Smartass Disciple: Master, where is exactly the edge of this universe ?
Master of Stupidity: Edge is wherever the absence of universal gravity.

Smartass Disciple: Master, tell me what is it beyond this universe ?
Master of Stupidity: No 'space' in no 'gravity'. No 'thing' in spaceless.

There are no walls at the edge of this universe...
absence of gravity is the limit of space existence.

There are no walls at the edge of this universe...absence of gravity is the limit of space existence.

If we presume that the boundary of the universe is a kind of surrounding wall, then we think like ancestors who thought there's abyss at the edge of flat earth.

No gravity, no fallen angels.