The Man in the Arena

It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the deeds; who knows great enthusiasms, the great devotions; who spends himself in a worthy cause; who at the best knows in the end the triumph of high achievement, and who at the worst, if he fails, at least fails while daring greatly, so that his place shall never be with those cold and timid souls who neither know victory nor defeat.

— Theodore Roosevelt

There are few short-cuts in life

The inferior man’s reasons for hating knowledge are not hard to discern. He hates it because it is complex—because it puts an unbearable burden on his meager capacity for taking in ideas. Thus his search is always for short cuts. All superstitions are such short cuts. Their aim is to make the unintelligible simple, and even obvious.

— H.L. Mencken

Alexander Aghassipour interview in Offscreen Magazine

I really enjoyed the interview with Alexander Aghassipour, Danish founder of Zendesk, in Issue 12 of Offscreen magazine. It’s always fun to read about the experiences of Europeans living in America, and vice versa.

A Dane will happily start a job interview buy telling you what they are -not- good at, something that would never happen in the US.

We Danes also tend to swear a lot and be less politically correct than Americans. We used to test new hires by throwing in a swear word here and there, and making them taste Danish liquorice. But we stopped doing that when we learned more about American “HR violations” as a legal concept.

People here are also obsessed with Ivy League schools. It’s the first thing a recruiter will mention to you. Although, after years of hiring many people, I still find no correlation beween top tier schools, and the value they provide to the company.

I’m just getting into it, but Issue 12 looks to be full of interesting content.

An eye-opening example of the importance of mathematical literacy

If you’d like to understand the importance of having a good knowledge of probability theory, consider the following eye-opening example (inspired by something I read at David Siegel’s site.)

A rare disease is known to exist in 1% of the population. A test for the disease is known to be 98% accurate, meaning that if you have the disease, the test will return positive 98% of the time.

Now, you’re curious whether you might have the disease and so you go take the test. It comes back positive. What is the probability you actually have the disease? The results might surprise you.

To solve this problem, we use Baysian probability theory, which says:

P(A|B) = P(A)*P(B|A)/P(B)


  • A = You have the disease
  • B = You test positive

In words, this means that the probability that you have the disease (A) and you test positive (B) is the probability that you have the disease, P(A), times the probability that you test positive given that you have the disease, P(B|A), divided by the probability that you test positive, P(B).

So to make this calculation we need three numbers:

  1. P(A) — We know that P(A) (the probability we have the disease) is 1%.
  2. P(B|A) — We know that P(B|A), the probability that we test positive if we have the disease, is 98%.
  3. P(B) — We don’t know this one, and have to calculate it.

We can compute P(B)—i.e. the probability that a random person taking the test returns positive—using “conditional” probability:

P(B) = P(B|A)P(A) + P(B|!A)P(!A)

This means that the probably of testing positive, is the sum of the conditional probabilities that (a) we test positive given that we have the disease times the probability that we actually have the disease, plus (b) the probability that we test positive given that we don’t have the disease, times the probability that we don’t have the disease.

In the above conditional probability equation, we know all the values except P(B|!A). How to determine this? Well, we know the following must be true:

P(B|A) + P(B|!A) = 100%

Therefore, since we know P(B|A) is 98%, we can conclude that P(B|!A) must be 2%.

P(B|!A) is known as the “false positives”, i.e. those who test positive but don’t have the disease.


P(B) = 0.98*0.01 + 0.02*0.99 = 0.0296

So now we have the all the numbers to calculate P(A|B), i.e. that chances that we actually have the disease given that we tested positive for it:

P(A|B) = 0.01*0.98/0.0296 = 0.33

Surprising no? If we went to the doctor, took this test, and tested positive, there would only be a 33% chance that we actually have the disease.

How can we make sense of this? It’s actually quite logical.

Imagine a random population sample of 1,000,000 people. Of those, 10,000 (1%) will have the disease. Of those 10,000 tested, 9,800 (98%) will diagnose correctly in the test. Of the 990,000 (99%) who don’t have the disease, 19,800 will test positive, i.e. the 2% false-positive percentage.

So of the 1,000,000 people tested, 29,600 will test positive, but very few of those will really have the disease, i.e. 9,800/29,600 or 33%.

