null island

Humble Pi: A Comedy of Maths Errors by Matt Parker

8-hour work day, Affordable Care Act / Obamacare, bitcoin, British Empire, Brownian motion, Chuck Templeton: OpenTable:, collateralized debt obligation, computer age, correlation does not imply causation, crowdsourcing, Donald Trump, fake news, Flash crash, forensic accounting, game design, High speed trading, Julian Assange, millennium bug, Minecraft, Neil Armstrong, null island, obamacare, off-by-one error, orbital mechanics / astrodynamics, publication bias, Richard Feynman, Richard Feynman: Challenger O-ring, selection bias, SQL injection, subprime mortgage crisis, Tacoma Narrows Bridge, Therac-25, value at risk, WikiLeaks, Y2K

The LAPD fixed this with a time-honoured method for taking care of a sudden glut of criminals: it transported them to a distant island. Null Island. Null Island is a small but proud island nation off the west coast of Africa. It’s located about 600 kilometres south of Ghana, and you can find it by putting its latitude and longitude into any mapping software of your choice: 0,0. Fun fact: its coordinates look like the facial expression of anyone deported there. For, you see, outside of databases, Null Island does not exist. It really does live up to its slogan: ‘Like No Place on Earth!’ Bad data is the scourge of databases, in particular when the data has been originally written down by fallible humans in their imprecise handwriting.

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Cartography was a rather antiquated and fusty old discipline until it was swept up by the modern tech revolution. Now, they have an audience for their own brand of humour. For generations, cartographers have been sneaking fictitious places into real maps (often as a way to expose people plagiarizing their work), and it was inevitable that Null Island would take on a life of its own. So, they literally put it on the map.fn2 If you believe their marketing material, Null Island has a thriving population, a flag, a department of tourism and the world’s highest per capita Segway ownership. Even when the data has made it into a database, it is not safe … which brings us, finally, to Microsoft Excel. My opinion of Excel is a matter of public record: I’m a big fan.

