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Celestial Sphere
Until now, we have not considered the rotation of the Earth around its axis. Let’s imagine an astrologer is in the Earth’s northern hemisphere. He sees a small portion of the Earth’s surface around him, bounded by the local horizon.
Due to humans’ small size compared to the Earth, the astrologer perceives the local ground surface as flat. The observer and his local horizon rotate with the Earth around the axis of the Earth’s rotation.
Now, let’s place the astrologer along with the rotating local surface at the center of the world. The observer will perceive the world as if the heavens are revolving around him while he remains stationary. The astrologer will observe a celestial sphere rotating around an axis coinciding with the axis of the Earth’s rotation. All the stars, the planets, and the degrees of the zodiac circle rise on the eastern horizon and then set in the west. Such a daily motion, connected with the rotation of the celestial sphere, is called a primary motion in contrast to the secondary motion of the planets along the zodiac circle. In the picture below, you see the moment when 0 Aries ascends right to the East. A few hours before it, 0 Capricorn ascends much closer to the South.
The power of gravity, which rotates the Earth (and consequently the heavens from the observer’s perspective), is called the Primum Mobile.
In the Northern Hemisphere, the axis of rotation of the celestial sphere points to the pole star.
The further north a person is, the higher the pole star appears. The closer he is to the equator, the closer the pole star is to the horizon. Strictly speaking, the angle of deviation of the axis of rotation of the celestial sphere coincides with the astrologer’s geographic latitude. When the astrologer is at the Earth’s equator, this angle is 0; when he is at the North Pole, this angle is 90 degrees, and the pole star is directly overhead.
Equinoxes and Solstices from the Observer's Perspective
The zodiacal circle rotates along with the celestial sphere. Its northernmost point is 0 degrees Cancer, and its southernmost is 0 degrees Capricorn.
- When the Sun is at 0 degrees Cancer, the Sun’s daily path from sunrise to sunset is much longer than the short path from sunset to sunrise, making the day significantly longer compared to the short night. It is called the summer solstice.
- When the Sun is at 0 degrees Capricorn, the opposite effect occurs — the night is significantly longer, and the day is very short. It is called the winter solstice.
- When the Sun is at the points 0 degrees Libra or 0 degrees Aries, the Sun’s daily path above the horizon and below the horizon coincide. It is called the equinox.
Cardinal Signs and Mystical Cults
The signs Aries, Cancer, Libra, and Capricorn are called cardinal. Notably, many religious and mystical cults are associated with moments when the Sun ingress into these signs.
If you observe the Sun’s daily motion every autumn day, the path from sunrise to sunset progressively further southhward while the Sun approaches 0 Capricorn. The day will become shorter and shorter.
The closer the Sun gets to 0 degrees Capricorn, the slower the movement of its daily path southward will be. Near the point of the winter solstice, the Sun’s daily path will seem to “freeze” in its northernmost position for 3 days. That is why we call that point winter solstice.
When the Sun passes through 0 degrees Capricorn, its daytime trajectory will shift back southward, increasing the length of the day.
The observer perceives the Sun’s passage through 0 degrees Capricorn as the three shortest days, during which the Sun’s daytime arc remains in its northernmost position. You may track the same idea in many religious cults—darkness engulfs the supreme god for three days, after which the god resurrects again.
Another example. You may notice that some ancient temple structures had a narrow entrance that was strictly oriented towards the east. It was not accidental.
As you can see from the illustration above, when the Sun is at the point of equinox, it rises directly in the east. The rays of the rising Sun penetrate the narrow entrance of the temple structure, fully illuminating the sacred altar located opposite. It was a signal from the heavens of the onset of the new astronomical year.
