Introduction
Have you ever wondered how many humans a Tyrannosaurus Rex would need to eat to meet its daily calorie requirements? Or what would happen if Jupiter suddenly appeared in your neighborhood, shrunk down to the size of a house? These are the kinds of questions that keep Randall Munroe, creator of the popular webcomic xkcd and former NASA employee, up at night. In his book "What If? 2," Munroe takes on some of the most absurd hypothetical questions submitted by his readers and answers them with rigorous scientific analysis and a healthy dose of humor.
This book is a celebration of curiosity, creativity, and the joy of scientific exploration. It reminds us that there's no such thing as a silly question, as long as you're willing to pursue the answer with seriousness and dedication. Through Munroe's witty and informative responses, readers are taken on a journey through various scientific disciplines, from physics and astronomy to biology and engineering.
Let's dive into some of the most intriguing questions and answers from "What If? 2," exploring the fascinating world of hypothetical scenarios and the science behind them.
The T. Rex Diet Plan
One of the first questions Munroe tackles is about the dietary needs of a Tyrannosaurus Rex. Specifically, how many humans would this fearsome predator need to consume to meet its daily caloric requirements?
The answer, it turns out, is surprisingly modest. A T. Rex would only need to eat about half of an adult human or one ten-year-old child to satisfy its daily energy needs. For those who prefer their measurements in fast food units, that's equivalent to roughly 80 Big Macs.
This question, while seemingly frivolous, actually provides insight into the energy requirements of large predators and how they compare to modern human diets. It also serves as a reminder of how efficient our bodies are at storing and using energy, compared to the massive creatures that once roamed the Earth.
Jupiter in the Suburbs
Another intriguing scenario Munroe explores is what would happen if Jupiter, the largest planet in our solar system, was suddenly shrunk to the size of a house and placed in a suburban street.
The good news is that a house-sized Jupiter wouldn't immediately form a black hole or cause major gravitational disturbances. At about 50 feet wide, it would weigh around 2,500 tons - heavy, but not cosmically catastrophic.
However, the bad news is that Jupiter's interior is incredibly hot and compressed. Without its enormous size and gravitational force to keep it contained, this miniature Jupiter would rapidly expand into a boiling-hot fireball. The resulting explosion would obliterate the entire neighborhood.
But there's a silver lining: once the initial explosion subsided, Jupiter's hot core would cool rapidly when no longer compressed. The planet would eventually return to its original form as diffuse clouds of gas floating through the sky.
This scenario illustrates the complex interplay of forces that keep planets stable and highlights the extreme conditions that exist within gas giants like Jupiter. It also serves as a reminder of why it's generally a good idea to keep planets where they belong - in space, far away from suburban neighborhoods.
Galactic Real Estate
Munroe also tackles a question about cosmic property rights: if countries' territories extended infinitely upward into space, which nation would own most of the galaxy?
The answer to this question is more complex than it might initially seem, due to Earth's rotation. The galactic airspace would actually change hands from country to country over the course of every 24 hours. However, countries in the Southern Hemisphere have a distinct advantage in this cosmic land grab.
Because the North Pole points away from the center of the Milky Way, the southern hemisphere is angled toward the galaxy's core. This means that countries like Australia, South Africa, Lesotho, Brazil, Argentina, and Chile would take turns claiming the most densely populated and resource-rich part of the galaxy, including the supermassive black hole at its center.
But don't feel too bad for the Northern Hemisphere. It's angled toward the outer galactic disk, which contains its own share of cosmic wonders. For instance, the star-devouring black hole Cygnus X-1 would pass through North Carolina's airspace daily. The star 47 Ursae Majoris, known to have three planets orbiting it, would spend time in U.S. airspace every day.
This hypothetical scenario provides an interesting perspective on Earth's position in the galaxy and how our planet's rotation affects our view of the cosmos. It also raises intriguing questions about space law and extraterrestrial jurisdiction - imagine New Jersey trying to prosecute a crime committed on a planet 40 light-years away!
Building Rome in a Day
We've all heard the saying "Rome wasn't built in a day," but Munroe decides to take this literally and ask: how many people would it actually take to build Rome in 24 hours?
The answer isn't as straightforward as simply throwing more people at the problem. As anyone who's ever tried to organize a large group knows, more people can often mean more complications. Issues like training, organization, avoiding bottlenecks, and coordinating massive supply chains would all come into play.
However, for the sake of argument, Munroe does some calculations. Using a formula developed by civil engineer Daniel M. Chan, and estimating Rome's real estate value at about $150 billion, Munroe estimates that it would normally take between 10 and 15 years to build Rome.