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Advertising Standards Authority: 198.64179–199.41791 Air Canada: 85.20896–85.23881, 87.41791–88.20896 Air Force: 69.00000–73.94216, 286.62687–287.50746 air traffic control: 302.95522–304.00000 Ariane rocket: 20.41791, 26.56530–27.26866, 29.80597–30.59515 attractiveness scores: 68.35821–69.53731 average Australian: 74.62687–75.95522, 77.56716–77.82090 Avery Blank: 258.02985–258.17910 Benford’s Law: 36.80597–40.95709 Big data: 259.62687–259.74627 big enough: 27.17910–27.47761, 40.50746, 73.14925, 171.20896, 196.02799, 303.08955–304.44776, 313.86567 big number: 47.74627, 203.55224, 253.77612, 289.05970, 310.00000–311.72948, 313.80597 Bill Gates: 141.11940, 160.05970 billion seconds: 290.23881–291.44776, 310.23881–310.41791 binary number: 34.29851, 179.38806–180.50746, 182.35821, 185.35821, 189.41791, 191.08955–191.53731, 246.23881, 250.05970–251.92537, 290.35821, 292.65672–292.80597, 301.00000 brewing beer: 147.89552, 149.59701 Brian Test: 258.02985–258.86567 Casio fx: 11.74627, 175.00000 cause problems: 81.23881, 122.29851–122.56716, 144.20896, 249.56716 CEO pay: 131.53731–131.62687, 133.29851–133.41791 cheese slices: 4.74627, 102.95709 classic football: 235.80597, 238.44776 clay tablets: 149.50746–150.89552 clocks going: 112.08955–114.71642 clockwise anticlockwise: 216.26866 Cluster mission: 29.68657–30.86381 computer code: 29.89552, 123.59701, 187.57836, 189.17910, 191.23881–192.68657, 250.14925, 256.56716, 261.80597, 289.53731, 302.38806–303.02985 constant width: 221.59701–222.86567 cot death: 167.56716–167.68657 crescent moon: 229.11940–231.92537 Datasaurus Dozen: 56.53731, 67.95709–68.92537 Date Line: 286.02985–286.56716 daylight saving: 64.11940–65.92537, 112.05970–114.83582 deliberately vague: somewhere in 7 to 10 and maybe 74 Dice O Matic: 52.20896–52.44776 diehard package: 34.00000–35.86567 Dow Jones: 125.29851, 143.00000–144.47761 drug trial: 62.47761–63.53731 electron beam: 184.05970, 186.53731–186.83582 expensive book: 141.14925–142.86567 explain why: 16.68657, 208.11940, 312.86567–312.89552 false positive: 64.62687, 154.74627, 247.08955, 252.50746, 276.86567, 301.20896, 308.26866–309.86567 fat fingers error: 143.44776, 150.11940 feedback loop: 144.35821, 268.08955–269.86567, 274.26866, 276.02985–277.80597 fence post problem: 208.83582–209.47761 Fenchurch Street: 280.20896, 282.35821–283.38806 fibre optic cable: 136.32836–136.89552, 138.08955 flash crash: 143.41791–144.38806 foot doughnut: 235.50933–235.71642 frigorific mixture: 92.44776–92.68657 fuel gauges: 85.05970–87.92537 full body workout: 213.71642–213.95522 functional sausage: 123.44776–123.47761 gene names: 247.00000–248.47761 Gimli Glider: 82.11940–83.68657 GOOD LUCK: 25.74627, 83.47761–84.83582, 288.74440 Gregorian calendar: 288.14925–288.41791, 293.08955–296.92537 Grime Dice: 160.56716–160.90672, 162.14925 Harrier Jet: 311.00000–313.65672 heart attacks: 64.11940–65.89552, 112.11940–114.92537 high frequency trading: 142.53731, 145.44776–146.71642 Hot Cheese: 1.92537, 4.59701 human brains: 149.05970, 159.00000, 266.29851, 308.02985–309.44776 Hyatt Regency: 264.80597, 267.95522 International Date Line: 286.02985–286.56716 JPMorgan Chase: 240.80597–241.68657 Julian calendar: 295.23881–297.59701 Julius Caesar: 206.32836–206.89552, 293.80597, 297.17910–298.56716 Kansas City: 264.80597–264.86567, 267.95522 lava lamps: 31.27612–32.82090 leap years: 206.29851, 288.47761, 295.26866, 297.00000–298.86567 Lego bricks: 201.05970–202.95522 long enough: 55.77425–56.83582, 99.20896–99.26866, 171.08955, 194.50746, 246.86567, 303.44776 Los Angeles: 255.17910–255.65672, 302.20896, 305.53731 magic squares: 6.11940–7.89552 Mars Climate Orbiter: 96.80410–97.87873 maths error: 9.91418, 11.29851, 28.56716, 79.62687, 97.75933, 147.50746, 175.00000, 181.56716, 245.68657, 304.29851–305.86567 maths mistake: 7.35821–8.11940, 89.65672, 149.80597, 174.11940–175.65672, 181.59701, 206.65672–206.71642, 210.14925, 259.71642, 264.41791, 300.08955, 305.47761, 308.74627–308.95522 McChoice Menu: 197.02985, 199.44776–200.00000 Millennium Bridge: 269.68657–269.83582, 274.26866–277.41791, 280.00000–281.68657 mobile phone masts: 57.19403–59.92537 most important: 6.00000, 190.62687 Mr Average: 74.14925–75.53731 NBA players: 166.17910–166.44776 non transitive dice: 141.17910, 160.00000–162.14925 non zero: 157.35821, 183.20896, 185.17910, 192.74627 Null Island: 254.50746–255.95522 null meal: 197.74627, 199.26866–200.50746 oddly specific: 117.2089552238806, 139.1194029850746, 190.5074626865672, 245.7462686567164 off-by-one errors: 206.53731, 209.65672–211.17910 Olympic Games: 293.26866, 300.14925 Parker Square: 5.05970–6.89552 Penney Ante: 163.32836–163.38806 Pepsi Points: 311.69963–313.71642 phone masts: 57.19403–59.92537 plug seal: 100.90672 Pseudorandom number generators: 43.74627–44.44776, 47.56716–48.86567 punch cards: 73.74627–73.77612, 75.08955–76.74627 real world: 38.34328–40.23881, 121.38806, 123.80597, 145.95522, 208.02985, 241.26866, 244.53731–245.95522 resonant frequencies: 269.68657–269.74627, 274.23881–280.95522 Richard Feynman: 154.95522, 222.00000–223.29851 rm -rf: 23.08955–23.47761 Rock Paper Scissors: 163.50746–163.71642 roll over errors: 25.38806, 180.32836, 184.53731, 190.26866–191.20896 Royal Mint: 215.92537–216.85075 salami slicing: 121.35821–123.80597 salt mines: 232.00000–233.80597 scientific notation: 249.32836–250.77612, 252.00000–253.83582 Scud missile: 179.00000–181.65672 sea level: 89.17910–89.83582 seemingly arbitrary: 53.20896, 190.38806, 296.86567, 302.23881 Sesame Street: 230.00000–230.26866 should open: 225.53731–225.62687, 227.41791–227.44776 skin tight garments: 73.23881–73.26866 something else: 57.29851, 64.65672, 247.02985, 270.11940, 301.14925 Space Invaders: 19.59701–21.83396 space shuttle: 4.10448–4.34328, 152.26866–153.50746, 223.14925–223.35821, 230.80597–230.89552 SQL injection: 250.11940, 256.02985 standard deviation: 34.35821–34.53731, 66.93097–68.83582, 73.65672, 132.86381 Steve Null: 258.00000–259.80597, 261.47761 Stock Exchange: 123.71642, 125.08955–125.65672, 145.29851–145.62687, 150.26866–151.92351 stock options: 131.14925–133.92537 street signs: 233.29851–234.38806, 238.35634–238.50746 survivor bias: 13.89552, 21.32836, 65.53731–66.77612 Swiss Cheese model: 4.56716–4.83582, 13.23881, 103.80597 synchronous lateral excitation: 276.38806–277.38806, 280.62687 T shirt: 5.00000–5.02985, 313.41791–313.62687 tabulating machines: 73.74627, 75.08955–76.65672 Tacoma Narrows Bridge: 268.47761–270.29851 tallest mountain: 115.11940–116.89552 tax return: 36.71642–36.80597, 38.61194, 41.05970–42.92537 Therac machine: 13.00000, 185.05970–185.80597 three cogs: 214.00000–215.74813, 219.02985–220.35821 Tokyo Stock Exchange: 125.38806, 150.26866–151.92351 torsional instability: 268.17910–271.89552 trading algorithms: 138.77612, 142.53731–142.74627, 144.23881–146.68657 Traffic Control: 302.20896–305.68657 Trump administration: 128.17910–129.89552 UK government: 52.47761, 233.23881–234.83582, 238.86567, 256.44776 UK lottery: 155.38806–155.86567, 159.41791–159.92537, 308.08955–308.14925 UK street signs: 238.35634–238.50746 US army: 179.77612, 181.68657–181.71642 USS Yorktown: 175.20896–175.77425 Vancouver Stock Exchange: 123.71642, 125.08955–125.65672 waka waka: 189.95709 went wrong: 27.62687, 29.80597, 84.41791, 134.80597–134.92537, 145.77612, 265.20896, 267.50746, 280.62687, 286.65672, 305.89552 Wobbly Bridge: 97.66978, 280.11940–280.41791 Woolworths locations: 60.00000–60.62687 world record: 119.11940–121.77612, 135.35261, 298.77612 wrong bolts: 99.02985–99.74627, 101.17910–102.70149, 104.77612 X rays: 185.86567–186.80597 THE BEGINNING Let the conversation begin … Follow the Penguin twitter.com/penguinukbooks Keep up-to-date with all our stories youtube.com/penguinbooks Pin ‘Penguin Books’ to your pinterest.com/penguinukbooks Like ‘Penguin Books’ on facebook.com/penguinbooks Listen to Penguin at soundcloud.com/penguin-books Find out more about the author and discover more stories like this at penguin.co.uk ALLEN LANE UK | USA | Canada | Ireland | Australia India | New Zealand | South Africa Allen Lane is part of the Penguin Random House group of companies whose addresses can be found at global.penguinrandomhouse.com.