The Box

When I was a child, I had a box in my bedroom that was full of all sorts of bits and bobs—ranging from batteries, to rubber bands to screws, string and discarded wood chips from my grandfather’s shop. Many hours were spent pouring over those items, arranging them in various combinations and imaginatively dreaming about what amazing things could be built from them.

Today while reading Ian Bernstein recount a similar story in Offscreen magazine, I wondered to what extent this is a shared experience amoung those of us who grew up to later dedicate our lives to the making of things.

Richard Feynman on knowing something

In the video The Pleasure of Finding Things Out I love this profound quote by Richard Feynman. He’s talking about pseudo-science, but it has broad applicability:

But I have an the advantage of having found out how hard it is to really get to know something. How careful you have to be about checking your experiments. How easy it is to make mistakes and fool yourself.

I know what it means to know something, and therefore I see how they get their information, and I can’t believe they claim to know something. They haven’t done the work necessary. They haven’t done the checks necessary. They have done the care necessary.

I think about this quote, when I see people making simple-minded, black-and-white statements on subjects like politics, economics, health and religion.

College wasn't his biggest mistake

Steven Corona wrote an article that details his path from failing out of college, through negotiating his first job, to ultimately becoming the successful CTO at Twitpic. It’s an inspiring article, but I think its title is unfortunate and sends the wrong message.

Rather than, “College was my biggest mistake”, the article should probably have been titled, “Believing that failing out of college would limit my success was my biggest mistake”—because the point is that graduating from college isn’t a prerequisite to success, and that you shouldn’t develop a self-limiting mindset if you didn’t go, or couldn’t finish.

Even though my own line of work ultimately differed from what I studied, my five years at college provided benefits that have proven of tremendous value in my life:

  • It showed me that I’m far more capable than I would have previously imagined.

  • It taught me the long-term benefits of consistent, day-to-day self-discipline.

  • It taught me the importance of doing the problems. There were countless times that I left lectures or finished reading a chapter in a textbook with the feeling that I understood the topic. Only later, when I actually tried to do the problems, did I begin to understand the difference between being taught, and true learning. I can’t over-emphasize the importance of this lesson.

These are things that, I suspect, are easier to learn in the externally-imposed, constrained environments created by colleges and universities.

My advice to the kids at Swans Career Day

My wife and I were invited to participate in the Swans school “Career Day”. We were assigned one of about 10 tables in a large ballroom, where 100 or so year-10 students walked around asking career-related questions. Here’s a summary of the advice we gave:

  1. Technology is a great field to pursue. It’s never boring. It has the potential to impact people in positive ways, and to change the world.

  2. Don’t worry about making the wrong choice when deciding what to study at university. Neither Pino nor I relied on what we learned at university in our careers. If you’re going into technology, you probably would be better off with engineering, than, say, painting, but other than that, don’t worry about it.

  3. Work on your writing skills. The best companies these days, in most any field, are looking for people who can communicate clearly, and concisely in writing.

  4. Travel. Spend your summers living in other countries, so that you can get a perspective of the world outside Marbella.

  5. Don’t hesitate to change careers, in search of work that you enjoy. You want to do good work, and you’ll only do good work if you’re doing something you enjoy.

Getting trapped in a cooling tower at the Georgia Power Company Plant Yates

Excluding a high-school job at the Kroger grocery store, my first real job was with the Georgia Power Company, at their electrical power generation plant in Newnan, Georgia — called Plant Yates. I had a very pleasant surprise this morning, to receive an email from an old colleague there.

Continue reading Getting trapped in a cooling tower at the Georgia Power Company Plant Yates

Why we get fat

From, “Why we get fat“, the fantastic follow-up to “Good calories, Bad calories” by Gary Taubes:

In other words, the science itself makes clear that hormones, enzymes and growth factors regulate our fat tissue, just as they do everything else in the human body, and that we do not get fat because we overeat; we get fat because the carbohydrates in our diet make us fat. The science tells us that obesity is ultimately the result of a hormonal imbalance, not a caloric one—specifically, the stimulation of insulin secretion caused by eating easily digestible, carbohydrate-rich foods: refined carbohydrates, including flour and cereal grains, starchy vegetables such as potatoes, and sugars, like sucrose (table sugar) and high-fructose corn syrup. These carbohydrates literally make us fat, and by driving us to accumulate fat, they make us hungrier and they make us sedentary.

