinct images. The power
of double refraction is possessed by all crystals except
those of the isometric system. A uniaxial crystal is said
to be optically positive (like quartz), or optically
negative (like calcite), or to have positive, or negative,
double refraction, according as the optic axis is the axis
of least or greatest elasticity for light; a biaxial
crystal is similarly designated when the same relation
holds for the acute bisectrix.
Index of refraction. See under Index.
Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction.
Refraction of latitude, longitude, declination, {right
ascension}, etc., the change in the apparent latitude,
longitude, etc., of a heavenly body, due to the effect of
atmospheric refraction.
Terrestrial refraction, the change in the apparent altitude
of a distant point on or near the earth's surface, as the
top of a mountain, arising from the passage of light from
it to the eye through atmospheric strata of varying
density.
[1913 Webster] |
Differential refraction
(gcide) | Refraction \Re*frac"tion\ (r?*fr?k"sh?n), n. [F. r['e]fraction.]
1. The act of refracting, or the state of being refracted.
[1913 Webster]
2. The change in the direction of ray of light, heat, or the
like, when it enters obliquely a medium of a different
density from that through which it has previously moved.
[1913 Webster]
Refraction out of the rarer medium into the denser,
is made towards the perpendicular. --Sir I.
Newton.
[1913 Webster]
3. (Astron.)
(a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly
body from which it emanates, arising from its passage
through the earth's atmosphere; -- hence distinguished
as atmospheric refraction, or astronomical refraction.
(b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of
atmospheric refraction, in order to obtain the true
altitude.
[1913 Webster]
Angle of refraction (Opt.), the angle which a refracted ray
makes with the perpendicular to the surface separating the
two media traversed by the ray.
Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone.
This occurs when a ray of light is passed through crystals
of some substances, under certain circumstances. Conical
refraction is of two kinds; external conical refraction,
in which the ray issues from the crystal in the form of a
cone, the vertex of which is at the point of emergence;
and internal conical refraction, in which the ray is
changed into the form of a cone on entering the crystal,
from which it issues in the form of a hollow cylinder.
This singular phenomenon was first discovered by Sir W. R.
Hamilton by mathematical reasoning alone, unaided by
experiment.
Differential refraction (Astron.), the change of the
apparent place of one object relative to a second object
near it, due to refraction; also, the correction required
to be made to the observed relative places of the two
bodies.
Double refraction (Opt.), the refraction of light in two
directions, which produces two distinct images. The power
of double refraction is possessed by all crystals except
those of the isometric system. A uniaxial crystal is said
to be optically positive (like quartz), or optically
negative (like calcite), or to have positive, or negative,
double refraction, according as the optic axis is the axis
of least or greatest elasticity for light; a biaxial
crystal is similarly designated when the same relation
holds for the acute bisectrix.
Index of refraction. See under Index.
Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction.
Refraction of latitude, longitude, declination, {right
ascension}, etc., the change in the apparent latitude,
longitude, etc., of a heavenly body, due to the effect of
atmospheric refraction.
Terrestrial refraction, the change in the apparent altitude
of a distant point on or near the earth's surface, as the
top of a mountain, arising from the passage of light from
it to the eye through atmospheric strata of varying
density.
[1913 Webster] |
Double refraction
(gcide) | Refraction \Re*frac"tion\ (r?*fr?k"sh?n), n. [F. r['e]fraction.]
1. The act of refracting, or the state of being refracted.
[1913 Webster]
2. The change in the direction of ray of light, heat, or the
like, when it enters obliquely a medium of a different
density from that through which it has previously moved.
[1913 Webster]
Refraction out of the rarer medium into the denser,
is made towards the perpendicular. --Sir I.
Newton.
[1913 Webster]
3. (Astron.)
(a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly
body from which it emanates, arising from its passage
through the earth's atmosphere; -- hence distinguished
as atmospheric refraction, or astronomical refraction.
(b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of
atmospheric refraction, in order to obtain the true
altitude.
[1913 Webster]
Angle of refraction (Opt.), the angle which a refracted ray
makes with the perpendicular to the surface separating the
two media traversed by the ray.
Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone.
