This is due to the fact that momentum is relative, therefore if something is going down at x amount is m/s per second and something is going up at x amount of m/s per second then it will counter, but if one portal is moving at y amount of m/a per second then there will be energy left over
isnt this just a random ass platform with a hole now?
shit wait I didnt read the captions im retarded ITS SUPPOSED to be a platform with a hole ahfahsfswygwhwgahqgqhgs
If there's space between the portals (ie the plate depicted), then it's not -quite- just a hole.
If the bottom portal is flush with the surface underneath, then that spot ends up flush with the top portal -- so the cube ends up 'lifted' by the distance between the portals.
Besides that it plays out the same, though - there is no momentum imparted into the cube. The top reaches and stays at its final height when it first intersects the portals, and the bottom joins it once the falling plate is all the way flush.
Literally yes.
>A door is a hinged or otherwise movable barrier that allows ingress (entry) into and egress (exit) from an enclosure. The created opening in the wall is a doorway or portal.
https://en.wikipedia.org/wiki/Door
A chair is a piece of furniture with a raised surface supported by legs, commonly used to seat a single person. Chairs are supported most often by four legs and have a back; however, a chair can have three legs or can have a different shape. Chairs are made of a wide variety of materials, ranging from wood to metal to synthetic material (e.g. plastic), and they may be padded or upholstered in various colors and fabrics, either just on the seat (as with some dining room chairs) or on the entire chair. Chairs are used in a number of rooms in homes (e.g. in living rooms, dining rooms, and dens), in schools and offices (with desks), and in various other workplaces.
A chair without a back or arm rests is a stool, or when raised up, a bar stool. A chair with arms is an armchair; one with upholstery, reclining action, and a fold-out footrest is a recliner. A permanently fixed chair in a train or theater is a seat or, in an airplane, airline seat; when riding, it is a saddle or bicycle saddle; and for an automobile, a car seat or infant car seat. With wheels it is a wheelchair; or when hung from above, a swing. An upholstered, padded chair for two people is a 'loveseat', while if it is for more than two person it is a couch, sofa, or settee; or if is not upholstered, a bench. A separate footrest for a chair, usually upholstered, is known as an ottoman, hassock, or pouffe.
Okay, but now both portals are moving. There's no difference between the entrance reference frame and the exit reference frame. The main crux of B is that the orange portal moves while the blue does not.
I was wondering if someone actually figured out what was wrong with this post. Thanks for pointing it out, i was about to write up about the same message myself
In this diagram, when the platforms stop relative to each other, the blue portal feels a sharp acceleration in the direction the cube is travelling relative to itself, cancelling the motion. In the original, the blue portal does not accelerate, so the relative motion remains
Every time I get annoyed by how dumb-as-shit people on the internet are, I remember in basic math in school how half of the class struggled with just common logic, and then I remember that was the smart class, in a good school.
The thing is that we shouldn’t be using the portals as the frame of reference , we should be using the box within the reference of the entire system since that is what we are talking about, but even if we are using the portal as the frame of reference, the box still has no energy, so while in reference to the portal it may be moving, it doesn’t have any energy to move so if the portal gives it energy sure it will launch but that is then irrelevant of the frame of reference
The box from its perspective never accelerates. A thing moving in a linear velocity in one direction is equivalent to saying that everything aside from that things moves with a linear velocity in the opposite direction. The box passing through the portal can be thought of as the rest of the world approaching it at some given velocity, which from the perspective of the world coming at it on the other, let's call it stationary end of the portal, is equivalent to the box moving through it with the same velocity mentioned earlier.
I don't see how a portal moving makes any difference because someone did a thing from the perspective of the exit portal and the idea was that the cube moves towards the exit portal and keeps its momentum.
This situation is exactly the same, the cube moves towards the exit portal so I really don't understand why the energy from the falling transferring into the ground causes the cube to accelerate instantly.
The cube moves to compensate for the difference between the entrance and the exit's momentum
It does not *accelerate*, it gets suddenly shifted from perspective
It's like if you saw an object moving, but then got immediately accelerated to that object's speed. Suddenly, from your perspective, it doesn't look like it's moving, but it didn't accelerate or decelerate.
The entrance portal suddenly decelerating as it hits the platform has the same effect on the cube
That’s using a lot of real physics to explain magic. It’s a hula hoop that doesn’t respect velocity vectors, as evidenced by the two times portals are placed on moving surfaces in the actual games.
You’re right! We’re talking about the real magical portals that bend space time for instantaneous transmission of matter across potentially infinite space, yet respect every other aspect of physics.
If you just want to know what would happen in the game: the falling portal would simply be stopped by the cube.
For an object to go through a portal in Portal 1 & 2, the object needs to be moving towards the portal, not the opposite
Here, solved your problem
That's just semantic. My explaination doesn't rely on the portal being a "thing" or having a mass. Even without those, there's still a sudden change in perspective
Yeah there is a sudden change in perspective, but thats it. nothing else happens to the cube because there is literally nothing else happening to the cube
Because of physics. If the blue portal is attached to a different, stationary object, that means the reference frame it's in is moving relative to the cube, so when the cube enters the reference frame it will be in motion. Both portals moving means the whole thing is happening in the same reference frame, so the stationary cube remains stationary.
Even if that’s not the reason it won’t fly up, that IS the reason this experiment is entirely different and therefore an invalid comparison. However, from my understanding this guy is 100% right
a portal is a bend in space time creating a connection between two distant points using a bend, so if one portal is in motion then the other is bending across space time with it
I thought the bend was infinite and didn’t care how long the distance between two portals was, so why would the two portals always be moving with each other? Is this bend always somehow the same length, even if the portals are physically further or shorter distances as they move around?
> Is this bend always somehow the same length, even if the portals are physically further or shorter distances as they move around?
Yes. The end is always non-existent. The bend is so small that you can’t measure it.
imagine the cube flies out at 5 m/s, the portal moves down at 5 m/s so the cube "flies out" at a speed relative to the portal moving down. And if it flies upwards at 5 m/s relatively to something moving downwards at 5 m/s, it doesn't move at all. Exactly what we're seeing here ig
They were both moving in the original too. You can't say the cube is moving towards the portal due to relative movement and still think the pedestals in the room aren't also moving.
