Friday, April 15, 2016

Useful Math for Liberal Arts Majors

In 1988, John Allen Paulous authored Innumeracy, a great little book that wondered why so many smart people are numerically illiterate, and what the consequences of such ignorance are.  Last week Paulous hit home for me when Donald Trump complained about delegate theft--despite having won 45% of all delegates on just 37% of the popular vote. 
Four out of three Americans have trouble with percentages, I’m told.  And something like 104% struggle with fractions.
I learned long ago, however, that numbers can be the key to success and happiness, if only presented in the proper fashion.  With that in mind, I have assembled some of the numerical rules and laws which can be understood by anyone--a hack for my fellow liberal arts majors--and can truly improve your life.
The 50% Rule of PowerPoint Fonts 
Most people know Guy Kawasaki’s 10/20/30 Rule of PowerPoint.  But here’s another, even simpler “golden rule” of PowerPoint presentations that will keep most of your decks in good working order: Always use a font size at least as large as half the age of the oldest person in the room. 
So, if you’re addressing the 70-year old Chairman, go no smaller than a 36-font.  If you are charming a 45-year old VC, insist on no less than a 24-font.  And it’s almost impossible to go too big.
The secret here is that large fonts aren’t just more legible but also mean fewer words.  Which helps with a corollary law that says managers over 50 will only pay attention for about 50% of the time you are presenting, anyway.

Three ingredients--a not unreasonable recipe.
Only Make Recipes with Three to Five Ingredients
Less than three and it’s mixing, not cooking.  More than five and it’s hard work, and easier to order a pizza.

Pain is Always a 10

If you should ever find yourself in a hospital emergency room dealing with something less than imminent death, and the nice lady at the check-in desk asks, "On a scale of 1 to 10, how badly does it hurt?"--you must say "10."  Do not let her see you hesitate.  You may not say, "Mostly 7 with spikes of 10." Anything less than a constant, unrelenting 10 and you will be placed at the end of the line.

Everybody lies about how many hours they work in a week, how much they read, how much they weigh, how old they are, how much TV they watch--and how much it hurts.  Lie about your pain or lose your place in line.

Double the Feeders, Triple the Feed

I'm not entirely sure why this is true, but my local Wild Birds Unlimited dealer, Henry, warned me--and he was right.  Suppose you have one bird feeder in your yard and you fill it with one bag of seed each week.  If you then install a second, equal-sized feeder, you will end up purchasing three bags of seed every week to keep the two feeders full.

There is some underlying socio-economic principle at work that probably has much broader applications.  Maybe Ayn Rand or Karl Marx could figure it out.  Maybe John Audubon.  There's maybe even a graduate economics thesis here.

Never Buy the Second Cheapest Bottle of Wine on the Menu

Sommeliers know where you live, and it's quite likely to be at the intersection of "don't know much about wine" and "don't want to look like a cheapskate."  Consequently, what you'll inevitably do is skim the wine list and purchase the second cheapest bottle of wine on the menu.  That's the one with the massive mark-up.

Why?  Because sommeliers know where you live.

The Rule of Twelve
This theory was devised by Scott Adams’ of Dilbert fame, and is perfect for most cocktail parties and virtually all business reviews.  Adams writes:

I call it the Rule of Twelve, and it states that if you know twelve concepts about a given topic you will look like an expert to people who only know two or three. If you learn more than twelve concepts about a topic, the value of each additional one drops off considerably.” 
Allow me to be the first to confess that twelve is not a magic and inviolable number.  It just sounds better than The Rule of Several, Give or Take Two or Three, With Lots of Exceptions. So don't get hung up on the number twelve.
So, how perfect a number hack is this—a number rule where you don’t have to worry about the number? 
Suppose your wife is a mathematician and you studied, say, History.  And you are going to a cocktail party with all of her friends.  Take 90 seconds and memorize the following:
  1. The Standard Model of particle physics is made up of twelve basic building blocks. 
  2. Six of these are quarks.
  3. The other six are leptons.  (Laugh every time you say “leptons.”)
  4. All of the different fundamental particles of the Standard Model are really just different manifestations of one basic object: a string!  (Pause for effect.  Making an imaginary cat’s cradle can also be quite effective here.)
  5. Under an extremely powerful microscope we would realize that an electron is not really a point, but a tiny loop of string.
  6. If string theory is correct, the entire world is made of strings!  (Pause again!)
  7. (Darken your demeanor here:) It should also be said that, to date, there is no direct experimental evidence that string theory itself is the correct description of Nature.
  8. This is mostly due to the fact that string theory is still under development. (Smile knowingly.)
  9. In recent years many exciting developments have taken place, radically improving our understanding of what the theory is.
Now, excuse yourself and walk toward the bar, saying “string theory always leaves me parched.”
There you go, just nine easy-to-remember factoids which you can employ over and over again in each cocktail circle during the evening.

