Correct.
It’s like dropping a hula hoop over it in this scenario. There is nothing to generate its motion.
Comment on Which is it Lemmy?
muusemuuse@sh.itjust.works 3 days ago
A
In this example, the object wasn’t moving. It has no momentum to continue moving. Instead, the world around it moved. So A
TheColonel@reddthat.com 3 days ago
iocase@lemmy.zip 3 days ago
Using portals rules yeah A is the correct answer.
B would be correct if this existed in real life and had to be compatible with general relativity. If we took this exact same setup and moved it into space, how could you tell if the cube is moving towards the portal or the portal is moving towards the cube? You also can’t use the blue portal as a reference point since it could also be moving indipendantly from the orange portal.
Honytawk@discuss.tchncs.de 3 days ago
Movement is relative.
You need a second reference point for movement to exist.
To the (for us) moving portal, the cube was moving. And it would keep that momentum.
CaptPretentious@lemmy.world 3 days ago
Get a hula hoop attach a camera to it. Drop hula hoop over something with it being in the middle. Did thing in hula hoop take off? No. Thing had no momentum. It’s velocity versus relative velocity.
Honytawk@discuss.tchncs.de 3 days ago
If the universe on the other side of the hula hoop moved with it, the thing did take off in reference to that universe.
A person in that universe would see a thing rapidly approaching the hula hoop from the other side, before it getting launched through.
iocase@lemmy.zip 3 days ago
You need to cut the hula hoop in half. The bottom moves and the top is stationary off to the side. The cube pops out at the same speed the bottom half is falling, but because the top half of the hula is stationary, the cube seems like it’s moving upwards.
iocase@lemmy.zip 3 days ago
Yeah if this existed IRL B is the correct answer. If you tried this in portal the video game A is the answer.
CaptPretentious@lemmy.world 3 days ago
If it were in real life it would be A. And if the game engine allowed you to move portals, it would also be A.
iocase@lemmy.zip 3 days ago
This has been really heavily debated before and the unanimous answer is B IRL and A for portal.
How does the cube move out of the blue portal? If you ignore the orangep portal entirely and consider just looking from the side as the cube emerges from the blue portal, the top has to be moving extremely fast. The cube needs to be moving relative to the blue portal at the same speed as the orange portal is descending or it doesn’t work.
You can also draw a force balance diagram and you get the same result…
But you’re welcome to disagree with me! That’s part of the wonder of the internet.