>>11425376...the blue portal is tilted backwards, retardo, if anything it loses a tiny amount of velocity to gravity (but no inertia*)
because it exits the blue portal at the same speed it enters the orange portal, it flies off, there is no way around this
*inertia itself is a wonky concept in this physics-breaking scenario, but it is clear that it happens from the point of view of the cube - if you were where the cube is, you might be looking at the oncoming orange portal, through that portal you'd see the world on the other side of the portal approaching you at high speed - why would you suddenly break to zero velocity once you're through? it makes no sense
imagine instead that the cube scenario is as picture, but you are standing in front of the blue portal so close that there is not enough room for the blue cube to fit between you and the portal, what would you feel as the cube exits? would it push on you? or would you just feel "gravity" or whatever? if you think it's the second, then assume that you are strong enough to lift the cube and that you do so, preventing it from moving out of the blue portal despite there being no room left available on the orange side... where is the cube?