Rules:
*You can teleport into and out of it at will
*It has a couple of plug sockets and can connect to internet from the region you teleported in from
*You can take objects and people with you
*As already stated, it is (3m)^3 (3m*3m*3m). The walls are plain plaster with a light in the middle of the ceiling. The pocket dimension is topologically toroidal, so if there weren’t walls and a ceiling/floor (which you can actually destroy) you would loop if you went more than 3m in any direction. Gravity, then, is artificial and can be altered to anywhere from 0 to 2g from a dial on the wall.
Edit: additional specifications
*You can only teleport out to where you teleported in from.
*Time proceeds at the same rate inside the pocket dimension
*There is an eject button for those inside to get out if something happens to you
I’d use it as a jizz shoebox but bigger. Since you can accelerate things inside if it, you can make my 27m^3 jizz flow at terminal velocity and then I can
Boy, oh boy, I Just finished reading the comment above about why the pocket dimension of falling rocks wouldn’t reach the speed of light using real physics explanations.
And then this guy wants to cum in it.
The Internet really does have everything.