Modulus is a common mathematical word which indicates the remainder of a division.
Thus:
and so on.
Midpoints Modulus has to do with the mathematical relationships of midpoints to the zodiacal circle. The midpoint positions of each planet are calculated and their longitude converted to degree sof a circle, starting at 0° Aries. This value is then converted to a value modulus.
For example if the midpoint between Sun and Mars is at 12° Gemini, this becomes a value of 72° as 12° Gemini is 72° from 0° Aries. A midpoint between Venus and Saturn that lies at 3° Sagittarius, becomes a value of 243°, as 3° Sagittarius is 243° from 0° Aries.
The value of the midpoint is then divided by the designated modulus value, and the modulus (remainder) value is obtained. This modulus value becomes the new position on the zodiac.
With a modulus of 90° for example, our Sun-Mars example of 72° would not change, as it is less than 90°. Its midpoint modulus 90° is 12° Gemini, the same as the midpoint itself.
With our Venus-Saturn example, 243° is divided by 90, giving it a midpoint modulus 90° of 3° Gemini (63° from 0° Aries).
Similarly, for Midpoints Modulus 45° the midpoint values are first calculated, then their values modulus 45°.
Thus, for a midpoint located in Taurus 16°00' (= 46°00' from 0° Aries) the midpoint modulus 45° will be 1°00'.
Clairvision Virtual Astrologer offers you Midpoints Modulus 360°, 90°, 45°, and 22.5°. There is also a user-defined modulus, which you select through a dialog box.
Clairvision Virtual Astrologer will print the lists of midpoint by planetary sequence (Sun-Moon, Sun-Mer, etc.) and by midpoint sort (from 0° to the modulus.)
Midpoints were first popularized by the German astrologer Alfred Witte in the 1920s, founder of the Hamburg School of Astrology and the Uranian system of Astrology. Besides working with midpoints, Uranian Astrology predicted the existence of several trans-Neptunian planets beyond Pluto's orbit, whose calculated positions were said to feature prominently in the charts of natural disasters.
After Witte's death in 1941 the system of midpoints was further developed by another German astrologer, Reinhold Ebertin. Discarding the hypothetical trans-Neptunian planets, Ebertin called his his system 'Cosmobiology' and became the major proponent of midpoints astrology.
In a chart midpoints can be interpreted in a similar way to other objects. For example the midpoint between natal Sun and Moon is treated by midpoints astrologers as a minor version of a Sun-Moon combination, and to form aspects to the natal and transiting planets just like any other object in the chart.
Witte found that the Mercury/Venus midpoint in the charts of artists was often aspected to the Midheaven, while a Mercury/Venus midpoint aspected to Uranus appeared to indicate mathematical ability. When working with midpoints Witte and his students used only the 'hard' aspects: conjunctions, oppositions and squares, as well as semisquares and sesquisquares.
(Alfred Witte and Hermann Lefeldt, Rules for Planetary Pictures: The Astrology of Tomorrow, 9th edition, 1998)
Beyond Ebertin's own system, the midpoints are of interest for anyone interested in sacred geometry. If you are in quest of sophisticated shapes and of geometrical relationships between planets, then you may want to consult midpoint lists and see how they fit with your calculations.
Midpoints can also be drawn in synastry (comparing 2 charts): one midpoint between the Sun of person 1 and the Sun of Person 2, one between the Sun of person 1 and the Moon of person 2, and so on.
copyright © 2008 Samuel Sagan, Ruth Helen Camden.