Astrology is a pseudoscience that imagines the places where the sun, moon and planets were when a child was born affect that child’s character and destiny. Very many proper scientific studies have shown that astrology doesn’t make sense.
The gravity of the planet Mars for example has less effect on a newborn child than the gravity of the doctor that delivers the child. Astrologers have to imagine that any emanation from a planet is stronger than gravity but despite its strength hasn’t been detected. Astrologers also should explain why these supposed emanations affect a child at birth but not when the child is in the womb. The brick, concrete and other material that makes a hospital or other building where a child is born don’t shield that child from astrological influences but somehow it seems to be assumed, the mother’s body does shield the child before birth.
Astrologers can get around that difficulty by claiming that it works by cosmic forces that have yet to be discovered. But it fails empirically also. Astrology apologists claim that the stars incline, but they do not compel (Latin: astra inclinant, non necessitant). But there is a field of mathematics for testing for influences that incline without compelling: statistics. Astrological predictions have yet to show statistical significance.
Professor Steve Farmer has argued in Neurobiology, layered texts, and correlative cosmologies: A cross-cultural framework for premodern history and elsewhere that "correlative cosmologies" were common before modern times. They associate members of various sets of entities, like astrology associating celestial and terrestrial ones. A past one was the medieval Western doctrine of signatures. It states that medicinal plants resemble parts of the body that they most useful for. Thus, liverwort is good for liver diseases because of its liver shape. The Wu Xing (Five Elements / Phases / Agents / Movements / Processes / Stages) was developed in China. It correlates sets of five of materials, elements, planets, cardinal directions, colors, shapes, seasons, etc. Astrology is thus the main survivor of a lost world of woo-woo.
Astrology's greatest "scientific triumph" is likely Francesco Sizzi's "demonstration" that Jupiter's four big moons cannot exist. He noted that the seven traditional planets correspond to the seven openings in the human head, the seven days of the week, the seven metals, etc. Those moons would disrupt that correlation.
Astrology does harm if people do things like planning their families to get their children born under particular star signs. If people believe that everything is decided by positions of whatever when they were born they may not do enough to put right what’s wrong in their lives.
One author thinks people choose to believe astrology because they imagine it gives them a system where things are predicted but doesn’t have the rules and priests requiring obedience and other difficulties with conventional religion.
- Astrology: Fraud or Superstition?
- Astronomical Pseudo-Science: A Skeptic's Resource List (Version 3.0; August 2003)
- Activities with Astrology