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

The two generals problem

The Two Generals Problem is a fun thought experiment highlighting the challenges of communicating over an unreliable channel. Your message may or may not get through, and how will you know if it didn't? The situation is that two armies on either side of a hostile valley are trying to coordinate an attack, and they want to attack simultaneously to be sure to succeed. The trouble is, to coordinate, they have to send brave messengers through the hostile valley to the other camp, and the messengers may or may not be captured along the way. To coordinate the attack, you have to know that your message got through, which you’d know if you received a confirmation. But how would the general sending the confirmation know that their confirmation got through unless they received a confirmation of the confirmation? And on… Also see: Metcalfe’s Law Idempotence…The Two Generals Problem is a fun thought experiment highlighting the challenges of communicating over an unreliable channel. Your message may or may not get through, and how will you know if it didn't? The situation is that two armies on either side of a hostile valley are trying to coordinate an attack, and they want to attack simultaneously to be sure to succeed. The trouble is, to coordinate, they have to send brave messengers through the hostile valley to the other camp, and the messengers may or may not be captured along the way. To coordinate the attack, you have to know that your message got through, which you’d know if you received a confirmation. But how would the general sending the confirmation know that their confirmation got through unless they received a confirmation of the confirmation? And on… Also see: Metcalfe’s Law Idempotence

14 Dec 2019

The cost of being late

It’s easy to think “it’s just a few minutes.” But as the number of people that you hold up increases, the true cost of being late scales rapidly. Being 10 mins late to a meeting with 10 others is 100 minutes. Holding the door for 20s on a train of 600 people is over 3 hours of time collectively. Unless your time is worth a lot more than everyone else’s it’s worth thinking twice before holding the door to a train or not taking the start of a meeting seriously. I think, at the end of the day, it’s really about respect.…It’s easy to think “it’s just a few minutes.” But as the number of people that you hold up increases, the true cost of being late scales rapidly. Being 10 mins late to a meeting with 10 others is 100 minutes. Holding the door for 20s on a train of 600 people is over 3 hours of time collectively. Unless your time is worth a lot more than everyone else’s it’s worth thinking twice before holding the door to a train or not taking the start of a meeting seriously. I think, at the end of the day, it’s really about respect.

7 Dec 2019

Law of diminishing returns

The law of diminishing returns: at some point, doing more of the same stops paying off like it used to. You might think that adding more of a good thing would make things better. And, yes, that’s often true, up to a point. However, the law of diminishing returns suggests that as you add more of a single factor, you are likely to yield progressively lower benefits. It’s like the old adage, “Too many cooks spoil the broth.” Another cook or two might help, but beyond that, they’ll probably start getting in each other’s way. Aside from cooking broth, you might see the law play out in spending on advertisements, quality improvements in production or your wealth. And we should also never forget that more is different. The sketchplanation is an homage to perhaps my favourite comedy sketch with an early-career Simon Pegg in the series Big Train: The Cake Factory (video). Well worth two and a half minutes. Also see: The law of diminishing brownies I updated this sketch for the release of Big Ideas Little Pictures. Here's the original…The law of diminishing returns: at some point, doing more of the same stops paying off like it used to. You might think that adding more of a good thing would make things better. And, yes, that’s often true, up to a point. However, the law of diminishing returns suggests that as you add more of a single factor, you are likely to yield progressively lower benefits. It’s like the old adage, “Too many cooks spoil the broth.” Another cook or two might help, but beyond that, they’ll probably start getting in each other’s way. Aside from cooking broth, you might see the law play out in spending on advertisements, quality improvements in production or your wealth. And we should also never forget that more is different. The sketchplanation is an homage to perhaps my favourite comedy sketch with an early-career Simon Pegg in the series Big Train: The Cake Factory (video). Well worth two and a half minutes. Also see: The law of diminishing brownies I updated this sketch for the release of Big Ideas Little Pictures. Here's the original

30 Nov 2019

Why do leaves change colour in fall and Autumn and what compounds make the colours?