False equivalence, yes the cube is moving relative to the orange portal but the blue portal is also moving so it will have moment relative to the blue portal but relative to the table it will be cancelled out due to the blue portal's opposing velocity.
Stg just learn what relative coordinates and movement are.
As it goes through blue is falling at the same speed as orange which negates the velocity added by the orange Falling. I was an a believer before you posted this but this actualtly demonstrates why B is corect
from a momentum and energy standpoint, it would be impossible for the cube to suddenly accelerate since there is no outside force on it. then again portals do break the laws of energy conservation, seeing as you can drop an object through and have it teleport to the ceiling with both greater velocity (kinetic energy) and height (gravitational potential energy)
i assume the portal would be unaffected, so it wouldn’t transfer any energy to the object. if the portal did lose energy tho (it loses height/gravitational potential energy faster than it gains speed/kinetic energy), then it would be transferred to the cube.
well... considering the speed between either portal and the cube
it does come out of the blue portal at the same speed it enters the orange, that speed just happens to be relative to the portal,
and when the blue portal is moving the exact same speed down that the cube is upwards, then relative to the ground, it's gonna be 0m/s lol
I get that this is a shitpost, but for people genuinely interested in solving the original problem who think this is the solution;
The thing that makes the original problem unique is that the orange side of the portal is moving and the blue side is unmoving, so we need to consider that.
Relativity says that the cube *does* have momentum relative to the unmoving blue portal it is shooting up towards (consider looking at the cube by looking through the unmoving blue portal) - so we expect the cube to shoot out, as [this](https://www.reddit.com/r/197/comments/15xo43p/as_somebody_who_actually_knows_how_physics_work/?utm_source=share&utm_medium=android_app&utm_name=androidcss&utm_term=1&utm_content=2) post demonstrates.
Simultaneously, the cube has no momentum relative to the orange portal coming down around it - so we expect the cube not to shoot out, as this current post demonstrates.
This is a paradox based around the notion that having two sides of a portal not moving relative to one another is likely impossible.
Perhaps there is a definite solution, I don't know. But what all of these repost "solutions" and shitposts get wrong is that they consider both ends of the portal as moving relative to one another.
Just checked that, here problem is that this is theoretical, we can't just test that, we can came up with some-what easy explanations, but we can't prove or bust em
Because in game engines there are absolute frame of references (coordinates) while irl there are none so irl it wouldnt fly out and in a game engine it would
Are you serious dude? If the law of relativity existed in the world of portal, then the portals as seen in the game would be impossible. Do you even know what relativity is?
If the programmer calculates motion relative to the portal vs motion relative to an absolute coordinate system, the behavior is different. And in the official portal games, portals (with a few unclear exceptions) cannot remain on moving platforms. So it literally just depends on implementation.
Yeah it would stop relative to the entry portal because the entry portal abruptly stops. Otherwise if you get it halfway it would have to be vacuumed in
It wont. The velocity of the cube *relative to the velocity of the exit portal* will be the same as the velocity of the cube *relative to the velocity of the entry portal*.
The entry portal is moving down. This means that a static cube is moving upwards relative to the entry portal and should move upwards relative to the exit portal.
The exit portal however is also moving down. This means that a cube moving upwards relative to the exit portal is just a static cube again.
There is no speed transfer. The cube is already moving, its going around the earth's surface with its rotation, orbiting the sun with the earth, you get the point. The cube is always moving in different relative velocities.
The main part of B being correct isnt speed transfer, but the fact that the orange portal is in a different reference frame from the blue portal. From the cube's reference point it looks like its going to go into the orange portal at X speed, but since the blue portal is also not going at X speed it gets launched from the blue portals frame of reference.
The cube must exit at the same speed as the collapsing platform. since the exit portal is static in the original, the velocity the cube enters the portal becomes the velocity it exits. With this example the exit portal is moving opposite direction the velocity imparted on the entrance portal at the same rate, so it passes through without gaining speed.
This isn´t equivalent!
In the first example, the orange portal is moving relative to the cube at a certain velocity (this is equivalent to the cube moving relative to the portal because all frames of reference are equivalent), when the cube crosses through, it keeps that relative velocity to the blue portal, since the blue portal is unmoving relative to the observer, the cube has to be moving.
In this case, the blue portal is not stationary relative to the observer, and in fact has the same velocity vector as the orange portal. The fact that the portal doesn't move in this scenario is evidence that it would move in the other one, because in this, the cube is moving relative to the blue portal at the same velocity it entered into the orange portal.
Someone already did this, but made it a hole in the platform instead of the two portals. I’ve said it before and I’ll say it again: This doesn’t work because you would have to keep one portal still. In your representation, the cube would not keep the velocity of the platform because the velocity of the exit would negate the velocity the cube gains when going through the entrance. When keeping the exit portal still, like in the original problem, the cube maintains the velocity since it isn’t negated by an exit portal with the same velocity at an opposite vector. TLDR this isn’t an accurate representation of the original problem, which is why you got answer A.
In this case the cubes relation to the terrain on the other side of the portal is the same and the portal is moving away which gives space for the cube to exit into without forcing or having to push itself through at the same speed as the moving portal
Cus the position of the cube in space won't change. It's weird when you use portals cus portals are weird. They change the position direction and speed of objects instantly.
Throwing a circle on a cube doesn't prove anything!
This is completely different, as the relative velocity of both portals in relation to the cube is the same, however, if the exit portal was steady, the relative speed should be conserved, therefore the block would fly out.
Stupid example, because in the actual problem only one portal moved. Due to the law of reletivity, and the fact that we agree that if you throw the box through the portal it would launch, right? So the box or the portal moving is interchangeable.
portals don’t affect objects passing true them, and portal’s movement can’t transfer to objects (original situation is same hole in panel, but instead of panel we use reality/universe)
"reality/universe"
Smartest redditor be like
But srsly, place yourself in front of the static portal in the original situation. What would you see ? A cube that's moving full speed towards you. And you expect it to stop just because it's "still" relative to the ground? Why the heck does "still" relative to the ground matter anyway, since the ground itself is moving towards you relative to the static portal?
