Fun with Fermi Problems

I’ve been messing with various Fermi problems over the last few days, so I thought I’d share a few for the weekend. The first ones are classics which many will have run into before. If previously puzzled it out, try solving the problem top-down rather than bottom-up, or vice-versa, depending on which way you tend to typically approach these things.

  • How many piano tuners are there in Los Angeles?
  • How many blades of grass are there on your front lawn?
  • What is the ratio of paved to unpaved surface area in California?

And some science-driven problems:

  • If the sun stopped radiating energy, what temperature would the surface of the Earth cool to?
  • In the above situation, could humans survive using current technology if given enough time to prepare?

Feel free to add more of your own, or just funky solutions, in comments to this post.

[via Steve Hsu]