What If? - critical summary review

When Randall Munroe was five years old, he asked his mother if there are more soft things or hard things in the world. Ever since then, he hasn’t stopped using math to try to deal with weird questions such as that. Based on his blog of the same name, “What If?” is a collection of light-hearted but scientifically-grounded answers to unusual and even absurd reader-submitted questions. So, get ready to find out a few things about the world you never knew you wanted to know!

What if everyone actually had only one soul mate?

In the world of romance, no cliché is more prevalent than that of the soul mate. Originating with Plato, the idea is rather simple: somewhere on this planet, there is a perfect match for each person, the other half to make them whole. While many people nowadays feel this is just an unfalsifiable myth, many others still believe that soul mates are real and spend their lives searching for theirs. Do they have any chance of finding them?

Let’s assume first that everyone actually has one – and only one – soul mate, randomly chosen at birth. Yes, that includes you too. Now, let’s also assume that your soul mate lives at the same time as you and is within a few years of your age. That excludes all those 93 billion people who have died, as well as the countless billions who aren’t born yet. That also takes into consideration the unwritten “half-plus-seven rule” – better known as the “age-gap creepiness formula” – which asserts that it is creepy to date anyone who is younger than half your age plus seven years. Complications aside, after applying all these restrictions, most people would have a pool of about half a billion potential matches. Remember: only one of them is the right one.

Now, as the romantic cliché goes, you shouldn’t know anything about who or where your soul mate is, but should be able to recognize them the very moment your eyes meet. Even if you are an extrovert living in New York, chances are you lock eyes with no more than a few dozen new strangers each day. If even 20% of them are close to your age, that would be around 100,000 people in the average lifetime. But that’s only a small part of the half billion potential matches we mentioned above. In other words, even if reincarnation exists and souls can travel across time and bodies, you would find your soul mate in just one lifetime out of 5,000!

Governments can make things easier if they collaborate to develop a modified global version of ChatRoulette, the popular online chat website that pairs random users for webcam-based conversations. But even then, every single person on this planet would have to use the website for eight hours a day, seven days a week – and decide within the first two seconds if someone is their soul mate or not – for the system to match everyone up with their soul mate in a few decades. Of course, in the real world, we all have jobs and many other responsibilities, and the system wouldn’t work if all people don’t use it as prescribed. So, all in all, the chances of finding your soul mate – given it exists – are incredibly small. “A world of random soul mates would be a lonely one,” concludes Munroe. “Let’s hope that’s not what we live in.”

Wouldn’t the common cold be wiped out if everyone was in self-isolation for some time?

The coronavirus pandemic of 2020 reminded us that we are not the only species on this planet; for better or worse, we share it with a variety of viruses. Several years before quarantines and self-isolations became a thing, a reader of Munroe’s blog wondered what these protective measures might do to the common cold? More precisely, what would happen to the viruses causing the disease if everyone on the planet stayed away from each other for a couple of weeks? Wouldn’t the common cold be wiped out entirely?

In theory, “yes.” From a purely biological point of view, most rhinoviruses – the most common culprit for the common cold – are completely eliminated from the body by the immune system. In other words, once the infection is gone, they don’t linger inside the body. So, if rhinoviruses – and most other RNA respiratory viruses – didn’t have enough humans to move between, they would be wiped out by our immune systems.

We know this for a fact. Far to the northwest of Scotland, there is an isolated archipelago called St. Kilda. It has been populated for millennia, but never by more than 180 people. In the past, whenever a boat would visit the island – a rare occurrence – an outbreak of an unusual syndrome, called “the stranger’s cough” by the natives, would almost immediately follow. However, after several weeks – when all St. Kilda residents would develop immunity –  with nowhere left to go, the rhinovirus would die out, and the stranger’s cough would disappear entirely. If everybody on this planet was put in a quarantine, the same would happen to the common cold.

There are three problems with this scenario. The first one considers the practical, financial consequences. Interrupting all economic activity for a few weeks would probably cause a global economic collapse. After all, even the partial pause of many activities during the coronavirus pandemic cost trillions of dollars and resulted in millions of unemployed people. The second problem is logistical. For everyone to be isolated from everyone else, some people would have to be stuck in a quarantine in the Sahara Desert or central Antarctica which are not very pleasant places to live in. 