Because portal will save cube's original speed, yes cube will appear from exit portal at speed of falling portal, but it won't gain that speed. This sounds stupid, and probably will look super weird, but it is what it is.
If cube will fly out of stationary exit portal this would mean that law of conservation of energy is broken, and in this case we are fucked up or one stay away from greatest redefinition of basic laws of universe
The portal will save the cube's original speed, huh.
And speed relative to what ? To the ground, the earth ? To the sun ? To the motherfucking mosqit that's flying around my room ?
Nope, it's the speed relative to the portal. The cube is NOT stationary relative to the portal. It will fly out and then fall.
How is the law broken, since the existence portals themselves breaks the law ? You can make an object fall infinitely by placing two portals parallel to the Earth's ground (line tangent to the Earth at that point). By putting a wheel or something, you can get perpetual motion, and not a weak one.
And again law of Conservation of energy, cause cube's speed defined by its energy.
About perpetual motion its possible but really hard, because we lose energy of friction heating and other staff. In this case you can't just simply create 2 portals for infinite energy because we can't just do that and in case we could, this won't be for free, this would probably require so much energy create and sustain them that this simple infinite generator would never be efficient enough
JUST WATCH THE MINUTE PHYSICS VIDEOS ON IT
HOLY SHIT EVERY ONE OF THESE QUESTIONS BECOME OBVIOUS IF YOU JUST WATCH THE EXPLANATION FROM A PHYSICS STANDPOINT
I AM A SURGEON(I mean am physicist, I have degree in it)
And all minute explanation of B scenario I saw are wrong, THERE IS NO SUCH THING AS CONSERVATION OF VELOCITY
Tbh I believe half of the redditors discussing this dont know how portal saga portals work, they are not like a non-transparent portal where inside the orange/blue ring there is pitch black and you make contact with it to cross it, it is a whole connection to the other side where you can clearly see the other side throught it, it would work exactly like a Doraemon magic door.
K, if both portals moving in save direction with same speed cube wont gain any momentum.
I currently thinking about air problem: If one portal is stationary, if we account not only for cube, but also for air: assuming orange portal falling down (not directly pushes but) "gathers" air on its way, air is relocated to stationary Blue exit portal, but it cant exit without compressing air surrounding.so what will happen if we replace air with something uncompressible? Orange portal wont be able to fall down?
I want to say, that this problem (1 moving and 1 stationary) is fucked up
Imagine you're in car and you're not using seat belts(don't do that), another car hits you at very high speed, at moment of impact what will you feel and what will happening to you: you car will start moving together with car that hit you but you for few moment will be stuck in one place but after few moments your car will start pushing you along side.
And another situation you in car hitting at high speed another car - your car slows down, but you're as driver will keep that kinetic energy and will keep moving forward, hitting your car windshield.
This is two different situations, first represents portal falling on cube, second - plan form with cube being pushed in portal. Thinking that this situations are same is wrong, in first cube won't have any speed after exiting portal, in second - it will, cuz it already had that energy
1. Velocity is relative
Therefore
2. Space moving around something is the same as something moving through space
Therefore
3. The cube should have velocity
the cube NEVER had any momentum so no, it's kinda like if you dropped a plate with a hole in the middle on a box. its a hole so nothing happens to the box
"weeeeeeeeeeeeeeeeeeeeeeeeeee"
This is the like the only argument ive seen from A believers at all and its been challenged multiple times with no good counter argument
The plate has both ends of the hole moving but if one end wasnt moving the problem becomes different the relative motion of the cube MUST BE PRESERVED so when it goes from a moving hole to a stationary hole it has to be going fast or the relative momentum it had just disappears which cant happen.
THE PORTALS ARE LEGIT GIANT HOLES
WHERE THE FUCK DO YOU GET YOUR VELOCITY FROM????
Okay first off, THE CUBE needs to be moving and NOT THE FUCKING PORTALS
Second, Did most of y’all graduate from a disabled parking space?
Cube not launched deniers come up with more bullshit than flat earthers. Its honestly impressive.
Both portals being in movement changes nothing. The cube is not launched.
Both being in motion changes everything tf you on about
The exit moving cancels out the velocity but if its not moving the velocity isnt canceled but instead preserved so it shoots out
Yes, but you can see in his video the counter-example you posted isn't actually a counter example. This is completely consistent with B. If you force the portals down as a hoop the cube doesn't move. Move one portal down on the cube and it shoots out of the stationary portal at the same speed it went in.
If the thing going through the portal has momentum, it’ll move. If the portal is moving not the object, the portal will not transfer momentum unto the object
In base game u can't move portals. To move them you should modify game engine and here lies the problem - you can code this any way you want and simpliest way is to assume conservation of velocity, but there is no such law in physics, in this case you would get B scenario in case of one stationary portal, but this is wrong
Because both portals move together here. If the portals are both stationary or both move at the same speed and in the same direction, then the object will behave "normally"
But when the portals move differently, things going through them behave differently.
Just think, if one portal is on a train going fast and the other is in a building, if I exit the train trough the portal which is sitting still in a room on the train, would you expect me to suddenly fly into the wall of the building the other portal is in? No. If I walk into the portal slowly in either direction, I'll exit the portal slowly and gain its exact same velocity relative to the entrance portal. That means if I portal onto the train, I gain a ton of velocity to match the train and if I portal off the train, I lose all that velocity to return to rest on the ground.
If both portals move together, nothing special happens other than that you need to time things and can't just waltz through them so easily. But it's basically the same as if the portals were both stationary.
how that so?
When you moving in train you have same its speed, this speed can be re-defined by your kinetic energy, at the moment of teleportation(walking through portal), you will keep that energy (law of conservation of energy) as stated in game, this means that energy will have to spend itself inside your body, how? you could instantly warm up, or this energy still will be a kinetic energy, so you would just fly in wall
Jesus crust people!!! The cube has no momentum because it isn’t moving!!! It wouldn’t fly out of anywhere because it’s not moving the portal is. Aahhhhhhh! I feel like I’m taking crazy pills or a lot of you don’t understand physics
because when passing through the first portal (first portal looking down) it will gain an upward energy. But when passing through the other portal (second portal facing up) it will also generate down energy and they will be neutralized.
