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?”

This Reddit thread led to interesting discussions, and thanks to the participants, I’ve discovered some beautiful web pages that I can rely on for explaining the topic to my son:

I still don’t find it easy to explain this to a 7.5-year-old, let alone a 5-year-old, but I think the existing material isn’t a bad starting point. If nothing else, it helps both me as a parent, and my very young son to move a bit out of our intellectual comfort zone, and stretch our thinking a bit. I find it a very good pedagogical exercise to force myself explain a complex topic to my son who’s not aware of many advanced mathematical and scientific concepts, because it helps to widen my perspective and try to attack the problem of explanation from various angles. I don’t always succeed, but every bit counts, and past failures may be paving the path to a future successful understanding of these complex matters.