The Portal Paradox
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- Опубликовано: 21 сен 2024
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This video is about the Portal Paradox - a paradox in the video game Portal (and Portal 2) regarding whether or not a companion cube passing through a moving portal plops out of the other end with no speed (velocity, momentum), or shoots out at high speed. It’s a question of conservation of momentum, relativity of velocities, wormholes, 3D printers and quantum teleportation, glitches, and more.
REFERENCES
Conservation of momentum
en.wikipedia.o...
Principle of Locality
en.wikipedia.o...
RUclips video of testing the Portal 2 game engine on the portal Paradox • Portal 2 - Moving Port...
Tutorial for how to program the Portal portals on your own: www.gamasutra....
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Created by Henry Reich
Aperture Science wants to remind you, that you can't put Portals on moving walls.
Thanks.
Edit: "Could you guys stop commenting the same stuff on my two year old comment."
Daniel Kröber I was looking for this comment xD it's been a very long while since I played the game, but I remember you are told it's not possible to place portals on moving surfaces, and if the surface with a portal starts moving the portal just fades
He referenced this in 0:55 . He is under the assumption "what if we can put it on a moving platform"
Except for that part near the end of Portal 2 where you put a portal in a moving surface?
@@GoudaBug right, the section where you had to cut the neurotoxin tubes with the lasers. Sadly, there's no way to actually go through the portals without console commands, but I'd assume it would be the same result as the portal moving down: no physical objects allowed.
What if the portal was a machine and was just pushed?
1: Put two portals on ceiling
2: Put a cube half way through
3: Gravity pulls on both sides equally therefore the cube doesn't fall
4: Profit
You would need to *perfectly* line it up though.
At this point it depends if the cup is half full or half empty
@@colingreen1006 that too it should have uniform distribution of mass
Umm you tried to out think the channel that is about physics so for that a sitting cat cannot sit
That is actually a very good thought experiment. Kudos.
There's only one way to address this issue: _Portal 3._
_Which in itself will cause a paradox because Valve don't count to three._
But half life three is coming out
What is they prank us and cancel it on the day that it’s supposed to be released on
STOP! you almost triggered the energy black hole that operates at the higgs field
They count to Alyx instead
Maybe it will not be half life 3 but half of 3 life, so that is half life 1.5.
my physics teacher (slightly suggested by me since we were both gamers and I was the one who provided him a copy of the game to play) used Portals related lessons several times to explain concept like inertia or the meaning of accumulated and static momentum
He used this problem in one of his lessons, and was the funniest one imho, since the class was very interested in this problem and came up with a lot of solutions for both option A and B
how can it be anything but A if no forces are applied to the cube other than the gravitational force of the planet that changes when cube comes out of the other end resulting in it just ploping out?
@@Fr33mxyess!! Im thinking the same thing. If nothing but gravity is moving the box why would it fling up like that
@@zRuSh_XraYbecause as layer of the cube come out of the blue portal they will push the layer before them out as fast as new layers are forming which is the same as the orange portal’s speed. The orange portal makes the most scenes as the reference frame (thing the speed is measured based on) because the environment does not even need to be there for the experiment.
@@bigshot103 with that logic… if a door flies past me standing still… i get launched at supersonic speeds fo no reason…? Cus thats the pov of the box. Nothing makes the box move since nothing is aplying any force to it. (Exept gravity ofc, hence the flop)
@@zRuSh_XraY
You’re missing the part where the rest of the world behind the door is also moving towards you in the case of portals. Your analogy doesn’t work because you’re only accounting for the door. If a portal is approaching you, the REST OF THE UNIVERSE behind the portal is also “approaching you.” A normal door does not “take” everything else with it, portals do.
"speedy thing goes in, speedy thing comes out"
but what if speedy thing was never speedy?
[queue vsauce music]
what if, instead, stationary thing goes in speedy hole: does it come out the other fast or slow?
Everything is speedy relative to something else. If the object exits at the same velocity relative to the ground, it would not exit at all. If the object exits slower than the velocity that the portal moves towards it, the object would compress. If the object passes through the speedy portal and its spacial dimensions do not change, than the object must be speedy.
@@CmdrShepard1001 i’m speedy relative to your mom
@@deffinatalee7699 lmao legend
Somewhere in the middle becuase the inertias would start to build on one side of the cube while the other is still moving relatively slow
slow. imagine istead of a portal it's just a hole. portals are like holes that defy euclidean space.
