Footnote Fever / What If? 2

The following is a list of examples of Footnote Fever within the book What If? 2.

• Chapter 4: Ironic Vaporization
  In real life, when people want to vaporize iron,* they generally don't just put it over a heat source.

  * Usually to use the vapor for metal plating, but maybe sometimes just out of spite.
  (...) your apparatus will have roughly the same total heat output as a raging house fire.*

  * If you do this project near your actual house, you may find it produces the heat of two house fires.

• Chapter 8: Geyser
  People who walk around the geysers regularly step through the crust and plunge to their deaths.*

  * In one incident in 1905, the unlucky person was actually taking notes on the geyser in a notebook when she fell in, which I find uncomfortably relatable. I'm pretty sure that's how I'll go.

• Chapter 10: Reading Every Book
  For example, when the Library of Alexandria burned, a lot of writing was lost,* but how much writing was lost is hard to pin down.

  * On the other hand, a lot of Egyptian readers were probably excited to get out of overdue book fines.

• Chapter 14: Paint the Earth
  (...) and make some assumptions about how we're painting the ground.*

  * When you get to the Sahara Desert, I recommend not using a brush.
  If I assume it would take me three hours to paint the room I'm in,* and 100 billion people ever lived (...)

  * This is probably optimistic, especially if there's an internet connection in the room.
  I vaguely remember that the world's real estate has a combined value of something like $400 trillion,* (...)

  * Citation: this really boring dream I had once.
  Of course, both of the building-related guesses could be overestimates (lots of buildings are not painted) or underestimates (lots of things that are not buildings* are painted).

  * EXAMPLES OF THINGS THAT ARE NOT BUILDINGS: ducks, leaves, M&Ms, cars, the Sun, sand grains, cuttlefish, microchips, nail polish remover, the moons of Jupiter, lightning, mouse fur, zeppelins, tapeworms, pickle jars, those sticks you use to toast marshmallows, alligators, tuning forks, minotaurs, Perseid meteors, ballots, crude oil, social media influencers, and catapults that throw handfuls of engagement rings. Those are all the nonbuildings I can think of; if you can think of anything I missed, you can make a note of it here in the margin.
  At 30 square meters per gallon,* that's enough to cover 11 trillion square meters (...)

  * "Square meters per gallon" is a pretty obnoxious nonmetric unit, but it could be worse. I've encountered acre-foot, a unit of volume equal to one foot times one chain times one furlong, in actual technical papers.

• Chapter 16: Star Sand
  Specifically, we need to have some idea of what grain sizes correspond to clay, silt, fine sand, coarse sand, and gravel, so we can understand how our galaxy would look and feel if it were a beach.*

  * Instead of just containing a bunch of them.
  If we assume the Sun corresponds to a typical sand grain, then multiply by the number of stars in the galaxy, we come up with a large sandbox worth of sand.*

  * I mean, we come up with a bunch of numbers, but our imagination turns them into a sandbox.

• Chapter 20: Elemental Worlds
  A cup of solar core material* produces about 60 milliwatts of thermal energy.

  * If you find a recipe that calls for this, do not make it.

• Chapter 21: One-Second Day
  By the time a second* had passed, (...)

  * I mean, a day.

• Chapter 23: $2 Undecillion Lawsuit
  The EPA currently uses $9.7 million as the "value of a statistical life," although they go out to great lengths to point out that this is absolutely not the value they place on any actual human life.*

  * I can't help but notice that they don't say whether they think that amount would be higher or lower.
  If you extracted all the elements, purified them, and sold them, the market would crash.*

  * Both in the sense that the supply would cause a drop in prices and the sense that the market is located 20 miles above the mantle and you just removed the crust supporting it.

• Chapter 31: Expensive Shoebox
  There are more expensive metals. A gram of pure plutonium, for example, would cost about $5,000.*

  * At least, as best as I can tell from some internet searches. In other news, I'm now on a lot of government watch lists.
  Cocaine's price varies a lot, but in many areas it is in the neighborhood of $100/gram.*

  * Update: I'm now on the rest of the government watch lists.

• Chapter 32: MRI Compass
  (...) which means that by scattering them across Canada you could create a magnetic net* that would capture roughly 1 in 1,300 pole-seeking explorers.

  * Or "magnet" for short.

• Chapter 37: Laser Umbrella
  But it gets worse! Vaporizing a droplet of water with a laser is more complicated than it sounds.*

  * And to be honest, it sounds pretty complicated.
  It might seem easier to forget about targeting completely and just fire lasers in random directions.*

  * Really, what problem can't this strategy solve?

• Chapter 40: Lava Lamp
  Even if we ignore the impurities from the hot lava that would probably cloud the glass, we're going to have a problem.* Molten glass is transparent. So why doesn't it look transparent?†

  * And later, when the school board finds out about this, we'll have another.

  † Which sounds sorta contradictory. "This music is loud, but it doesn't sound loud."
  A solidified lava lamp is just about the most boring thing in the world. But the scenario made me wonder: If making a lamp out of molten lava wouldn't be very exciting, then what about a volcano made of lamps? This is probably the most useless calculation I've ever done,* but... what if Mount Saint Helens erupted again today, but instead of tephra,† it spewed compact fluorescent bulbs?

  * Okay, there's no way that's true.

  † The technical term for "whatever that stuff is that comes out of a volcano."

• Chapter 42: Blood Alcohol
  If someone has a blood alcohol concentration (BAC) of 0.40, and you drank all 14 glasses of their blood in a short time,* you would throw up.

