Art to science

Art and science of baseball bats

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Shattering bats are dangerous for both the players and the fans. Why do bats shatter? Why did the incidence jump? 

Source: The Reason Baseball Bats Break Is More Complicated Than You Think Gizmodo, which  pulled the story from YouTube’s Practical Engineer.

Comment: In terms of technological knowledge, the shift from ash to maple wood for bats made some of the manufacturing and hitting knowledge obsolete. It took an MLB study to identify the problem. The solution was to adjust a seemingly minor design decision — the direction they place their logo. The intermediate causal variables were the different grain structures of the two woods.

Recently, bat-makers have started rotating their logos by 90 degrees on maple bats, as well as marking the grain on the handles. Bat breaks have gone down about 50 percent as a result

Is technical knowledge fractal?

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My analysis of technical knowledge in manufacturing, aviation, and elsewhere suggests that it is fractal, i.e. that any portion of a knowledge graph can be further decomposed into a detailed knowledge graph in its own right. Limits on human knowledge mean that the frontiers of current graphs are always “fuzzy,” i.e. at low stages of knowledge. Further technology development will clarify clarify the current periphery of a graph, but reveals new fuzzy portions.

To the extent this hypothesis is true, i.e. that knowledge is fractal, it has a lot of implications. For example, high-tech industries must operate in frontier regions where much is known, but some important issues are not well understood. People are better than machines at dealing with ambiguity, so the faster the rate of technological progress, the more an industry needs people and cannot automate its activities.

 

Tumblr? Pinterest? What should I use?

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What’s a good place to put supplemental information, especially photos and tables, for my book? I have a lot of old photographs, and putting them into the book itself gets expensive. Some are in color and some are very large. Here are a few examples.
I could set up my own site, or use my publisher’s, but places like Tumblr know how to run photo sites. The ideal features I want include being able to link to pictures on other sites (due to copyright restrictions), able to create tables of contents, etc. Straight chronology won’t suffice.

Obvious candidates

include Tumblr, Pinterest, Instagram. I don’t use any of them except to dabble, so I don’t know their strengths. Possibly Twitter or Facebook?

All advice welcome. Email me, or post comments here.

How to reduce chances of a hoverboard fire

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Wired has a good article on fires from “hoverboards,” which are essentially very small hands-free electric scooters. Here is an example. Start at about the :30 mark to see how these devices explode, and can easily set a house on fire.


Neither Wired nor other news stories have much constructive advice about how to reduce the chance of fires. As they point out, buying a well-made model is important, but at present there is no way to distinguish the well-made ones from the knock-offs. And most are cheap knock-offs by companies that will be gone in a year.

I have some experience with the underlying cause of these fires,  their Lithium-based batteries, because I use them in radio controlled aircraft. Fires of these batteries are not common, but they happen. Two people in San Diego who I know directly have had major fires. One lost a 2-unit condo, the other a detached workshop. The second one happened to an expert in RC flying!

Continue reading →

Airbus design again contributes to crash

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One contributor to the A320 crash off Brazil in 2009 (Air France 447) was that the two pilots were making opposite inputs on their control sticks. The aircraft was in a stall, and therefore it was crucial to push the nose down, to regain airspeed. The instinctive human reaction (of untrained people) is to pull the nose up, since the airplane is falling. To oversimplify a long sequence of events drastically, pilot made the correct move, but the other pilot apparently panicked, and pulled back on his control stick. He continued to do this as they fell from 40,000 feet all the way to the Atlantic Ocean.

A new accident report says that the same thing happened in the crash of an  Indonesia AirAsia Airbus A320, flight QZ8501, last year.

Continue reading →

Are urban hospitals better?

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I was teaching the Virginia Mason VMMC case in Tech & Operations Management yesterday, and made a loose comment about busy urban hospitals being better than suburban ones. For example in the UC San Diego system, when someone is my family is really sick  I try to take them to the downtown (dilapidated, overcrowded) UCSD hospital before I’d go to the one near campus (hotel-like, luxurious).

A student asked “why”, forcing me to do a little research. Here is my answer to her. Continue reading →

How often do pilots skip checklist steps?

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Board blames fatal overrun on pilot error.
Source: NTSB Issues Bedford Gulfstream IV Crash Report | Flying Magazine

Checklists were a major innovation in flying, and are now being pushed in health care. But as I research this, it’s clear that although pilots all swear by them, use is less than 100%. Perhaps less than 99% – and a 1% error rate is very high when there are hundreds of items on a flight.

It’s very hard to know the real number. But the pilots in this crash, both very experienced, did pre-takeoff control checks for less than 10% of their flights!

Data from a recorder installed in the airplane showed that in the previous 176 takeoffs, full flight control checks as called for on the GIV’s checklist were carried out only twice and partial checks only 16 times. The pilots on the evening of the accident skipped the flight control check, which might have revealed to them that the gust lock mechanism was still engaged.

This particular item – forgetting to unlock the “gust locks” – has been killing pilots since the first gust locks. Famous examples in the 1930s were the prototype B-17, and the head of the German Air Force. (Both discussed in my forthcoming chapter on standard procedures in aviation.)
Gulfstream IV jet with six on board - crashed and burned after failed takeoff.