Rubber Sheet
Rubber Sheet
[Beret guy is standing on a giant bowling ball on a rubber sheet. Megan is watching.] Beret Guy: Imagine a giant bowling ball on a rubber sheet. Beret Guy: The ball's weight makes a dent in the sheet.
[A rope is pulling the ball down into the sheet.] Beret Guy: Now imagine a rope that pulls the ball down even further. Beret Guy: ...Annnnd...
[Rope lets go. Ball is catapulted with Beret Guy on it.] BOOOIING Beret Guy: Wheee
[Beret guy and ball are falling back down.] Megan: ...Oh. I thought this was about physics. Beret Guy: Imagining is fun!

This comic refers to a common analogy used to explain how mass distorts space-time — a bowling ball resting on a sheet of rubber distorts the sheet due to its weight. The system has some qualitative features in common with gravity; it's often misused to show that "mass warps spacetime" ( 895: Teaching Physics ).
The next part of the original analogy explains a black hole: the slope of the sheet becomes so deep that you can't climb out from the bottom any more, similar to a black hole, which even light can't escape from. However, the comic subverts the analogy, and the sheet becomes a trampoline instead.
Reading onwards, it seems that Beret Guy is just messing about with the scenario.
The line "Imagining is fun! " is also a homage to Richard P. Feynman 's "Fun to Imagine" Series of Interviews. The power of Beret Guy's imagination—so that he can physically experience what he imagines—is reminiscent of 248 .
The title text also states that the rubber sheet, broken rope and trampoline are still all about physics (see also 435: Purity ).
[Beret guy is standing on a giant bowling ball on a rubber sheet. Megan is watching.] Beret Guy: Imagine a giant bowling ball on a rubber sheet. Beret Guy: The ball's weight makes a dent in the sheet.
[A rope is pulling the ball down into the sheet.] Beret Guy: Now imagine a rope that pulls the ball down even further. Beret Guy: ...Annnnd...
[Rope lets go. Ball is catapulted with Beret Guy on it.] BOOOIING Beret Guy: Wheee
[Beret guy and ball are falling back down.] Megan: ...Oh. I thought this was about physics. Beret Guy: Imagining is fun!
