xkcd's What If?

This question comes from Nina, who asks: if someone's DNA suddenly vanished, how long would that person last?

This question comes from Rob, who asks: is it possible to build a jetpack using downward firing rifles? I was sort of surprised to find that the answer was yes!

This question comes from Rebecca, who asks: if you suddenly began rising steadily at one foot per second, how exactly would you die? Would you freeze or suffocate first? Or something else?

This question comes from Jack, who asks: what would happen if I dug straight down, at a speed of 1 foot per second? What would kill me first? Today’s topic is the reverse of the video which asked how you'd die if you rose steadily at a foot per second. Digging at the same rate would kill you more quickly.

This question comes from Ji, who asks: “I heard bananas are radioactive. If they’re radioactive, then they radiate energy. How many bananas would you need to power a house?” Yes, bananas emit radiation, but not very much of it. They’re very safe – until you use them to power a house.

This question comes from Doug, who asks: If you were in a boat directly over the Mariana Trench and dropped a 7 kilogram bowling ball over the side, how long would it take to hit the bottom? It’s a good thing you mentioned the mass, because of a very surprising fact: Most bowling balls float.

This question comes from Sean, who asks: What if everything was antimatter, EXCEPT Earth? This one doesn't end well for us. But—unlike most scenarios involving the word "antimatter"—the end is surprisingly slow and drawn-out.

This question comes from Raga, who asks: since rainbows are caused by the refraction of sunlight by tiny droplets of water, what would a rainbow look like if we had two suns like Tatooine? A planet with double suns would have double rainbows. Or rather, quadruple rainbows.