Einstein’s Lesser-Known Thought Experiments

In 1905, Einstein changed the world by introducing a new theory of space and time. The theory came to him, famously, after months of contemplating a thought experiment (known as a “gedankenexperiment”) about what would happen if a person were to race a beam of light. What is often forgotten is that this was only one of several gedankenexperiments that captured Einstein’s attention at the time. The Record has collected here just a few others which ultimately failed to have the same impact on the course of history.

1. Imagine everybody has hamburgers for hands. Would people still eat hamburgers, or would that be too weird?

2. Imagine the Supreme Court is hearing a case about the constitutionality of the number four. They rule in a 5-4 decision that the number violates the Constitution. But then they realize that the number four appears in their ruling, and thus that the ruling must also be against the Constitution. But if the ruling is against the Constitution, it is illegitimate and the number four is still allowed. But then, of course, that would mean the ruling is legitimate again. What should the court do?

3. Imagine a cylinder of radius R, density p, and infinite length. A friend gives you the cylinder for your birthday. You don’t want it, but you know if your friend comes over to your house in a few days and sees it’s not there he’ll make a whole passive-aggressive fuss about it. He’s that sort of person. So where do you keep the cylinder?

4. Imagine trees are people and people are trees. Should we call ourselves “people-trees” or “tree-people”? How about “treeple”?

5. Imagine everybody in the United States is President except for Teddy Roosevelt. Is the First Lady still his wife?

6. Imagine Marie Curie naked. She’s probably pretty hot, right?

—B. Garfinkel