Explaining the world one sketch at a time

Simplifying complex ideas through fun and insightful sketches. Explore topics from science, creativity, psychology, and more explained in pictures.

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Learn something new in a sketch each Sunday

Recent sketches

Jevon’s Paradox

Jevon's paradox is that improvements in fuel efficiency tend to increase fuel use, not decrease it as you might expect. In 1865, a chap named William Stanley Jevons noted that while there had been a number of improvements in coal efficiency in steam engines and the like, the effect was to increase consumption instead of reduce it. This observation became known as Jevon's paradox. While it’s not a surefire outcome, there are plenty of parallels like more efficient batteries leading to more overall battery use, washing machines leading to doing more washes rather than less time spent washing, or the ability to recycle some plastics leading to more overall plastic consumption. In her book More Work for Mother, Ruth Cowan addresses the ironies of household technology and how improvements in the efficiency of household devices often led to more work, not less. This is sometimes known as the rebound effect. Also see: the fifth fuel: energy efficiency save some landfill the automation paradox…Jevon's paradox is that improvements in fuel efficiency tend to increase fuel use, not decrease it as you might expect. In 1865, a chap named William Stanley Jevons noted that while there had been a number of improvements in coal efficiency in steam engines and the like, the effect was to increase consumption instead of reduce it. This observation became known as Jevon's paradox. While it’s not a surefire outcome, there are plenty of parallels like more efficient batteries leading to more overall battery use, washing machines leading to doing more washes rather than less time spent washing, or the ability to recycle some plastics leading to more overall plastic consumption. In her book More Work for Mother, Ruth Cowan addresses the ironies of household technology and how improvements in the efficiency of household devices often led to more work, not less. This is sometimes known as the rebound effect. Also see: the fifth fuel: energy efficiency save some landfill the automation paradox

2 Dec 2018

Marchetti’s constant

Marchetti's constant is the idea that people across history budget, on average, about an hour a day for travelling. Originally observed by Yacov Zahavi, it came from the observation that even as our means of transport sped up, instead of travelling less each day, we would just travel further. As in the sketch, this leads to a conclusion that the size of our cities increases partly according to how efficiently we can travel in and out—they generally increase to a size that maintains about an hour round-trip journey. Cesare Marchetti observed that Greek villages and ancient walking cities, for example, as marked by ancient city walls, tend to share a radius of about 2.5km. Walking at a typical 5km/hr makes a one-hour round-trip journey. He also pointed out that: “Even people in prison for a life sentence, having nothing to do and nowhere to go, walk around for one hour a day, in the open.” Unfortunately, if you live in London, the average round-trip seems to be an exception of 1h30. This is also known as the constant travel time budget hypothesis. Also see: Isochrones. It might be interesting to look at these according to transport method Our senses are built to take in information at human pace Image adapted from: Marchetti, C., 1994: Anthropological Invariants in Travel Behavior, Technological Forecasting and Social Change , 47 :75–88, Internal Publication, International Institute for Applied Systems Analysis.…Marchetti's constant is the idea that people across history budget, on average, about an hour a day for travelling. Originally observed by Yacov Zahavi, it came from the observation that even as our means of transport sped up, instead of travelling less each day, we would just travel further. As in the sketch, this leads to a conclusion that the size of our cities increases partly according to how efficiently we can travel in and out—they generally increase to a size that maintains about an hour round-trip journey. Cesare Marchetti observed that Greek villages and ancient walking cities, for example, as marked by ancient city walls, tend to share a radius of about 2.5km. Walking at a typical 5km/hr makes a one-hour round-trip journey. He also pointed out that: “Even people in prison for a life sentence, having nothing to do and nowhere to go, walk around for one hour a day, in the open.” Unfortunately, if you live in London, the average round-trip seems to be an exception of 1h30. This is also known as the constant travel time budget hypothesis. Also see: Isochrones. It might be interesting to look at these according to transport method Our senses are built to take in information at human pace Image adapted from: Marchetti, C., 1994: Anthropological Invariants in Travel Behavior, Technological Forecasting and Social Change , 47 :75–88, Internal Publication, International Institute for Applied Systems Analysis.

25 Nov 2018

The Availability Heuristic illustration: Plane crashes, cold snaps, and winning lottery tickets are shown as examples of uncommon but widely reported events that might affect the significance we associate with them.

