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

by Randall Munroe

Based on estimates from a 2009 study by Natalie Mahowald et al., over the three hours it takes to vaporize your 8-ton iron cube, desert winds will blow 30,000 tons of iron into the air, and industrial facilities will add another 1,000 tons.

If you collected all the guns in the world and put them on one side of the Earth, then shot them all simultaneously, would it move the Earth? —Nathan No, although in my personal opinion, if you could get them to stay there, it would make the other side of the Earth a nicer place to live.

There’s gold, of course. Thirteen liters of gold is worth about $14 million as of 2021. Platinum is a little more expensive at $16 million/shoebox, about 10 times the value density of $100 bills. On the other hand, a shoebox full of gold would weigh as much as a small horse, so it might not be as practical as $100 bills if you’re trying to go shopping.

Snow has a tensile strength, which means it resists being pulled apart. Its tensile strength isn’t that high—which is why you don’t see a lot of ropes made of snow—but it’s not zero. A typical tensile strength for well-packed snow might be a few kilopascals, which is stronger than wet sand, weaker than most kinds of cheese, and about 1/10,000th that of most metals.

There’s a neat way to answer “Will it float?” questions without doing too many complicated calculations. Water is roughly 1,000 times denser than air, [*] so if you want to know whether something could float if you filled it with helium, just estimate how heavy it would be when filled with water, then move the decimal point over 3 places. That’s how much buoyancy it could produce, so it’s how light the solid parts have to be in order to float.