I think this paradox is the entire reason that Valve implemented a "no portal on moving platforms" policy except for one exception where it would be impossible to put an object through it
That just opens up another problem: What do they mean by "not moving"? How is a reference frame chosen and with what justification?
Also, aren't there two exceptions? The one where you shoot it onto the moving platform and the one where you shoot it on the moon which I'm pretty sure is not stationary with respect to earth.
just go into the console and enable that
Well this and it also the programming headaches.
No that's not right.
At the end you open a portal on the moon and it works. And the moon is moving damn fast.
@@SuperDeinVadda Don't forget the moving panels in the neurotoxin generator scene.
The player was prohibited from ever placing moving portals in any situation where they could be interacted with directly. That doesn't mean they can't canonically be moving.
My science teacher used portal as an example to explain this and he played it for us as well which is super surprising
I want that person as my teacher
Fucking legend
Good teachers are the ones who've realized the indelible impact of well made RUclips videos. Thankfully my teachers understood that back in my days and showed us episodes of Reading Rainbow and Bill Nye the Science Guy in class.
Great teacher.
Which part or game
Years ago, I was trying to program a small 2-D platformer game that had a mechanic where a user exiting one side of the screen would reappear on the opposite side (same with top to bottom). I tried adding an extra mechanic where the user could resize the game frame to solve puzzles and I ran into this same question. I realized that I had accidentally backed into creating a Portal style game in 2D with moving portals. In terms of physics, the proper answer is that the object leavers the exit portal with the speed and acceleration it had RELATIVE to the entrance portal. And that speed and acceleration is relative to the exit portal (not the environment). While it makes for an interesting thought experiment, it creates a lot of problems for a programmer. For example, if the user is shrinking the game frame, the portals are moving toward each other. An object entering a portal gets a speed boost from both the entrance AND the exit portals (because they are moving toward each other). If a user allows the player to go through the portal several times while shrinking the screen, the user will accelerate each time, until the player is going so fast that the frame rate of the program can't keep up. This creates weird problems with the collision engine (player is moving so fast they pass straight through solid objects) and the rendering engine (player is moving so fast that it creates an optical illusion where it looks like they are moving backward). After breaking my brain on this for a while, I realized why portals really aren't allowed to move - it creates physical possibilities that are impossible to replicate with a computer. I ended up abandoning the project because the physics was not something that could be simulated with a computer. I'm guessing that the developers of Portal had these same issues, which is why the portals can't be placed on moving surfaces.
Do you have any published games that I can play? I want to see what kind of games you’ve made 😊
There's already a game similar to what you're describing, about wrapping around the screen edges. Look up "Four Sided Famtasy". I got 100% completion on it. Enjoy ...
You could always try to dampen any speed above the maximum natural speed that your character can attain by themselves without portals and call it simulated wind resistance.
To quote GLaDOS from Test chamber 10, "Momentum, a function of mass and velocity, is conserved between portals. In layman's terms: speedy thing goes in, speedy thing comes out."
So what happens when a stationary thing goes in? A stationary thing can't come out
@@trash9378 yes it can. Replace the term portal with hole. The hole is in motion, not the box. the hole is being pushed down around the box. Only external forces on the other side cause it to fall over.
Option A is the correct one by any means, I don't know why would anyone even question that, portals are just a continuation of certain space in one place on another place, they only transfer the existing mass and energy as a continuation of space, they are not some energy generating force.
@@trash9378 The answer is "Momentum, a function of mass and velocity, is conserved between portals. In layman's terms:stationary thing doesn't go in because it's stationary! Stationary things can't go."
@@cyraknoss Technically the velocity being measured is the velocity at which the object enters the portal. Although the object may seem stationary to you, to the portal it is moving toward it at a rate of distance over time. Think of it as you riding a train. You are stationary, however, you also maintain the velocity of that train.
I rule in favour of Option D. When the stationary object is consumed by the portal, the source engine crashes.
the entire universe is running on source engine.
No no, it’s option *3* .
@@hiu2ying *critical error*
You call d the teir zoo route or else
Option E: Portal crashes to desktop and a pop-up with the secret download link for portal 3 is shown
Minutephysics: It depends whether you think more like a programmer or more like a physicist.
