To build the future, we must escape the present, or, "The bullet hole misconception"


Originally published at:


Also related is the history of the Davey Lamp. It was a mining lamp that was designed in such a way that it wouldn’t ignite flammable gasses in mines. But it’s adoption didn’t lead to safer mines. Rather the owners went back and resumed mining areas that had previously been considered unsafe.
And then we end up with the way the pooling and trancheing mortgages in such a way that you could create bonds that would only fail if there was a nationwide fall in RE prices ENSURED that there would be a nationwide fall in RE prices.


Deadly accurate flak tore through the bombers. More often than not friendly bombs dropped from above.

My father worked on these statistics. He said that it was obvious that the smallest risk came from bombs from aircraft above you. The bombs were supposed to detonate at ground level. If you hit a plane on the way down, they should not explode. The antiaircraft fire on the way up was intended to explode when it got to the right height. The best thing you could do was to send in three levels of bombers at different heights, and swamp the ack-ack crews with too many things to shoot at. The anti-aircraft fire fuses could only be set to detonate at one height. There were proximity fuses, but they probably did not work very well.

So, given three bombing levels, which one should be the safest? Actually, the bottom one was the safest. You might have a dead-on hit with a bomb from the two levels above; but you were lower, which mean that any anti-aircraft gun had to track faster in order to follow you.

I guess what he could have done was to set up scale models in an aircraft hanger, and show the pilots how hard it was to hit an aircraft below, by dropping peas or something. But I doubt if anyone would have understood. Somehow, bombing your own chappies was much worse than taking one from Fritz. Go figure.


All analogies are wrong, but this one is silly and unhelpful. The engineers looking at bullet patterns on planes were united in purpose - they wanted to win the war, and therefore they wanted the planes to make it home.

The issue with modern problems is not some misconception about bullet patterns, it’s that people do not have the same goal.


Abraham Wald’s name should always be mentioned in this context.


The problem is… You american people entertainize everything…



It’s helpful to me to think about thinks like this.

I have a goal of increasing sales on my website, and I want to spend my effort where it will do the most good.

The customers who contact me most often ask what their shipping cost will be, so I assume that I’m not effectively communicating our free shipping policy to my customers, and that’s where I should put my effort.

However, I have a bounce rate approaching 60% of unique visits. Those customers don’t contact me. I have no idea what brought them to my site, or why they leave so quickly. This challenges my assumption that our shipping costs (or lack thereof) are our biggest obstacle to sales.


Holy crap! I’m sure the last thing an engineer would ever, ever want to hear is “This problem is hard to solve, but you solve similarly difficult technical problems every single day.” Horror-show material! I get shivers just thinking about it.

"Also, when you implement the radical new idea that augments human capabiltiies, can you make it look like a kitten?"


Indeed, you can smell a story somebody grabbed to make a point but wasn’t really true.


Short answer: because nobody pays them to do that. They pay them for exactly the sort of banal stuff that they churn out. There was somebody working on each of those at one points. Nobody bought his shit, and he quit.

There are of course, more specific answers for each of them. For example, the first two questions seem to amount to 1) why aren’t you more careful about breaking things, and 2) why haven’t you broken more things, but in a useful way?


… in an effort to save airmen, the Allies used statistical analysis to determine where the planes that limped home had taken flak and armored up those sections – which totally failed to work. That’s because …

For the purposes of the post this is an ok version of the story. It’s worth noting, though, that it completely inverts the story. Stats were used to solve the problem (or, at least, to mitigate the problem), not make it worse.

There were proximity fuzes, and they worked startlingly well. However, it’s an interesting design problem^, and one that only the Western Allies (UK and US) managed to solve during the war.

^ for one thing, the power supply must sit safely and inertly in storage for years or decades at a time AND spring instantly into life when the round is fired. In addition the sensor must be sufficiently robust to survive the shock of firing when it will accelerate from 0 - 3,000 fps in the space of 15 feet AND be sufficiently sensitive that it accurately register the fleeting presence of an aircraft and initiate the detonation sequence within the space of microseconds. And the whole thing had to fit into a space about 1/3rd the size of your coffee cup … using 1940s electronic components.


This is why we need fewer engineers and more hackers, inventors, and weirdos.


How does it go?

Prehistoric bodies.

15th century laws and culture.

21st century technology.


…our computers have turned out to be mind-numbing consumption devices. What happened to the bicycle for the mind that Steve Jobs envisioned?

LOL. Wasn’t he the one who turned it into a mind numbing consumption device?


I’d be surprised if this hasn’t come up in one episode or another of the BB “You Are Not So Smart” podcast…


That is the recipe for one of those charming ventures that attracts millions of dollars in seed capital before it goes belly-up and they have to start selling off all the extravagant playground equipment they bought for the employee lounge because there’s no one present who actually knows how to put a saleable product together.

Which is not to say that it always has to end up that way, or that it’s hopeless to try. But it seems to be a recurring narrative.


…via Medium, an excerpt from How Not to Be Wrong: The Power of Mathematical Thinking by Jordan Ellenberg]:

Abraham Wald and the Missing Bullet Holes

An interesting (and far more accurate!) account of the work of SRG, the Statistical Research Group headed by Wald.


Well, here I thought this was going to patch up a Globe-Post assertion, that all the Google and Amazon ads at news sites profit the newspapers nothing…which then went on to discuss Buzzfeed or something. You sure had a long article to summarize! (The tour winds through early CS design engineering.) And not one UML diagram proper.

If you liked the Singer-Towley Inequality, you’ll love Jamiroquai At The Office…


When I meet people who work at the world’s leading tech companies, I ask them about why they don’t look at the long term consequences of what they do on society? And I ask why they don’t allow radical new ideas that augment human capabilities?

That’s really two gigantic assumptions, isn’t it? What makes him think the world’s leading tech companies don’t look at long term consequences? Maybe they have some department that looks really hard at those things, but doesn’t report back to you.

And what makes him think they don’t allow radical new ideas that augment human capabilities? Wasn’t Google Glass meant to be exactly that? For that matter, doesn’t the cell phone fit that description really well? Anybody here remember sitting by the phone, waiting for it to ring?


I remember the British photoelectric proximity fuse having problems. I don’t think the Germans had a successful proximity fuse, though they did have substantial radar guided artillery. So, proximity fuses used against allied aircraft probably didn’t work very well. The US radar fuse was successful, but you still had to fire off 250 shells to hit one hostile aircraft, though this was a substantial improvement over the original 1000.