---
title: "What If? (book)"
chunk: 2/2
source: "https://en.wikipedia.org/wiki/What_If?_(book)"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:35:07.917301+00:00"
instance: "kb-cron"
---

What would happen if you tried to hit a baseball pitched at 90% the speed of light?
Using mathematics and physics, Munroe concluded such a situation would result in a nuclear fusion explosion, and that ultimately, the result would be a ruling of hit by pitch. What If? approaches its subject matter with a sense of wit and sometimes makes use of approximations to answer questions that seem impossible to solve. Most questions demand assumptions and cross-disciplinary science skills to answer, resulting in "back-of-the-envelope" calculations. What If? is interspersed with "charmingly-amateur" stick figure illustrations.
The book also features periodic sections titled "Weird (and Worrying) Questions from the What If? Inbox", which are short collections of questions Munroe had not answered because he did not "want to think about that". In an interview, Munroe stated that he "never got past the initial mental image" of the question "How cold would your teeth have to get in order for a cup of hot coffee to make them shatter on contact?"

== Reception ==
The book was received positively by critics. Ethan Gilsdorf of the Boston Globe stated that "it's fun to watch as Munroe tackles each question and examines every possible complication." According to Gilsdorf, What If? gives a view into "Munroe's playful yet existentially-tinged worldview" by contrasting cataclysmic scenarios with more heady ideas, such as examining the effects of a magnitude minus-7 Richter scale earthquake. The Huffington Post remarked that "What makes Munroe's work so fantastic is a combination of two elements: his commitment to trying to answer even the weirdest question with solid science, and his undeniable sense of humor." Rhett Allain of Wired praised What If? because even his 12-year-old son was able to enjoy it, though he found a minor error in one of the sections.
Sam Hewitt of Varsity and Marla Desat of The Escapist noted that the first print run had some issues processing mathematical symbols, as a square box was displayed where a delta is supposed to be printed.
What If? was well-received commercially upon its release and reached the top of the New York Times bestsellers list on September 21. It was also featured as the "Amazon Best Book of the Month", and was translated into 35 languages.

== Notes ==

== References ==