What If? 2: Additional Serious Scientific Answers to Absurd Hypothetical Questions

Question: “What would happen if the Solar System was filled with soup out to Jupiter?” (1).

The pressure of gravity would immediately crush everyone on Earth. The soup would be so dense that it would form a giant black hole pulling everything it covers to the center of the solar system within half an hour. Over the next few thousand years, the black hole would consume much of the Milky Way. The type of soup would be irrelevant because black holes don’t retain the characteristics of what they consume.

Question: “What if you were hanging on a helicopter blade by your hands and then someone turned it on?” (6).

Centrifugal force would increase the weight dangling from your hands so that you would have to let go before the blade finished its first, slow rotation. If your hands were adhered to the blade, then the force applied by the rotor’s increasing speed would rip them off in under 30 seconds. Your weight would prevent the rotor from accelerating properly and destabilize the careful balance of the helicopter; it would tip back and forth, flip over, and be torn apart without ever leaving the ground.

Question: “Would there be any danger from standing next to a large object that was 0 Kelvin?” (11).

Cold objects don’t radiate cold in the way hot objects radiate heat energy, so it wouldn’t be dangerous unless you touched it. The nearby presence of an extremely cold block of iron would feel cold only because it wouldn’t radiate heat back to compensate for lost body heat. The night sky has a similar cooling effect, which can freeze water but which one can block using an umbrella, just as one can block the iron’s cold by wearing a coat. Note that dangerously reactive liquid oxygen might condense on the block’s surface like dew and that the iron would remain solid as it slowly warmed to room temperature.

Question: “What if we somehow evaporated a solid block of iron on earth?” (16).

Iron has an extremely high boiling point and often reacts to form alloys when molten, so it is usually vaporized using induction heating or electron beams. Iron vapor is not harmful (though it still shouldn’t be inhaled) and quickly oxidizes. Evaporating an iron block would have little impact on the global atmosphere, as far more iron is released by desert winds and industrial processes. Doing so at home would likely annoy downwind neighbors by leaving a layer of settled iron oxide particles on their property. Theoretically, vaporized iron could help combat climate change by reflecting the sun or settling in the ocean to fertilize photosynthesizing algae.

Question: “If the universe stopped expanding right now, how long would it take for a human to drive a car all the way to the edge of the universe?” (22).

Driving at 65 miles an hour, it would take 35 million times the current age of the universe to reach the edge of the known universe. The universe likely continues beyond this point, which is simply the edge of the map, so one could then continue onward indefinitely into the unknown. (Munroe notes the logistical difficulties and dangers in undertaking such a long journey by car.)

Question: “How many pigeons would it require in order to lift the average person and a launch chair to the height of Australia’s Q1 skyscraper?” (27).

Pigeons can take off while carrying up to 25% of their body weight, so 600 pigeons could carry a passenger and launch chair. However, flying upwards takes a lot of energy, so this group of pigeons would be unable to carry their passenger more than five meters off the ground. If additional groups of pigeons were stationed at height intervals, each group taking a turn at towing the passenger five meters higher, it would take only several thousand pigeons to reach the top of the Q1 skyscraper. (However, Munroe notes the unreliability of a bird-dependent propulsion system.)

In this chapter, Munroe answers several user-submitted questions via a short, written answer, a comic, or both.

Question: “What if your blood became liquid uranium? Would you die from radiation, lack of oxygen, or something else?” (30).

You’d die from not having any blood and from being full of molten uranium.

Question: “Could someone have an anime-style attack where they created a sword out of air? I’m not talking about an air blade, but something like cooling the air enough so that you had solid air to attack people” (31).

This would be possible, although the sword would not be very good. Whether it were made of oxygen or nitrogen, the blade would be quite soft, would be difficult to sharpen, and would give the wielder’s hand frost damage.

Question: “How much water do you have to drink to become 99 percent water?” (31).

You’d have to drink approximately 1,900 liters or 500 gallons.

Question: “What would we see if we attached a lightweight camera to a balloon and let it fly away?” (32).

A comic strip shows two figures watching a balloon fly away, before realizing that they should attach a transmitter next time.

Question: “How many calories does Mario burn a day?” (33).

Based on the calories in the total number of mushrooms in Super Mario Bros, Mario consumes 1.1 calories per day, meaning that Mario died of starvation in 1985.

Question: “If a snake unhinged its jaw and swallowed a balloon whole, could/would the balloon carry the snake up?” (33).

No.

Question: “If you were to jump out of an airplane that was travelling at Mach 880980 that was 100,000 feet above the ground in New York City, with skydiving gear, could you survive?” (34).

No.

Question: “If there was no water on Earth, would we all live?” (34).

No.

Question: “Is it possible to make a homemade jet pack?” (34).

Yes, it’s quite easy to make a jetpack that takes off once. It’s more difficult to make one that can land safely to take off a second time.

Question: “I was wondering whether there’s a specific way to use my welder as a defibrillator? (The specific model I own is an Impax IM-ARC140 arc welder.)” (35).

You should not try to use a welder as a defibrillator. Anyone asking such a question should probably also not use it as a welder either.

