If “always” means in our collective lives, the answer yes. If “always” though means throughout all of time, no. The UK magazine, How it Works, has an illustrative article that explains that because of “precession of the equinoxes” Polaris — i.e.: Alpha Ursae Minoris, commonly called the North Star will not always be north, nor has it always been north.
Is Precession a New Idea?
No, Hipparchus discovered precession somewhere in the 2nd century B. C. The dates are cloudy but we do know that Hipparchos in Greek (the Latinization is what most use) was born in Nicaea, Bithynia [now Iznik, Turkey — see our map to give a fair idea of where along the southern border of the Black Sea that was found. He died around 127 BC in Rhodes Greece. He was Greek astronomer and mathematician who made several fundamental contributions to astronomy and trigonometry. based solely on Ptolemy’s writing in the Almagest more widely known as the pivotal work in the annals of astrology with a geocentric point of view.
The discovery of precessional movement and nutation (wobbling) of the earth around its axis is major finding, so Hipparchos is considered the Father of Astronomy. While he did build upon his predecessor’s theories, it was his calculation of point “γ” at the intersection of the celestial equator on the ecliptic, for the next 26,000 years that is remarkable. This allowed the science of the stars (astronomy & astrology) to develop, and then without internet, snapchat and television he mapped about 1,000 stars in his almanac.
Why does Hipparchus want to go to Y?
Y is not the name of the place, instead Y is a point of reference — it can be anywhere on the globe, but in the sciences such general points are shown by a letter, and in this case Hipparchus chose Y. So Y represents both where he is now and how far from there it is that he wants to go. Here is an example:
- Hipparchos is in Athens. He wants to go to Crete, but he also wants to return to Athens and not get lost. How would he do this? For us we would look at a map and plan our journey. But assume there are not any maps, or worse they are not reliable, an idea similar to trekking in the woods & you do not have a map for your particular forest.So the following questions become pertinent:
- How do you get out of the forest? Do you remember how you got it in? What if it is getting dark and you lost track of time, shadows make landmarks change, would you still recognize them?
- And if you are at sea, or on a flat plane like desert or steep mountains what if there are no landmarks? How do you do return to home then?
To answer all of those question, Hipparchus needed to introduce the idea of “y’ and then figure out how to answer all of those questions. To do this, as in our trekking example, he would need a landmark if he is gone for a short time, or event, that always happens, so he could be sure that it will occur, if the journey is longer than a day. [For us trekking we need to notice some landmarks that every member of the party agrees upon at the outset as a lamppost for our return and this becomes their “Y” .
For Hipparchus “Y” reckoned that “Y” had to be celestial event for longer distances where walking was not feasible and where he would need either a donkey for transportation ( there are neither cars, trains nor buses in Ancient Greece) el, or ships for even longer or more treacherous distance travel. He decides he wants to see the Pyramids and decides to leave from Athens by boat. To do this Hipparchos realizes that “Y” was required and to formulate ‘Y” he needs where it is in the heavens and that requires knowing “Y’s” Declination (latitude) and Right Ascension (longitude) so he can measure from that point (artists do something similar with the sight size method of painting via a plumb line).
The atomic theory was needed too
With his “sky map”, Hipparchus choose as his landmark, the Aries Point or the first day of spring because of its importance in the Greek calendar. He built upon Democritus’s (the father of atomic theory) idea that the earth did not revolve vertically (straight up and down) but rather on a tilt because without one, the sun would always be in the same spot and there would be neither day nor night nor summer or winter.¹
This led to another realization of Democritus, that the earth was not perfectly round but spherical and he calculated we had a tilt of 23.5°. Hipparchus wisely accepted both of Democritus’s theories (that the earth was spherical and on a tilt) noting the Pole Star (Polaris because Athens is in the Northern Hemisphere and it is constant in its sky) on the first day of Spring (the Aries Point) as his “Y”.
What neither of these great men realized, but implicitly assumed, was that there was gravity ² — that magnetic force that is generated close to the Equator and stops the earth from moving this way and that in our galaxy. Gravity is also why we do not fall off. These g-forces (gravitational field or force) occur because of the combination of the Sun’s rays, the Moon and the other celestial planets and that make the Earth’s orbit spin — like a top on a table or in the sky the celestial plane.
While Hipparchos did not know of gravity explicitly, he realized that as a tilted sphere, that the earth must have some type nutative effect (wobbling) that may only happen only periodically, and hen it does happen it causes the precession of the poles to follow a wavy rather than a circular path. Hipparchus called this the “Precession of the Equinoxes” or more colloquially known just as precession. The kicker is that the travel time (rotation around the celestial plane) takes 26,000 years, a time so long that you will not see any discernible difference night to night or in yours or Hipparchus’s lifetime and yet he discovered and explained it. Hence this makes him the Father of Astronomy and Astrology.
In our modern era, meteorologist-astrologer Carl Tobey did a lot of work on the moon wobbling and its effect on weather and its prediction through astrology.
Footnotes:
- This can be tested at home with a flashlight and a bunch of paper scrunched into a ball shape. Hold the ball steady and watch it for a minute. What happens? Nothing, the light always shines in the same spot.
- Now put a pencil in the paper ball and move it around slowly from side to side, and then all the way around. If you do this at a steady rate sunrise and sunset (when the light hits and leaves the ball will always be the same).
- This time tilt the ball on the pencil stick at an acute angle of about 25 degrees and measuring again & you notice sunrise and sunset are not only at different times but it slowly moves up and down the stick — through this experiment you have now emulated precession.
- The discovery of gravity is credited to Sir Isaac Newton (1642-1727).
Our articles are vetted for accuracy. This one was revised on 28 July 2018.
