Hello internet. While working on a future video, I offhandedly wrote,

Venus, the closest planet to Earth. But later, while editing, I thought,

you know, let me check that. Which led me to this video by Dr. Stockman, explaining how,

no, Venus is not the closest. This blew my mind, and I contacted the author to adapt his

video into the one you probably just watched.

It blew my mind not just because it was surprising, but also because I taught physics for years

and probably said Venus is the closest planet dozens of times without ever thinking about it.

How does that happen? First, asking the precisely right question is vital.

Which planet is closest is not the precisely right question, because it's really made of four

parts. Which planet ever gets the closest? Which planet is the closest for the longest time?

Which planet has the shortest average distance to Earth? Which planet takes the least amount of time to travel to?

The answer to the first one is Venus, the second to Mercury, the last, it's complicated, get a physics degree.

Literal rocket scientists think mostly about that last question, and the rest of us are probably vaguely asking about the first when we say which is the closest,

because we're not thinking about the planets in motion.

If we were, we'd ask something closer to questions two and three, which is what the main video is about.

Mercury, on average, has the shortest distance to all the other planets, and for the inner planets, it's also the closest planet most of the time.

But to get an answer that precise requires a precise question.

Unlike the way things are done in school, where questions yield knowledge, it's knowledge

that yields questions which yield knowledge.

Now, it's hard to think about the raw knowledge of everything all at once, so we condense

down part of what we know into a model to help us think, like with the line of the planets.

But as with fuzzy questions, models can trick us too. Which planet is the closest looks like a simple and easy question when the solar system is shown this way.

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