Me, dual majoring physics and computer science: *Visible confusion*
I go with the B option even tho I work as a programmer
Jesus christ. You're a next level masochist. I'm having a difficult enough time just with CS
This your time, to discover your real you; my advice; follow you heart
You wanna get more confused? Imagine the portal wouldnt move at all and the moving pillar would be pushed through the entrance portal from the backside. With enough pressure anything bigger than the portal would just be cut off. But when its true that the portal doesnt move at all, it wouldnt move with the earth spinning and flying through the universe thus cutting a giant hole in the earth while the earth is moving through the portal.
Although i guess the portal cant not move since relativity or smth
Portals are just holes that happen to connect, if you cut a hole in a piece of cardboard and set a leggo in a table then slammed the cardboard with the hole onto the lego so that the lego went thru the hole would it shoot out the other end?
if a portal in this game's rules, as I have understood, is in a surface and it starts moving, the portal disappear instantly
except in one level of portal 2. where you can place in a moving surface when ||you and wheatley are cutting the neurotoxin supply|| although there is no way for the player to enter the portal
you can enable movable portals in console
@@marengo6990 how?
@@marengo6990 necc
@@ajgumpper necc
"The portals never move"
*Cough cough* neurotoxin generator *cough cough*
Very true
Exactly.
Yeah but that's kinda the game's fault at this point
True, but the entry point is stationary, and only the exit point moves. It doesn't create the same paradox, since entry and exit are different when thjnking about the paradox
@@TheSpyroplayer Now that I think about it, you are right. The entry portal is still, and the exit portal is moving, but the thing moving through the portals is light; a laser. Light always travels at C.
I feel like Henry just tackled this century-old paradox because he just bought it from the Steam Summer Sale lmao
Gaben is pleased
Steam sales pushing educational technology since...
I bought it yesterday :)
@@skeletonrowdie1768 Playstation VR Convenience Store Simulator Demonstration?
What about one portal moving into the the other end??
"Speedy thing goes in, speedy thing comes out."
Unrated comment
Speedy portal sucks something in shoots like cannon
But the cube isn't moving relative to the exit so it shouldn't be moving relatively when it comes out
@@crazynachos4230 but thats the thing the portal gives the energy to the cube shooting it out of the outside like a cannon
@@warpedmine9682 that's not how physics works tho, there is no force being applied to the cube, which means it cannot acquire velocity by Newton's first law. The Portal doesn't apply force, it's just a hole in space. The result would be the same as if the portal was just a wall with a hole in it.
Consider what you would see looking into the exit portal. You would essentially see the ground pushing the cube out of it. When you think about it like that, it seems like it would have to be relative to the object and the entry portal.
I'd think of it like slamming down a ring around a wooden cube. Except the ring is now in two seperate places. Box go plop
@@SkyeBerryJam in the ring plopping down scenario The exit portal is moving opposite of the object exiting it canceling out the momentum. Imagine you have your exit portal on a wall and you're standing right next to it. Looking into it. The entrance portal is coming down at the box very fast so what you see is the box coming at you very fast. The box goes through the portal slams into you and sends you flying. Speedy thing go in. Speedy thing come out. It doesn't matter that everything else on the other side of the portal was stationary in reference to the box or the none of it went through the portal. The box was speedy going in so it must be speedy coming out. When a portal is moving literally everything is speedy relative to the portal.
@@ahrengroesch8774 I mean if we want to get really technical I think none of these things happen and we need to know how objects interact with the edge of portals/how gravity works for something with its two halves on opposite ends of a portal
@@SkyeBerryJam I am dying for someone to get technical with me on the topic of portal thought experiments. On interactions with the edges of portals, I lean towards it working effectively like it's just a plain hole in a flat surface. I see a portal less as teleporting something that goes through it, and more like creating a normal man sized hole in a wall/ceiling/floor that has another universe on the other side of it that is also the same universe from a different direction. I think you could grab the inside edge of a portal just like you could stick your hand through and hold onto a hole in anything.
On gravity, it being described as the bending of space time, and a portal seeming to be connected tears in space time, I lean towards gravity from either side stopping at the portal. Thus if you were half way through it you would be pulled or pushed in both directions. So if both portals were on the floor you could float there feeling pressure in the middle of yourself. Or if both were on a ceiling it would feel like you were being pulled in two. I believe this is a plausible explanation explain of the behavior observed in the game.