This occurs when a ray of light is passed through crystals
of some substances, under certain circumstances. Conical
refraction is of two kinds; external conical refraction,
in which the ray issues from the crystal in the form of a
cone, the vertex of which is at the point of emergence;
and internal conical refraction, in which the ray is
changed into the form of a cone on entering the crystal,
from which it issues in the form of a hollow cylinder.
This singular phenomenon was first discovered by Sir W. R.
Hamilton by mathematical reasoning alone, unaided by
experiment.
Differential refraction (Astron.), the change of the
apparent place of one object relative to a second object
near it, due to refraction; also, the correction required
to be made to the observed relative places of the two
bodies.
Double refraction (Opt.), the refraction of light in two
directions, which produces two distinct images. The power
of double refraction is possessed by all crystals except
those of the isometric system. A uniaxial crystal is said
to be optically positive (like quartz), or optically
negative (like calcite), or to have positive, or negative,
double refraction, according as the optic axis is the axis
of least or greatest elasticity for light; a biaxial
crystal is similarly designated when the same relation
holds for the acute bisectrix.
Index of refraction. See under Index.
Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction.
Refraction of latitude, longitude, declination, {right
ascension}, etc., the change in the apparent latitude,
longitude, etc., of a heavenly body, due to the effect of
atmospheric refraction.
Terrestrial refraction, the change in the apparent altitude
of a distant point on or near the earth's surface, as the
top of a mountain, arising from the passage of light from
it to the eye through atmospheric strata of varying
density.
[1913 Webster]Double \Dou"ble\ (d[u^]b"'l), a. [OE. doble, duble, double, OF.
doble, duble, double, F. double, fr. L. duplus, fr. the root
of duo two, and perh. that of plenus full; akin to Gr.
diplo`os double. See Two, and Full, and cf. Diploma,
Duple.]
1. Twofold; multiplied by two; increased by its equivalent;
made twice as large or as much, etc.
[1913 Webster]
Let a double portion of thy spirit be upon me. -- 2
Kings ii. 9.
[1913 Webster]
Darkness and tempest make a double night. --Dryden.
[1913 Webster]
2. Being in pairs; presenting two of a kind, or two in a set
together; coupled.
[1913 Webster]
[Let] The swan, on still St. Mary's lake,
Float double, swan and shadow. --Wordsworth.
[1913 Webster]
3. Divided into two; acting two parts, one openly and the
other secretly; equivocal; deceitful; insincere.
[1913 Webster]
With a double heart do they speak. -- Ps. xii. 2.
[1913 Webster]
4. (Bot.) Having the petals in a flower considerably
increased beyond the natural number, usually as the result
of cultivation and the expense of the stamens, or stamens
and pistils. The white water lily and some other plants
have their blossoms naturally double.
[1913 Webster]
Note: Double is often used as the first part of a compound
word, generally denoting two ways, or twice the number,
quantity, force, etc., twofold, or having two.
[1913 Webster]
Double base, or Double bass (Mus.), the largest and
lowest-toned instrument in the violin form; the
contrabasso or violone.
Double convex. See under Convex.
Double counterpoint (Mus.), that species of counterpoint or
composition, in which two of the parts may be inverted, by
setting one of them an octave higher or lower.
Double court (Lawn Tennis), a court laid out for four
players, two on each side.
Double dagger (Print.), a reference mark ([dag]) next to
the dagger ([dagger]) in order; a diesis.
Double drum (Mus.), a large drum that is beaten at both
ends.
Double eagle, a gold coin of the United States having the
value of 20 dollars.
Double entry. See under Bookkeeping.
Double floor (Arch.), a floor in which binding joists
support flooring joists above and ceiling joists below.
See Illust. of Double-framed floor.
Double flower. See Double, a., 4.
Double-framed floor (Arch.), a double floor having girders
into which the binding joists are framed.
Double fugue (Mus.), a fugue on two subjects.
Double letter.
(a) (Print.) Two letters on one shank; a ligature.
(b) A mail requiring double postage.
Double note (Mus.), a note of double the length of the
semibreve; a breve. See Breve.
Double octave (Mus.), an interval composed of two octaves,
or fifteen notes, in diatonic progression; a fifteenth.
Double pica. See under Pica.
Double play (Baseball), a play by which two players are put
out at the same time.
Double plea (Law), a plea alleging several matters in
answer to the declaration, where either of such matters
alone would be a sufficient bar to the action. --Stephen.
