A while ago, my 7.5 year old son asked a seemingly simple question that had no easy answers at all. Instead of struggling with the question alone, I decided to tap into the collective intelligence of the whole world. Internet, after all, is supposed to be used for more than sharing cat videos, right? Right?

So, I asked:

One of the Internet denizens suggested that I ask the same question on Reddit’s ELI5 channel, that is, “Explain it Like I’m 5” channel. Being a casual Redditor for the last 14 years, I said “why not?” More