If you think none of the video's or my explanations thus far is how it would work I'm dying to know your ideas.
Okay but what you see and what is happening are not the same thing.
The portals aren't teleportation. It's just making a continuous space where there normally isn't one, it's no more teleportation than you walking into your kitchen.
Then wtf is teleportation
That's why I imagine it as A. If blue portal was on a wall, and orange portal was above you moving down wards, you would be half in one portal and half in the other. Legs would be glued to the floor due to gravity until enough of your weight was through the blue portal and then you'd fall to the floor there. From the perspective of blue portal, it would look like the floor you are on is the part moving, moving up and putting you through. It wouldn't behave any different than a doorway moving past you when you're standing still, you just have to factor how you'll be impacted by different gravity on different parts of your body.
Teleportation is Half-Lifes thing. It is used to move to point a between dimensions to move to point b. It is brought back in 2 where they manages to just sling past Xen and just telelport, but it takes some time and I am sure it Deatamizes you in one space and Reatamizes you in another.
Portals'... portal's are just tears in space time or a small form a time travel as in Portal 2 Cave Johnson mentions that the you in a Portal is you from another time, so don't stare at it. Also portals are like folding a piece of paper and poking a hole through it to walk through between those points. You stay as you just moving through a hole instantly. So you are you just walking through what is essential a door.
So you could imagine that the portal accelerating to you would be like a door accelerating to you. Option A is the answer.
exactly. imagine i drop a hula hoop around someone, they pass right through it. the fact that one side of the hoop is on the other side of the room is completely irrelevant.
Everyone should play portal once in their life. Such a great game
Not on console sadly
@@kiven_gamez4474 ...why not? Ive played portal 1 on 360 and portal two on both console and PC. They seemed great except you can't play the costume maps on console (that's how it was 7+ years ago, things may have changed)
*at least once . ?
Kiven_Gamez I play 1 and 2 on Xbox 1 bruh 🤣 what world you live in?
I've played portal 2 at least 30 times
Moving portals should be in portal 3.
But that will never happen because valve can't count to 3.
Just remember at a gaming event Gabe said "yove killed more than 2 people but less than 4"
Like come on just say 3
Portals *can* move so long as the surface they're on is moving within the same plane, and not changing orientation. As in, not on a surface that lifts, pivots, or flips.
connor harker
Oh my god, did he actually said that?
Give me the damn link!
@@stardustcorpse It can, because the velocity is relative to the portal. If the portal flips then the object flips too. In space we measure by relativity so instead of measuring its velocity relatively to earth we measure its velocity relatively to the portal. That way it is as if the object is standing still but just surrounded by a moving gravity.
Six comments, divide by portal 2... Portal 3 confirmed!
Imagine a flat surface with 2 portals connecting one side to the other, this would basically simulate a flat surface with a big hole in it.
If you agree that a cube "crushed" by this portal surface would remain unchanged, in the same way it would if "crushed" by a surface with a big hole on it, then you simply have to agree that the cube's velocity is relative to both portals and have to accept scenario B.
I'm not sure what you mean by "crushed". A cube travels through a portal or through a hole. Please elaborate.
Portal right now costs 0,81€ on steam. This can't be a coincidence.
RiꜱᴇnHᴇᴇd 1$=0.81€
I think it is. Cause we have Summer Sale. And Valve gives good offs of their products.
It's Steam Summer Sale. Valve always makes their games dirt cheap during this time.
TBH Valve has frequently given Portal (1) away for free several times. But I'm guessing by "not a coincidence" you mean to imply that the sale is what brought it to the top of Minute Physics' mind.
Great games for cheap prices...
Minutephysics: the portal para-
Me: *Speedy Thing Goes In Speedy Thing Comes Out*
Yes, The first law of portal physics.
In layman’s terms:
But the thing isn't speedy. The things "speed" relative the environment is 0. That's the entire point of this video.