…and later…

If your goal in reading this book is simply to be told the answer to the question, “What do I do to remain lean, or lose the excess fat I have?” then this is it: stay away from carbohydrate-rich foods, and the sweeter the food or easier it is to consume and digest—liquid carbohydrates like beer, fruit juices and sodas are probably the worst—the more likely it is to make you fat, and the more you should avoid it.

Dieting and weight loss report.

In the sport of Brazilian Jiu-Jitsu, I’ve been fortunate (having trained under some great coaches) to have won gold medals two times at the European BJJ championships. On both occasions, I fought in the lightweight division, 76 kg (including the gi/kimono). Generally walking around at 76 kg, I would need to only lose about 2 kg a couple days before the event (to compensate for the weight of the gi), and would generally be one of the bigger and stronger participants in the division (being at the very top of the weight range).

Continue reading Dieting and weight loss report.

You are what you eat

One of our neighbors who works in the Spanish agriculture business was telling us, in passing conversation one day, about the steroidal products that are used nowadays in the produce industry. It was interesting to hear that one of the main uses for such products was the production of crops which simply look good. She explained, for example, how unnatural it turns out to be, that each piece of a given fruit or vegetable happens to grow to precisely the same shape and size as all the others.[email protected]/2800690738

Skip ahead a few weeks, and we were reminded of this conversation when we received the first delivery from a new service we’ve subscribed to. A group of local organic farmers have organized themselves into a cooperative, and for about 20 Euros per week, will deliver a large box full of locally grown seasonal fruits and vegetables to your door each Tuesday.

The above photo illustrates how different organically grown, untreated carrots can turn out!

Rinky the Cat

Last night I was out on a bike ride, from Monda to Tolox. About 8:30 PM, I was on my way back, and had just turned the corner at junction to Guaro. My eye caught what looked like a mouse on the side of the road. As I approach, I saw it was a little abandoned kitten.

I hopped off the bike, but it ran off the road, and into a pile of large rocks. It was obviously pretty scared.

After waiting 10 minutes, I decided to continue on.

Continue reading Rinky the Cat

Matt's Corollary to Moore's Law

Moore’s Law states (roughly) that the speed of computers doubles every two years, and he’s been more or less on the money. Today I introduce a corollary to Moore’s Law, which I expect to come to be known as Matt’s Corollary:

Except for the first couple days of ownership, the perceived speed of computers, over time, remains a constant (and a slow one at that).

My shiny new MacBook has become dog slow. Some people claim it’s the fact I didn’t do a clean install. Niall probably figures it has something to do with the 25+ apps I run at the same time. But you and I now know the truth — Matt’s Corollary.

Five Things

Now that I’m back to blogging, I’d better catch up on a long overdue task. My office colleague Arto Bendiken pinged me with the Five Things meme, so here goes: Five Things you probably didn’t know about me:

  1. I’ve climbed down an 800 foot smoke stack. Not sure I can tell this story… but what the heck, it was a long time ago…

    As a young co-op student working at Georgia Power’s Plant Yates, my co-op colleague Eric Garris came in one morning and informed me that the Plant Manager wasn’t in that day, and this was our grand opportunity to take the elevator to the top of the smoke stack and look around. So we squeezed into the rickety old cage elevator, and rattled our way to the top of the 800 foot structure. We looked around a bit, discovered some Playboy magazines up there, and decided to head on down. (I’m afraid of heights.) Getting back in the elevator, we pressed the down button, over and over. The elevator fought hard, but wouldn’t move. After a couple tries, we heard a boom from below, and the elevator was dead.

    Couple minutes later we discovered the elevator had a phone. They were calling, “Who the HECK is up there!!!”. “Uh, hi! It’s the coops! :)”…”You idiots, you burned out the elevator motor!” Turned out, we didn’t realize the elevator locks when it reaches the top, and you have to unlock it before it will move.

    The bad news is that they told us we had to climb down an emergency ladder that scales the entire inside wall of the smoke stack. I begged for them to fly in a helicopter, but no-can-do. I was in tears as I climbed out of the elevator, and made the hair-raising swing over and onto the ladder. (After Eric, of course– I wasn’t about to have him falling and knocking me off the ladder…)

    After, I don’t know, a few hours (?) we made it down, both covered in soot and looking like those cartoons characters after an explosion.

