4:57

Another Portal Paradox

24:14

The Banach–Tarski Paradox

8:05

Resumo de viagens no tempo na ficção

43:08

Every Softlock in Portal

8:53

I Made Portal 3 Because Valve Wouldn't

17:33

There's a NEW PORTAL that ADDS A FOURTH DIMENSION!? Portal Reloaded!

4:05

Passing A Portal Through Itself

15:53

What Actual Aliens Might Look Like