Double point (Geom.), a point of a curve at which two
branches cross each other. Conjugate or isolated points of
a curve are called double points, since they possess most
of the properties of double points (see Conjugate). They
are also called acnodes, and those points where the
branches of the curve really cross are called crunodes.
The extremity of a cusp is also a double point.
Double quarrel. (Eccl. Law) See Duplex querela, under
Duplex.
Double refraction. (Opt.) See Refraction.
Double salt. (Chem.)
(a) A mixed salt of any polybasic acid which has been
saturated by different bases or basic radicals, as the
double carbonate of sodium and potassium,
NaKCO3.6H2O.
(b) A molecular combination of two distinct salts, as
common alum, which consists of the sulphate of
aluminium, and the sulphate of potassium or ammonium.
Double shuffle, a low, noisy dance.
Double standard (Polit. Econ.), a double standard of
monetary values; i. e., a gold standard and a silver
standard, both of which are made legal tender.
Double star (Astron.), two stars so near to each other as
to be seen separate only by means of a telescope. Such
stars may be only optically near to each other, or may be
physically connected so that they revolve round their
common center of gravity, and in the latter case are
called also binary stars.
Double time (Mil.). Same as Double-quick.
Double window, a window having two sets of glazed sashes
with an air space between them.
[1913 Webster] |
Double refraction micrometer
(gcide) | Micrometer \Mi*crom"e*ter\, n. [Micro- + -meter: cf. F.
microm[`e]tre.]
An instrument, used with a telescope or microscope, for
measuring minute distances, or the apparent diameters of
objects which subtend minute angles. The measurement given
directly is that of the image of the object formed at the
focus of the object glass.
[1913 Webster]
Circular micrometer, or Ring micrometer, a metallic ring
fixed in the focus of the object glass of a telescope, and
used to determine differences of right ascension and
declination between stars by observations of the times at
which the stars cross the inner or outer periphery of the
ring.
Double image micrometer, a micrometer in which two images
of an object are formed in the field, usually by the two
halves of a bisected lens which are movable along their
line of section by a screw, and distances are determined
by the number of screw revolutions necessary to bring the
points to be measured into optical coincidence. When the
two images are formed by a bisected object glass, it is
called a divided-object-glass micrometer, and when the
instrument is large and equatorially mounted, it is known
as a heliometer.
Double refraction micrometer, a species of double image
micrometer, in which the two images are formed by the
double refraction of rock crystal.
Filar micrometer, or Bifilar micrometer. See under
Bifilar.
Micrometer caliper or Micrometer gauge (Mech.), a caliper
or gauge with a micrometer screw, for measuring dimensions
with great accuracy.
Micrometer head, the head of a micrometer screw.
Micrometer microscope, a compound microscope combined with
a filar micrometer, used chiefly for reading and
subdividing the divisions of large astronomical and
geodetical instruments.
Micrometer screw, a screw with a graduated head used in
some forms of micrometers; turning the head one full
revolution advances the position of the tip of the screw
only by a little.
Position micrometer. See under Position.
Scale micrometer, or Linear micrometer, a minute and very
delicately graduated scale of equal parts used in the
field of a telescope or microscope, for measuring
distances by direct comparison.
[1913 Webster] Micrometric |
Index of refraction
(gcide) | Index \In"dex\, n.; pl. E. Indexes, L. Indices(?). [L.: cf.
F. index. See Indicate, Diction.]
[1913 Webster]
1. That which points out; that which shows, indicates,
manifests, or discloses; as, the increasing unemployment
rate is an index of how much the economy has slowed.
[1913 Webster +PJC]
Tastes are the indexes of the different qualities of
plants. --Arbuthnot.
[1913 Webster]
2. That which guides, points out, informs, or directs; a
pointer or a hand that directs to anything, as the hand of
a watch, a movable finger or other form of pointer on a
gauge, scale, or other graduated instrument. In
(printing), a sign [[hand]] (called also fist) used to
direct particular attention to a note or paragraph.
[1913 Webster]
3. A table for facilitating reference to topics, names, and
the like, in a book, usually giving the page on which a
particular word or topic may be found; -- usually
alphabetical in arrangement, and printed at the end of the
volume. Typically found only in non-fiction books.