    Next morning, the plant manager was about to fire us, but then we were saved by an idea! About a month later, me and Erik appeared on the cover of the company wide “Safety” magazine. The article read, “On a routine inspection of the smoke stack, coop students Matt Henderson and Erik Garris found themselves stuck in a malfunctioning elevator. Due to their familiarity with safety procedures and training, they were able to safely escape the situation!”

  2. I’ve trekked to the Base Camp area of Mount Everest.

    My wife, three friends and I (and a German guide) spent two weeks trekking from Lukla (a mountain city in Nepal) to the base camp area of Mount Everest. Since all the expeditions had returned home, we foregoed going to the actual base camp, instead choosing to climb the nearly 6000 meter peak of Kala Patar.

    Climbing that mountain, with 50% oxygen in my blood, must have been the most difficult physical thing I’ve ever done. After what seemed like an eternity, I reached the top, pulled out the camera, snapped a picture of Everest, packed up, and headed down.

    A few weeks later, back home, I had the film developed, and discovered that the very peak of Everest was obscured in the photo by the bill of my hat! Three. Weeks. Of. Trekking. and I get a chopped off picture of Everest.

  3. I’ve been cussed out by ex-Van Halen lead singer, David Lee Roth.

    My high school best friend, Todd Stover, and I were major fans of David Lee Roth, and traveled around (anywhere practically) to see him play. We drove one weekend to somewhere in Alabama, and given that the floor seating was first-come / first-serve, we camped out for hours at the door, to be the first in line.

    We ended up first row, and they sat everybody down on the floor, as we waited for Cinderella to come out (they were the warm-up band). The guards working the stage told us that many of us were heading to the hospital within an hour. “What???!!!” They told us that as soon as the lights went out, everybody sitting on the floor would stand up, and rush forward, and that many of us would get crushed against the barrier.

    Sure enough, lights out, and I experienced something I never want to experience again. I had no control of my body, as I was lifted a few inches off the ground by the mass of people and moved left, right, left and right again. I watch as my friend Todd drifted off in the opposite direction. We waved bye-bye to each other. Pretty soon unconscious bodies were being passed overhead to the guards. It was unreal.

    I got shifted left, and eventually spit out on the side next to the big speakers. I decided to leave the floor, and climb up into the seats. (I didn’t really pay attention to who I was sitting next to.)

    So eventually Dave comes over, jumps up on the speaker, and sings, “…Reach down, between my legs, ease the seat back…” Then, SMACK, he gets hit with a ball of ice in his face.

    He stops the music, mad as can be, and gets them to shine the spotlight down on us — on ME! He looks at me and starts cussing me out. I’m in shock. I can’t repeat all he said, but it included what he’d do to my GIRLFRIEND. My girlfriend!!!??? I look to my left, and there’s this fat girl sitting there eating a bucket OF ICE! So Dave sees this girl, and assumed I’d thrown the ice!

    After the concert, back at the car, my friend Todd says, “Oh man, can you believe what happened to that dude that threw the ice!!”. “Yeah, Todd, I can believe it…”

  4. I was a European Brazilian Jiu-Jitsu gold medalist.

    Ok, it was the senior division, blue belt, ad the 73 kg weight class, but I beat everybody to become the European BJJ champion last year.

  5. I love country music. (Hey, I grew up in Duluth, Georgia. What do you expect?)

    The sappier the better. It’s one of the things I miss most about the United States. There just aren’t any country music stations in this part of Spain. Thank goodness for iTunes.

And with that, the meme stops here. 🙂

Traffic ticket in historic Whitesburg Whitesville, Georgia

UPDATE: Well, my memory must be going with age. As pointed out in the comments, it was Whitesburg, not Whitesville!

Somehow things happen to me that don’t seem to happen to others, and a friend recently suggested I start documenting some of my past and future stories on my weblog. This is the first installment, about a traffic ticket I once received, in historic Whitesville Whitesburg, deep south Georgia.

I worked my way through Georgia Tech as a coop student, initially spending alternate quarters at the Georgia Power Company’s power generation plant, Plant Yates, in lovely Newnan, Georgia. It was an interesting experience, some of which I’ll be documenting in future stories. (Like the time me and the other coop got stuck at the top of the 800 ft tall smoke stack.) Just to set the mood, on my first day at Plant Yates, I was told by the lead engineer that “coop” is the sound horse crap makes when it hits the ground. Welcome to your new job.

