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Episode 6: Astrology Basics and a (Non-?)Changing Sky

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Recap: Astrology is an ancient science about the predictive power of the heavens. But put under a modern light, what are its inherent contradictions, observational problems, and what do statistical studies show?

Puzzler: An astrologer claims, "Venus will make a rare planetary loop above the Orion [constellation]." What is she talking about?

Solution to Episode 5's Puzzler: To understand why the fourth option is the fastest method, you need to go back to the discussion of how heat is transferred. With heat going into the frozen chicken without cooking it, on Earth, we're left mainly with conduction where heat is transferred from one object to another by physically touching. Options 1, 2, and 3 are fairly straight-forward conduction problems. The difference between placing it in a refrigerator or on the kitchen counter is that room temperature is warmer than the refrigerator, so placing the chicken on the counter will defrost it faster than in the refrigerator.

The difference between 2 and 3 has to do a lot with the density of the material - air or water - that is touching the chicken. The water is denser and so will be able to transfer more heat to the chicken faster than the air can, defrosting it more quickly. So far 3 is better than 2, then.

The difference between 3 and 4 is that you get to mix conduction and convection. A steady stream of water running over the chicken will both transfer heat to the chicken, cooling the water down, but then that cooled water goes down the drain and you have more water at that original temperature transferring more heat to the chicken. This is as opposed to the third method where the same pool of water will cool down with the chicken in it and thus not defrost as quickly an hour from when you began. Therefore the fourth option is the fastest.

A really easy experiment you can do to see this effect is the following: Take four ice cubes of the same size. Put one in a small bowl in the refrigerator, one in a small bowl on the counter, one in a small bowl with water, and then one in a plastic cup with a hole in the bottom and run water over it. See which one melts the fastest!

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It's actually hard to nail down a single astrology claim because there are almost as many ideas as there are astrologers. What they CAN agree on is that astrology is the idea that the positions of planets, stars, the sun, moons, asteroids, etc. can be used to describe someone or something and to predict the future.

Now, within this episode, I'm not going to go into huge detail on the historical background, nor am I going to go through and "debunk" a particular astrologer. Rather, I'm going to discuss many of the inconsistencies, disagreements among astrologers, and how many claim its supposed to work and why they're wrong.

I should also state at this point that I'm talking about western astrology in this episode, not Eastern. So, no, I'm not going to talk about if you're born in the Year of the Boar nor where you fit on the Vedic zodiac. The system I'll be talking about is that codified by Ptolemy in the second century AD, though that itself was based on Babylonian tradition., and while it focuses somewhat on sun-sign astrology, it's applicable to both sun- and star-signs.

I'm going to organize this episode a little differently this time, going through the background information when it's relevant for each one.

Basic Idea: Historical Correlations

It's hard to really get an idea of what astrologers think astrology is in detail. You get ten in a room and ask them and you'll have twelve different answers.

That said, the majority opinion seems to be that at a basic level, astrology is a correlational system. If Jupiter appears to be at a certain location in the sky and something bad happens, then astrology predicts that something bad will happen the next time Jupiter is in that location in the sky.

It gets MUCH more complicated when you add in more planets, prograde and retrograde motion, houses, squares, and other things, but really at a BASIC level, that's what most western astrology is.

So when you really get down to it, astrology relies upon knowing where celestial objects are relative to other ones.

To Precess?

This brings up an interesting issue and one that has the astrological community disagreeing with each other, and that's the issue with precession. "Precession" is the process where Earth's axial tilt will stay at the same angle, but it will point in different directions. To understand this in words, you first need to picture Earth going around the sun in a circular path. The north and south poles of Earth - its spin axis - is tilted by about 23.5° relative to that orbital path. This 23.5° is Earth's orbital inclination. Throughout the entire time it orbits the sun, that angle does not change, and the north and south poles stay pointed at the same points in space.

Precession is where the angle stays the same, but the place the poles are pointing will slowly move. It takes roughly 26,000 years for Earth's axis to fully precess.

There are consequences to precession. For example, you may have heard that when the pyramids in Egypt were built, Thuban was the North Star. This is because of precession. The very bright star Vega will be somewhat close to the North Star in about 12,000 years.

What this also means is that the sun will appear to be in a different location relative to the stars on a given date during the year. So if you know your "sun sign" for horoscopes, you probably noticed that the dates for that sign don't actually coincide with when the sun is in that constellation. That's because the sun WAS there way back when western astrology was codified, but because it's been a few thousand years, precession has changed this.

Hence we get into the debate of whether an astrologer should take into account precession - so where things ACTUALLY ARE IN THE SKY TODAY - versus not taking into account precession - or where things WERE IN THE SKY THOUSANDS OF YEARS AGO.