PostGIS in Action by Regina O. Obe, Leo S. Hsu

business logic, call centre, crowdsourcing, database schema, Debian, domain-specific language, en.wikipedia.org, Firefox, functional programming, Google Earth, job automation, McMansion, Mercator projection, Network effects, null island, openstreetmap, planetary scale, profit maximization, Ruby on Rails, Skype, South of Market, San Francisco, SQL injection, traveling salesman, web application

How far am I from pizza (spheroid distance) SELECT h.name As house, p.name As pizza, ST_Distance(h.my_point, p.my_point) As dist FROM (SELECT name, my_point FROM ch02.my_geogs WHERE name = 'Home') As h CROSS JOIN (SELECT name, my_point FROM ch02.my_geogs WHERE name LIKE 'Pizza%') As p; For listing 2.13, the distance is 156899.568... meters for both pizza parlors. Points in geography correspond to longitude and latitude, and distances are always computed in meters. This example puts your home on the Republic of Null Island (http://www.nullisland.com), and the pizza stores are on islands to the northeast and the southeast. If you performed the same distance computation using geometry, you’d end up with 1.414... (the square root of 2)—a straightforward Pythagorean calculation. At the equator, one degree is approximately 110.944 meters, so the previous geometry answers tell you that you’re about 156,874 meters from pizza.

PostGIS in Action, 2nd Edition by Regina O. Obe, Leo S. Hsu

business logic, call centre, crowdsourcing, database schema, Debian, domain-specific language, en.wikipedia.org, Firefox, functional programming, Google Earth, job automation, McMansion, megacity, Mercator projection, Network effects, null island, openstreetmap, planetary scale, profit maximization, Ruby on Rails, Skype, South of Market, San Francisco, SQL injection, traveling salesman, web application

Listing 2.13 How far am I from pizza (spheroid distance) SELECT h.name As house, p.name As pizza, ST_Distance(h.my_point, p.my_point) As dist FROM (SELECT name, my_point FROM ch02.my_geogs WHERE name = 'Home') As h CROSS JOIN (SELECT name, my_point FROM ch02.my_geogs WHERE name LIKE 'Pizza%') As p; For listing 2.13, the distance is 156899.568... meters for both pizza parlors. Points in geography correspond to longitude and latitude, and distances are always computed in meters. This example puts your home on the Republic of Null Island (http:// www.nullisland.com), and the pizza stores are on islands to the northeast and the Licensed to tracy moore <nordick.an@gmail.com> www.it-ebooks.info 54 CHAPTER 2 Spatial data types southeast. If you performed the same distance computation using geometry, you’d end up with 1.414... (the square root of 2)—a straightforward Pythagorean calculation.