Autumn leaves and the compounds that cause their colours

What a lovely time of year—when the leaves of deciduous trees in many forests change from the deep greens of summer to the yellows, oranges and reds of autumn. But what makes the leaves change colour, and what compounds are responsible for nature's spectacular display? Many of us will know the green of chlorophyll, but leaves also contain carotenoids. As the chlorophyll fades, the golden oranges of these carotenoids start to shine through. You may recognize one carotenoid, beta-carotene, from carrots. Another carotenoid, xanthophyll, is responsible for the beautiful bright yellows. The leaves of some trees also produce anthocyanin as autumn begins, which produces those beautiful deep reds. This sketch features in my book Big Ideas Little Pictures Also see: What causes seasons?…What a lovely time of year—when the leaves of deciduous trees in many forests change from the deep greens of summer to the yellows, oranges and reds of autumn. But what makes the leaves change colour, and what compounds are responsible for nature's spectacular display? Many of us will know the green of chlorophyll, but leaves also contain carotenoids. As the chlorophyll fades, the golden oranges of these carotenoids start to shine through. You may recognize one carotenoid, beta-carotene, from carrots. Another carotenoid, xanthophyll, is responsible for the beautiful bright yellows. The leaves of some trees also produce anthocyanin as autumn begins, which produces those beautiful deep reds. This sketch features in my book Big Ideas Little Pictures Also see: What causes seasons?

23 Nov 2019

Stock, Broth, Jus

Traditionally, stocks have the flavour and gelatinous collagen-y thickness that comes from cooking bones. Broth was cooked not with bones but with the meat itself. While a jus is a sauce made from the pan drippings, usually from a roast. This simple distinction I learned from Thomas Keller. Now, you can also have vegetable stock, so some other useful distinctions between stock and broth include that, generally, stock is intended to be used in the preparation of another dish rather than eaten directly like broth. As such, you would more likely use whole vegetables in stock to impart the flavour, but still scoop them out afterwards, while a broth would have cut vegetables ready to eat in the broth itself.…Traditionally, stocks have the flavour and gelatinous collagen-y thickness that comes from cooking bones. Broth was cooked not with bones but with the meat itself. While a jus is a sauce made from the pan drippings, usually from a roast. This simple distinction I learned from Thomas Keller. Now, you can also have vegetable stock, so some other useful distinctions between stock and broth include that, generally, stock is intended to be used in the preparation of another dish rather than eaten directly like broth. As such, you would more likely use whole vegetables in stock to impart the flavour, but still scoop them out afterwards, while a broth would have cut vegetables ready to eat in the broth itself.

16 Nov 2019

Who cut down the last tree?

If you lived on Easter Island, would you really cut down the last mighty tree knowing that would be it? It seems either foolhardy or desperate to knowingly cut down the last of a kind and your last source of timber. So how could it happen? Jared Diamond, in his book Collapse and article Easter’s End, explains how this situation could happen through a gradual, hardly noticeable decline over many years. Those who remembered the great trees which they used to make rafts, canoes and ships were old or had long since died. The trees seen today may be nothing like the forests and towering trunks of tens or hundreds of years ago. As Jared puts it: Gradually trees became fewer, smaller, and less important. By the time the last fruit-bearing adult palm tree was cut, palms had long since ceased to be of economic significance. That left only smaller and smaller palm saplings to clear each year, along with other bushes and treelets. No one would have noticed the felling of the last small palm. For another perspective, Seth Godin asks who cut down the second-to-last-tree?…If you lived on Easter Island, would you really cut down the last mighty tree knowing that would be it? It seems either foolhardy or desperate to knowingly cut down the last of a kind and your last source of timber. So how could it happen? Jared Diamond, in his book Collapse and article Easter’s End, explains how this situation could happen through a gradual, hardly noticeable decline over many years. Those who remembered the great trees which they used to make rafts, canoes and ships were old or had long since died. The trees seen today may be nothing like the forests and towering trunks of tens or hundreds of years ago. As Jared puts it: Gradually trees became fewer, smaller, and less important. By the time the last fruit-bearing adult palm tree was cut, palms had long since ceased to be of economic significance. That left only smaller and smaller palm saplings to clear each year, along with other bushes and treelets. No one would have noticed the felling of the last small palm. For another perspective, Seth Godin asks who cut down the second-to-last-tree?

10 Nov 2019

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