[1913 Webster +PJC]
4. A prologue indicating what follows. [Obs.] --Shak.
[1913 Webster]
5. (Anat.) The second finger, that next to the pollex
(thumb), in the manus, or hand; the forefinger; {index
finger}.
[1913 Webster]
6. (Math.) The figure or letter which shows the power or root
of a quantity; the exponent. [In this sense the plural is
always indices.]
[1913 Webster]
7. The ratio, or formula expressing the ratio, of one
dimension of a thing to another dimension; as, the
vertical index of the cranium.
[Webster 1913 Suppl.]
8. A number providing a measure of some quantity derived by a
formula, usually a form of averaging, from multiple
quantities; -- used mostly in economics; as, the index of
leading indicators; the index of industrial production;
the consumer price index. See, for example, the {consumer
price index}.
[PJC]
9. (computers) A file containing a table with the addresses
of data items, arranged for rapid and convenient search
for the addresses.
[PJC]
10. (computers) A number which serves as a label for a data
item and also represents the address of a data item
within a table or array.
[PJC]
11. (R. C. Ch.), The Index prohibitorius, a catalogue of
books which are forbidden by the church to be read; also
called Index of forbidden books and {Index Librorum
Prohibitorum}.
[PJC]
Index error, the error in the reading of a mathematical
instrument arising from the zero of the index not being in
complete adjustment with that of the limb, or with its
theoretically perfect position in the instrument; a
correction to be applied to the instrument readings equal
to the error of the zero adjustment.
Index expurgatorius. [L.] See Index prohibitorius
(below).
Index finger. See Index, 5.
Index glass, the mirror on the index of a quadrant,
sextant, etc.
Index hand, the pointer or hand of a clock, watch, or other
registering machine; a hand that points to something.
Index of a logarithm (Math.), the integral part of the
logarithm, and always one less than the number of integral
figures in the given number. It is also called the
characteristic.
Index of refraction, or Refractive index (Opt.), the
number which expresses the ratio of the sine of the angle
of incidence to the sine of the angle of refraction. Thus
the index of refraction for sulphur is 2, because, when
light passes out of air into sulphur, the sine of the
angle of incidence is double the sine of the angle of
refraction.
Index plate, a graduated circular plate, or one with
circular rows of holes differently spaced; used in
machines for graduating circles, cutting gear teeth, etc.
Index prohibitorius [L.], or Prohibitory index (R. C.
Ch.), a catalogue of books which are forbidden by the
church to be read; the index expurgatorius [L.], or
expurgatory index, is a catalogue of books from which
passages marked as against faith or morals must be removed
before Catholics can read them. These catalogues are
published with additions, from time to time, by the
Congregation of the Index, composed of cardinals,
theologians, etc., under the sanction of the pope. --Hook.
Index rerum [L.], a tabulated and alphabetized notebook,
for systematic preservation of items, quotations, etc.
[1913 Webster]Refraction \Re*frac"tion\ (r?*fr?k"sh?n), n. [F. r['e]fraction.]
1. The act of refracting, or the state of being refracted.
[1913 Webster]
2. The change in the direction of ray of light, heat, or the
like, when it enters obliquely a medium of a different
density from that through which it has previously moved.
[1913 Webster]
Refraction out of the rarer medium into the denser,
is made towards the perpendicular. --Sir I.
Newton.
[1913 Webster]
3. (Astron.)
(a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly
body from which it emanates, arising from its passage
through the earth's atmosphere; -- hence distinguished
as atmospheric refraction, or astronomical refraction.
(b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of
atmospheric refraction, in order to obtain the true
altitude.
[1913 Webster]
Angle of refraction (Opt.), the angle which a refracted ray
makes with the perpendicular to the surface separating the
two media traversed by the ray.
Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone.
This occurs when a ray of light is passed through crystals
of some substances, under certain circumstances. Conical
refraction is of two kinds; external conical refraction,
in which the ray issues from the crystal in the form of a
cone, the vertex of which is at the point of emergence;
and internal conical refraction, in which the ray is
changed into the form of a cone on entering the crystal,
from which it issues in the form of a hollow cylinder.
This singular phenomenon was first discovered by Sir W. R.
Hamilton by mathematical reasoning alone, unaided by
experiment.
