In second grade we had a model of the solar system, of course, it wasn’t to scale. One student asked which planet representent the Earth, I quickly pointed and said it was the third one from the Sun. Another student didn’t agree and confidently claimed it must be the biggest one because the Earth is so big.

It was clear to me that I wasn’t going to win this argument, so I suggested we ask the teacher. We explained each of our positions and asked for authoritative confirmation. The teacher looked bewildered, almost sad and said “I really don’t know”. I knew I was right because my brother and my father followed the space program closely in those days.

What was worse: no other student could identify the Earth, the teacher herself didn’t know, or that no one was willing to look it up in an established reference?