Today’s issue of Nature contains a letter from a Physics prof, who has found a very creative way to both teach newtonian physics and debunk Astrology!

(he doesn’t, however, indicate that it was James Randi who first developed the technique he is using, or that the proceedure is also described in the book “how to think about wierd things.” It may simply be that smart people think alike.)

Nature 447, 528 (31 May 2007) | doi:10.1038/447528a; Published online 30 May 2007. Treating astrology’s claims with all due gravity. Steven K. Lower

“I teach an introductory science class at my university, which typically enrols many non-science majors. During a lecture on the gravitational force, I imply that if planets such as Mars exert a force on any object, including humans, then perhaps there is something to astrology’s idea that celestial bodies exert a force of influence on our lives. I encourage my students to undertake a test I have designed for this notion.

I present the students with 12 randomly numbered horoscopes from the previous day, with the corresponding signs of the zodiac removed. I ask each student to record the horoscope that best describes the day she or he had, and the astrological sign (for example, Aries) corresponding to her/his birthday. My scientific hypothesis is that planets may exert a force on our bodies, but it is purely random — 1 out of 12 (8.3%) — whether a horoscope foretells the events of one’s life.

I am pleased to report that, as Shawn Carlson has noted, “astrology failed to perform at a level better than chance” (Nature 318, 419–425; 1985). The results from my classes are: 8.0% (n = 163 students), 8.4% (n = 155), 7.0% (n = 143), 8.0% (n = 138) and 8.0% (n = 100). In other words, as John Maddox has commented “astrology is a pack of lies … There is no evidence that the positions of the planets can affect human behaviour” (Nature 368, 185; 1994)./”

Cool video of Mr. Randi in a classroom, doing a similar exercise:

Posted by Gwen Pearson

Writer. Nerd. Insect Evangelist. Have you heard the good news? BUGS!


  1. I just realized–I did this same/similar exercise in my class for years, and I never thought to write it up for NATURE.

    God Damn It!

  2. I know how you feel. That whole “E=MC2” thing was my idea. Oh, well. Back to work on how to figure out some kind of relationship between the sides of this darn right triangle!

  3. It’s more the lost opportunity for a paper in Nature that I’m kicking myself for, rather than any ownership issues.
    I never think of these things until after someone else publishes them. Hence, my lackluster vita.

  4. Hey, Buggie, no offence, you know I really like you (and I’m glad I found your blog (okay, Phil Plait linked to it)), but astrologers are going to tear this argument to shreds. All this guy has done is debunked sun-sign astrology, which most astrologers say is bogus anyway.

    Not to toot my own horn, but my debunking of astrology is here:

    I start out with sun-sign astrology, and then I use the words of an actual astrologer to go beyond that into issues of the zodiac, precession, etc., and finally end up citing a study that DOES prove that ALL astrology is bunk.

    It’s kind of raw; it’s the first one I did. But I’m still pretty proud of it.

  5. Right, most astrologers think sun sign astrology is bunk except for the many thousands who swear by it. And let us not forget the millions of daily newspaper readers who check theirs out every day. Do we really need a study to prove that astrology is bogus? Whatever happened to good old fashioned plausibility?

  6. Hey! This was mentioned by Mr. Randi in his newsletter!

    Welcome Skeptics! :D

  7. Clark: No, we don’t NEED one, but isn’t it great to have?

    The time-twins study ABSOLUTELY nixes ANY possibility of ANY kind of astrology working.

    (Yeah, I guess it was Randi and not Phil who linked here…that’s what I get for reading one right after the other.)

  8. Thanks for the welcome – I did come via this week’s Swift. :-)

    Nice post!

  9. Actually, this works really, really well in the classroom Shane. I think you aren’t taking the “peer pressure” factor in account for teenagers.
    Of course, no, it wouldn’t work at a psychic conference. But really–nothing would. Evidence isn’t what it’s all about for them.

  10. Unfortunately, for the “true believers” even this blatant kind of evidence is not enough. Back when I was in high school (back in 1997… YIKES!) something similar to this was done in my physics class. Unfortunately, there were these two people in the class that just couldn’t come to grips with the fact that their entire belief system was debunked right in front of their eyes. I guess some people are just unconvertible?

  11. Sadly enough, many people are uncovertible. However, the people who do need to be converted are those who may seem under the impression (like an ex of mine) that astrology (and other psuedoscience) is actually scientific.

    I dimly recall Asimov or Clarke writing of a taxi driver that believed crystalogy (or whatever it’s called) was supported by science. This comes partly through a misunderstanding of the meaning of science. It is that sort of person who will listen to your debunking.

  12. Another visitor from the Swift Newsletter here. We did a slightly similar exercise in my High School Physics class, where we calculated whether or not distant celestial bodies (I think we used Mars or Jupiter) had a gravitational effect on humans at the moment of their births. The numbers came out positive and looked significant, thus lending some credibility to Astrology.

    We then proceeded to do another calculation to utterly debunk it: the gravitational effect on you at your birth of the doctor delivering you. Once you see the huge difference in orders of magnitude, the idea that Mars being in the seventh house has more to do with your development than the weight and proximity of your delivery doctor suddenly seems pretty ludicrous.

  13. X the Unknown June 14, 2007 at 4:01 pm

    @Shane Killian: “The time-twins study ABSOLUTELY nixes ANY possibility of ANY kind of astrology working.”

    Well, not quite. To be properly scientific about it, we must say that it nixes any possibility of Natal astrology working.

    Astrology as a propituousness tool (e.g. “The Gods say next Wednesday at 2:00 PM is the best time to start the project”) still need a good debunking.

  14. X the Unknown June 14, 2007 at 4:07 pm

    @Tom Foss

    Do you know of any studies about the effects of planetary-positions on Solar Effulgence (radiance/brightness), Sunspots, Solar Flares, etc?

    Of course, if there are any at all, it probably mostly consists of “where is Jupiter?”, as all the rest of the planets combined mass less than our main gas giant.

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