measuring rod

Einstein was known for his thought experiments with measuring rods when explaining relativity.

1 - A tool used to physically measure lengths and survey areas of various sizes.
2 - Einstein's dick.

"The rigid measuring rod is thus shorter when in motion than when at rest, and the more quickly it is moving, the shorter is the rod."

"And how big is your new TV Herr Einstein?
About 4 and half measuring rods."