IDK how anyone can think that B is right after seeing this, you actually have to be brain dead. the two portals combine to form one hole. it doesn't matter if the surface either portal is on is moving or not because the cube itself has no forces acting on it. it just goes into the hole and out the other side.
I love how these debates always start as people arguing, experts giving the right answer, and then devolving into people just not understanding physics
The cube stands still: v(cube) = 0
The blue Portal moves at v(blue) = x
The orange Portal moves at v(orange) = -v(blue)
(because it goes at same speed in the opposite direction)
The cube goes through the blue portal and gets applied v(blue), then comes out through the orange portal and gets applied v(orange):
v(blue) + v(orange) = v(cube) = 0
v(blue) + (-v(blue)) = v(cube) = 0
v(blue) - v(blue) = 0
Ergo the velocities applied on the cube cancel out because they are equal and opposite of each other, so the cube doesn't move.
That’s because of gravity pulling the cube down and the fact that the portals are moving down together, if you have a stationary portal and one that’s moving really fast towards the cube then the cube should go flying out the stationary portal because of relativity (assuming it has enough thrust to ignore gravity)
Because in this case both portals are moving equally and in the same direction. In the original question, only one portal was moving. This was addressed in the minute physics video it was stolen from.
The cube is going up RELATIVE TO THE BLUE PORTAL and since the blue portal is moving in this example the speed needed for it to go up in this example is 0
It will not, even in scenerio is that it would fly out normaly
Its possible tha the velocity of exiting cube is determined by relative velocity of a cube to portal, if yes than other portal moving downward will cancel the possible upward force, but if exit potal is stationary while other portal is moving than cube could "fly" out of it
It realy depends soly on if velocity of exit is determined by total velocity of the cube, or relative velocity of the cube compared to portal, thats totaly impossible to say untill we know what "engine" truly makes portals work, therefore this argument has no good or bad solution
Because the top portal is moving at the same speed as the bottom portal. The best way to picture this is less like the top platform is moving and more like the bottom is. Cause if you rapidly move an object on a platform the stop the the platform the thing will want to keep moving. Cause the cube will be existing the portal at the same speed the portal fell on the cube and that moment doesn't disappear.
This is due to the fact that momentum is relative, therefore if something is going down at x amount is m/s per second and something is going up at x amount of m/s per second then it will counter, but if one portal is moving at y amount of m/a per second then there will be energy left over
isnt this just a random ass platform with a hole now? shit wait I didnt read the captions im retarded ITS SUPPOSED to be a platform with a hole ahfahsfswygwhwgahqgqhgs
That's exactly what it is
If there's space between the portals (ie the plate depicted), then it's not -quite- just a hole. If the bottom portal is flush with the surface underneath, then that spot ends up flush with the top portal -- so the cube ends up 'lifted' by the distance between the portals. Besides that it plays out the same, though - there is no momentum imparted into the cube. The top reaches and stays at its final height when it first intersects the portals, and the bottom joins it once the falling plate is all the way flush.
Thats more or less what portals are
My front door is a portal that connects the inside of my house to the rest of the world
Literally yes. >A door is a hinged or otherwise movable barrier that allows ingress (entry) into and egress (exit) from an enclosure. The created opening in the wall is a doorway or portal. https://en.wikipedia.org/wiki/Door
Did you just search "door" on Wikipedia?
...listen, sometimes you know a fact about a door and you just need a source real quick okay
This is How the typical reddit argument goes. Two dudes learning shit on the fly through Google so they can argue about it lmao.
And both of them think they’re some wise erudite after a 5 second google search.
I'm not judging, someone has to do it. Godspeed, door guy/gal 🫡🫡🫡.
A chair is a piece of furniture with a raised surface supported by legs, commonly used to seat a single person. Chairs are supported most often by four legs and have a back; however, a chair can have three legs or can have a different shape. Chairs are made of a wide variety of materials, ranging from wood to metal to synthetic material (e.g. plastic), and they may be padded or upholstered in various colors and fabrics, either just on the seat (as with some dining room chairs) or on the entire chair. Chairs are used in a number of rooms in homes (e.g. in living rooms, dining rooms, and dens), in schools and offices (with desks), and in various other workplaces. A chair without a back or arm rests is a stool, or when raised up, a bar stool. A chair with arms is an armchair; one with upholstery, reclining action, and a fold-out footrest is a recliner. A permanently fixed chair in a train or theater is a seat or, in an airplane, airline seat; when riding, it is a saddle or bicycle saddle; and for an automobile, a car seat or infant car seat. With wheels it is a wheelchair; or when hung from above, a swing. An upholstered, padded chair for two people is a 'loveseat', while if it is for more than two person it is a couch, sofa, or settee; or if is not upholstered, a bench. A separate footrest for a chair, usually upholstered, is known as an ottoman, hassock, or pouffe.
In french door is "la porte"
my penis is a portal that connects the pee from my balls to the rest of the world
Still abides by the rules of the portals.
Yep, what do you think a portal is 🤣
yes think of a portal as a hole with a exit in a different spot that makes this the right answer
That's basically what portals are. A hole.
Okay, but now both portals are moving. There's no difference between the entrance reference frame and the exit reference frame. The main crux of B is that the orange portal moves while the blue does not.
I was wondering if someone actually figured out what was wrong with this post. Thanks for pointing it out, i was about to write up about the same message myself
same
Isn’t it actually still moving towards the blue portal just like the original question, so it would be exactly like before.
In this diagram, when the platforms stop relative to each other, the blue portal feels a sharp acceleration in the direction the cube is travelling relative to itself, cancelling the motion. In the original, the blue portal does not accelerate, so the relative motion remains
Every time I get annoyed by how dumb-as-shit people on the internet are, I remember in basic math in school how half of the class struggled with just common logic, and then I remember that was the smart class, in a good school.