To those of you who are science-minded, or rational thinkers, or base anything on observations, this may seem like an obvious choice: Of course things should be analyzed based on where they are now.

Take the following example: As this podcast comes out on the first of October, 2011, the planet Venus is smack dab in the middle of the constellation Virgo, the virgin. But if we ignore precession, Venus is a constellation away in Libra, the scales. I would think this would give you a different interpretation of what to predict.

Similarly, last summer, Mars was squarely in the constellation Leo. But if you ignore precession, it was in Virgo. That's the god of war being in the heart of the lion versus the belly of the virgin. If this were an actual science that made unambiguous predictions, we wouldn't have different astrologers arguing about whether to include precession or not. It would be very obvious very quickly.

Remember: Astrology claims to predict things based on where an object in the sky is relative to other objects based on what happened last time.

If You Don't Precess, How Do You Have Different "Ages?"

The issue of precession raises another question, and this is a contradiction for most western astrologers that they seem to ignore.

I would guess that the VAST majority of everyone has heard of the "Age of Aquarius" and hence other astrological ages. If for no other reason than the song about the "Dawning of the Age of Aquarius." But, since "Big Astronomy's" last check bounced, I don't have a budget to play that for you now.

Different astrological ages RELY upon precession. They are DEFINED as being what constellation the sun is in on the Spring equinox in the northern hemisphere. This year, and indeed over the past thousand years, the sun is in Pisces, the fish, constellation on March 21. Roughly in 300 B.C., it was in the constellation of Ares. In around 2675, it will be in Aquarius. All of this is based upon accurately taking into account precession as well as using the constellation boundaries as defined by the International Astronomical Union in 1930.

Now right there, I do realize that an astrologer listening to this is going to go "A-ha!" because I mentioned the constellation boundaries according to the International Astronomical Union. This is actually a point I am perfectly willing to concede to astrologers because the constellation boundaries are entirely arbitrary.

It is true that astrologers define them differently, as they divide the sky into 12 equal parts and put the 12 classic Zodiacal constellations in those 12 equal divisions. Astronomers don't. Virgo is much larger than Cancer and Pisces is much wider than Aries. Again, I'm willing to give the astrologers this one.

But again, the ONLY reason that the sun would be in a different constellation on a given day from one year to the next is precession. So for an astrologer to "believe" in different ages based on where the sun is on the Spring equinox relative to the constellations, they HAVE to take into account some form of precession, which most western astrologers don't, but then they don't have different ages, except they do have different ages, but their predictions don't take into account precession, but their ages do, but their predictions don't, but their ages do, but ...

No Mechanism

Sorry about that. I had to force-quit an infinite loop there. So far in this podcast I've discussed what astrology claims to be and then the issue of precession and internal and observational inconsistencies. Now we get into the issue that most skeptics as well as most astronomers know best in terms of complaints: There is no mechanism for astrology to work.

This is true, but this is personally not my favorite method of analyzing and quote-unquote "debunking" astrology because in science, we will not infrequently have observations for which there is no known mechanism at the time. A good example is Kepler's Three Laws of Planetary Motion that I discussed in the first and second episode. Kepler developed these laws based upon observations of the positions of the planets, but there was no actual known mechanism at the time. It was when Newton came along and developed the theory of gravity that physicists were able to give a theoretical backing to Kepler's Laws.

So, it's not impossible that some theoretical mechanism for astrology could be determined at some future time. That's if astrology actually worked ... more on that later. But it is true that at the moment there is absolutely positively no physical mechanism for planets and moons and their positions relative to other ones in the sky to affect people through any known force.

To briefly go into this - since many many other people have in the past - there are four fundamental forces as modern physics understands them. The Strong and Weak nuclear forces only operate at atomic scales and have absolutely nothing to do at the scales of inches, let alone billions of miles. The other two are the electromagnetic and gravitational. The problem for astrology with both of these is that their relative strength decreases with the square of the distance. What this means is that if I'm twice as far away from the sun, its gravitational pull on me is only 1/4. If I'm 10 times farther away from the sun, the pull is 1/100.

And the distance between objects in the sky and Earth is, well, astronomical. The moon's gravitational force on Earth is MANY times that of the other planets -- in fact it's about 100x that of Jupiter, 1000x that of Saturn, and 5000x that of Mars. The sun is about 180x stronger than the moon. Distant stars, asteroids, Pluto ... these wouldn't even be a blip.

So what these boil down to is that there is no known force that could affect us the way astrologers claim these objects do. We don't have a force that is stronger from Jupiter than the Sun that is also dependent upon where it appears relative to other stars and the direction in which it's traveling that also has as much of an effect from Ceres or Pluto during a Void Moon.

