Search results
Results from the WOW.Com Content Network
is the number of days since Jan 1st, 2000 12:00. is the Julian date; 2451545.0 is the equivalent Julian year of Julian days for Jan-01-2000, 12:00:00. 0.0008 is the fractional Julian Day for leap seconds and terrestrial time (TT). TT was set to 32.184 sec lagging TAI on 1 January 1958. By 1972, when the leap second was introduced, 10 sec were ...
A mean solar day (what we normally measure as a "day") is the average time between local solar noons ("average" since this varies slightly over a year). Earth makes one rotation around its axis each sidereal day; during that time it moves a short distance (about 1°) along its orbit around the Sun.
On a prograde planet like the Earth, the sidereal day is shorter than the solar day. At time 1, the Sun and a certain distant star are both overhead. At time 2, the planet has rotated 360° and the distant star is overhead again (1→2 = one sidereal day). But it is not until a little later, at time 3, that the Sun is overhead again (1→3 = one solar day). More simply, 1→2 is a complete ...
The equation of time is obtained by substituting the result of the right ascension calculation into an equation of time formula. Here Δ t ( M ) = M + λ p − α [ λ ( M )] is used; in part because small corrections (of the order of 1 second), that would justify using E , are not included, and in part because the goal is to obtain a simple ...
Daytime or day as observed on Earth is the period of the day during which a given location experiences natural illumination from direct sunlight. Daytime occurs when the Sun appears above the local horizon, that is, anywhere on the globe's hemisphere facing the Sun. In direct sunlight the movement of the sun can be recorded and observed using a ...
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
A calendrical calculation is a calculation concerning calendar dates. Calendrical calculations can be considered an area of applied mathematics. Some examples of calendrical calculations: Converting a Julian or Gregorian calendar date to its Julian day number and vice versa (see § Julian day number calculation within that article for details).
At local midnight the summer Sun culminates at 3.44°. Said another way, it does not set; it is the polar day. Solstice day arcs as viewed from either pole (90° latitude). At the time of the summer or winter solstices, the Sun is 23.44° degrees above or below the horizon, respectively, irrespective of time of day.