53 pages 1 hour read

Randall Munroe

What If?: Serious Scientific Answers to Absurd Hypothetical Questions

Nonfiction | Book | Adult | Published in 2014

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Chapters 51-69Chapter Summaries & Analyses

Chapter 51 Summary: “Lego Bridge”

Question: “How many Lego bricks would it take to build a bridge capable of carrying traffic from London to New York?” (222).

The two cities are separated by a distance equal to 350 million LEGO bricks. A sturdy bridge one meter thick and five meters wide could support car traffic.

Subject to the stresses of the high seas, though, the bridge would have to be taller and wider still, coated in sealant for buoyancy, tied by cables to the ocean floor, and supported by LEGO pylons. Costs would exceed $5 trillion. It would be cheaper to dismantle all of London, ship it to New York, and reassemble it there.

Chapter 52 Summary: “Longest Sunset”

Question: “What is the longest possible sunset you can experience while driving […]?” (228).

Near the poles, the sun can set in odd ways. The furthest-north decent road is Norway’s Route 69, on which, driving north as the sun begins to set, you can stretch out the sunset to 95 minutes.

Chapter 53 Summary: “Random Sneeze Call”

Question: “If you call a random phone number and say ‘God bless you,’ what are the chances that the person who answers just sneezed?” (233).

Research suggests that the average person sneezes roughly once a day. The odds that, when you call, they’ve just sneezed are one in 40,000.