The third problem is the most serious one and it unravels the whole plan. Namely, not everyone has a healthy immune system, and in immunocompromised people (more than 3% of the world’s population) a rhinovirus can linger for weeks, months, and even years. What’s scarier is that the virus would need to survive in just a few hosts for a few weeks to reappear in the world once the quarantine was over. So, unless a vaccine stops them, we cannot. Not even if we tried really, really, really hard.

What would happen to the Earth if the Sun suddenly switched off?

According to Munroe, this question is “the single most popular submission to What If.” Since the consequences of the Sun becoming “a cold, inert sphere” are many, we’ll have a look at just a few, but quite enough to give you a good idea:

• Reduced risk of solar flares. Solar flares are sudden flashes of increased brightness on the Sun, usually accompanied by geomagnetic storms which induce electric currents in wires. When one of these occurred on September 1, 1859, it knocked out communications and caused telegraph equipment to catch fire. Nowadays, we have a lot more wires, so, if the 1859 solar flare reoccurred, the economic damage to the U.S. alone would be several trillion dollars. But, if the Sun is suddenly switched off, we would never have to worry about solar flares anymore!
• Better astronomy. The cooler the air, the less the atmospheric noise. Consequently, without the Sun, ground-based observatories would not only be able to operate around the clock but would also produce sharper images.
• Improved satellite service. The Sun interferes with radio signals coming from satellites when they pass in front of it, causing an interruption in service. A cold Sun would solve this problem.
• Reduced infrastructure costs. Most bridges are over water. However, without the Sun, we would be able to save a lot of money “by simply driving on a strip of asphalt laid across the ice.”
• Cheaper trade. In the absence of the Sun, time zones would become obsolete. And if every country in the world switched to one time zone, it would be a lot easier to do business around the world.
• Safer children. Because babies have very sensitive skin, it is advised that those younger than six months are kept out of direct sunlight at all times. But no Sun means no problem for babies – and no worries for their parents. 
• Safer combat pilots. For reasons unknown, bright sunlight causes sneezing. When combat pilots sneeze during flight, it poses danger to them and everyone around them. If the Sun went dark, pilots would never have to deal with this strange reflex anymore.

So, all in all, if the Sun suddenly switched off, “we would see a variety of benefits across many areas of our lives.” There’s only one, single downside. Unfortunately, it is a big one. A very, very big one. If the Sun went out, we would all freeze and die.

Some of our other favorite what if’s: a short-answer section

“What If?” thoroughly and scientifically answers more than 50 questions such as the three above. Since many of them are enjoyable and attention-grabbing, rather than going over Munroe’s argumentation for a fourth one, we opted to share with you a few short answers to several other “what if’s.” Here they are: 

• How much computing power could we achieve if the entire world population stopped whatever we are doing right now and started doing calculations? Believe it or not, the equivalent of just one single typical desktop computer, produced in 1994! Yes, that’s how powerful modern computers are. 
• How many unique English tweets are possible? A lot. Back when tweets were only 140 characters long, the answer was: no less than 2 x 1046 “meaningfully different English tweets.” To better understand the size of that number, think about it this way: if the entire human population read these tweets aloud for 16 hours a day, every single day, it would hardly “make a meaningful dent” in the list of potential tweets by the time the Earth is absorbed by the Sun more than 7.5 billion years from now. “While 140 characters may not seem like a lot,” comments Munroe, “we will never run out of things to say.”
• If you had a printed version of the whole English Wikipedia, how many printers would you need in order to keep up with the changes made to the live version? As of January 2020, a hypothetical printed Wikipedia would span about 2,700 volumes. Keeping up with the live edits is a different matter altogether. Quite surprisingly – it’s something you should be able to do at home, using just six printers! The caveat? They would need to be running constantly and be managed 24/7. Not to mention, it would probably cost you half a million dollars in the first two months alone!
• When, if ever, will Facebook contain more profiles of dead people than of living ones? If Facebook remains with us for generations, and never declines in popularity, the crossover date would be somewhere in the 2130s. However, it’s highly unlikely this would happen. A more likely scenario is that Facebook will start losing market share over the next decade. In that case, the dead should outnumber the living sometime during the 2060s, or, just a few decades from now. 

Final Notes

Dubbed “required reading” by The New York Times, “What If?” is a sweeping triumph. To paraphrase a Register review, the book not only makes science “really, really cool,” but it also makes adults feel like they are kids with chemistry sets all over again.

Randal Munroe is a national treasure and “What If?” a book so terrific you’ll want to read it more than twice. Yes, we said twice, because that’s a given.

12min Tip

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