Question: “What if all atoms on Earth were expanded to the size of a grape? Would we survive?” (35).

The author doesn’t know, but he is now hungry for grapes.

Question: “If a T. rex was released in New York City, how many humans/day would it need to consume to get its needed calorie intake?” (37).

Experts theorize that a T. rex weighed the same as an elephant and had a metabolism similar to that of a Komodo Dragon. A T. rex would need to eat an estimated 40,000 calories—equal to half an adult or one 10-year-old child—per day, although it would probably prefer to eat larger meals more rarely. Based on birth rate alone, New York could sustain a population of 350 tyrannosauruses. Alternatively, 80 hamburgers a day could sustain one T. Rex, meaning that each of the 39,000 McDonald’s restaurants worldwide could sustain more than a dozen tyrannosaurs.

Question: “If one were to stand on top of the Old Faithful geyser in Yellowstone National Park, at what speed would they be launched upwards by the water, and what injuries would they likely sustain?” (40).

Many people have been injured looking into the vents of Old Faithful, and many more have been killed in nearby geothermic pools. Old Faithful shoots steam and water with thousands of pounds of force, and the trajectory of a person standing on top of the geyser would be dependent on how the stream hit them. By standing directly on top of the geyser, blocking the vent with a sturdy umbrella, a person could be launched hundreds of feet into the air. Even if they survived the severe burns, they would not survive the landing.

Question: “If you shot a ridiculously powerful gun/laser, would it go off the edge of the world in a straight line or curve around the world?” (43).

It would most probably go off the edge of the world into space. Differences in air temperature can make light bend, however, so if a laser were fired over the sea, then the colder air directly above the water could make the light bend around the curve of earth.

Question: “At what point in human history were there too many (English) books to be able to read them all in one lifetime?” (47).

This is very difficult to answer since it is impossible to know how many books existed at any given time. Based on the average writing speeds of different authors over their lifetimes, Munroe estimates that the average person reading 16 hours a day could keep up with the output of a population of 500-1,000 active writers. This threshold was likely surpassed around the year 1500CE.

This section lists several submitted questions that Munroe does not answer via text but instead responds to via small comics or doodles.

Question: “Can bees or other animals go to hell? Or can they murder other bees without consequences?” (50).

A drawing depicts a bee holding a pitchfork, labeled “bee-lzebub.”

Question: “How many mirrors reflecting (sun)light would it take to kill or, at least, injure somebody?” (50).

A figure addresses a mirror as though it were magic, asking for a favor.

Question: “If you had to remove the tonsils of a giant, what would be the safest way for you to do it? The surgeon is a normal human” (50).

In a comic showing a giant and a surgeon, the giant implies that the prospective surgeon is not, in fact, a normal human.

Question: “What would it take to defeat Air Force One with a drone?” (50).

A drawing depicts the author holding a phone, speaking to the Secret Service.

Question: “Can all the world’s bananas fit inside all of the world’s churches? My friends have had this argument for a little over 10 years now” (52).

Yes, because the entire population of the world could fit into all the world’s places of worship, and the average person does not eat their bodyweight in bananas each year. The world’s bananas would barely be ankle deep; there would need to be at least 2,000 bananas per person to completely fill all the places of worship.

Question: “Is there any way to fire a gun so that the bullet flies through the air and can then be safely caught by hand? E.g., the shooter is at sea level and the catcher is up a mountain at the extreme range of the gun” (55).

It is technically possible that if a gun were fired upwards, someone stationed above it—in a hot air balloon or on a mountain peak—could catch the bullet at the apex of its trajectory. However, the inherent uncertainty of the bullet’s exact trajectory would make it extraordinarily unlikely that the catcher would actually be in the correct position to actually catch the bullet.

Question: “I want to lose 20 pounds. How much of the Earth’s mass would I have to ‘relocate’ to space in order to achieve my goal?” (57).

Peeling off Earth’s outer layers to remove mass would actually see you gain weight before losing it, since Earth is denser the deeper you go, cancelling out the lost mass. If you started at 190 pounds, your weight would peak at 207 pounds after having removed two thirds of Earth’s mass and reach the requisite 170 pounds after 3,750 kilometers of rock—85% of Earth’s mass—was removed. It would be more efficient to dig a tunnel and go under the outer layers of Earth instead of removing them, since they no longer contribute to your weight once you are below them.

Question: “Has humanity produced enough paint to cover the entire land area of the Earth?” (66).

Munroe uses Fermi estimations to guess at the answer to this question, rounding values from a number of avenues to the nearest order of magnitude to make easy calculations that are at least within the correct ballpark. His estimations indicate that humanity has not produced enough paint to cover the land area of Earth, which is backed up by his more precise calculations based on paint production and economic growth.

Question: “Dear Randall, what would happen if you shrunk Jupiter down to the size of a house and placed it in a neighborhood, say, replacing a house?” (71).

A house-sized Jupiter would not have enough gravity to keep its mass together, so its core of hydrogen gas would rapidly expand in a giant explosion. This would resemble the formation of Jupiter in reverse and would flatten the entire neighborhood. A thin, cool cloud of hydrogen gas would then settle in Earth’s atmosphere.