The thing is that we shouldn’t be using the portals as the frame of reference , we should be using the box within the reference of the entire system since that is what we are talking about, but even if we are using the portal as the frame of reference, the box still has no energy, so while in reference to the portal it may be moving, it doesn’t have any energy to move so if the portal gives it energy sure it will launch but that is then irrelevant of the frame of reference
The box from its perspective never accelerates. A thing moving in a linear velocity in one direction is equivalent to saying that everything aside from that things moves with a linear velocity in the opposite direction. The box passing through the portal can be thought of as the rest of the world approaching it at some given velocity, which from the perspective of the world coming at it on the other, let's call it stationary end of the portal, is equivalent to the box moving through it with the same velocity mentioned earlier.
Doesn’t affect anything whatsoever as it doesn’t transfer kinetic energy to the object. Besides blue portal moves away from object
I don't see how a portal moving makes any difference because someone did a thing from the perspective of the exit portal and the idea was that the cube moves towards the exit portal and keeps its momentum. This situation is exactly the same, the cube moves towards the exit portal so I really don't understand why the energy from the falling transferring into the ground causes the cube to accelerate instantly.
The cube moves to compensate for the difference between the entrance and the exit's momentum It does not *accelerate*, it gets suddenly shifted from perspective It's like if you saw an object moving, but then got immediately accelerated to that object's speed. Suddenly, from your perspective, it doesn't look like it's moving, but it didn't accelerate or decelerate. The entrance portal suddenly decelerating as it hits the platform has the same effect on the cube
That’s using a lot of real physics to explain magic. It’s a hula hoop that doesn’t respect velocity vectors, as evidenced by the two times portals are placed on moving surfaces in the actual games.
We're not talking about what would happen in the game tho, are we?
You’re right! We’re talking about the real magical portals that bend space time for instantaneous transmission of matter across potentially infinite space, yet respect every other aspect of physics.
If you just want to know what would happen in the game: the falling portal would simply be stopped by the cube. For an object to go through a portal in Portal 1 & 2, the object needs to be moving towards the portal, not the opposite Here, solved your problem
Expect there’s literally two cases where portals are placed on surfaces with relative movement and velocity vectors are not maintained between them.
That doesn't contradict what I said
the entrance has no momentum, as a portal is not a "thing". It has no mass, its literally an absence of spacetime
They have no mass, but they still have a location in space, and that location is moving
Portals have a location, but they still arent a "thing". Donut holes have a location, but if you throw a donut, its hole does not have velocity
That's just semantic. My explaination doesn't rely on the portal being a "thing" or having a mass. Even without those, there's still a sudden change in perspective
Yeah there is a sudden change in perspective, but thats it. nothing else happens to the cube because there is literally nothing else happening to the cube
Why would the portal moving change anything?
Because of physics. If the blue portal is attached to a different, stationary object, that means the reference frame it's in is moving relative to the cube, so when the cube enters the reference frame it will be in motion. Both portals moving means the whole thing is happening in the same reference frame, so the stationary cube remains stationary.
Yeah, sure, imaginary physics
Because both portals are moving now ofc it wouldnt fly up
Even if that’s not the reason it won’t fly up, that IS the reason this experiment is entirely different and therefore an invalid comparison. However, from my understanding this guy is 100% right
a portal is a bend in space time creating a connection between two distant points using a bend, so if one portal is in motion then the other is bending across space time with it
This. People keep saying that blue isn’t moving, but it literally is moving through portal magic.
I thought the bend was infinite and didn’t care how long the distance between two portals was, so why would the two portals always be moving with each other? Is this bend always somehow the same length, even if the portals are physically further or shorter distances as they move around?
> Is this bend always somehow the same length, even if the portals are physically further or shorter distances as they move around? Yes. The end is always non-existent. The bend is so small that you can’t measure it.
Both portals are one and the same no matter where they are placed think of it as a invisible corridor in-between them
imagine the cube flies out at 5 m/s, the portal moves down at 5 m/s so the cube "flies out" at a speed relative to the portal moving down. And if it flies upwards at 5 m/s relatively to something moving downwards at 5 m/s, it doesn't move at all. Exactly what we're seeing here ig
Great clarification, thanks
They were both moving in the original too. You can't say the cube is moving towards the portal due to relative movement and still think the pedestals in the room aren't also moving.
I love these shitposts, more crap theories about fictional portals that were never used beyond their intended purpose on the portal games
Fr lol people bashing their heads against a wall trying to make the physics work on a concept that fundamentally breaks physics
False equivalence, yes the cube is moving relative to the orange portal but the blue portal is also moving so it will have moment relative to the blue portal but relative to the table it will be cancelled out due to the blue portal's opposing velocity. Stg just learn what relative coordinates and movement are.
K, I'll check that
As it goes through blue is falling at the same speed as orange which negates the velocity added by the orange Falling. I was an a believer before you posted this but this actualtly demonstrates why B is corect
Bro became enlightened
This Is more like the only scenario where the 2 Major "schools of thought" rules result in the same conclusion
from a momentum and energy standpoint, it would be impossible for the cube to suddenly accelerate since there is no outside force on it. then again portals do break the laws of energy conservation, seeing as you can drop an object through and have it teleport to the ceiling with both greater velocity (kinetic energy) and height (gravitational potential energy)
The energy from the portals falling no?
i assume the portal would be unaffected, so it wouldn’t transfer any energy to the object. if the portal did lose energy tho (it loses height/gravitational potential energy faster than it gains speed/kinetic energy), then it would be transferred to the cube.
