Eclipse Chaser Terminology -- A -- Alt-Azimuth - Altitude and
Azimuth - a way to express spherical coordinates. Normally in
degrees. Allais Effect - Allais Effect - an anomalous change
sometimes observed in a pendulum during a solar eclipse. First
reported by Maurice Allais in 1954 and observed again during the
1959 eclipse. Repeating the observations has not met with
consistent results thus the anomaly remains in question. Angular
size - Angular size - the size of something in sky is typically
expressed in terms of degrees. You can think of the visible sky
as 180 degrees. From the horizon to over head is ninety degrees.
Annular Eclipse - Annular Eclipse - A solar eclipse where the
angular size of the moon is smaller than the angular size of the
sun's photosphere. The umbra shadow of the moon does not touch
the surface of the Earth. Aperture - Aperture - The size of the
light gathering lens or mirror. Typically expressed in
millimeters or inches. Aphelion - Aphelion - the furtherest
possible point in the Eart