Imagine if New York bagels weren’t scarce in Ithaca — no one would settle for powdered eggs on a mediocre CTB bagel ever again. Imagine if classes had more seats — that would certainly make this week’s course enroll easier. We imagine a world with less scarcity all the time. Other things, like the laws of physics, affect our lives. But we don’t usually imagine a world where the atomic weight of hydrogen were different — or at least, I’m not smart enough to imagine it.