The availability heuristic (and bias)

The availability heuristic is a deceptively simple, almost too simple to notice, heuristic where we consider the likelihood of events by the ease with which relevant instances come to mind. In simple terms, things that we can easily recall or where we can think of examples, we generally consider as more important or more common than other things. A heuristic is a mental shortcut to solve a common problem. If we were asked to consider the divorce rate in the community, we might evaluate that by considering how many of our acquaintances are divorced. If none of your friends are divorced, you’re naturally less likely to think the divorce rate locally will be high. In many situations, it makes good sense to give credence to what you remember easily. However, in situations involving probabilities, in particular, the heuristic will lead us predictably astray such that more often I think of it as an availability bias — a predictable pattern of thought and behaviour leading to incorrect conclusions. So, the vividness of shark attacks causes us to overrate how likely they are to actually occur. Or we’re more likely to worry about lions than hippos, even though hippos kill more people each year than lions. Or the risk of being struck by lightning vs stuck by a car crossing a road. Or, the prevalence of violent crime on the news compared to the likelihood of you being a victim. Or the fact that it’s cold outside and yet the planet is gradually warming. Here’s a 1973 Kahneman and Tversky paper: Availability: A Heuristic for Judging Frequency and Probability…The availability heuristic is a deceptively simple, almost too simple to notice, heuristic where we consider the likelihood of events by the ease with which relevant instances come to mind. In simple terms, things that we can easily recall or where we can think of examples, we generally consider as more important or more common than other things. A heuristic is a mental shortcut to solve a common problem. If we were asked to consider the divorce rate in the community, we might evaluate that by considering how many of our acquaintances are divorced. If none of your friends are divorced, you’re naturally less likely to think the divorce rate locally will be high. In many situations, it makes good sense to give credence to what you remember easily. However, in situations involving probabilities, in particular, the heuristic will lead us predictably astray such that more often I think of it as an availability bias — a predictable pattern of thought and behaviour leading to incorrect conclusions. So, the vividness of shark attacks causes us to overrate how likely they are to actually occur. Or we’re more likely to worry about lions than hippos, even though hippos kill more people each year than lions. Or the risk of being struck by lightning vs stuck by a car crossing a road. Or, the prevalence of violent crime on the news compared to the likelihood of you being a victim. Or the fact that it’s cold outside and yet the planet is gradually warming. Here’s a 1973 Kahneman and Tversky paper: Availability: A Heuristic for Judging Frequency and Probability

17 Nov 2018

The Pomodoro Technique ®

The Pomodoro technique, or Pomodoro method, is a super simple method to help you get your tasks done. Named after a pomodoro (tomato) kitchen timer, the essence of it involves considering in advance how many pomodoros you might need for what you want to get done, setting your timer for, normally, 25 minutes and then focusing on your task until the time’s up. Then take a 5-minute break. That’s one pomodoro. After you’ve done four pomodoros take a longer break, of about 30 minutes. Some tips: Protect your pomodoro from distractions — make sure that you spend the full 25 minutes on your task. If people want things let them know you’ll get back to them after your pomodoro. Properly break in your breaks — no sneaky working. It’s flexible, not rigid. If you need longer or shorter times, that’s OK. It’s about what helps you focus. You only need a timer, but there are a number of simple apps that can help if you want to try it too, like this nice one with a bear: Bear Focus Timer. The Pomodoro Technique ® was created and named by Francesco Cirillo. If you like the Pomodoro Technique, you might also like the other sketches of my toolkit for life in my book Big Ideas Little Pictures, which even has a lovely review from Bill Gates.…The Pomodoro technique, or Pomodoro method, is a super simple method to help you get your tasks done. Named after a pomodoro (tomato) kitchen timer, the essence of it involves considering in advance how many pomodoros you might need for what you want to get done, setting your timer for, normally, 25 minutes and then focusing on your task until the time’s up. Then take a 5-minute break. That’s one pomodoro. After you’ve done four pomodoros take a longer break, of about 30 minutes. Some tips: Protect your pomodoro from distractions — make sure that you spend the full 25 minutes on your task. If people want things let them know you’ll get back to them after your pomodoro. Properly break in your breaks — no sneaky working. It’s flexible, not rigid. If you need longer or shorter times, that’s OK. It’s about what helps you focus. You only need a timer, but there are a number of simple apps that can help if you want to try it too, like this nice one with a bear: Bear Focus Timer. The Pomodoro Technique ® was created and named by Francesco Cirillo. If you like the Pomodoro Technique, you might also like the other sketches of my toolkit for life in my book Big Ideas Little Pictures, which even has a lovely review from Bill Gates.

