What If? 2 Book Summary - What If? 2 Book explained in key points

Listen to the Intro

00:00

What If? 2 summary

Name: What If? 2
Rating: 4.1 (197 reviews)
Author: Randall Munroe

Randall Munroe

Additional Serious Scientific Answers to Absurd Hypothetical Questions

4.1 (197 ratings)

17 mins

Table of Contents

What If? 2
summarized in 7 key ideas

Audio & text in the Blinkist app

Key idea 1 of 7

What’s in it for me? Serious silliness.

How was the universe made? What is the meaning of life? What happens to us after we die? And how many humans would a Tyrannosaurus Rex need to eat to reach its recommended daily caloric intake?

This Blink can’t tell you the answers to the first three questions – but it might just give the answer to that last one!

Randall Munroe is the creator of the beloved webcomic xkcd as well as a physicist and a NASA alum. And he believes there’s no such thing as a silly question. Since 2012, Munroe has been inviting readers of his blog to send in the most absurd hypothetical questions they can think of – and answering them as seriously and scientifically as possible. This Blink collects Munroe’s answers to some of the strangest questions he’s ever received. Yes, like that one about the Tyrannosaurus Rex.

The answer, by the way, is about half a human adult, or one ten-year-old child. Or, if you want to avoid a scenario where you’re eaten by a T. Rex and there’s a McDonald’s nearby, approximately 80 Big Macs.

What would happen if Jupiter was shrunk to the size of a house and placed in a suburban street?

Do you want the bad news first, or the good news?

Well, let’s go with the good news: Jupiter is roughly the same density as water. If Jupiter was house-sized – so, let’s say about 50 feet wide – it would only weigh 2,500 tons. Meaning, your new neighbor isn’t about to mess around with your gravity by forming a black hole.

The bad news is that Jupiter isn’t actually made of water. Before Jupiter was, well, Jupiter, it was a big diffuse cloud of gas floating through space. Then, gravity caused this gas cloud to collapse in on itself. When gas is compressed it gets hot. Seriously hot. Jupiter, much like Earth, is formed of a thin, cool surface layer that keeps a lid on a scorching hot interior. As in, tens of thousands of degrees hot. Like all things that are blazing hot and super-compressed, Jupiter’s interior wants to expand. It doesn’t, but only because its own super-strong gravitational forces counteract that impulse.

Shrink Jupiter down to the size of a house and that massive gravitational force disappears.

So here’s what would happen.

Jupiter would expand rapidly outward in a boiling-hot fireball. That’s going to have quite a negative impact on property values in your street; because your street is going to be obliterated. In fact, your whole neighborhood is toast.

But, hey, let’s finish off with some more good news. This explosion will be fairly contained. When it’s not densely compressed, Jupiter’s molten hot core will cool rapidly. And Jupiter will return to its original form – as diffuse clouds of gas floating through the sky.

If the territories of Earth’s countries extended into the sky, which country would own most of the galaxy?

If every country’s territory extended infinitely upward, then Australia would be known not just as the land of kangaroos and the Hemsworth brothers but as the controller of the galaxy. How does this work?

Well, the Earth rotates, meaning that galactic airspace would actually change hands from country to country over the course of every 24 hours. But countries in the Southern Hemisphere, like Australia, have an unfair advantage here. The North Pole points away from the center of the Milky Way, leaving the southern hemisphere advantageously angled toward the galaxy’s core. The galaxy’s core – which by the way is a supermassive black hole – would rotate through the airspace of Australia, South Africa, Lesotho, Brazil, Argentina, and Chile. When the galaxy’s core was centered in Australian airspace, it would be able to lay claim to more galactic territory than any other country.

How many people would you need to actually build Rome in a day?

First things first – we all know how the expression goes. Rome was categorically not built in a day. But could it have been?

Well, the question assumes that simply putting more people on the job would speed up its completion. That’s almost definitely not the case as anyone who’s ever tried to plan a get-together of three-plus people can tell you; more people can mean more problems. And in the case of building Rome in one day, those problems include but aren’t limited to training and organizing a massive number of people to do specialized construction work all while avoiding bottlenecks as enormous crowds of laborers move around the relatively small city and coordinating supply chains to deliver huge loads of building materials when and where they’re needed.