But today’s story deals with a speeding ticket that I recieved, when returning to my dorm room at West Georgia University, where I stayed while working at Plant Yates.

It was around two in the morning, and I was returning home in my 1982 diesel Volkswagen Rabbit along the highway towards Carrollton (the home of West Georgia University). The highway speed limit was something like 50 mph, and that’s about what I was doing. What I didn’t realize, though, was that once you enter the city limits of tiny little Whitesville Whitesburg — and you need to understand, you could, back then, enter and exit Whitesville Whitesburg in about 15 seconds — the speed limit drops to 30 mph.

Just as I exited Whitesville Whitesburg (in fact, I didn’t even realized I’d passed a town), I saw a police car pull out of the forest on the outskirts of town, and fire up the lights and sirens, in hot pursuit of my little Rabbit. I pulled over, and a somewhat overweight Officer Buford (or something like that like) came moseying up alongside the driver’s window, hand on his gun. He looks in, chompin’ on a wad of chewing tobacco, and we have the following conversation:

Officer: Boy, I don’t know about Gwinnett county (spit) but down here in Whitesville Whitesburg we have traffic laws. You know how fast you just drove through town? 70 MILES-AN-HOUR!

Me: Sir, that’s kinda hard to believe, since my diesel Rabbit only has 42 horsepower. I actually don’t think I’ve ever exceeded 65 mph in this car.

Officer: Don’t go gittin’ smart with me, BOY! (Hand tightens up on the gun. Spit.) You wanna come look at the screen of my radar?

Me: No, no.. that’s ok, sir.

So Officer Buford proceeds to write me out a $50 speeding ticket, and sends me on my way.

Now, 50 bucks was quite a lot for a struggling coop student. I got to thinking on the way back home, that (a) he was perpendicular to the road on a secluded forest path when he scanned me, (b) I may have been going above 30 mph, but my diesel Rabbit really wasn’t capable of going 70, and (c) this just wasn’t right! Talking to a friend who said he knew something about police radars, I was later told that often the radar’s calibration speed is 70 mph — meaning, if he was right, that Office Buford could make his radar read 70 mph anytime he wants.

So, I decided to fight the ticket in court.

Well, turns out court in Whitesville Whitesburg only happens every now and then, when the traveling Judge makes his rounds, and so my date was scheduled for a month into the future, when I’d already be back in Atlanta at school.

I carefully prepared my case, with charts, diagrams, analysis and references, explaining how radar doesn’t work on a perpendicular vector, how Buford’s calibration frequency needs to be checked to see if it was a coincidental 70 mph, how my little car doesn’t go 70 mph, and, for good measure, how it was my first offense. With that all ready, I was convinced I’d win.

So, on a Thursday afternoon, I confidently headed back down to Whitesville Whitesburg. As at the time, there was no courthouse in Whitesville Whitesburg, court was held in the basement of a Miss Dorothy’s lovely colonial house. Miss Dorothy even had chocolate cookies ready for the occassion. All us accused sat in little metal folding chairs, and the Honorable Judge behind a fake wood-grain folding table.

Court began, and there were about 27 other cases to be heard, — half of which were DUI’s and the other half, wife beatings. Somehow, mine was the last case to be heard, and the Judge woke up when I was the first person to plead, “Not Guilty.”

So after painstakingly walking through my presentation and analysis, the judge, with furrowed brow, looks at me over the top if his spectacles and thoughtfully says, “Mister Henderson, I’m pretty sure you didn’t mean to be traveling 70 mph. (long pause) But, Officer Buford here says you were traveling 70 mph, and I do believe him. Now, son, since this is your first offense, I’m gonna go easy on you. Plaintiff to pay a fee of $50. [gavel slams down on table] See you all next month.”

Beautiful Home for Sale on Lake Lanier

Last March my brother and I started a business, Henderson & Henderson LLC, in Georgia (USA). We’re building really nice residential homes. Our first is nearly completed. It’s a beautiful home, situated on Lake Lanier, about 40 minutes north of Atlanta. The house has 2400 square feet upstairs, and 1600 in the basement. It sits directly on the lake, in a deep-water cove, and has a double-slip dock. The asking price $530,000 (which is below the recent appraisal price).

We’ve got a downloadable PDF with more information.