To compress this into a single day would require an enormous workforce. Munroe calculates that it would take about 2 billion hours of labor to build Rome from start to finish. This means that if 8 billion people (more than the current world population) were on the job, they could theoretically complete the task in just over 15 minutes.
But Rome isn't just buildings and roads - it's also filled with artistic masterpieces like the Sistine Chapel ceiling. Taking into account the time it took Michelangelo to paint his famous frescoes, Munroe estimates that it would take 20 billion hours to construct all of Rome to the same level of detail. With 8 billion workers, this could be done in about 2.5 hours.
This thought experiment not only provides a fun way to think about large-scale construction projects but also highlights the immense amount of human labor and creativity that went into building one of the world's most iconic cities over many centuries.
A Glass Tube to the Ocean Floor
Munroe then tackles a question about deep-sea exploration: what would it be like to stand at the bottom of the ocean in an indestructible glass tube extending from the surface to the seafloor?
The experience would be quite different from what you might expect. For one thing, it would be incredibly cold. Unlike in deep mines, where temperatures increase as you go deeper due to proximity to Earth's core, the bottom of the ocean is only slightly above freezing.
It would also be pitch black most of the time. Sunlight would only reach the bottom of your tube twice a year, when the sun passes directly overhead. The rest of the time, you'd be in complete darkness unless you brought a powerful light source.
Getting back to the surface would be a challenge too. If you simply let water rush in from the bottom, it would create a supercharged jet that could be fatal. The safest way to ascend would be to slowly let water in through a controlled opening, then ride the rising water level back to the surface.
This scenario illustrates the extreme conditions present in the deep ocean and the engineering challenges involved in deep-sea exploration. It also highlights how different the deep ocean environment is from other extreme environments on Earth.
Eating a Cloud
In one of the more whimsical questions, Munroe considers whether it would be possible for a person to eat a cloud.
At first glance, it might seem feasible. After all, clouds are made of water, which is certainly edible. However, the reality is more complicated. Clouds are mostly air with a small amount of water suspended in it. If you tried to eat a cloud, you'd end up swallowing a lot of air, which your body would need to expel.
Interestingly, when you burp out this air, it would absorb moisture from your body and form a new cloud when it meets the cooler outside air. You'd essentially be creating more cloud faster than you could eat it!
If you could somehow extract just the water content from a cloud, you might have more success. A cloud the size of a small house contains about 2-3 liters of water, which is about the maximum amount a human stomach can comfortably hold.
This thought experiment not only provides insight into the composition of clouds but also illustrates some interesting principles of thermodynamics and the water cycle.
The Great Everest Snowball
Finally, Munroe considers what would happen if you tried to roll a snowball from the top of Mount Everest all the way to the bottom.
Contrary to what you might expect, the snowball wouldn't grow much at all. The snow on Everest is typically dry and fluffy, not the wet, sticky kind that's good for snowball making.
But let's say, for the sake of argument, that Everest was covered in perfect snowball snow. How big could your snowball get? Munroe calculates that theoretically, a snowball rolling down one of Everest's main slopes (each about 5 kilometers long) could grow to between 10 and 20 meters wide.
However, in reality, a snowball would collapse under its own weight before it reached more than a few meters in width. It would break apart into smaller snowballs, each of which would grow until they too broke apart, creating a cascade of snowballs tumbling down the mountain.
This scenario provides an interesting look at the physics of snow and the concept of exponential growth. It also serves as a reminder that sometimes, the reality of a situation can be very different from our initial expectations.
Final Thoughts
"What If? 2" is a testament to the power of curiosity and the joy of scientific inquiry. Through these seemingly absurd questions, Randall Munroe takes readers on a journey through various scientific disciplines, from physics and astronomy to biology and engineering.
The book reminds us that science doesn't have to be serious to be meaningful. By applying rigorous scientific analysis to whimsical scenarios, Munroe demonstrates how the tools of science can be applied to any question, no matter how outlandish it may seem.
Moreover, the book encourages readers to think creatively and to question the world around them. It shows that there's value in asking "what if," even (or especially) when the questions seem silly or impossible. By stretching our imaginations and applying scientific principles to hypothetical scenarios, we can gain new insights into how the world works and develop our analytical thinking skills.
"What If? 2" is more than just a collection of amusing thought experiments. It's a celebration of human curiosity, a demonstration of the versatility of scientific thinking, and a reminder that learning can be fun. Whether you're a science enthusiast or just someone who enjoys pondering life's stranger questions, this book offers a unique and entertaining perspective on the world of scientific inquiry.
In the end, "What If? 2" leaves readers with a renewed appreciation for the complexity of the world around us and the power of scientific thinking to illuminate even the most unlikely corners of our imagination. It's a book that will make you laugh, make you think, and quite possibly inspire you to start asking your own "what if" questions about the world around you.