10 Nov 2018

Mercator Projection illustration: shows the consequences of flattening out a spherical globe. Whilst it's a handy exercise for navigating and producing maps, it can inflate the size of land masses the in the north and the south. In a Mercator projection Greenland is comparable in size with Africa. In reality, it's much smaller.

The Mercator projection

All maps involve decisions. Whenever you compress real life onto something smaller and less detailed you have to choose what to keep in and what to leave out. And in the case of printing a map of the Earth, you have to figure out how to get something that is curved onto something that is flat, and this involves trade-offs and decisions as well. 3 dimensional space just doesn’t flatten to 2 dimensional paper without choices. In 1569 Gerardus Mercator created a map that brilliantly solved a pressing problem — that of being able to follow a straight line while sailing and it correspond to a straight line on the map. His map also did a good job of preserving the shape of countries. But to do this you have to stretch the areas at the top and bottom of the Earth. Because most of the land on Earth is in the Northern hemisphere, and because that land is generally further north than the land in the southern hemisphere is south, it has the effect of enlarging Northern countries such as Europe, the US and Canada, Scandinavia and Russia as compared to countries closer to the equator and in the Southern hemisphere. Most world maps you see are still similar to Mercator’s projection. In fact Google Maps desktop used it until just recently. It could well be that this distorts our worldview by emphasizing Northern countries in size and therefore importance. When I see a more size accurate Gall-Peters projection I have to say it’s hard to argue. The West Wing did this brilliantly. HT: Paul Lewis…All maps involve decisions. Whenever you compress real life onto something smaller and less detailed you have to choose what to keep in and what to leave out. And in the case of printing a map of the Earth, you have to figure out how to get something that is curved onto something that is flat, and this involves trade-offs and decisions as well. 3 dimensional space just doesn’t flatten to 2 dimensional paper without choices. In 1569 Gerardus Mercator created a map that brilliantly solved a pressing problem — that of being able to follow a straight line while sailing and it correspond to a straight line on the map. His map also did a good job of preserving the shape of countries. But to do this you have to stretch the areas at the top and bottom of the Earth. Because most of the land on Earth is in the Northern hemisphere, and because that land is generally further north than the land in the southern hemisphere is south, it has the effect of enlarging Northern countries such as Europe, the US and Canada, Scandinavia and Russia as compared to countries closer to the equator and in the Southern hemisphere. Most world maps you see are still similar to Mercator’s projection. In fact Google Maps desktop used it until just recently. It could well be that this distorts our worldview by emphasizing Northern countries in size and therefore importance. When I see a more size accurate Gall-Peters projection I have to say it’s hard to argue. The West Wing did this brilliantly. HT: Paul Lewis

3 Nov 2018

The Diderot Effect

Coined after the French philosopher Denis Diderot’s remarkably titled essay “Regrets on Parting with My Old Dressing Gown”. The gist of the effect is that we generally surround ourselves with objects that fit our current sense of identity. If we get something that doesn’t fit that identity, we may find ourselves replacing the rest to match the new identity. Poor Diderot was given a fancy new dressing gown, but he ended up replacing most of his possessions and ultimately living in poverty, to paraphrase a little. The Diderot Effect was introduced by Grant McCracken, and I learned about it, once again, from Atomic Habits. Diderot also played a key role in the development of the encyclopedia as I learned from Seth Godin’s podcast, Akimbo. Also see: The Diderot effect, The Streisand effect…Coined after the French philosopher Denis Diderot’s remarkably titled essay “Regrets on Parting with My Old Dressing Gown”. The gist of the effect is that we generally surround ourselves with objects that fit our current sense of identity. If we get something that doesn’t fit that identity, we may find ourselves replacing the rest to match the new identity. Poor Diderot was given a fancy new dressing gown, but he ended up replacing most of his possessions and ultimately living in poverty, to paraphrase a little. The Diderot Effect was introduced by Grant McCracken, and I learned about it, once again, from Atomic Habits. Diderot also played a key role in the development of the encyclopedia as I learned from Seth Godin’s podcast, Akimbo. Also see: The Diderot effect, The Streisand effect

28 Oct 2018

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