@@Arkouchie yes but relative to the Portal there is speed
Is it bad I read that in glados's voice
According to GLaDOS in the first game: "Momentum, the function of mass and velocity, is conserved between portals. In laments terms: Speedy thing goes in, speedy thing goes out". Since the object enters the portal with zero momentum, we must assume it leaves the portal with the same momentum. Thus, the correct answer, according to GLaDOS, is option A
What the1necromancer just said in laments terms means that the speed is relative to the portals. So if portal is speedy and moving towards speedy companion cube, lets say, the same speed towards eachother, then the cube would come out at 2x the speed.
You are exactly right, I can’t believe they don’t say this in the video. The box has no kinetic energy so it cannot have kinetic energy going out of the portal
@@adamguenther190 he never said it because there was never a need to say it. Things like speed and measurement are not definite, they are relative. Meaning it is measured relatively to another object. So the cubes speed is measured relatively to the portal, meaning that if the cube and a portal were moving towards eachother at the same speed, then the cube would leave the exit portal at twice the speed.
This
The portal is basically a door
If you are not moving and a door with a door moves towards you, you will still not be moving by the time you arrive to the other side of the door
@@yaddar how many times do i have to say that speed is measured RELATIVELY.
Imagine you are walking in the same direction a train is moving, lets say you and the train were moving 3 MPH. If your speed was measured relative to the ground, you would be moving 6 MPH. If your speed was measured relatively to the train, it would be 3 MPH.
Its basically the same thing for the portal, except this time, the portal would be moving at you. Its literally what the1necromancer said.
If you are moving towards a portal which is moving towards you at the same speed, your body would go theough twice as fast as opposed to having the portal stay in the same place.
I always thought of the portals as gates or doors. Normally stationary you walk through one side come out the other. If a door frame is throw thrown at you yourself won't gain any momentum from that. Also my problem with B is, you don't have any momentum to start with even if a portal is moving at you fast and slams down on top of you you should still be standing on the same ground so what force will pull you up.
Except in your analogy, both portals would essentially be moving, not just one of them. If you throw a door frame (entry and exit), you're throwing both portals (entry and exit). But in this conundrum, only one of the portals is moving. So how are you gonna throw only one side of a door frame?
The correct answer is B.
@@Athinira I can see where you are coming from but that's not quite how I see it. I just have a hard time seeing how the portals are impeding a force on the object. I see a port as infinitely thin if some goes in one side it comes out the other maintaining its own momentum. So If you go through a portal that's coming at you rapidly it would act just as if you walked through the portal and came out the other side. I'd love to make a video on it to better explain my point of view.
@@edbproductions Let me put up a scenario for you then.
Imagine that you have the Orange portal on a moveable ceiling (that is, the portal is facing downwards).
Imagine you have the blue portal on the floor (facing up).
Now, imagine that you are halfway through the portal. Your lower body (waist down) is on the orange portal side, standing on the floor below the orange portal on that ceiling. Your upper body is sticking out of the blue portal on the floor.
Suddenly the moveable ceiling with the orange portal slams down to the floor fast, bringing your whole body through the orange portal so you're now fully on the side of the blue portal. What is going to happen?
Well, initially, your upper body has no momentum. It's just stationarily sticking out of the floor. But once the orange portal comes down, your upper body needs to move up to make room for your legs coming through the portal (assuming that the force the ceiling smahes with isn't enough to just crush your legs).
However, moving requires momentum. To move anything, momentum has to be build. Therefore, once the orange portal touches your floor, this entire time, the lower part of your body on the orange portal side has been pushing the parts of your body that has already passed through the portal. Pushing builds momentum, just like if i pushed you in real life. So once the orange portal touches the floor and stops, your body will continue and do a small jump.
The thing people get wrong here is the transfer of power. Usually people would assume that there is no transfer of power, therefore there can be no momentum. There is however a transfer of power. The power in this case just doesn't come from the floor you're standing on, but rather from the moveable ceiling with the portal. Since the ceiling is moving, it has momentum. And it's that momentum (rather than the momentum from a stationary floor or platform) that is transferred to your body.
@@Athinira ok I've been absolutely spiraling for like an hour thinking about different references planes, portal orientation, 1 portal moving 1 not, both portal moving, moving in the same direction moving in opposite directions..... Etc. Honestly at the end of it all I feel like both of our arguments have equal standings. Because here's one counter argument for gaining from a portal like in your example.
If you are standing in front of a stationary portal and the portal is going 100+mph on the other side could you physically move through your stationary portal on your side without moving at least 100+mph.