Assuming you’re in a totally indestructible glass tube extending from the ocean’s surface to its bottom, what would it be like to stand at the deepest part of the ocean?

The answer to that question depends on whether or not you brought a nice thick sweater and a torch with long-life batteries down to the bottom of the ocean with you. If your totally indestructible glass tube stretched from above the surface of the sea right down to the deepest depths of the Mariana trench, you’d be three times deeper below sea level than the world’s deepest mines. In a mine, the deeper you go, the hotter you become. That’s because mines are drilled into rocks, which grow hotter the closer they get to Earth’s core. But the temperature at the bottom of the ocean is only slightly above freezing. So, you’re going to be cold. On the plus side, you’ll be able to see one of the least-visited sites on the planet, the floor of the Mariana Trench.

Just kidding. You won’t be able to see much at all, unless the sun passes directly over the mouth of your glass tube, which it will do exactly twice a year, around April 20 and August 23. After that, it’s another six months of total darkness. Unless that appeals, you should probably get in your elevator and come out.

Could a person eat a cloud?

Clouds are made of air and water. And water’s edible, right? Or potable, at least? So in theory, there should be nothing to stop a person from eating a cloud – apart from, you know, common sense, having better things to do with one’s time and the challenges of getting a cumulonimbus to sit still on your plate.

But here’s the problem. Unless you could come up with some way to squeeze the air out of the cloud before you started chewing it, it’s going to be impossible to ingest.

How big would a snowball grow if it was rolled from the top to the bottom of Mt. Everest?

Snowballs only grow in size when they’re rolled through wet, sticky snow which adheres to their surface. Mt. Everest is covered in dry, fluffy snow. So, even if you did manage to roll a snowball from the top to the bottom of Mt. Everest, your snowball would stay about the same size it was when you first rolled it.

Hypothetically, if Mt. Everest were covered in wet, sticky snow, how big would your snowball grow? Well, the bigger a snowball gets, the more snow it picks up. So it stands to reason that the more time a snowball spends rolling, picking up more and more snow, the faster it will grow. After all, we wouldn’t use the word snowballed to refer to exponential growth if it weren’t 100 percent accurate … would we?

Final Summary

Science doesn’t have to be serious, and math needn’t be monotonous! Stretching your brain by trying to find the answers to silly questions is a great way to train your analytical mind, while still having some fun.

Want to see all full key ideas from What If? 2?

Key ideas in What If? 2

More knowledge in less time

Read or listen

Get the key ideas from nonfiction bestsellers in minutes, not hours.

Find your next read

Get book lists curated by experts and personalized recommendations.

Shortcasts ^New

We’ve teamed up with podcast creators to bring you key insights from podcasts.

What is What If? 2 about?

What If? 2 (2022) is Randall Munroe’s follow-up to the New York Times best-selling What If? Like its predecessor, it comprises Munroe’s serious scientific answers to the absurd, funny, and whimsical questions submitted to him by readers, ranging from “How big would a snowball be if rolled from the top of Mt. Everest to the bottom?” to “Could a person eat a cloud?”

Who should read What If? 2?

Fans of xkcd’s nerd-culture humor
People who love science but don’t take it too seriously
Anyone who’s ever wondered what would happen if Jupiter were shrunk to the size of a suburban house

About the Author

Randall Munroe trained as a physicist and worked building robots at one of NASA’s research labs before quitting to focus full-time on his wildly successful webcomic xkcd, a tongue-in-cheek take on subjects including science, math, computer programming, and internet culture.

Categories with What If? 2

Science

Books like What If? 2

What If?

Randall Munroe

Serious Scientific Answers to Absurd Hypothetical Questions

18 min

3.5

The Biggest Ideas in the Universe

Sean Carroll

Space, Time, and Motion

Absurd Scientific Advice for Common Real-World Problems

"The Story of Radiation – How the New Science of the Human Body Is Changing the Way We Live"

