It's in the Rock Stars

I wrote a blog post two years ago on the topic of astrology. I looked at the prevalence of the signs of the zodiac for 189 mathematicians born between 1800 and 1840. Now I would think that mathematicians would tend to share certain personality traits. If there is anything to the standard zodiacal theory (that your sign of the zodiac determines your personality), then mathematicians should tend to have one astrological sign.

My research on mathematicians showed that there was no predominant sign of the zodiac associated with this group of mathematicians. They were pretty much evenly distributed across the zodiac. Note to self: Someone's birth sign can be used to predict their personality, except if they happen to be a mathematician born between 1800 and 1840.

One of the readers of this blog threw down the gauntlet, offering up one group of people who fit with their astrological predictions. Here is the comment: 

Hi

I have noticed that famous musicians that are just as famous for their politics as they are for their music are overwhelmingly Libras.

The only exception is the guy from U2.

Here are some:

John Lennon

Thom Yorke

Bruce Springsteen

There also seem to be an almost total lack of Scorpio musicians unless you count vanilla ice.

Aries musicians tend to make exciting music.

I missed a couple of example:

Sting -Mr Rainforest

Bob Geldof - Feed the world

Most musicians who are famous for their politics seem to be libra. But not all libra musicians are publicly political.

<Posted by Chunkations>

On reading this list, my first thought was ... what about the other Beatles? John Lennon wasn't the only one of them making a peace sign. Then, since I am a child of that era, a long list of other names came to mind: Bob Dylan, Pete Seeger, Peter, Paul, and Mary...

The Experiment

I decided to test Chunkation's hypothesis. I sent a Facebook message to each of my 16 friends, all of whom are into music. Note that I copied the words from the Chunkations'  comment directly. I did not try to spin my own interpretation of Chunkations' words, and I did not tell people what I planned on doing with the list.

I'm asking people for a little help with a future blog post. I am compiling a list of famous musicians that are just as famous for their politics as they are for their music. Could you nominate the five who you think are most qualified?

13 of the friends gave me their list. (To be perfectly honest, one of my friends was me. Another was my wife, who sometimes is my friend.) The combined list included 38 different musicians.

I had to do a little editing. Some people offered more than five. People just can't follow directions, you know? I went back and asked them to pick five from the list, or I just took the first five from their list.

Many people offered up music groups. People just can't follow directions, you know? Rage Against the Machine got three votes! Not sure what to do, I went to Wikipedia and used the name of the first group member that was listed. I tabulated with and without these.

Here is a list of all the musicians, a count of the number of people who mentioned them, and their birthday (according to Wikipedia) and their sign, according to the Zodiac table on Wikipedia.

Artist	Count	Bday	Sign
Country Joe McDonald	1	1-Jan	Capricorn
Joan Baez	4	9-Jan	Capricorn
Zack de la Rocha (Rage Against the Machine)	3	12-Jan	Capricorn
Bob Marley	2	6-Feb	Aquarius
Cheryl Crow	1	11-Feb	Aquarius
Buffy Saint-Marie	1	20-Feb	Pisces
Harry Belafonte	1	1-Mar	Pisces
Miriam Makeba	1	4-Mar	Pisces
Dee Snyder	1	15-Mar	Pisces
Brian Warfield (The Wolfe Tones)	1	2-Apr	Aries
Al Green	1	13-Apr	Aries
Barbra Streisand	2	24-Apr	Taurus
Willie Nelson	1	29-Apr	Taurus
Pete Seeger	4	3-May	Taurus
Richie Furay (Buffalo Springfield)	1	9-May	Taurus
Bono	5	10-May	Taurus
Bob Dylan	4	24-May	Gemini
Bruce Cockburn	1	27-May	Gemini
Peter Yarrow	1	31-May	Gemini
Audra McDonald	1	3-Jul	Cancer
Arlo Guthrie	1	10-Jul	Cancer
Woodie Guthrie	2	14-Jul	Cancer
Serj Tankian	1	21-Aug	Leo
Beyonce	1	4-Sep	Virgo
Chrissy Hynde	1	7-Sep	Virgo
Ani DiFranco	1	23-Sep	Libra
Bruce Springsteen	2	23-Sep	Libra
Sting	1	2-Oct	Libra
John Mellencamp	1	7-Oct	Libra
John Lennon	4	9-Oct	Libra
Martie Maguire (Dixie Chicks)	1	12-Oct	Libra
Nadezhda Tolokonnikova (Pussy Riot)	1	7-Nov	Scorpio
Neil Young	1	12-Nov	Scorpio
Aaron Copeland	1	14-Nov	Scorpio
Kevin Gilbert	1	20-Nov	Scorpio
Ted Nugent	4	13-Dec	Sagittarius
Eddie Veder (Pearl Jam)	1	23-Dec	Capricorn
Odetta	1	31-Dec	Capricorn

Here is the count for each of the signs. The first column is the sign. The second column is the count including the music groups, and the third column is the count leaving out Pussy Riot and the other groups.