Differential refraction (Astron.), the change of the
apparent place of one object relative to a second object
near it, due to refraction; also, the correction required
to be made to the observed relative places of the two
bodies.
Double refraction (Opt.), the refraction of light in two
directions, which produces two distinct images. The power
of double refraction is possessed by all crystals except
those of the isometric system. A uniaxial crystal is said
to be optically positive (like quartz), or optically
negative (like calcite), or to have positive, or negative,
double refraction, according as the optic axis is the axis
of least or greatest elasticity for light; a biaxial
crystal is similarly designated when the same relation
holds for the acute bisectrix.
Index of refraction. See under Index.
Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction.
Refraction of latitude, longitude, declination, {right
ascension}, etc., the change in the apparent latitude,
longitude, etc., of a heavenly body, due to the effect of
atmospheric refraction.
Terrestrial refraction, the change in the apparent altitude
of a distant point on or near the earth's surface, as the
top of a mountain, arising from the passage of light from
it to the eye through atmospheric strata of varying
density.
[1913 Webster] |
Plane of refraction
(gcide) | Plane \Plane\, n. [F. plane, L. plana. See Plane, v. & a.]
1. (Geom.) A surface, real or imaginary, in which, if any two
points are taken, the straight line which joins them lies
wholly in that surface; or a surface, any section of which
by a like surface is a straight line; a surface without
curvature.
[1913 Webster]
2. (Astron.) An ideal surface, conceived as coinciding with,
or containing, some designated astronomical line, circle,
or other curve; as, the plane of an orbit; the plane of
the ecliptic, or of the equator.
[1913 Webster]
3. (Mech.) A block or plate having a perfectly flat surface,
used as a standard of flatness; a surface plate.
[1913 Webster]
4. (Joinery) A tool for smoothing boards or other surfaces of
wood, for forming moldings, etc. It consists of a
smooth-soled stock, usually of wood, from the under side
or face of which projects slightly the steel cutting edge
of a chisel, called the iron, which inclines backward,
with an apperture in front for the escape of shavings; as,
the jack plane; the smoothing plane; the molding plane,
etc.
[1913 Webster]
Objective plane (Surv.), the horizontal plane upon which
the object which is to be delineated, or whose place is to
be determined, is supposed to stand.
Perspective plane. See Perspective.
Plane at infinity (Geom.), a plane in which points
infinitely distant are conceived as situated.
Plane iron, the cutting chisel of a joiner's plane.
Plane of polarization. (Opt.) See Polarization.
Plane of projection.
(a) The plane on which the projection is made,
corresponding to the perspective plane in perspective;
-- called also principal plane.
(b) (Descriptive Geom.) One of the planes to which points
are referred for the purpose of determining their
relative position in space.
Plane of refraction or Plane of reflection (Opt.), the
plane in which lie both the incident ray and the refracted
or reflected ray.
[1913 Webster] |
refraction
(gcide) | Refraction \Re*frac"tion\ (r?*fr?k"sh?n), n. [F. r['e]fraction.]
1. The act of refracting, or the state of being refracted.
[1913 Webster]
2. The change in the direction of ray of light, heat, or the
like, when it enters obliquely a medium of a different
density from that through which it has previously moved.
[1913 Webster]
Refraction out of the rarer medium into the denser,
is made towards the perpendicular. --Sir I.
Newton.
[1913 Webster]
3. (Astron.)
(a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly
body from which it emanates, arising from its passage
through the earth's atmosphere; -- hence distinguished
as atmospheric refraction, or astronomical refraction.
(b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of
atmospheric refraction, in order to obtain the true
altitude.
[1913 Webster]
Angle of refraction (Opt.), the angle which a refracted ray
makes with the perpendicular to the surface separating the
two media traversed by the ray.
Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone.
This occurs when a ray of light is passed through crystals
of some substances, under certain circumstances. Conical
refraction is of two kinds; external conical refraction,
in which the ray issues from the crystal in the form of a
cone, the vertex of which is at the point of emergence;
and internal conical refraction, in which the ray is
changed into the form of a cone on entering the crystal,
from which it issues in the form of a hollow cylinder.
This singular phenomenon was first discovered by Sir W. R.
Hamilton by mathematical reasoning alone, unaided by
experiment.
