Ragebait answers only
Most likely option is it flops out but only if the angle is sufficient for the cube to overcome its centre of gravity and topple. And do so before the orange portal rises again. Also depends if the downward orange portal directly touches the base or not, since there might be a bit of a “lip” to overcome too.
B
The cube gets sucked into the portal with the same force the platform in A is getting sucked upwards.
https://www.youtube.com/watch?v=B19nlhbA7-E
Not providing a link to alternative platforms is my ragebait
Niether. Moving surfaces break portals instantaneously.
Portal 2 has moving surfaces, with the cop-out that it’s accelerating surfaces that cause the portal to break.
spoiler
No matter that you literally put a portal on a different planet…
Portal 2 (story mode) only has laterally moving surfaces, that inherently don’t cause things to enter the portal. The moon portal is stationary in the engine.
Ragebait answers only
I’m giving so many people Fs on this assignment because you failed to read all the instructions.
The correct answer is B due to the graphical conservation of speed lines.
I think any answer is a ragebait answer because nobody here understands physics
I did it deliberately.
Lemmy reads more than most but people aren’t good at reading
Trick question. Fun answers are not ragebait. Serious answers (correct or incorrect) are ragebait. You get an F.
This is Einstein’s elevator thought experiment but with portals.
B
Also, if the cube has to emerge out of the blue portal top first it has momentum moving out of the blue portal, as seen by the blue portals frame of reference. It can’t emerge with zero momentum or it wouldn’t move relative to the blue reference frame.
But in portals physics the answer is A.
B.
Momentum/velocity is not an intrinsic property of an object, it is a relative property between two objects in a frame of reference.
Behind the yellow portal is the part of the universe where the blue portal is. The yellow portal, and therefore the space where the blue portal is, has momentum relative to the cube.
Put yourself in the frame of reference of the cube. You see the yellow portal come toward you. Imagine there are objects on the other side of that portal. You see those objects rush toward you through the portal. Why would the objects just stop dead when you came through the portal? (If they did just stop, it would be as though you hit a wall, and you wouldn’t actually go through the portal at all.)
Agreed. Also consider the duration of the time that the portal is passing over the cube. It is moving at speed, the entire way through the portal and out the other side and then it just stops dead immediately once through? That would hardly be a conservation of momentum anyway from any frame of reference and does not make any intuitive sense.
This exactly. Consider an object that isn’t a point mass (like the cube) going through. As the first atoms go through: if they just stopped relative to the portal boundary, that would suggest the next layer of atoms need to exert force on the first layer to push through. But portals in the game Portal do not have any resistance to objects passing through them.
Portals don’t stay on moving platforms.
But if they did, it would be A as the cube itself has no momentum.
WHAT DID YOU NOT UNDERSTAND ABOUT RAGEBAIT. ANSWERS. ONLY.
… Uh
u mad?
So really I saved this comment and you’re all welcome.
The speed of one thing is the same speed of the other if you change the reference point. So the cube has momentum but the moving platform does not. It’s more about having a velocity in respect to the portal it’s going in or coming out of or an average of both. Like when you jump into a portal, you come out faster on the other side. Now what if that out portal was traveling at the same rate? Would you be traveling just outside the portal or double speed (in relation to the ground and static objects in the same room)?
Except that one time when you use portals to cut the neurotoxin pipes.
Yeah, but those are moving from side to side. To my recollection, you never see a portal in a wall that’s moving in a direction that’s perpendicular to the plane it’s in.
A
In this example, the object wasn’t moving. It has no momentum to continue moving. Instead, the world around it moved. So A
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.
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.
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.
I hope that makes sense
Yeah if this existed IRL B is the correct answer. If you tried this in portal the video game A is the answer.
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.
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.
Correct.
It’s like dropping a hula hoop over it in this scenario. There is nothing to generate its motion.
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 independantly from the orange portal.
Ragebait aside the answer is B.
If you had a table with a cylinder, with a ping pong ball in it, and a circular weight dropped around the top of the cylinder that hits the table, the ping pong ball will bounce due to the forces of the weight hitting the table. Enough energy would be transferred through the impact, that would cause the ball to seemingly jump up in the cylinder.
Physics are weird.
nice ragebait answer, but I’m not falling for it
It depends. It looks like the orange portal is being moved by a hydraulic cylinder (aka laminar flow), which means the relative positions and velocities of things moving through the orange portal are conserved, and A is correct.
If instead that’s (yuck) an air fired cylinder… Then it’s going to be B.
If the movement is handled by a threaded rod, then the box will emerge from the blue portal spinning, and (perhaps contrary to expectations) if the orange portal is moving because of gravity, then the bouyant force of the box progressing through the portal will stop it from falling further, and the box will end up just less than halfway (because of the angle) through the blue portal.
And as a matter of fact the fastest possible velocity you can get is with a hydraulic cylinder because of the immense amount of force it applies using the orange portal.
If you used magnetic levitation to move the orange portal the box would never make it through, because it’s made of metal and will be attracted to the levitation equipment.
Real world B. In-game, A
divide by zero
I choose A because that would mean I could use the portal to fuck myself in the ass easier.
“Plop”
Trying to conceptualize what that would be like is making my head hurt.
You would need the portal panties to make it work. Portal A would be on a wall, or whatever object you want to thrust towards, and Portal B would be on the panties aimed at your opening. When you thrust forward at portal A, it would exit Portal B, and since Portal B is stationary (panties are magical, yo) to your opening, the pillar would rise from the portal and enter the opening.
Of all the days to be literate…
…
I’m glad this is one of them
Let’s make sure you feel the same about your eyes: https://e621.net/pools/20220
I hadn’t considered panties, but I was thinking about how you’d just be chasing yer pecker around trying to back up on that thing.
It’s like Zeno’s arrow, but kinky.
This was answered decades ago
In that situation both portals (the inside and the outside window frame) have equal, but opposite velocities and therefore cancel out any momentum from the person.
When dealing with OP’s scenario, only one portal is moving.
wikipedia.org/wiki/Steamboat_Bill,_Jr.
Nearly a century ago. Fun fact, this movie inspired Steamboat Willie, the very first appearance of Micky Mouse.
The problem with this analogy is that both sides of the window are at the same point in space so there is no pressure differential. What if the blue portal was at the bottom of the Mariana’s Trench? What force displaces the water to place the cube on the other side?
It wouldn’t. Same as if the other side of the portal was a brick wall. It wouldn’t go through or would be smooshed by whatever force is driving the portal.
I guess the odd thing is, if the orange portal can be moved, the pressure from the brick wall would be directed at the attachment point of the orange portal, otherwise why wouldn’t the orange portal keep moving, since it is not “touching” anything?
If the blue portal was deep under water, the pressure would force the water out the orange portal.
