Terence Hines - Pseudoscience and the Paranormal

One of the best examples of astrology’s refusal to change in the light of new knowledge is its failure to take into account the astronomical phenomenon of precession. The assignment of certain dates to certain signs of the zodiac (e.g., Aries ruling the period from March 21 to April 19) was made two thousand years ago (Abell 1981a) and has been followed by astrologers ever since. When it is said that the Sun is “in” Aries between March 21 and April 19, this means that the Sun, as seen from Earth, is in the same part of the sky as is the constellation Aries. The correspondences between the twelve constellations of the zodiac and their assigned dates were correct two thousand years ago—but not today. Earth “wobbles” slowly as it rotates, and because of this the position of the Sun relative to the constellations of the zodiac (as seen from Earth) changes over the centuries. By now, the difference is almost one complete sign—so the Sun is not in Aries from March 21 to April 19, but in Pisces for most of that period. Thus, if you are an Aries (born between March 21 and April 19), the sun was almost certainly not in Aries when you were born, but in Pisces! Most astrologers have been making predictions and casting horoscopes for the wrong signs for all these years. Many so-called tropical astrologers are aware of precession but choose to ignore it, arguing that somehow the “signs remember the influence of the constellations that corresponded to them two thousand years ago” (p. 86). This does not explain “why those same signs do not also recall the influence of other constellations that corresponded with them in even earlier millennia” (p. 86).

Astrologers claim that astrology is a science. When confronted with the fact that their “science” has hardly changed at all in the last two thousand years, they respond that astrology was so well established twenty centuries ago that there has never been any need to change, in spite of the vast changes that have taken place in our knowledge of the universe over the same period of time. Linda Goodman, best-selling author of popular books on astrology, sums up the astrologers’ position by saying, “Alone among the sciences, astrology has spanned the centuries and made the journey intact. We shouldn’t be surprised that it remains with us, unchanged by time—because astrology is truth—and truth is eternal” (Goodman 1971, p. 475).

Unfortunately for astrologers and their “ancient truths,” these “truths” are not true. The best example is the ancient astrological teaching that there are only seven heavenly bodies, other than Earth, in the solar system—the Sun, the Moon, Mercury, Venus, Mars, Jupiter, and Saturn. All ancient astrological teachings, the same that have been handed down to the likes of Linda Goodman, had this as a basic tenet. Unfortunately, it is totally wrong. Three additional planets have been discovered since the eighteenth century—Uranus in 1781, Neptune in 1846, and Pluto in 1930. These planets, which can be seen only through telescopes or binoculars, were unknown to the ancient astrologers.

The ability to derive, test, and verify or falsify predictions is one of the most important characteristics of science. Astrologers never predicted the existence of the three outer planets, and never even had the slightest hint that the planets existed—until astronomers discovered them. On the other hand, astronomers predicted the existence of Neptune twelve years before it was first identified through observation, and also predicted with great accuracy just where in the sky it could be found. It is in the discovery of Neptune that the contrast between the pseudoscience of astrology and the science of astronomy is most clearly seen. The exciting intellectual detective story of the discovery of Neptune is told in detail in Grosser’s The Discovery of Neptune (1962) and Standage’s The Neptune File (2000). It will be briefly summarized here to further highlight the differences between astrology and astronomy.

The prediction of the existence of a planet beyond Uranus was based on observed irregularities in Uranus’s orbit. Uranus was discovered in 1781, and astronomers noted almost at once that its orbit was irregular and could not be predicted with the same ease as the orbits of the other planets. In 1834 the British astronomer Thomas Hussey was the first to suggest that the perturbations of Uranus’s orbit were caused by the gravitational influence of an as-yet-unknown planet (Grosser 1962). In the early 1840s two young scientists, the English mathematician John Couch Adams and the French astronomer Urbain Jean Joseph Leverrier, independently began working on the problem of Uranus’s orbit with the goal of finding the unknown planet that was responsible for the perturbations. Their predictions were tested in 1846, and the previously unknown planet was found to be almost exactly where Adams and Leverrier had said it would be found.

Today, astrologers claim to understand the astrological influences of the three new planets. The addition of the new planets didn’t even cause much fuss among astrologers when they were discovered (Culver and Ianna 1984). But for nearly two thousand years, apparently not one astrologer ever noticed a planetary influence where there was no known planet, or was able to predict the existence or location of additional planets. Again, the history of astrological practice is inconsistent with the astrologers’ claims that astrology is a precise science. If, as astrologers claim, each planet has an influence on human behavior, even a small one, and if that influence varies according to where the planet is located, then predictions of at least the existence of the new planets should have been made long ago. But one will search the writings of Ptolemy and later astrologers in vain for any hint of such a prediction.

Goodman (1968) explains astrology’s failure to note the influences of the three “new” planets before their discovery by saying that a planet doesn’t have any astrological influence until it is discovered!

Astrologers are now claiming that there are more than nine planets in the solar system, apparently not wanting to be left out in the cold again should an additional planet be discovered. A favorite of astrologers is a planet called Vulcan that is said to orbit the Sun inside the orbit of Mercury. In 1968 Goodman said of this planet, “It’s important to mention here the still unseen planet Vulcan, the true ruler of Virgo, since its discovery is said to be imminent…. Many astrologers feel that Vulcan, the planet of thunder, will become visible through telescopes in a few years” (p. 203). Well, more than a few years have passed, and no one has yet seen Vulcan.

Actually, the idea of Vulcan is an old one that astrologers latched onto long after it was abandoned by the astronomers who first proposed that such a planet might exist. Vulcan was proposed to account for deviations in the orbit of Mercury, using the same logic that led Adams and Leverrier to hypothesize the existence of Neptune. In fact, it was Leverrier who in 1859 published a prediction about where Vulcan would be found. In the next few years sightings of the planet were made, but these were due to “hoaxes or wishful thinking at the telescope” (Culver and Ianna 1984, p. 164) and could not be confirmed. It is another important characteristic of science that incorrect predictions are recognized as such and dropped; astronomers wasted no further effort on Vulcan after it had been shown not to exist. The deviations in Mercury’s orbit turned out not to be due to the effects of a planet, but are explained by the General Theory of Relativity. The fascinating story of the search for Vulcan, the erroneous sightings of the planet and the final resolution of the deviation of Mercury’s orbit by Einstein is told by Baum and Sheehan in their excellent In Search of Planet Vulcan (1997).