Here's a bet we're willing to make:

You, the reader of this website, have no idea who Edgar Rubin is. None.

Oh, you can quickly google him, or jolt to Wikipedia, but, unless you are up on your Danish Jewish psychologists who specialized in visual perception, you are highly unlikely to know.

However, you are very likely familiar with Rubin's most famous invention, although you probably don't know its name: Rubin's vase.

Here, we made a Rubin's vase with Rubin's face.