Sketchplanations

Explaining one thing a week in a sketch

Sketchplanations

Explaining one thing a week in a sketch

Idling

An average car, sat idling, can produce exhaust emissions to fill 150 balloons. That's a lot of balloons to imagine puffing away out of the cars idling outside a school for a pickup, say. Other tests have found (pdf) that for any time over 10s fuel use and emissions are always greater when idling than turning off the engine and restarting. Spread the word. Of course, if you have an electric car this won't apply. I did draw 150 balloons, but a few of them didn't fit on the page.
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The haversine formula

It might seem straightforward to pull out a map and measure the distance between two distant points, however, the larger the distance the bigger the distortion caused by traveling on the curved surface of the Earth as opposed to flat 2D space. So while the distance you measure to your neighbouring town won't be too bad, if you're measuring between London and Rio the curvature of the Earth will make a big difference to the distance that you'll travel. To help figure out the correct distance there's the haversine formula. The haversine formula allows you to calculate the shortest distance between two points on a sphere using their latitudes and longitudes — this will be the arc between them on the great circle that includes both points. A great circle is a circle on a sphere with the same centre as the sphere, like the Equator. The haversine formula isn't perfect in practice, as Earth isn't a perfect sphere — see the 3 tallest mountains. It was invented around two hundred years ago, together with tables to speed any calculations, to help sailors navigate. Also see, the Mercator projection
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The goal-gradient effect

Intuitively, we can relate to this: as we get closer to completing a goal we can feel more motivation to complete it. Getting close to the last piece of a puzzle, the last clue of a murder mystery or escape room, the final chapter of your book (perhaps), the final kilometre of a marathon, or as you find you need just one more stamp to get a free coffee, being so close to our goal can give us a motivation lift to get to the end. It has a name: the goal-gradient effect*. In the example in the sketch, Oleg Urminksy and coauthors found that as people approached the final stamp towards a free coffee they were more likely to pick up the rate of buying coffees. And when issued with the new card, the coffee buying rate went back down again. They also found that it wasn't so much the absolute 'distance' from a goal, but the perception of distance. So, people who started out on a 12 stamp card with 2 stamps already complete tended to complete the card faster than the people who had a 10 stamp card starting empty even though it was the same number of stamps to the goal. Read more in Katy Milkman and Kassie Brabaw's Scientific American article, Why Feeling Close to the Finish Line Makes You Push Harder. Katy Milkman also educated me about the fresh start effect. *The goal-gradient effect is also known as the goal-gradient hypothesis
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The Swiss Cheese Model

Despite all our best intentions, accidents happen. Analysis of accidents in large complex systems such as power stations or plane crashes led to an understanding that "no one failure, human or technical, is sufficient to cause an accident. Rather, it involves the unlikely and often unforeseeable conjunction of several contributing factors arising from different levels of the system." James Reason's Swiss Cheese Model is a memorable visual metaphor that illustrates how each safeguard may contain a latent flaw, or hole, and that an unfortunate circumstance, may result in these holes lining up to disastrous effect. It's also a nice reminder that multiple layers of defence will be more effective, but even with our best efforts, there's still potential for something to go wrong. Excerpt from Revisiting the "Swiss Cheese" Model of Accidents (pdf), Reason, Hollnagel and Paries, 2006. Coronavirus example from the Cleveland Clinic.
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The 4 horsemen of relationship apocalypse

John Gottman and colleagues identified what he calls the four horsemen of the apocalypse for relationships. They are called this as, left unchecked, they can spell the death knell to a once healthy relationship. In fact, they found that by watching just 3 mins of a conflict conversation between a couple they could predict whether they would still be together years later with over 90% accuracy. The four horsemen are: Criticism: framing problems as the partner's defect Defensiveness: counterattacking, whining, being the innocent victim Contempt: talking down from a position of superiority, insults, eye-rolling, name-calling — the most dangerous of all Stonewalling: withdrawing from the conflict, refusing to engage In my first draft of this sketch I left it at that, but it felt a bit negative to leave it hanging on everything we do that's wrong and harmful. Fortunately, there are antidotes to the four horsemen, the traits they saw the masters at relationships use instead. The Gottman Institute explains the four horsemen and their antidotes in more detail. Watch John Gottman explain the four horsemen in his own words.
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