【医】 角距, 视角距离

[ noun ]
the angular separation between two objects as perceived by an observer
<noun.shape>
he recorded angular distances between the stars

Angular \An"gu*lar\, a. [L. angularis, fr. angulus angle,
corner. See {Angle}.]
1. Relating to an angle or to angles; having an angle or
angles; forming an angle or corner; sharp-cornered;
pointed; as, an angular figure.

2. Measured by an angle; as, angular distance.

3. Fig.: Lean; lank; raw-boned; ungraceful; sharp and stiff
in character; as, remarkably angular in his habits and
appearance; an angular female.

{Angular aperture}, {Angular distance}. See {Aperture},
{Distance}.

{Angular motion}, the motion of a body about a fixed point or
fixed axis, as of a planet or pendulum. It is equal to the
angle passed over at the point or axis by a line drawn to
the body.

{Angular point}, the point at which the sides of the angle
meet; the vertex.

{Angular velocity}, the ratio of anuglar motion to the time
employed in describing.


Distance \Dis"tance\, n. [F. distance, L. distantia.]
1. The space between two objects; the length of a line,
especially the shortest line joining two points or things
that are separate; measure of separation in place.

Every particle attracts every other with a force . .
. inversely proportioned to the square of the
distance. --Sir I.
Newton.

2. Remoteness of place; a remote place.

Easily managed from a distance. --W. Irving.

'T is distance lends enchantment to the view. --T.
Campbell.

[He] waits at distance till he hears from Cato.
--Addison.

3. (Racing) A space marked out in the last part of a race
course.

The horse that ran the whole field out of distance.
--L'Estrange.

Note: In trotting matches under the rules of the American
Association, the distance varies with the conditions of
the race, being 80 yards in races of mile heats, best
two in three, and 150 yards in races of two-mile heats.
At that distance from the winning post is placed the
distance post. If any horse has not reached this
distance post before the first horse in that heat has
reached the winning post, such horse is distanced, and
disqualified for running again during that race.

4. (Mil.) Relative space, between troops in ranks, measured
from front to rear; -- contrasted with {interval}, which
is measured from right to left. ``Distance between
companies in close column is twelve yards.'' --Farrow.

5. Space between two antagonists in fencing. --Shak.

6. (Painting) The part of a picture which contains the
representation of those objects which are the farthest
away, esp. in a landscape.

Note: In a picture, the

{Middle distance} is the central portion between the
foreground and the distance or the extreme distance. In a
perspective drawing, the

{Point of distance} is the point where the visual rays meet.

7. Ideal disjunction; discrepancy; contrariety. --Locke.

8. Length or interval of time; period, past or future,
between two eras or events.

Ten years' distance between one and the other.
--Prior.

The writings of Euclid at the distance of two
thousand years. --Playfair.

9. The remoteness or reserve which respect requires; hence,
respect; ceremoniousness.

I hope your modesty
Will know what distance to the crown is due.
--Dryden.

'T is by respect and distance that authority is
upheld. --Atterbury.

10. A withholding of intimacy; alienation; coldness;
disagreement; variance; restraint; reserve.

Setting them [factions] at distance, or at least
distrust amongst themselves. --Bacon.

On the part of Heaven,
Now alienated, distance and distaste. --Milton.

11. Remoteness in succession or relation; as, the distance
between a descendant and his ancestor.

12. (Mus.) The interval between two notes; as, the distance
of a fourth or seventh.

{Angular distance}, the distance made at the eye by lines
drawn from the eye to two objects.

{Lunar distance}. See under {Lunar}.

{North polar distance} (Astron.), the distance on the heavens
of a heavenly body from the north pole. It is the
complement of the declination.

{Zenith distance} (Astron.), the arc on the heavens from a
heavenly body to the zenith of the observer. It is the
complement of the altitude.

{To keep one's distance}, to stand aloof; to refrain from
familiarity.

If a man makes me keep my distance, the comfort is
he keeps his at the same time. --Swift.