100 Billion

For those cocktail conversations where you'd like to escape more quickly, simply mention that there are about 100 billion stars in the Milky Way.  Then note that there are about 100 billion galaxies in observable space.  Then, lower your voice and add: "And there are 100 billion neurons in a human brain."  Pause.  "Coincidence?"

Bolt for the bar.

80% of Everything is Crap 
Is there a less elegant, more powerful rule of life?   
Let’s say, for example, that you live near ten restaurants.  My guess is there will be only one really exceptional joint, one good one, a few me-toos, and a handful of abominations.  You can live in Kankakee or Paris—your odds are generally the same, despite.
The other way to state this rule, of course, is to understand that 20% of almost everything is worthwhile.  So part of your life’s work becomes finding and enjoying that great 20% while scrupulously avoiding the rest.  20% of movies.  20% of new music.  20% of your co-workers.  
This gets to the issue of "curating," which seems to me one of the increasingly important functions in daily life.  Do not trust it to an algorithm.  Or Facebook.

It’s Always the Third Thing
This may be the most important advice of all.  Let’s assume your boss calls you in for a meeting.  He asks, “Did you have a good weekend?”  Then he says, “I really liked the way you handled the Rutabaga account.”  
Then he says. . .and this is the moment to listen hard.  It's the third thing.  The third thing is the real reason he wants to speak with you.  Trust me.
For spouses the rule is a little different: If you've been married less than a year, it's still the third thing.  After that, it's the first thing.

Rule of Thirds (A Picture is Worth 1,000 Words)
I took maybe 25,000 pictures before I learned this rule.  So, 25,000 times I put the subject smack dab in the middle of the picture—while cursing the little 3-by-3 grid in my camera for getting in the way of my shot. 
Here’s the rule in action (borrowed from here), recognizing that a picture really is worth 1,000 words:
Why didn't someone say not to do this?
Why didn't someone say those little grids weren't just for show?
On-Average Portrait Taking

We have three children and have taken vacation and holiday pictures for 25 years, so you can trust the math on this one.

The equation for taking one good picture of any group of people is:

GP = 2n

where GP is the good picture you desire, and n is number of people in the shot.

So, if you want a good selfie of yourself; that'll be two shots.  (This explains why every other selfie you see if awful.)  A good selfie of you and your friend will take four shots.

And a holiday picture of your three children will be eight shots, on average.

On average.

Always Start With the Fourth Review
This is also called “the Amazon Rule of Life,” but applies to nearly any rating service.  Assume you want to purchase a book on Amazon but wonder how good it really is. 
The first review will be a guaranteed 5-Star review because, well, this is almost certainly the author’s best friend.  Maybe even his spouse, or his agent.  Likewise, the next two “5-Star” reviews are guaranteed friends of the author.  The real readers don’t start until (give or take) about the fourth review.  If the author has fanboys/girls, or is particularly good at gaming the system, real reviews might start at seven or eight.  But the caution stands: never pay attention to the first few reviews.  
A sure sign of a planted review on Amazon: it's cogent and grammatical.
By the way, if the second or third review is bad, you know one of two things: The book really is awful, or the author doesn’t even have three friends.  In either case, avoid that book.

50% of All Species on Earth will be Extinct in 100 Years 
In fact, it’s estimated that 99% of all species that ever existed are now extinct.  Permanent destruction is going on all around us.

I offer this final factoid as parting motivation to make it a point to find the best 20% of everything out there before it disappears.

(This post was updated from one I did in 2009 that 5 out of 4 people didn't read.)