Differential refraction (Astron.), the change of the
apparent place of one object relative to a second object
near it, due to refraction; also, the correction required
to be made to the observed relative places of the two
bodies.
Double refraction (Opt.), the refraction of light in two
directions, which produces two distinct images. The power
of double refraction is possessed by all crystals except
those of the isometric system. A uniaxial crystal is said
to be optically positive (like quartz), or optically
negative (like calcite), or to have positive, or negative,
double refraction, according as the optic axis is the axis
of least or greatest elasticity for light; a biaxial
crystal is similarly designated when the same relation
holds for the acute bisectrix.
Index of refraction. See under Index.
Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction.
Refraction of latitude, longitude, declination, {right
ascension}, etc., the change in the apparent latitude,
longitude, etc., of a heavenly body, due to the effect of
atmospheric refraction.
Terrestrial refraction, the change in the apparent altitude
of a distant point on or near the earth's surface, as the
top of a mountain, arising from the passage of light from
it to the eye through atmospheric strata of varying
density.
[1913 Webster]Angle \An"gle\ ([a^][ng]"g'l), n. [F. angle, L. angulus angle,
corner; akin to uncus hook, Gr. 'agky`los bent, crooked,
angular, 'a`gkos a bend or hollow, AS. angel hook, fish-hook,
G. angel, and F. anchor.]
1. The inclosed space near the point where two lines meet; a
corner; a nook.
[1913 Webster]
Into the utmost angle of the world. --Spenser.
[1913 Webster]
To search the tenderest angles of the heart.
--Milton.
[1913 Webster]
2. (Geom.)
(a) The figure made by. two lines which meet.
(b) The difference of direction of two lines. In the lines
meet, the point of meeting is the vertex of the angle.
[1913 Webster]
3. A projecting or sharp corner; an angular fragment.
[1913 Webster]
Though but an angle reached him of the stone.
--Dryden.
[1913 Webster]
4. (Astrol.) A name given to four of the twelve astrological
"houses." [Obs.] --Chaucer.
[1913 Webster]
5. [AS. angel.] A fishhook; tackle for catching fish,
consisting of a line, hook, and bait, with or without a
rod.
[1913 Webster]
Give me mine angle: we 'll to the river there.
--Shak.
[1913 Webster]
A fisher next his trembling angle bears. --Pope.
[1913 Webster]
Acute angle, one less than a right angle, or less than
90[deg].
Adjacent or Contiguous angles, such as have one leg
common to both angles.
Alternate angles. See Alternate.
Angle bar.
(a) (Carp.) An upright bar at the angle where two faces of
a polygonal or bay window meet. --Knight.
(b) (Mach.) Same as Angle iron.
Angle bead (Arch.), a bead worked on or fixed to the angle
of any architectural work, esp. for protecting an angle of
a wall.
Angle brace, Angle tie (Carp.), a brace across an
interior angle of a wooden frame, forming the hypothenuse
and securing the two side pieces together. --Knight.
Angle iron (Mach.), a rolled bar or plate of iron having
one or more angles, used for forming the corners, or
connecting or sustaining the sides of an iron structure to
which it is riveted.
Angle leaf (Arch.), a detail in the form of a leaf, more or
less conventionalized, used to decorate and sometimes to
strengthen an angle.
Angle meter, an instrument for measuring angles, esp. for
ascertaining the dip of strata.
Angle shaft (Arch.), an enriched angle bead, often having a
capital or base, or both.
Curvilineal angle, one formed by two curved lines.
External angles, angles formed by the sides of any
right-lined figure, when the sides are produced or
lengthened.
Facial angle. See under Facial.
Internal angles, those which are within any right-lined
figure.
Mixtilineal angle, one formed by a right line with a curved
line.
Oblique angle, one acute or obtuse, in opposition to a
right angle.
Obtuse angle, one greater than a right angle, or more than
90[deg].
Optic angle. See under Optic.
Rectilineal or Right-lined angle, one formed by two right
lines.
Right angle, one formed by a right line falling on another
perpendicularly, or an angle of 90[deg] (measured by a
quarter circle).
Solid angle, the figure formed by the meeting of three or
more plane angles at one point.
Spherical angle, one made by the meeting of two arcs of
great circles, which mutually cut one another on the
surface of a globe or sphere.
