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

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What If? 2 summary

Name: What If? 2
Rating: 4.1 (202 reviews)
Author: Randall Munroe

Randall Munroe

Additional Serious Scientific Answers to Absurd Hypothetical Questions

4.1 (202 ratings)

17 mins

Brief summary

What If? 2 by Randall Munroe is a book that answers bizarre hypothetical questions with science, wit and creativity. It offers fascinating insights into the forces that shape our world and expands our knowledge in a fun and engaging way.

Topics

Physics Space Natural Sciences Learning

Table of Contents

What If? 2
Summary of 7 key ideas

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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.

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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.

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