Cosmic Perspectives on Civilization

A Philosophical Masterpiece on the Boundaries Between Good and Evil

30 min

4.7

Be Your Future Self Now

Dr. Benjamin Hardy

The Science of Intentional Transformation

16 min

4.6

Rewire Your Anxious Brain

Catherine M. Pittman & Elizabeth M. Karle

How to Use the Neuroscience of Fear to End Anxiety, Panic, and Worry

17 min

4.7

The Book of Five Rings

Miyamoto Musashi

A Classic Text on the Japanese Way of the Sword

18 min

4.6

The Future is Faster Than You Think

Peter H. Diamandis

How Converging Technologies Are Transforming Business, Industries, and Our Lives

The Hidden Determinants of Human Behaviour

A Comprehensive New Look at What Makes Us Women

18 min

4.5

How Big Things Get Done

Bent Flyvbjerg and Dan Gardner

The Surprising Factors Behind Every Successful Project, from Home Renovations to Space Exploration

15 min

4.0

Welcome to the Universe

Neil deGrasse Tyson

An Astrophysical Tour

37 min

4.8

On the Origin of Time

Thomas Hertog

Stephen Hawking's Final Theory

The Modern Prometheus

An uncommon guide to rapid fat-loss, incredible sex and becoming superhuman

Shackleton's Incredible Voyage

22 min

4.7

The Greatest Show on Earth

Richard Dawkins

The Evidence for Evolution

End Self-Sabotage and Demand Your Life Back

A Tell-All Memoir of the British Royal Family and the Institution

19 min

4.1

Change Your Brain, Change Your Life

Dr. Daniel G. Amen

The Breakthrough Program for Conquering Anxiety, Depression, Obsessiveness, Anger, and Impulsiveness

14 min

4.2

Procrastination

Jane B. Burka & Lenora M. Yuen

Why You Do It, What to Do About It Now

Where Science Meets Pseudoscience

22 min

4.0

DIRTY LAUNDRY

Richard Pink & Roxanne Emery

Why adults with ADHD are so ashamed and what we can do to help

17 min

4.4

The Communist Manifesto

Karl Marx and Friedrich Engels

Workers of the world unite!

A Guide To Spiritual Enlightenment

An Epic Science Fiction Novel on the Politics of Humanity

21 min

4.3

Powerful Phrases for Dealing with Difficult People

Renée Evenson

Over 325 Ready-to-use Words and Phrases for Working with Challenging Personalities

And How We Can Get There

Upgrade Your Brain, Learn Anything Faster, and Unlock Your Exceptional Life

An influential existentialist essay about living your life with greater passion and freedom

14 min

4.7

(Article) Why can't the world's greatest minds solve the mystery of consciousness?

Oliver Burkeman

Original article published in The Guardian

The Fight to Master Our Greatest Opponent

Classic military strategy for politics, business, and everyday life

Why We Do What We Do in Life and Business

28 min

4.4

Guns, Germs and Steel

Jared Diamond

The Fates Of Human Societies

The Magic and Mayhem of Growing Up a Wizard

Uncover Your Power and Set Yourself Free

A Very Short Introduction

21 min

4.4

The January 6th Report

Select Committee to Investigate the January 6th Attack on the United States Capitol

The Final Report on the Capitol Insurrection That Shook America

A Mindful Guide to Breaking the Cycle of Reactive Parenting and Raising Kind, Confident Kids

How to Forge the Deep Connections That Make Great Things Happen

26 min

4.2

Impromptu

Reid Hoffman with GPT-4

Amplifying Our Humanity Through AI

17 min

4.4

Becoming Supernatural

Dr. Joe Dispenza

How Common People are Doing the Uncommon

15 min

4.2

Million Dollar Habits

Brian Tracy

Proven Power Practices to Double and Triple Your Income

18 min

4.4

The Emperor's New Mind

Roger Penrose

Concerning Computers, Minds, and the Laws of Physics

A Dystopian Classic on the Dark Side of Human Nature and Survival

19 min

4.6

Meditations on First Philosophy

René Descartes

Descartes Most Famous Philosophical Classic

11 min

4.2

People ❤️ Blinkist

Sven O.

It's highly addictive to get core insights on personally relevant topics without repetition or triviality. Added to that the apps ability to suggest kindred interests opens up a foundation of knowledge.

Thi Viet Quynh N.

Great app. Good selection of book summaries you can read or listen to while commuting. Instead of scrolling through your social media news feed, this is a much better way to spend your spare time in my opinion.

Jonathan A.

Life changing. The concept of being able to grasp a book's main point in such a short time truly opens multiple opportunities to grow every area of your life at a faster rate.

Renee D.

Great app. Addicting. Perfect for wait times, morning coffee, evening before bed. Extremely well written, thorough, easy to use.