what if?

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Not to be confused with 17: What If.


what if? is a blog hosted on the xkcd.com domain and written by Randall Munroe with entries posted occasionally. Before publishing the what if? book, articles were posted weekly.

On the blog, Randall uses his degree in physics and strong scientific background to discuss hypothetical physics questions apparently submitted by readers. Since 2014, there's also a book of the blog.

Unlike other sites which answer readers' questions, what if? typically takes the question beyond the original scope likely intended by the reader and takes it to some extreme for humorous effect. For example, in the first article, he discusses what would happen if a baseball were pitched at 90% of the speed of light. After effectively describing what would occur as a nuclear explosion, leveling the stadium and the surrounding mile radius, he concludes with the note "A careful reading of official Major League Baseball Rule 6.08(b) suggests that in this situation, the batter would be considered 'hit by pitch', and would be eligible to advance to first base."

The questions Randall tackles range from realistic possibilities (e.g. the probability of achieving a perfect SAT score by guessing) to completely fictional questions (e.g. How much Force power can Yoda output?). In his explanations, Randall, often uses diagrams in an xkcd style. Regardless of the context, Randall tends to take the questions extremely literally and responds seriously to them, even if they are whimsical (such as the Yoda question). This is clear from his response to the question of what would happen if everybody on Earth stood together and jumped at the same time. After acknowledging that the question has been answered elsewhere, he recaps the result, but then focuses more intently on the unasked resulting issue of the aftermath of everyone on Earth being magically transported to one location as they all try to return home.

This site is not under Creative Commons Attribution-NonCommercial 2.5 License like xkcd is.

Randal took a hiatus from updates from May 2015 to July 14th 2015 with a note stating "What If updates are temporarily on hold, and will resume on July 14th, 2015 at 7:49:59 AM EDT." This was the date and time that the New Horizons probe achieved its closest approach to Pluto. The article for July 14th was about the New Horizons probe.

[edit] The book

Randall announced his what if? book on 12 March 2014 in the blag. It was published on September 2, 2014, and the UK edition of the book was published on September 4, 2014.

The general cover of the book

It is just like 'xkcd:volume 0' a compilation of some questions from the website, but half of them are new.

In the UK edition of the book, Randall included a preface about his thoughts on the units used in the UK. (The Metric System)

[edit] Summary

The summary on the back of the book reads:

Randall Munroe left NASA in 2005 to start up his hugely popular site XKCD 'a web comic of romance, sarcasm, math and language' which offers a witty take on the world of science and geeks. It now has 600,000 to a million page hits daily. Every now and then, Munroe would get emails asking him to arbitrate a science debate. 'My friend and I were arguing about what would happen if a bullet got struck by lightning, and we agreed that you should resolve it . . . ' He liked these questions so much that he started up What If.

  • If your cells suddenly lost the power to divide, how long would you survive?
  • How dangerous is it, really, to be in a swimming pool in a thunderstorm?
  • If we hooked turbines to people exercising in gyms, how much power could we produce?
  • What if everyone only had one soulmate?
  • When (if ever) did the sun go down on the British empire?
  • How fast can you hit a speed bump while driving and live?
  • What would happen if the moon went away?

In pursuit of answers, Munroe runs computer simulations, pores over stacks of declassified military research memos, solves differential equations, and consults with nuclear reactor operators. His responses are masterpieces of clarity and hilarity, studded with memorable cartoons and infographics. They often predict the complete annihilation of humankind, or at least a really big explosion. Far more than a book for geeks, WHAT IF: Serious Scientific Answers to Absurd Hypothetical Questions explains the laws of science in operation in a way that every intelligent reader will enjoy and feel much the smarter for having read.

The summary on the back of the UK edition of the book reads:

Hey! Thanks for looking at my book. If you're thinking about buying it, here are some things you might want to know:

Humans can't digest the cellulose in paper, but if we could, eating this book would give you about 2,300 calories (including the cover).

This book can't stop most bullets; if you want to use it for armour, you may want a lot more than one copy.

If you have a good arm, you could probably throw this book about 45 feet. With practice, it's possible to throw a book every 800 milliseconds, which means that if human attackers are sprinting towards you, you'll have three or four chances to hit them before they reach you. If, on the other hand, you're being attacked by a coyote, it's higher top speed means you'll have only one chance to hit it. Aim carefully.