Visual angle, the angle formed by two rays of light, or two
straight lines drawn from the extreme points of an object
to the center of the eye.
For Angles of commutation, draught, incidence,
reflection, refraction, position, repose, fraction,
see Commutation, Draught, Incidence, Reflection,
Refraction, etc.
[1913 Webster] |
Refraction circle
(gcide) | Refraction \Re*frac"tion\ (r?*fr?k"sh?n), n. [F. r['e]fraction.]
1. The act of refracting, or the state of being refracted.
[1913 Webster]
2. The change in the direction of ray of light, heat, or the
like, when it enters obliquely a medium of a different
density from that through which it has previously moved.
[1913 Webster]
Refraction out of the rarer medium into the denser,
is made towards the perpendicular. --Sir I.
Newton.
[1913 Webster]
3. (Astron.)
(a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly
body from which it emanates, arising from its passage
through the earth's atmosphere; -- hence distinguished
as atmospheric refraction, or astronomical refraction.
(b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of
atmospheric refraction, in order to obtain the true
altitude.
[1913 Webster]
Angle of refraction (Opt.), the angle which a refracted ray
makes with the perpendicular to the surface separating the
two media traversed by the ray.
Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone.
This occurs when a ray of light is passed through crystals
of some substances, under certain circumstances. Conical
refraction is of two kinds; external conical refraction,
in which the ray issues from the crystal in the form of a
cone, the vertex of which is at the point of emergence;
and internal conical refraction, in which the ray is
changed into the form of a cone on entering the crystal,
from which it issues in the form of a hollow cylinder.
This singular phenomenon was first discovered by Sir W. R.
Hamilton by mathematical reasoning alone, unaided by
experiment.
Differential refraction (Astron.), the change of the
apparent place of one object relative to a second object
near it, due to refraction; also, the correction required
to be made to the observed relative places of the two
bodies.
Double refraction (Opt.), the refraction of light in two
directions, which produces two distinct images. The power
of double refraction is possessed by all crystals except
those of the isometric system. A uniaxial crystal is said
to be optically positive (like quartz), or optically
negative (like calcite), or to have positive, or negative,
double refraction, according as the optic axis is the axis
of least or greatest elasticity for light; a biaxial
crystal is similarly designated when the same relation
holds for the acute bisectrix.
Index of refraction. See under Index.
Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction.
Refraction of latitude, longitude, declination, {right
ascension}, etc., the change in the apparent latitude,
longitude, etc., of a heavenly body, due to the effect of
atmospheric refraction.
Terrestrial refraction, the change in the apparent altitude
of a distant point on or near the earth's surface, as the
top of a mountain, arising from the passage of light from
it to the eye through atmospheric strata of varying
density.
[1913 Webster] |
Refraction of latitude
(gcide) | Refraction \Re*frac"tion\ (r?*fr?k"sh?n), n. [F. r['e]fraction.]
1. The act of refracting, or the state of being refracted.
[1913 Webster]
2. The change in the direction of ray of light, heat, or the
like, when it enters obliquely a medium of a different
density from that through which it has previously moved.
[1913 Webster]
Refraction out of the rarer medium into the denser,
is made towards the perpendicular. --Sir I.
Newton.
[1913 Webster]
3. (Astron.)
(a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly
body from which it emanates, arising from its passage
through the earth's atmosphere; -- hence distinguished
as atmospheric refraction, or astronomical refraction.
(b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of
atmospheric refraction, in order to obtain the true
altitude.
[1913 Webster]
Angle of refraction (Opt.), the angle which a refracted ray
makes with the perpendicular to the surface separating the
two media traversed by the ray.
Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone.
This occurs when a ray of light is passed through crystals
of some substances, under certain circumstances. Conical
refraction is of two kinds; external conical refraction,
in which the ray issues from the crystal in the form of a
cone, the vertex of which is at the point of emergence;
and internal conical refraction, in which the ray is
changed into the form of a cone on entering the crystal,
from which it issues in the form of a hollow cylinder.
This singular phenomenon was first discovered by Sir W. R.
Hamilton by mathematical reasoning alone, unaided by
experiment.
Differential refraction (Astron.), the change of the
apparent place of one object relative to a second object
near it, due to refraction; also, the correction required
to be made to the observed relative places of the two
bodies.