  * If you drink all of someone's blood, there's a 100 percent chance that they'll die.
  If, after you drank all this blood, someone killed you and drank your blood,* they would then have a BAC of 0.006. if this process were repeated about 25 times, there would be fewer than 8 molecules of ethanol left in the last person's blood. After a few more cycles, there would likely be none;† they'd just be drinking regular blood.‡

  * It's only fair.

  † By homeopathic standards, this is still quite concentrated.

  ‡ Like a loser.

• Chapter 44: Spiders vs. the Sun
  The goliath bird spider* weighs as much as a large apple.†

  * Wikipedia helpfully notes that, despite its name, it "only rarely preys on birds."

  † This is correct whether I mean the fruit or an iPhone; the spider weighs about as much as each.
  As described in a fascinating and horrifying article published by the Entomological Society of America,* (...)

  * The conclusion of the article contains this absolutely incredible passage:

  Our recommendations for amelioration included the following general points:

  1) On-site personnel should be reassured that the spiders are harmless and the facility's immense shroud of silk should be presented in a positive light as a record-breaking natural history wonder.

• Chapter 46: Candy Crush Lightning
  (...) but the old Wint-O-Green flavor* of Life Savers candies (...)

  * Which has apparently been spelled like that all along and I never noticed until now. I guess the O in Wint-O-Green is like the a in Berenstain Bears.

• Chapter 49: Eyeball
  If you don't want to perform barehanded ophthalmological surgery,* (...)

  * For some reason.

• Chapter 51: Fire from Moonlight
  It can be shown* (...)

  * This is physics-speak for "this probably isn't too hard, but I don't want to do it."
  If you're "surrounded" by the Sun's surface material, then you're effectively floating within the Sun, and will quickly reach the temperature of your surroundings.*

  * See chapters 61, 62, and 63, along with Short Answers #5, for more on the exciting experiences you can have by visiting the Sun.

• Chapter 52: Read All the Laws
  Most of the laws don't apply to you. For example, 42 U.S. Code § 2141(b) sets limits on the Department of Energy's ability to distribute nuclear materials. If you're not the Department of Energy, you don't need to worry about that.*

  * To those of you who are at the Department of Energy, hi! I'm a huge fan of your work, and of energy in general.

• Chapter 53: Saliva Pool
  If you're collecting your saliva,* you can't use it to eat.†

  * This question is gross, by the way.

  † I hope.
  (...) you'd have an Olympic-size swimming pool full of saliva. And isn't that, deep down, all any of us really want?*

  * No. It is not.

• Chapter 55: Niagara Straw
  You can't use pressure to accelerate water through an opening faster than the speed of sound (in water).*

  * It's sort of like a traffic jam—forcing more cars into the back of a traffic jam won't make the ones in the front come out faster. The analogy between traffic jams and choked flows isn't perfect, but I still like it because it's fun to imagine someone trying to solve traffic jams by using a bulldozer to push more cars into them.
  (Niagara's flow rate) is monitored by the International Niagara Board of Control, which consists of one American and one Canadian.*

  * As of 2021, the waterfall guardians are Aaron Thompson of Canada and Stephen Durrett of the United States. I'm guessing their enforcement protocol is just some variation on "filing a report," but I like to imagine that they're empowered to physically return the stolen water to the falls by any means necessary.

• Chapter 58: Earth-Moon Fire Pole
  In real life, we can't put a metal pole between the Earth and the Moon.*

  * For one, someone at NASA would probably yell at us.
  There's one* more problem: (...)

  * Okay, that's a lie—there are, like, hundreds more problems.
  At the equator, (Earth's surface) can reach over 1,000 miles per hour.*

  * It's common knowledge that Mount Everest is the tallest mountain on Earth, measured from sea level. A somewhat more obscure piece of trivia is that the point on the Earth's surface farthest from its center is the summit of Mount Chimborazo in Ecuador, due to the fact that the planet bulges out at the equator. Even more obscure is the question of which point on the Earth's surface moves the fastest as the Earth spins, which is the same as asking which point is farthest from the Earth's axis. The answer isn't Chimborazo or Everest. The fastest point turns out to be the peak of Mount Cayambe,† a volcano north of Chimborazo. You just learned that.

  † Mt. Cayambe's southern slope also happens to be the highest point on Earth's surface directly on the equator. I have a lot of mountain facts.

• Chapter 61: Into the Sun
  The temperature of the surface if the Sun is about 5,800 K,* give or take.

  * Or °C. When temperatures start having many digits in them, it doesn't really matter.
  (...) but a nanosecond is not very long—it's enough time for light to travel almost exactly a foot.*

  * A light-nanosecond is 11.8 inches (0.29979 meters), which is annoyingly close to a foot. I think it would be nice to redefine the foot as exactly 1 light nanosecond. This raises some obvious questions, like "Do we need to redefine the mile to keep it at 5,280 feet?" and "Do we redefine the inch?" and "Wait, why are we doing this?" But I figure other people can sort that out. I'm just the idea guy here.

• Chapter 63: Walking on the Sun
  As the core collapses under its own weight, the heat of the collapse will trigger several desperate spasms of fusion that will inflate the outer layers* and then blast them away.

  * And maybe consume the Earth.†

  † The fact that the destruction of the Earth is relegated to a footnote is a good sign for where this chapter is headed.

• Chapter 64: Lemon Drops and Gumdrops
  Lemon drops and gumdrops are denser than water,* (...)

  * Citation: I just poured a glass of water and tried dropping various candies in. Science!