HIDDEN FEATURE: The inside of this book has words and pictures, plus a special UK foreword. It answers many important questions, including whether you could jump from a plane with a helium tank and inflate balloons fast enough to slow your fall and survive (yes) and whether you could hide from a supersonic windstorm in Finland (yes, but it won't help).

[edit] Articles

  1. Relativistic Baseball
  2. SAT Guessing
  3. Yoda
  4. A Mole of Moles
  5. Robot Apocalypse
  6. Glass Half Empty
  7. Everybody Out
  8. Everybody Jump
  9. Soul Mates
  10. Cassini
  11. Droppings
  12. Rain Drop
  13. Laser Pointer
  14. Short Answer Section
  15. Mariana Trench Explosion
  16. Today's Topic: Lightning
  17. Green Cows
  18. BB Gun
  19. Tie Vote
  20. Diamond
  21. Machine Gun Jetpack
  22. Cost of Pennies
  23. Short Answer Section II
  24. Model Rockets
  25. Three Wise Men
  26. Leap Seconds
  27. Death Rate
  28. Steak Drop
  29. Spent Fuel Pool
  30. Interplanetary Cessna
  31. FedEx Bandwidth
  32. Hubble
  33. Ships
  34. Twitter
  35. Hairdryer
  36. Cornstarch
  37. Supersonic Stereo
  38. Voyager
  39. Hockey Puck
  40. Pressure Cooker
  41. Go West
  42. Longest Sunset
  43. Train Loop
  44. High Throw
  45. ISS Music Video
  46. Bowling Ball
  47. Alien Astronomers
  48. Sunset on the British Empire
  49. Sunless Earth
  50. Extreme Boating
  51. Free Fall
  52. Bouncy Balls
  53. Drain the Oceans
  54. Drain the Oceans: Part II
  55. Random Sneeze Call
  56. Restraining an Airplane
  57. Dropping a Mountain
  58. Orbital Speed
  59. Updating a Printed Wikipedia
  60. Signs of Life
  61. Speed Bump
  62. Falling With Helium
  63. Google Datacenters on Punchcards
  64. Rising Steadily
  65. Twitter Timeline Height
  66. 500 MPH
  67. Expanding Earth
  68. Little Planet
  69. Facebook of the Dead
  70. The Constant Groundskeeper
  71. Stirring Tea
  72. Loneliest Human
  73. Lethal Neutrinos
  74. Soda Planet
  75. Phone Keypad
  76. Reading Every Book
  77. Growth Rate
  78. T-rex Calories
  79. Lake Tea
  80. Pile of Viruses
  81. Catch!
  82. Hitting a Comet
  83. Star Sand
  84. Paint the Earth
  85. Rocket Golf
  86. Far-Travelling Objects
  87. Enforced by Radar
  88. Soda Sequestration
  89. Tungsten Countertop
  90. Great Tree, Great Axe
  91. Faucet Power
  92. One-Second Day
  93. Windshield Raindrops
  94. Billion-Story Building
  95. Pyramid Energy
  96. $2 Undecillion Lawsuit
  97. Burning Pollen
  98. Blood Alcohol
  99. Starlings
  100. WWII Films
  101. Plastic Dinosaurs
  102. Keyboard Power
  103. Vanishing Water
  104. Global Snow
  105. Cannibalism
  106. Ink Molecules
  107. Letter to Mom
  108. Expensive Shoebox
  109. Into the Blue
  110. Walking New York
  111. All the Money
  112. Balloon Car
  113. Visit Every State
  114. Antimatter
  115. Into the Sun
  116. No-Rules Nascar
  117. Distant Death
  118. Physical Salary
  119. Laser Umbrella
  120. Alternate Universe What Ifs
  121. Frozen Rivers
  122. Lava Lamp
  123. Fairy Demographics
  124. Lunar Swimming
  125. Bowling Ball
  126. Stairs
  127. Tug of War
  128. Zippo Phone
  129. Black Hole Moon
  130. Snow Removal
  131. Microwaves
  132. Hotter Than Average
  133. Flagpole
  134. Space Burial
  135. Digging Downward
  136. Spiders vs. the Sun
  137. New Horizons
  138. Jupiter Submarine
  139. Jupiter Descending
  140. Proton Earth, Electron Moon
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