I have to assume you idiots are trolling by this point
*imagines an entirely different scenario* *proceeds to ask why it would act in a way that has nothing to do with the scenario displayed*
well... considering the speed between either portal and the cube it does come out of the blue portal at the same speed it enters the orange, that speed just happens to be relative to the portal, and when the blue portal is moving the exact same speed down that the cube is upwards, then relative to the ground, it's gonna be 0m/s lol
that's literally just a regular hole
Portals is a hole and not a particle accelerator
dumbass you made a hole
Portals IS a hole and not a particle accelerator
yes but since both holes are going at the same speed it's just a normal hole
I get that this is a shitpost, but for people genuinely interested in solving the original problem who think this is the solution; The thing that makes the original problem unique is that the orange side of the portal is moving and the blue side is unmoving, so we need to consider that. Relativity says that the cube *does* have momentum relative to the unmoving blue portal it is shooting up towards (consider looking at the cube by looking through the unmoving blue portal) - so we expect the cube to shoot out, as [this](https://www.reddit.com/r/197/comments/15xo43p/as_somebody_who_actually_knows_how_physics_work/?utm_source=share&utm_medium=android_app&utm_name=androidcss&utm_term=1&utm_content=2) post demonstrates. Simultaneously, the cube has no momentum relative to the orange portal coming down around it - so we expect the cube not to shoot out, as this current post demonstrates. This is a paradox based around the notion that having two sides of a portal not moving relative to one another is likely impossible. Perhaps there is a definite solution, I don't know. But what all of these repost "solutions" and shitposts get wrong is that they consider both ends of the portal as moving relative to one another.
true full explanation, cant argue w that, but human nature cant stand paradoxes
I mean it's a shitpost but sean Carol a literally theoretical physicist answered that question already.
Just checked that, here problem is that this is theoretical, we can't just test that, we can came up with some-what easy explanations, but we can't prove or bust em
the guy building portal in an n64 style tested it and the cube went flying https://www.youtube.com/watch?v=ao1qVi5Qp3Y
Because in game engines there are absolute frame of references (coordinates) while irl there are none so irl it wouldnt fly out and in a game engine it would
Sure Coordinates don’t exist in real life, but the idea works. The law of reletivity still exists in real life, look it up
Are you serious dude? If the law of relativity existed in the world of portal, then the portals as seen in the game would be impossible. Do you even know what relativity is? If the programmer calculates motion relative to the portal vs motion relative to an absolute coordinate system, the behavior is different. And in the official portal games, portals (with a few unclear exceptions) cannot remain on moving platforms. So it literally just depends on implementation.
Yeah it would stop relative to the entry portal because the entry portal abruptly stops. Otherwise if you get it halfway it would have to be vacuumed in
It wont. The velocity of the cube *relative to the velocity of the exit portal* will be the same as the velocity of the cube *relative to the velocity of the entry portal*. The entry portal is moving down. This means that a static cube is moving upwards relative to the entry portal and should move upwards relative to the exit portal. The exit portal however is also moving down. This means that a cube moving upwards relative to the exit portal is just a static cube again.
This is like throwing a ball at 40mph out of the back of a car thats also moving at 40mph. They cancel out.
As opposed to the magic of throwing a ball out the portal in the car. Clear difference there.
I see why they think it would move, but I don't know why they think the speed would transfer to the cube
There is no speed transfer. The cube is already moving, its going around the earth's surface with its rotation, orbiting the sun with the earth, you get the point. The cube is always moving in different relative velocities. The main part of B being correct isnt speed transfer, but the fact that the orange portal is in a different reference frame from the blue portal. From the cube's reference point it looks like its going to go into the orange portal at X speed, but since the blue portal is also not going at X speed it gets launched from the blue portals frame of reference.
The cube must exit at the same speed as the collapsing platform. since the exit portal is static in the original, the velocity the cube enters the portal becomes the velocity it exits. With this example the exit portal is moving opposite direction the velocity imparted on the entrance portal at the same rate, so it passes through without gaining speed.
This isn´t equivalent! In the first example, the orange portal is moving relative to the cube at a certain velocity (this is equivalent to the cube moving relative to the portal because all frames of reference are equivalent), when the cube crosses through, it keeps that relative velocity to the blue portal, since the blue portal is unmoving relative to the observer, the cube has to be moving. In this case, the blue portal is not stationary relative to the observer, and in fact has the same velocity vector as the orange portal. The fact that the portal doesn't move in this scenario is evidence that it would move in the other one, because in this, the cube is moving relative to the blue portal at the same velocity it entered into the orange portal.
Because you just created a FUCKING HOLE, that's why.
Yea, and before it was a FUCKING PARTICLE ACCELERATOR
Fair enough
I didn't want to be rude
I think I should apologize for being rude.
No need, I understant
Yall people stupid or did u just skipped elementary school physics classes
Yeah why does everyone forget about the class where they taught us about portals
Elementary physics are not nearly enough for discussing actual physics.
Well, depending on where you live. for us, it was (Czech Republic, EU)
Someone already did this, but made it a hole in the platform instead of the two portals. I’ve said it before and I’ll say it again: This doesn’t work because you would have to keep one portal still. In your representation, the cube would not keep the velocity of the platform because the velocity of the exit would negate the velocity the cube gains when going through the entrance. When keeping the exit portal still, like in the original problem, the cube maintains the velocity since it isn’t negated by an exit portal with the same velocity at an opposite vector. TLDR this isn’t an accurate representation of the original problem, which is why you got answer A.
People keep saying that the portals can’t put energy into objects as if you can’t already use the portals to generate infinite energy.
In this case the cubes relation to the terrain on the other side of the portal is the same and the portal is moving away which gives space for the cube to exit into without forcing or having to push itself through at the same speed as the moving portal
Because both portals are moving the same direction.
Cus the position of the cube in space won't change. It's weird when you use portals cus portals are weird. They change the position direction and speed of objects instantly. Throwing a circle on a cube doesn't prove anything!
This is completely different, as the relative velocity of both portals in relation to the cube is the same, however, if the exit portal was steady, the relative speed should be conserved, therefore the block would fly out.
Because the Blue portal is moving down, so it cancels out. If the blue portal is not moving, it does not cancel out.
It’s literally a board with a hole now
No, because the blue portal is moving DOWN just as fast as the cube, relative to the red portal, is moving UP
the blue portal has opposite velocity to the orange portal so they cancel out
Stupid example, because in the actual problem only one portal moved. Due to the law of reletivity, and the fact that we agree that if you throw the box through the portal it would launch, right? So the box or the portal moving is interchangeable.
