There's still a lot we don't know about the Aperture Science Handheld Portal Device, or portal gun as it's more succinctly refered to.
Throughout Valve's testing puzzler we were subjected to a number of experiments by the vindictive AI GLaDOS, during which the player was forced to jump through countless portals. But even after all that, we still have no idea about what lies inside these mysterious ovals, if anything.
Fortunately Youtuber CrowbCat decided to conduct an experiment of his own. For science.
He's manipulated the Portal 2 development kit to find out what happens when the player finds themselves crushed between two portals, and the results are quite spectacular:
It turns out that what lies inside is a kaleidoscopic acid trip that, visually speaking, has more in common with some particularly abstract modern art than it does with video games. These screenshots wouldn't look all that out of place on a wall at the Met...
That's one more mystery solved by science!