Related Words

Angles: The Ascendant, Descendant, Midheaven and Imum Coeli; the four cardinal points in a horoscope.

Eulerian Angles: a set of three angles that define an orientation, or direction, in space. It goes back to the mathematician Euler, and was used to describe motions in celestial mechanics.

Triangles: An image to suggest the internal and external oblique abs, which run on opposite diagonals across the front of your torso. Visualize two triangles: The first triangle uses the horizontal lin . . . View Full Definition

Camera Angles: Various positions of the camera with respect to the subject being photographed, each giving a different viewpoint and perspective.

Three-Dimensional Projection Matching: a method of refinement in reconstructing single particles from their projections [Penczek et al., 1994]. A preliminary 3D map, obtained by random-conical reconstruction or angular reconstitu . . . View Full Definition

Polarization: The orientation in space of the electrical axis of a radar wave. This electrical axis which is at right angles to the magnetic axis may be horizontal, vertical, or circular. With circular po . . . View Full Definition

Shadow Sector: A sector on the radarscope in which the appearance of radar echoes is improbable because of an obstruction near the antenna. While both blind and shadow sectors have the same basic cause, bl . . . View Full Definition

Angular Reconstitution: a common-lines method designed to determine the relative angles between three projections of an object with arbitrary symmetry [van Heel, 1987a]. The method works on the basis of comparing s . . . View Full Definition

Reflection: The return of all or part of a sound beam when it encounters the boundary between two media. The most important rule of reflection is that the angle of incidence is equal to the angle of ref . . . View Full Definition

Evection: A perturbation of the Moon depending upon the alternate increase and decrease of the eccentricity of its orbit, which is always a maximum when the Sun is passing the Moon's line of apsides a . . . View Full Definition