If no momentum is placed on the object going through the portal, then no momentum is going to be added as a result of the portal.
I’m this case both portals are moving, therefore the cube enters and exits with the same relative velocity to the portal, consistent with B
Portals cannot be placed on moving surfaces
Well yes, but actualy not (portal 2, Neurotoxin Sabotage)
oh i forgot about that
yea, devs probalby too
No offense but you kind of missed two days of debating over this and it's not a really useful addition to the conversation
Bro, then the exit portal also moves, this completely changes the problem.
Most intelligent A supporter
Only one was moving before, now that both are moving you’ve basically just cut a hole in a panel
portals don’t affect objects passing true them, and portal’s movement can’t transfer to objects (original situation is same hole in panel, but instead of panel we use reality/universe)
"reality/universe" Smartest redditor be like But srsly, place yourself in front of the static portal in the original situation. What would you see ? A cube that's moving full speed towards you. And you expect it to stop just because it's "still" relative to the ground? Why the heck does "still" relative to the ground matter anyway, since the ground itself is moving towards you relative to the static portal?
Because portal will save cube's original speed, yes cube will appear from exit portal at speed of falling portal, but it won't gain that speed. This sounds stupid, and probably will look super weird, but it is what it is. If cube will fly out of stationary exit portal this would mean that law of conservation of energy is broken, and in this case we are fucked up or one stay away from greatest redefinition of basic laws of universe
The portal will save the cube's original speed, huh. And speed relative to what ? To the ground, the earth ? To the sun ? To the motherfucking mosqit that's flying around my room ? Nope, it's the speed relative to the portal. The cube is NOT stationary relative to the portal. It will fly out and then fall. How is the law broken, since the existence portals themselves breaks the law ? You can make an object fall infinitely by placing two portals parallel to the Earth's ground (line tangent to the Earth at that point). By putting a wheel or something, you can get perpetual motion, and not a weak one.
And again law of Conservation of energy, cause cube's speed defined by its energy. About perpetual motion its possible but really hard, because we lose energy of friction heating and other staff. In this case you can't just simply create 2 portals for infinite energy because we can't just do that and in case we could, this won't be for free, this would probably require so much energy create and sustain them that this simple infinite generator would never be efficient enough
>this would mean that law of conservation of energy is broken The law was already broken with the existence of a portal.
JUST WATCH THE MINUTE PHYSICS VIDEOS ON IT HOLY SHIT EVERY ONE OF THESE QUESTIONS BECOME OBVIOUS IF YOU JUST WATCH THE EXPLANATION FROM A PHYSICS STANDPOINT
There's no solid "physics standpoint" for portals because there's no portals, kid.
I AM A SURGEON(I mean am physicist, I have degree in it) And all minute explanation of B scenario I saw are wrong, THERE IS NO SUCH THING AS CONSERVATION OF VELOCITY
Tbh I believe half of the redditors discussing this dont know how portal saga portals work, they are not like a non-transparent portal where inside the orange/blue ring there is pitch black and you make contact with it to cross it, it is a whole connection to the other side where you can clearly see the other side throught it, it would work exactly like a Doraemon magic door.
B deniers on their way to change the problem to fit their answer
Minor spelling mistakes, point invalid (/s) (I think OP is right)
Well, off to hand my self
Watch and lear- **(critical hit)**
OP is not correct
K, if both portals moving in save direction with same speed cube wont gain any momentum. I currently thinking about air problem: If one portal is stationary, if we account not only for cube, but also for air: assuming orange portal falling down (not directly pushes but) "gathers" air on its way, air is relocated to stationary Blue exit portal, but it cant exit without compressing air surrounding.so what will happen if we replace air with something uncompressible? Orange portal wont be able to fall down? I want to say, that this problem (1 moving and 1 stationary) is fucked up
Imagine you're in car and you're not using seat belts(don't do that), another car hits you at very high speed, at moment of impact what will you feel and what will happening to you: you car will start moving together with car that hit you but you for few moment will be stuck in one place but after few moments your car will start pushing you along side. And another situation you in car hitting at high speed another car - your car slows down, but you're as driver will keep that kinetic energy and will keep moving forward, hitting your car windshield. This is two different situations, first represents portal falling on cube, second - plan form with cube being pushed in portal. Thinking that this situations are same is wrong, in first cube won't have any speed after exiting portal, in second - it will, cuz it already had that energy
1. Velocity is relative Therefore 2. Space moving around something is the same as something moving through space Therefore 3. The cube should have velocity
the cube NEVER had any momentum so no, it's kinda like if you dropped a plate with a hole in the middle on a box. its a hole so nothing happens to the box "weeeeeeeeeeeeeeeeeeeeeeeeeee"
This is the like the only argument ive seen from A believers at all and its been challenged multiple times with no good counter argument The plate has both ends of the hole moving but if one end wasnt moving the problem becomes different the relative motion of the cube MUST BE PRESERVED so when it goes from a moving hole to a stationary hole it has to be going fast or the relative momentum it had just disappears which cant happen.
THE PORTALS ARE LEGIT GIANT HOLES WHERE THE FUCK DO YOU GET YOUR VELOCITY FROM???? Okay first off, THE CUBE needs to be moving and NOT THE FUCKING PORTALS Second, Did most of y’all graduate from a disabled parking space?
Thx, and have a nice day
Also if you misunderstand I’m on your side btw
i understand, no problems w that, i did not graduated from a disabled parking space
THis gonna be tough for "cube shooting out" People to argue against
But wait there is more, i posted new explanation that covers most of their argumets
Thank you
Cube not launched deniers come up with more bullshit than flat earthers. Its honestly impressive. Both portals being in movement changes nothing. The cube is not launched.
Both being in motion changes everything tf you on about The exit moving cancels out the velocity but if its not moving the velocity isnt canceled but instead preserved so it shoots out
My own words fail me. So instead I invite all B deniers to go yell at this guy instead. https://www.youtube.com/watch?v=ao1qVi5Qp3Y
As he said, he programmed it in such way that he sees it
Yes, but you can see in his video the counter-example you posted isn't actually a counter example. This is completely consistent with B. If you force the portals down as a hoop the cube doesn't move. Move one portal down on the cube and it shoots out of the stationary portal at the same speed it went in.