Capricorn	5	3
Aquarius	2	2
Pisces	4	4
Aries	2	1
Taurus	5	4
Gemini	3	3
Cancer	3	3
Leo	1	1
Virgo	2	2
Libra	6	5
Scorpio	4	3
Sagittarius	1	1

Are the folks in this list "overwhelmingly" Libras? Somehow I picture "overwhelmingly" to mean something like "most of". Like if 30 of the 38 were Libras, then I would be overwhelmed.

How about the softer claim at the end of the blog comment? "Most musicians who are famous for their politics seem to be libra." I think "most" would mean at least 20. Hmmm... there were only 6.

There are more Libras (6) than there are any other group, but that's not saying much, statistically. There are 5 each of Capricorns and Tauruses. Even if we exclude the music groups (where I might have erred) the story is the same.

So, the experiment failed to support even a much weaker version of Chunkation's hypothesis.

Is the data skewed by non-famous people? Hmmm... There are more than a few people on the list that I have to admit I never heard of. How can they be famous?

I came up with the A list of those people who were nominated by more than one person. And I also left out those who were mentioned only by the band name. Ten people were left: Baez, Marley, Streisand, Seeger, Bono, Dylan, Guthrie, Springsteen, Lennon, and Nugent. I count only one Libra in this group. There are three Tauruses, though.

I think this pretty well busts that myth.

Thank you Anne, Betsy, Dave, Doug, Gringo, John, Madelaine, Mike, Paul, Rachel, Steve, Toby, and Tom for volunteering your lists of famous musicians and activists.

In conclusion

What does this say for the theory that your sign of the zodiac predicts stuff about you and your life?

Someone may well post on this blog that 93% of all left-handed cab drivers in Queens are Pisces. (Or maybe they are just pissed?)  I imagine that such a post might end with something like "How can you explain that, Mr. Smarty Math Guy Pants!!??!??"

A theory is useful if it can make predictions. I have given two examples where the birth sign makes absolutely lousy predictions, so it is not useful, and perhaps even harmful. In order for the theory to hope to prove itself useful, it has to include an instruction manual that tells me how to avoid making these two bad predictions. Until I have that manual, I have to assume that the whole theory is not useful.

But there is an odd thing about Springsteen...

I noticed one interesting thing comparing Chunkations' list with my own list. He/she listed Springsteen as a Libra. I initially counted my pal Bruce as a Virgo. I double checked Wikipedia's entry on Zodiac for the date range for the signs, and saw that I didn't mess up. It lists Virgo as August 23rd to September 23rd, and the Boss was born on Sept. 23. By that definition, I was correct.

But then I looked further... The Wikipedia page for Virgo tells a slightly different story: "[T]he Sun transits this area on average between August 23 and September 22". By this definition, Springsteen falls into the Libra camp along with Mellencamp.

So I started furiously googling. I found 21 website that gave a definition of the date range for Libra, and there were four different date ranges associated with Libra. There was one website (I won't tell which one) that contradicted itself about the date range for Libra. On the same page.

Why the confusion? The transitions between the signs of the zodiac are defined based on the position of the Sun and Earth with respect to one another and the stars, and also on what part of the globe you were born on. Springsteen (and Ani DiFranco) were born on a cusp, the edge between two birth signs. They could go either way.

Incidentally, when I did my analysis before, the count of six Libras included Springsteen and DiFranco. With a slightly different definition of Libra, the count of correct guesses would have been only four.  

The hidden meaning of "What's your sine?"

Time for a little math history trivia. I thought my little pun on "What's my sine?" was cute. But it later occurred to me that there was another little twist.

Long ago, people invented astrology as a way to help explain the world and make predictions about whether to go to war or just throw a big block party. This perceived need fostered early astronomers to take detailed notes on the positions of the moon, the stars and the planets.

The astronomers had all this data, but they needed something to do with it. They needed to develop math to be able to predict the future positions of the celestial bodies. Consequently, trigonometry was invented. And it was invented almost a millennium before algebra. So there is another connection between the words "sign" and "sine".