Double refraction (Opt.), the refraction of light in two
directions, which produces two distinct images. The power
of double refraction is possessed by all crystals except
those of the isometric system. A uniaxial crystal is said
to be optically positive (like quartz), or optically
negative (like calcite), or to have positive, or negative,
double refraction, according as the optic axis is the axis
of least or greatest elasticity for light; a biaxial
crystal is similarly designated when the same relation
holds for the acute bisectrix.
Index of refraction. See under Index.
Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction.
Refraction of latitude, longitude, declination, {right
ascension}, etc., the change in the apparent latitude,
longitude, etc., of a heavenly body, due to the effect of
atmospheric refraction.
Terrestrial refraction, the change in the apparent altitude
of a distant point on or near the earth's surface, as the
top of a mountain, arising from the passage of light from
it to the eye through atmospheric strata of varying
density.
[1913 Webster] |
Terrestrial refraction
(gcide) | Refraction \Re*frac"tion\ (r?*fr?k"sh?n), n. [F. r['e]fraction.]
1. The act of refracting, or the state of being refracted.
[1913 Webster]
2. The change in the direction of ray of light, heat, or the
like, when it enters obliquely a medium of a different
density from that through which it has previously moved.
[1913 Webster]
Refraction out of the rarer medium into the denser,
is made towards the perpendicular. --Sir I.
Newton.
[1913 Webster]
3. (Astron.)
(a) The change in the direction of a ray of light, and,
consequently, in the apparent position of a heavenly
body from which it emanates, arising from its passage
through the earth's atmosphere; -- hence distinguished
as atmospheric refraction, or astronomical refraction.
(b) The correction which is to be deducted from the
apparent altitude of a heavenly body on account of
atmospheric refraction, in order to obtain the true
altitude.
[1913 Webster]
Angle of refraction (Opt.), the angle which a refracted ray
makes with the perpendicular to the surface separating the
two media traversed by the ray.
Conical refraction (Opt.), the refraction of a ray of light
into an infinite number of rays, forming a hollow cone.
This occurs when a ray of light is passed through crystals
of some substances, under certain circumstances. Conical
refraction is of two kinds; external conical refraction,
in which the ray issues from the crystal in the form of a
cone, the vertex of which is at the point of emergence;
and internal conical refraction, in which the ray is
changed into the form of a cone on entering the crystal,
from which it issues in the form of a hollow cylinder.
This singular phenomenon was first discovered by Sir W. R.
Hamilton by mathematical reasoning alone, unaided by
experiment.
Differential refraction (Astron.), the change of the
apparent place of one object relative to a second object
near it, due to refraction; also, the correction required
to be made to the observed relative places of the two
bodies.
Double refraction (Opt.), the refraction of light in two
directions, which produces two distinct images. The power
of double refraction is possessed by all crystals except
those of the isometric system. A uniaxial crystal is said
to be optically positive (like quartz), or optically
negative (like calcite), or to have positive, or negative,
double refraction, according as the optic axis is the axis
of least or greatest elasticity for light; a biaxial
crystal is similarly designated when the same relation
holds for the acute bisectrix.
Index of refraction. See under Index.
Refraction circle (Opt.), an instrument provided with a
graduated circle for the measurement of refraction.
Refraction of latitude, longitude, declination, {right
ascension}, etc., the change in the apparent latitude,
longitude, etc., of a heavenly body, due to the effect of
atmospheric refraction.
Terrestrial refraction, the change in the apparent altitude
of a distant point on or near the earth's surface, as the
top of a mountain, arising from the passage of light from
it to the eye through atmospheric strata of varying
density.
[1913 Webster] |
angle of refraction
(wn) | angle of refraction
n 1: the angle between a refracted ray and a line perpendicular
to the surface between the two media at the point of
refraction |
double refraction
(wn) | double refraction
n 1: splitting a ray into two parallel rays polarized
perpendicularly [syn: double refraction, birefringence] |
index of refraction
(wn) | index of refraction
n 1: the ratio of the velocity of light in a vacuum to that in a
medium [syn: refractive index, index of refraction] |
refraction
(wn) | refraction
n 1: the change in direction of a propagating wave (light or
sound) when passing from one medium to another
2: the amount by which a propagating wave is bent [syn:
deflection, deflexion, refraction] |
|