Because In my head you could poke your out and it would be moving 100+mph and your feet would still be stationary.
@@edbproductions Yes, that's exactly what would happen. Your two body parts would be moving at different speeds.
Imagine this scenario: You're standing stationary in front of a statinary orange portal. You poke your hand through. The other side of the portal (blue) is moving sideways at 100 kph (sorry, I'm european - no mph 😉 ) in a completely wind-still environment.
Would you feel the air brush against your hand even though there's no wind? Of course, because since the portal is moving 100 kmh, so is your hand. That makes it a 100 kmh difference between the wind speed and your hand, even if the rest of your body is standing still. For the air to brush against your hand, there HAS to be a difference of speed between air and hand - even if it _appears_ from the side you're standing at that it's the wind blowing.
So imagine something else: You're standing in front of a stationary portal. On the other side is a portal moving at 100 kph towards a floor. You poke just the front of your head through the portal and see the floor zooming towards your head. Would the floor smash your head once the portal reaches it, even though the floor is technically stationary? What if you didn't put your head through the portal, but the floor had a spear sticking out that would eventually enter the portal and hit you on the other side. Would it impale you through the portal, even though it's stationary? The answer is obviously: Yes.
0:16 the technical term is "Speedy thing goes in, speedy thing comes out,"
Exactly, and in order for something to enter a portal, it must have some relative movement toward said portal. Whether it's the portal or the object that are in motion shouldn't matter in that respect. I'd imagine if portals like these actually did exist, they'd lead to quite a few changes in our current understanding of physics.
Aaron Yeetosaurous
yep
why did they make this video it’s obviously a
Aaron Yeetosaurous the thing is not speedy, the thing it’s going through is though. If stood on a platform and a ring was lowered down to your feet really fast would you get yote out? No.
@@robertjones6891 if you drop a slab of wood with a hole over a rubiks cube. Does the same apply?
@@kevinvu5432 both ends of the hole have opposite velocities relative to the cube so it cancels out
absolutely no one:
minutephysics: lets give this old paradox that the internet has argued about for a decade another step of complexity
We definitely need to think about accelerating portals.
Its just /v/ shilling
@@luck3949 but first, let's talk about parallel universes
327likes in 1hours? I cant even get 10likes in year
You're so original
Quote by GlaDOS:
"Momentum, a function of mass and velocity, is conserved between portals.
In layman's terms, speedy thing goes in, speedy thing comes out."
conversely, if a speedy thing comes out, a speedy thing went in
Counterpoint momentum is not conserved because the direction of the object changes therefore glados is a lying pos
When neither portal is moving 👍
When one of the portals is moving with constant speed as in 0 acceleration the object passing trough orange portal experience 0 acceleration and comes out of blue portal with same speed as Orange Portal had.
What happens when you stop the portal mid point of the box? in that moment when you stop the portal instantly in place trough the object is felt two foces that pull each other one tries to stay still and other is moving 50km/h and if your human neck can with stand that kind of instant pull 😏 15 hours later while super drunk someone said "it is like hula hula rim!" and we came in to conclusion the moment you slam it to someones head and start pulling the head should be flying off in the most brutal way possible 😂
yeah but it's not "speedy portal rams into, speedy thing comes out"
@@valentinorubio703 I spend 17h drunk arguing about this topic and to sum it up: Orange Portal's speed is given to the object without acceleration.
Everything else ended up with "Well that that can't be right" and we also never agreed who of us won the argument :D perhaps we all lost.
The cube isn't going into the portal at speed, the portal is going around the cube at speed, so I'd think that the cube would just plop down as if you'd dropped it on the other side of the portal
@@MikeMichelson-vv4zb it'd be like if I had a cup and slammed it down around a wooden block. The block doesn't jump up and hit the bottom of the cup, it stays still, if the entrance to the cup, is just a portal this time, I'd expect the same result. It's fun to speculate either way and I DO realise that this video is just for fun speculation
Maybe this is why you can't have a portal on a moving object.
Yeah... I think Valve notice that it would be even more tricky to move the portals around, so they made every puzzle with static portals XD
There is one puzzle in Portal 2 that has you putting a portal on a platform that is moving vertically, so lasers can cut down a pipe. I think the dev commentary says that is the only instance in the whole game such thing happens, every other moving object (a hatch door, for example) instantly disintegrates the portal it has on.