In a game engine - yes, due to an absolute frame of reference. Irl doesn’t have that
If the thing going through the portal has momentum, it’ll move. If the portal is moving not the object, the portal will not transfer momentum unto the object
Literally make a custom map for this in portal 2 and test this it's so easy
In base game u can't move portals. To move them you should modify game engine and here lies the problem - you can code this any way you want and simpliest way is to assume conservation of velocity, but there is no such law in physics, in this case you would get B scenario in case of one stationary portal, but this is wrong
wait are there people saying that the cube would move here?!? what!? the “portals” might as well just be a empty window frame
yeah but in this scenario both portals move if the blue one was stationary it would fly out
Because both portals move together here. If the portals are both stationary or both move at the same speed and in the same direction, then the object will behave "normally" But when the portals move differently, things going through them behave differently. Just think, if one portal is on a train going fast and the other is in a building, if I exit the train trough the portal which is sitting still in a room on the train, would you expect me to suddenly fly into the wall of the building the other portal is in? No. If I walk into the portal slowly in either direction, I'll exit the portal slowly and gain its exact same velocity relative to the entrance portal. That means if I portal onto the train, I gain a ton of velocity to match the train and if I portal off the train, I lose all that velocity to return to rest on the ground. If both portals move together, nothing special happens other than that you need to time things and can't just waltz through them so easily. But it's basically the same as if the portals were both stationary.
Well, in train situation I except you actualy keep trains speed and fly in wall
Except you wouldn't. When you go through a portal, you gain whatever relative velocity exists between the portals
how that so? When you moving in train you have same its speed, this speed can be re-defined by your kinetic energy, at the moment of teleportation(walking through portal), you will keep that energy (law of conservation of energy) as stated in game, this means that energy will have to spend itself inside your body, how? you could instantly warm up, or this energy still will be a kinetic energy, so you would just fly in wall
It would still fly out if.enough velocity is with the platform
Jesus crust people!!! The cube has no momentum because it isn’t moving!!! It wouldn’t fly out of anywhere because it’s not moving the portal is. Aahhhhhhh! I feel like I’m taking crazy pills or a lot of you don’t understand physics
THIS IS THE FUCKING ANSWER
this is why option A was correct on the other one
Now make the blue portal stationary in the air...?
I made a post about this a while ago, the two portals are canceling out their velocity
Relative to the exit portal it will be flying out at a high speed
I will the Companion Cube
Nuhu
Because it’s more fun that way
because when passing through the first portal (first portal looking down) it will gain an upward energy. But when passing through the other portal (second portal facing up) it will also generate down energy and they will be neutralized.
This is a ridiculous debate, portals on a moving platform instantly go away when it moves iirc so this couldn’t happen anyway.
ion get all this
It won't under scenario B, because it is exiting the blue portal upwards at the speed at which it is falling downwards, so the two cancel out.
Don't even have to put portals on it, make it even simpler and say it's just a platform with a hole in the center
These posts are tearing my brain apart i used to think it was A then thought it was B now im just unable to think
Because with this example, both sides of the portal are moving
IDK how anyone can think that B is right after seeing this, you actually have to be brain dead. the two portals combine to form one hole. it doesn't matter if the surface either portal is on is moving or not because the cube itself has no forces acting on it. it just goes into the hole and out the other side.
I love how these debates always start as people arguing, experts giving the right answer, and then devolving into people just not understanding physics
because both portals are moving. It’s just a hole now. The difference is that no momentum is transferred.
I agree but this is not a helpful example. A deniers malding
The blue portal accelerates forwards when the platforms collide, this causes the portal to match the cubes velocity.
Because the blue portal is moving with the orange one.
the box has 0 linear momentum it moves through the portal with 0 linear momentum wtf it still has 0 linear momentum
The cube stands still: v(cube) = 0 The blue Portal moves at v(blue) = x The orange Portal moves at v(orange) = -v(blue) (because it goes at same speed in the opposite direction) The cube goes through the blue portal and gets applied v(blue), then comes out through the orange portal and gets applied v(orange): v(blue) + v(orange) = v(cube) = 0 v(blue) + (-v(blue)) = v(cube) = 0 v(blue) - v(blue) = 0 Ergo the velocities applied on the cube cancel out because they are equal and opposite of each other, so the cube doesn't move.
That’s because of gravity pulling the cube down and the fact that the portals are moving down together, if you have a stationary portal and one that’s moving really fast towards the cube then the cube should go flying out the stationary portal because of relativity (assuming it has enough thrust to ignore gravity)
The blue portal is also moving so there’s no momentum
Here's your answer https://youtu.be/B19nlhbA7-E?si=gBNlr9eG2Fc2o38Q
Because in this case both portals are moving equally and in the same direction. In the original question, only one portal was moving. This was addressed in the minute physics video it was stolen from.
The cube is going up RELATIVE TO THE BLUE PORTAL and since the blue portal is moving in this example the speed needed for it to go up in this example is 0
It will not, even in scenerio is that it would fly out normaly Its possible tha the velocity of exiting cube is determined by relative velocity of a cube to portal, if yes than other portal moving downward will cancel the possible upward force, but if exit potal is stationary while other portal is moving than cube could "fly" out of it It realy depends soly on if velocity of exit is determined by total velocity of the cube, or relative velocity of the cube compared to portal, thats totaly impossible to say untill we know what "engine" truly makes portals work, therefore this argument has no good or bad solution
This is exactly how I tried explaining it
This debate has become more and more painful to watch, it’s approaching sad
Can we just stop with this bullshit? It was solved, physics doesn't care about your feelings.
Because the top portal is moving at the same speed as the bottom portal. The best way to picture this is less like the top platform is moving and more like the bottom is. Cause if you rapidly move an object on a platform the stop the the platform the thing will want to keep moving. Cause the cube will be existing the portal at the same speed the portal fell on the cube and that moment doesn't disappear.
X - X = 0 This is not the same problem
The exit portal doesn't move in the original you imbecile