Really WTF does happen?
i think you broke me
my brain hurts
You’re thinking too hard with Portals now. :I
a) It would accelerate, as acceleration is not canceled by portals.
b)The moving portal would vanish and the rod would fall to the ground. Portals can only be created on non-moving surfaces and if they move they close.
c) I have no idea what would happen.
It may well not accelerate, because the metal rod is now a contiguous object. As for b), no, portals can be shot onto moving platforms just fine. I think it would bend the rod, though, because it’s essentially pushing itself down and up at the same time. In case c) I’d hazard a guess that there would be a really awful scrunching noise and, depending on how far away the portal was, the rod would break or bend.
This test would be much more amusing with a very, very strong metal such as titanium. Basically, though, what’s important to remember in these cases is that a) it’s one rod at this point - pretend you’re a two-dimensional being on a piece of paper with a line on it, and the paper gets folded into a cylinder so the ends of the line touch. In scenario b), the rod is pushing on itself and so the effect is a lot like shoving two metal rods together end-to-end, only with one rod. And in c), the rod still has finite length. It will break or bend if it’s moved around like that, just as a normal rod would if an unstoppable force moved half of it to the other side of the room.
A) would accelerate; gravity isn’t canceled out just because something is touching itself through a portal.
B) the games are consistant that portals can’t be opened on moving surfaces in the first game but there’s spots in the second when they definitely are opened on moving surfaces just fine in the second. (See: disabling the neurotoxin generator for example) But basically the rod would be pressed against itself and probably break or bend depending on the material.
C) The obvious question is whether the portal would cut the object severed by the closing portal. Obviously in the game, it never does and moves the half the object sticking out the portal to the new portal location. My suspicion is, in this case, it would probably just undo the solder, possibly rather cleanly as the half the bar is suddenly teleported to a new location.
This leads to obvious questions on how a portal determines what a complete object is, but at this point the answer is basically “magic” so application of physical principles doesn’t really work here anymore.