The recent resurrection of the name Brontosaurus well illustrates the temporary nature of all scientific understanding. Because scientific understanding is based on our best known knowledge and interpretation of that knowledge, there’s the possibility that with more knowledge or with better interpretation, pieces of our understanding could be wrong.

We live in a world, however temporary, in which Brontosaurus is real again. For the sake of this thought experiment, let’s assume that other subjects, small and large, are also just as easy to change from unreal to real, or real to unreal. Other than the obvious answer of Pluto being a planet again*, what’s the scientific fact/theory/idea that you would undo?

Give a link to the fact/theory/idea if it’s something that might be kind of niche in its level of popular science understanding, and tell why it’s something you want to undo and what the implications of its undoing would be. All(?) answers get a picture of a pizza roll, the best answer gets a picture of two pizza rolls.

* Pluto is still a planet. It’s just not a non-dwarf planet. Planetary systems are messy and apparently the one we grew up in has a few easy planets and then thousands of dwarf planets.

Top image: Brontosaurus and other Jurassic denizens in Rudolph Zallinger’s The Age of Reptiles mural at the Yale Peabody Museum of Natural History. Image previously used by io9 two years ago, it’s always fun to recycle web content.