Ruff, I know what you are going to say. “Well, then how would you explain this idea to these kids?” Couldn’t you just say “oh look, it started high enough to make it to the top of the loop, but it still fell down.” And then when they started it higher and it worked, you could say “Wow! It worked. I guess it is not enough to just get back to the top of the loop, it had to be still going fast to not fall”.
Or how about: “wow, gravity gave it energy and the Flying Spaghetti Monster made it stay on the loop”.
And he just totally hits the nail on the head. It’s clear, sticks to the facts, and doesn’t try to add in anything fancy with weak (and ultimately false) information. I ask my physics students to explain their reasoning in writing a lot. Due to their previous experiences, many of them think that any good explanation needs to be detailed and long. Detailed: Yes. Long: No.
They try to make their explanation longer than necessary and they run out of new things to say. Then they start to write down the exact opposite of what they just said. I die a little each time I write feedback that says, “you contradicted yourself here, which is right?” The fact that I’m writing a blog post about this clearly indicates that some explicit instruction on good explanations is necessary within the first few weeks of physics.
Or maybe we just stick with attributions to the flying spaghetti monster. In a pinch.