@@geraq0 portals can only be placed on conductive surfaces. The doors aren't conductive,and aren't coated in conductive material either.
That's why you can make portals on white surfaces, because that has ground up moon rocks. The white gel is made with moon dust,which is why it makes surfaces conductive. And the ending of Portal 2 shows this as well.
@@c0ldshock927 Yes, I know that. That wasn't my point at all. I was talking about hatches activated by switches, for example, that change angles hence deleting any portal created over them.
Earth is moving.
"It's a paradox, there is no answer!"
~GLaDOS, 2011
XD
I remember she said something like this when trying to beat wheatley with paradoxes.
Yes I answer yes
Wheatly 2011
True, I’ll go true
"Don't think about it. Don't think about it. Don't think about it. Don't think about it." Glados 2011
But GLaDOS already answered that. "In layman's terms: Speedy thing comes in, speedy thing comes out."
But that's for stationary portals. Moving portals would be different because their rules aren't defined in the game.
Therefore, 'Stationary thing comes in, Stationary thing comes out" #thinkinglikeaprogrammer
yes they are, portal 2 has a moving portal in the section where you cut neurotoxin pipes, and the laser exiting the portal has the same wavelength/colour as the one entering.
@@ChrisPepper1989 I read that as pro gamer
TornadoATP but the portals obey the laws of nature it exists in. And the cube has no momentum while the portal has one. This cannot be translated without adding energy to the cube.
So either the portal translates energy from the portal itself to an object. Option B.
Or its the objects momentum that matters. Option A.
Any one who argues for case A seems to forget a fundamental thing here.
Even in the worst case scenario.
The first part of the cube, the top, goes through the portal.
And then the rest of the box pushes it through, giving it some velocity.
The way by which you go from orange portal to blue is irrelevant
Think of the situation at the destination, static portal. Thing comes out at speed.
Just because it was standing still before the moving portal hits it doesn't change that
It's moving on the exit side. And will hold that velocity
Oh and before any armchair experts try to mention it.
Portals, if they could exist, break the laws of thermodynamics and energy conservation by merely existing.
Acquiring velocity and energy through this isn't that much of a stretch
Don't worry, the only other person who tends to bother responding to these comments is me and I'm fully with you.
@@J4hk2 yea I got recommended this video again, and option B feels so obvious that it bugs me that people try to ignore the fact were working with entry and exit points that can be in different states of motion
I always thought of them as a ring that was split. Teleportation is like putting a ring around something else, but this coming out of the ring is placed different in spaces. As if it was a tunnel with the length of 0.
so A, right?
@@Lance3015 it'd still be B. From the perspective of the side of the ring the cube is leaving, it's still coming out of that side at a certain velocity relative to it, therefore that velocity would be maintained.
@@hushwonder2070 Not true, it makes no interaction with the cube itself therefore it would not carry over the velocity.
There is effectively no space; open air in-between the portal boundaries and they've never interfered with the objects passing through them like you say
@@Wert-eo7sz Maybe the portal is not moving but disappearing and reappearing at a different point in space quickly that case the object would go through you. and the laws of physics still would work.
@@Wert-eo7sz Our current understanding of the universe isn't very great...
Valve: Portals can't move
Also valve: Let's use moving portals towards the end of the second games
moon rotation yes
i mean.. they must be able to move since we are all moving.
That moment is near the middle.
your logic can apply to earth too, making the portal gun useless
@@moonl1314 earth moving too)
*Minutepsysics:* Let's talk about Portal Paradox which isn't actually a paradox...
*Me:* That's a nice paradox.
Quite frankly, A makes no sense at all unless you only think of the (impossible) case in which the entire solid object instantaneously moves from one side of the portal to the other.
I've always arrived at B by imagining what happens while the portal is in the process of moving over the object. While this is happening, the object is presumably emerging from the out-portal at the same rate that the in-portal is traveling downwards. If this is the case, then the particles composing the object ARE moving with momentum through the out-space, unquestionably. And there's no reason that they wouldn't retain that momentum as the object finishes emerging.
