See Inside

# Math Rules

Some equations touch all our lives--whereas others, well, not so much

Image: Illustration by Matt Collins

In his new book, In Pursuit of the Unknown: 17 Equations That Changed the World, Ian Stewart recounts one of the worst jokes in the history of science. You can develop your own setup from first principles once you know the punch line: “The squaw on the hippopotamus is equal to the sum of the squaws on the other two hides.” Never mind how Native Americans were in possession of a hippopotamus—the important thing is that the Pythagorean theorem is so well known that comedy writers consider it fair game even if that game couldn’t possibly be found on the correct continent.

Stewart, who formerly wrote the Mathematical Recreations column for Scientific American, takes the reader on an engaging tour of vital math for a modern world. We go from Pythagoras’ right triangle (a2 + b2 = c2)—nice—to Newton’s law of gravity (F = G)—good—to Einstein’s special theory of relativity (E = mc2)—still with you—to the Navier-Stokes equation governing the movement of fluids——which pretty much convinced me to change my career trajectory from science to science journalism.

I highly recommend Stewart’s wonderfully accessible book and now share with you some additional equations not in its pages but of importance to me, personally.

HA > H at any time (t)
Technically an inequality, HA > H (t) means that at any time (t), the number of horses’ asses (HA) will exceed the number of horses (H). (Time should be understood to be limited to the period starting with the evolution of modern humans and ending with our eventual extinction.)

This concept is so obvious as to practically have the standing of axiomatic truth. The inequality clearly holds at racetracks and equestrian events, where HA may only slightly outnumber H. (Have you seen the hats some of those horsey folk wear?) Its true power to describe reality, however, is on display in situations where H may vanish to 0, such as professional wrestling or the vast majority of the programming on C-Span.

PSM (L) = 0
Someone’s winning the lottery, but not me.

MS1 + S2 + 3d = WTS
I discovered this equation only in the past few months, when I was traveling and working odd hours to the point of abandoning customary daily ablutions. The equation states that three days (3d) after your last shower (S1) and shave (S2), any man (M) will look exactly like William Tecumseh Sherman.

20x + 10y + 5z = 0C
This equation clearly states that when attempting to use a vending machine that takes singles, you will have in your possession some integer numbers of 20s, 10s and fives but no ones—and, therefore, no candy.

OPS =  [AB × (H + BB + HBP) + TB × (AB + BB + SF + HBP)] /
[AB × (AB + BB + SF + HBP)
]
When I was 10 years old, I started devoting ridiculous amounts of time to the analysis and generation of baseball statistics. Back then, it only got about as complicated as batting average equaling hits divided by at bats. Now, thanks to Bill James and other mathematically oriented fans, we have much more valuable stats, such as on base plus slugging (OPS), which also stands for the reaction of more casual fans to one’s spouting about it—namely, “Oh, please, shuddup.”

0.5x = 100
This equation had a major effect on a friend, which cascaded in my direction. The friend wanted to be an automotive engineer. But he had performed poorly in high school algebra and knew that there was more complex math to come on the way to any engineering career. So we worked for many hours on the algebraic basics. At the end of said hours, my friend was able to determine that 0.5 × 100 was equal to 50. But the leap to determining the X in 0.5X = 100 remained unleapt, which led to my advice that he consider a career as rewarding as automotive engineering that avoided complicated figuring. He went on to become an automobile insurance adjuster and is an invaluable resource to me whenever my car is struck by some HA.

Rights & Permissions

View
1. 1. pickenspilot 08:01 PM 4/18/12

equations:

What about the integral of e to the x power = function of u to the n power?

2. 2. PNorton 12:01 PM 4/28/12

Related to the equation in the first comment, an oft-quoted equation while I was in college was
(M/F) + (3/4)Y = B
The B's, while few, have flourished over the decades.

-- Peter Norton, Reed College x65

3. 3. promytius 10:04 AM 4/29/12

story=3/17
How many of the equations were actually revealed in your "review"
3/17 = 17.647058823529411764705882352941%, score for review.

4. 4. geojellyroll 11:01 AM 4/29/12

Thumbs up! Take math out of the classrooms into the realm of 'fun'.

Math classes are like piano lessons...destroy the inate eagerness of kids to be creative.

5. 5. And Then What? 04:51 PM 4/29/12

I remember one time we had university “ Physics Open House” and our Prof., who had a dry sense of humor, puts some equations on the board to make it look impressive to the public, and one in particular caught my eye. It was written out in scientific notation as: the integral of e to the power x = F of u to the power n. which of course makes no sense, except when it is translated into Sex=Fun.

6. 6. And Then What? in reply to pickenspilot 04:54 PM 4/29/12

my apologies sir it looks like we had the same prof.

7. 7. monk_the_dog 08:56 PM 4/29/12

That's not the punchline. It's:

“The squaw on the hippopotamus is equal to the *sons* of the squaws on the other two hides.” (sons, not sums)

And that's nowhere near the worst joke in the history of science.

8. 8. SCAMdan1 01:14 PM 5/2/12

The HA inequality reminds me of the definition of a horse show:

It's a bunch of HA's showing their HA's to a bunch of HA's!

9. 9. JonnieBean44 10:44 PM 5/8/12

Not only is the punch line wrong, it is: "the sons of the s_____ on the hippopotamus are equal to the sons of the s_____ on the other two hides" but the word used for a Native American woman is offensive in the extreme, being the equivalent of calling a woman a c**t or a whore.

10. 10. djangadjo 09:01 AM 6/19/12

Jonniebean44 is correct. This is an offensive joke to native peoples. Stewart and Mirsky might not have known that, but their editors should have. The same situation occurred with Carol Higgins Clark, who titled her latest mystery Gypped. What are editors for, anyway, if they don't have some cultural sensitivity? [Note: this has nothing to do with "correctness", political or otherwise. It's an ethnic slur.]

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Click one of the buttons below to register using an existing Social Account.

## More from Scientific American

• News | 1 hour ago

### 3-D Printed Windpipe Gives Infant Breath of Life

• News | 12 hours ago

### Studies Cast Doubt on Cancer Drug as Alzheimer's Treatment

• News | 12 hours ago | 1

### An Itch Is Not a Low-Level Form of Pain

• Extinction Countdown | 15 hours ago

### Amphibians in U.S. Declining at `Alarming and Rapid Rate'

• News | 19 hours ago | 7

More »

## Latest from SA Blog Network

• ### #SciAmBlogs Thursday - science diagrams, mental illness art, beavers are fish, amphibian decline, cicadas, and more.

STAFF
The Network Central | 9 hours ago
• ### Hip Hop Evolutionary Tales

Video of the Week | 11 hours ago
• ### Protist-y art continued: the protist zodiac

The Ocelloid | 13 hours ago
• ### Amphibians in U.S. Declining at `Alarming and Rapid Rate'

Extinction Countdown | 16 hours ago
• ### A new way has been found to make truck emissions testing more accurate and less costly

Guest Blog | 17 hours ago

## Science Jobs of the Week

Math Rules: Scientific American Magazine

X

### Subscribe Today

Save 66% off the cover price and get a free gift!

X

X

###### Welcome, . Do you have an existing ScientificAmerican.com account?

No, I would like to create a new account with my profile information.

X

Are you sure?

X