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

by Randall Munroe

Normally, when you get close to a black hole, tidal forces tear you apart. But tidal forces are weaker for larger black holes,

Everything inside it would flow inward toward the singularity. In the regular universe, we’re all dragged forward through time with no way to stop or back up. Inside a black hole’s event horizon, in a sense time stops flowing forward and starts flowing inward. All time lines converge toward the center.

A really cold object can set your house on fire.

Since a pigeon can carry only a quarter of its body weight, it takes four flying pigeons to carry one resting pigeon. That means each “stage” will need at least four times as many pigeons as the one above it.

Arguably, this is because geology and soil science are more complicated than astrophysics.

There’s a surprisingly large amount of research into the physics of swing sets, partly because pendulums are really interesting physical systems and probably also because all physicists were once children.

Using measurements for an average rider, the ideal swing for reaching maximum altitude turns out to be 10 or 15 feet—exactly the size of a large playground swing. Once again, the kids have things figured out.

It would actually be great if the tire rubber did stay stuck to the road, at least from an environmental point of view, but for the most part it doesn’t.

Breathing all those tires probably isn’t great for us, and it’s not great for the environment, either. Tire rubber particles are a major source of microplastics in our rivers and oceans, where they affect the chemistry of the water and are often eaten by marine animals.

Why don’t compasses point toward the nearest hospital because of the magnetic fields created by MRI machines? —D. Hughes They do, and it can be a problem!

In other words, if you try to eat a cloud, you’ll just burp out more cloud faster than you can eat it.

The Sun sets later for taller people, because the higher up you are, the farther you can see over the horizon.