Sketchplanations - A weekly explanation in a sketch

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Explaining the world one sketch at a time

Prospect theory

Dan Kahneman and Amos Tversky’s behavioural economics theory modeling how we make decisions. It illustrates, among other things, some of the non-rational decisions we make as we are guided by emotion and heuristics in decisions. The sketch points out a few of the key points: Loss aversion - the different shape of the curves as we make gains or losses (either side of the centre) represents how a loss of £100 annoys us much more than a gain of £100 gives us pleasure. Diminishing sensitivity - the levelling off of the curves represents that we’ll enjoy winning £100, if we only have £100, much more than we’d enjoy winning £100 if we had £900. Adaptation level - We don’t evaluate from some absolute level - we evaluate whether something is good or bad from a neutral reference point that we adapt to. So, by the end of a movie the movie theatre doesn’t feel dark, yet walking out feels blinding. Your reaction to the £100 example above was probably affected by whether you think £100 is a lot of money or a little, which is all to do with your adaptation level.…Dan Kahneman and Amos Tversky’s behavioural economics theory modeling how we make decisions. It illustrates, among other things, some of the non-rational decisions we make as we are guided by emotion and heuristics in decisions. The sketch points out a few of the key points: Loss aversion - the different shape of the curves as we make gains or losses (either side of the centre) represents how a loss of £100 annoys us much more than a gain of £100 gives us pleasure. Diminishing sensitivity - the levelling off of the curves represents that we’ll enjoy winning £100, if we only have £100, much more than we’d enjoy winning £100 if we had £900. Adaptation level - We don’t evaluate from some absolute level - we evaluate whether something is good or bad from a neutral reference point that we adapt to. So, by the end of a movie the movie theatre doesn’t feel dark, yet walking out feels blinding. Your reaction to the £100 example above was probably affected by whether you think £100 is a lot of money or a little, which is all to do with your adaptation level.

14 May 2015

How to find south using the Southern Cross and The Pointers in the Southern hemisphere using the stars and the night sky

Use the Southern Cross to find South (Southern Hemisphere)

Navigating by the stars is both lovely and handy. Unlike the Northern Hemisphere, where you can find Polaris, the North Star, to know which way is north, there's no obvious star that indicates south in the Southern Hemisphere. Instead, you have to use two handy indicators: the Southern Cross—easily spotted, fortunately—and two stars known as The Pointers. Find where these intersect, as in the sketch, and you’ve found due south. Or, if you prefer, you can follow the direction the Southern Cross is pointing for a distance equal to 4.5 times the length of the constellation to arrive at the spot. Incidentally, I wondered about reliable methods of finding south in the Northern Hemisphere and north in the Southern Hemisphere. The simple answer is to find north or south and turn around. Related Ideas to Use the Southern Cross to Find South Find North with the North Star (Northern Hemisphere) Redshift Orbit Looking Back in Time I updated this sketch for my book Big Ideas Little Pictures…Navigating by the stars is both lovely and handy. Unlike the Northern Hemisphere, where you can find Polaris, the North Star, to know which way is north, there's no obvious star that indicates south in the Southern Hemisphere. Instead, you have to use two handy indicators: the Southern Cross—easily spotted, fortunately—and two stars known as The Pointers. Find where these intersect, as in the sketch, and you’ve found due south. Or, if you prefer, you can follow the direction the Southern Cross is pointing for a distance equal to 4.5 times the length of the constellation to arrive at the spot. Incidentally, I wondered about reliable methods of finding south in the Northern Hemisphere and north in the Southern Hemisphere. The simple answer is to find north or south and turn around. Related Ideas to Use the Southern Cross to Find South Find North with the North Star (Northern Hemisphere) Redshift Orbit Looking Back in Time I updated this sketch for my book Big Ideas Little Pictures

7 May 2015

How to find the North Star in the northern hemisphere and find north using the stars and the night sky

How to Find the North Star to Find North (Northern Hemisphere)

The Pole Star or North Star (Polaris) is a navigator’s best friend as it is always due North. To find it, follow the two stars on the end of the cup in the Big Dipper (or the Plough in the UK)—part of the constellation Ursa Major or Great Bear—to the most prominent star. The North Star happens to be the last star in the tail of the Little Dipper—the constellation Ursa Minor or the Little Bear. Handy for a navigation sanity check at night. The North Star is the star that stays fixed in those neat star trail photos in which all the other stars rotate in a circle as the Earth turns. In the Southern hemisphere, you can use the Southern Cross and the Pointers to find South, but it's not quite as simple as in the North. Related Ideas to Use the Southern Cross to Find South Find South with the Southern Cross (Southern Hemisphere) Redshift Orbit Looking Back in Time I updated this sketch for my book Big Ideas Little Pictures…The Pole Star or North Star (Polaris) is a navigator’s best friend as it is always due North. To find it, follow the two stars on the end of the cup in the Big Dipper (or the Plough in the UK)—part of the constellation Ursa Major or Great Bear—to the most prominent star. The North Star happens to be the last star in the tail of the Little Dipper—the constellation Ursa Minor or the Little Bear. Handy for a navigation sanity check at night. The North Star is the star that stays fixed in those neat star trail photos in which all the other stars rotate in a circle as the Earth turns. In the Southern hemisphere, you can use the Southern Cross and the Pointers to find South, but it's not quite as simple as in the North. Related Ideas to Use the Southern Cross to Find South Find South with the Southern Cross (Southern Hemisphere) Redshift Orbit Looking Back in Time I updated this sketch for my book Big Ideas Little Pictures

30 Apr 2015

Pole star

Aligned with Earth’s axis of rotation. Appears largely fixed above the poles. The Northern Hemisphere has a Pole Star that will point you North, and the Southern hemisphere’s Pole Star will point you towards South. Handy. Also responsible for some great photography worth checking out.…

23 Apr 2015

POSH: Port Out Starboard Home (apocryphal)

Sadly it turns out that there is not reliable evidence for this derivation of the word POSH, but it’s so nice I’d finished the sketchplanation before I knew it. The story went that if you were travelling by boat from Western Europe to India and the Far East by boat back in the day the rich people naturally took the best cabins. And the best cabins on the way Out, were on the Port side so you got a great view of the coast all the way around Africa. And on the way back on the Starboard site to enjoy the view once more. Et voila POSH as a synonym for rich. After much digging I had to conclude that the story was apocryphal, but it’s nice nonetheless. I apologise for maintaining this rumour.…Sadly it turns out that there is not reliable evidence for this derivation of the word POSH, but it’s so nice I’d finished the sketchplanation before I knew it. The story went that if you were travelling by boat from Western Europe to India and the Far East by boat back in the day the rich people naturally took the best cabins. And the best cabins on the way Out, were on the Port side so you got a great view of the coast all the way around Africa. And on the way back on the Starboard site to enjoy the view once more. Et voila POSH as a synonym for rich. After much digging I had to conclude that the story was apocryphal, but it’s nice nonetheless. I apologise for maintaining this rumour.

16 Apr 2015

Scoville scale: chile heat via capsaicin content

The scale of spicy.…

9 Apr 2015

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