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Encyclopaedia Britannica, 11th Edition, "Equation" to "Ethics": Volume 9, Slice 7Various

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Encyclopaedia Britannica, 11th Edition, "Equation" to "Ethics": Volume 9, Slice 7

Name: Encyclopaedia Britannica, 11th Edition, "Equation" to "Ethics": Volume 9, Slice 7
Author: Various

Various

Encyclopedias and dictionaries

[4] The square root of [alpha] + [beta]i can be determined by the
    extraction of square roots of positive real numbers, without the
    trigonometrical tables.




EQUATION OF THE CENTRE, in astronomy, the angular distance, measured
around the centre of motion, by which a planet moving in an ellipse
deviates from the mean position which it would occupy if it moved
uniformly. Its amount is the correction which must be applied positively
or negatively to the mean anomaly in order to obtain the true anomaly.
It arises from the ellipticity of the orbit, is zero at pericentre and
apocentre, and reaches its greatest amount nearly midway between these
points. (See ANOMALY and ORBIT.)




EQUATION OF TIME, the difference between apparent time, determined by
the meridian passage of the real sun, and mean time, determined by the
passage of the mean sun. It goes through a double period in the course
of a year. Its amount varies a fraction of a minute for the same date,
from year to year and from one longitude to another, on the same day.
The following table shows an average value for any date and for the
Greenwich meridian for a number of years, from which the actual value
will seldom deviate more than 20 seconds until after 1950. The + sign
indicates that the real sun reaches the meridian _after_ mean noon; the
- sign _before_ mean noon.

  _Table of the Equation of Time._

            m. s.            m. s.           m. s.
  Jan.  1  +3  26  Mar.  1 +12  39  May  1  -2  55
        6   5  45        6  11  35       6  -3  27
       11   7  51       11  10  20      11  -3  46
       16   9  43       16   8  58      16  -3  51
       21  11  19       21   7  30      21  -3  40
       26  12  36       26   5  59      26  -3  16

  Feb.  1 +13  42  Apr.  1  +4   9  June 1  -2  32
        6  14  14        6   2  40       6  -1  44
       11  14  25       11  +1  15      11  -0  48
       16  14  17       16  -0   3      16  +0  14
       21  13  52       21  -1  12      21   1  19
       26  13  11       26  -2  10      26   2  24

  July  1  +3  26  Sept. 1  +0   9  Nov. 1 -16  18
        6   4  21        6  -1  28       6 -16  19
       11   5   8       11  -3  10      11 -15  58
       16   5  44       16  -4  55      16 -15  15
       21   6   8       21  -6  41      21 -14  12
       26   6  18       26  -8  25      26 -12  49

  Aug.  1  +6  10  Oct.  1 -10   5  Dec. 1 -11   7
        6   5  47        6 -11  38       6 - 9   9
       11   5   9       11 -13   2      11 - 6  57
       16   4  17       16 -14  14      16 - 4  35
       21   3  12       21 -15  11      21 - 2   7
       26   1  55       26 -15  52      26 + 0  23

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Encyclopaedia Britannica, 11th Edition, "Equation" to "Ethics": Volume 9, Slice 7

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