No Big Predictions Based on What to Include

Speaking of Pluto and Ceres, this brings us to the point in the podcast where I talk about how astrologers haven't made predictions. No, I don't mean predictions like you see in horoscopes in the Sunday paper, I mean predictions about astronomy. After all, if the entire mechanism of astrology is that things happen because of where objects appear to be relative to other ones, then it stands to reason that they should be able to predict where an undiscovered body in the solar system may be based upon inaccurate predictions over time. After all, this was how astronomers found Neptune ... but that's a subject for a future podcast.

But no, astrologers didn't do this. In fact, they were slow to adopt the new planet discovered in the 1800s, and after being criticized, they jumped on the quote-unquote "discovery" of Planet Vulcan, the planet closest to the sun. Haven't heard of it? That's because it doesn't exist, or at least has never actually been detected. But when some astronomers around that time claimed to have discovered it, many astrologers jumped on it and started to include it in astrologic charts.

And today, there's still no real agreement on what to actually include in the charts. Some astrologers include Pluto, others don't. Some include Ceres, others don't. Some even include the dwarf planets beyond Pluto, like Eris or Haumea or Makemake. And some include the even more distant object Sedna.

If astrology were a real science, there would be a set of things to include. It's like one group of rocket scientists ignoring Earth's gravity, another ignoring the moon's, another ignoring Jupiter and all the asteroids, and another ignoring the sun's all when trying to plan a mission to Saturn.

"But It Works!"

This brings us to the final claim, "But it works!" In itself, this would actually be a valid claim and it should be examined. After all, if something is real and works, in some sense it doesn't matter if we can't explain it -- in fact, that's what science IS, it is a framework to use to develop a model to explain observations.

So, if astrology DOES work, then everything I said before doesn't matter since it just means that those things can't be used to explain how it works and we would need to look for something else. And, that would be really neat, to create a new science based on what had been considered a paranormal phenomenon.

Unfortunately for astrology, it DOESN'T work. The VAST majority of astrological claims are incredibly vague and non-specific. Here's an example of Bull ... I mean, Taurus: "This suggests that the Moon in Virgo today influencing your solar 5th House of love, romance, and fun, do something to unwind and have fun, don't worry so much." [from]. It's kinda like a fortune cookie. Here's another example: "Your great energy is perfect for social events today, so grab a friendly companion and head out to that party or nightclub for some good times. Things should go your way if you're part of a group." [from]. Or: "Your headstrong nature may lead you astray unless you temper it with your more pragmatic side." [from me].

Is there any real difference in these? Not really. All three are vague and have weasel words like "suggests," "if," and "unless." All three would apply to anyone regardless of when they're born. And the first two were taken from supposedly very reputable websites -- the first being Terry Nazon the World Famous Celebrity Astrologer, the second from I wrote the last one.

With these in mind, there HAVE been a few genuine statistical studies of astrology. The most famous is the Carlson "Double-blind test of astrology" that was published in the science journal Nature in 1985; I've linked to it in the shownotes and it's short and I recommend reading it if you're at all interested. It has some interesting quips like, "Two roommate [volunteers] became emphatically convinced that astrology was the work of the devil, and refused to continue in what they called 'an experimental test of evil.'"

Carlson's study involved two parts, and both of these were heavily vetted by professional astrologers who were well regarded in their field. The first had astrologers construct charts for each person, and then the volunteers had to pick out which chart was theirs as well as rank all of them based on how well they thought it fit them. The second part gave the astrologers a chart as well as three results from a personality test where one of them was from the same person as the chart, and they had to match them under the idea that the sun sign you were born in dictates one's personality. As controls in both cases, they included ones that did NOT match at all. The results from the first part were inconclusive. But the results from the second part showed that the astrologers were at chance level and actually BELOW what they themselves had predicted for their hit rate.

Another well regarded and perhaps largest ever study of astrology was done by David Voas in 2007 using census data in England and Wales for 20 MILLION people. The census data records birthdays and marriage status and Voas' premise was simple: Most astrologers claim that sun-sign will determine personality and so will help you figure out who you should marry. But, after a thorough analysis of the data, he showed that there was absolutely no statistical significance in terms of what sign was more or less likely to marry or be divorced from another sign.

Of course, astrologers have criticized both studies as would be expected. I've posted some examples in the show notes. The criticism for the Carlson study is more technical so I won't go into detail here, while the main criticism for the Voas study is that astrologers claim that you need a lot more information than "what sign you are" in order to figure out personality. Tell that to pretty much ANY astrology website or newspaper that has horoscopes.


With all of this said, if you are an astrologer and I've made a mistake in what I said astrologers generally believe, please write to me and let me know and I'll make corrections or a follow-up episode about it. What I've been discussing is what I've gathered is the GENERAL CONSENSUS of western astrology from listening to interviews of astrologers and reading astrologers' writings over the past several years.

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