Another way to think about it, in light of your example at 3 minutes, is that those slices DO appear on the other side, unmoving, but the next slice is right behind it and pushes it forward... which just produces the same effect as B. Or, if you assume that the slices don't retain their bonds and can't affect each other when on opposite sides of the portal, then they're just going to become a soup of particles trying to occupy the same space. (Though, since characters never have to consider the risk of being cut in half by going partway through a portal and then stepping back, I would assume that atomic bonds do hold.)
There's no model in which an object can emerge from the portal both intact and without momentum. The option are B and disintegration.
A much simpler example that indicates why it's B is this: Consider what would happen if the box were sitting on a tall pillar, narrow enough to pass through the portal. The portal passes over the box, and the box is now on the opposite side, but so is a portion of the pillar. As the in-portal continues to go lower, more of the pillar emerges from the portal as well, pushing the box diagonally up and to the right. And then, if you stop, the box is going to go flying in that direction. (this is essentially the same thing as what happens in the box-only case, just on an object scale rather than an atomic scale)
Aperture Labs uses quantum tunneling if I remember correctly whereas Black Mesa was dabbling in wormholes
Yep
@cak01vej this would obviously not be the case for wormholes, as I think you already know!
@cak01vej don't forget that portals are essentialy just doors that open elsewhere so using a portal like this would act the same way as hitting a static object on a table with a tennis racket without strings the only loophole is the laws of gravity not momentum
@cak01vej That would hurt a bit
B seems the most intuitive and so also applies to the final puzzle: object would exist at an angle.
In the games, the portals disappear if placed on a moving surface. Which can be explained by the logic that portals must remain at a constant distance and orientation from each other.
I don't think so. In Portal 2, when you're destroying the neurotoxin tubing, you do utilize portals that move relative to each other.
except if they are moving continously at the same speed
How about the moon portal?
In Portal 2 there is 1 moving portal
No there's moving platforms in Portal.
Portals don't work on moving platform... Except for that one time in the neurotoxin generator room
@Cris Angelo D.C I think that that was actually a storage unit not a generator but wheatley was kinda dumb so he thought it made it
That's what I was thinking about
So weird how it's just that one spot where it works and nowhere else
Ascaban I’m p sure u can do it in Portal 2 custom editor
@@makinbacon21 you cant. as far as i know, there is a console command that, if 'true' causes a portal to disappear if the ground they're on moves. that command always stays active, apart from that one level.
The portal, in my opinion, would behave as if the bottom platform was pushing it into the portal, since the platform moving towards the portal, and the portal moving towards the platform are essentially the same thing in this context.
no they are not. if drop a tube on the ball it would not be launce up into the tube. if you however slam the ball into the tube it would. its not essentailly the same at all.
@@erikcarl2384 what
I need context here, what tube, and what ball?
@@SleepyFunkin any tube and any ball that fits into a tube. you dont need any context.
@@erikcarl2384 No, it is. You're assuming there's a surface the ball is sitting on. Physically speaking, if you move a tube over a ball floating in space, such that the ball goes through the tube, it's the same thing as moving the ball through a stationary floating tube.
This is the main principle behind the theory of special relativity. The common example provided for this, is an elevator floating in space with you inside of it.
You feel yourself being pulled to the bottom of the elevator at an acceleration of 10m/s^2. You cannot see outside the elevator. You are tasked with discerning which of the following is true:
a) You are inside an elevator that is accelerating upwards; or
b) You are inside a stationary elevator that is near a massive body, and are thus experiencing a gravitational pull
Which is it? You actually can't tell.
If the elevator were to accelerate upwards at a constant rate-let's say 10m/s^2-you would feel the elevator pushing up against you with a force proportional to that acceleration (due to F=ma). If there were a gravitational field, perhaps that of a planet nearby (but invisible to you since you are inside the elevator), pulling you down at a rate of 10m/s^2, and if the elevator were stationary in this case, you'd likewise feel the elevator pushing up on you with the same force.
Einstein's theory basically says that, no, there is no way of differentiating these two scenarios:
"The laws of physics are invariant (identical) in all inertial frames of reference."
The thing is that reactionary forces only applies to objects that COLLIDE with eachother. If there was no portal, then yes the cube getting hit by the wall and the wall getting hit by the cube would be the same, but since the cube doesn't collide with anything, it simply goes through the portal unaffected, and thus does not react to anything.
I'm surprised you didn't mention gravity. The block sitting experiences torque as soon as it begins to pass through. It should exit the second portal with rotation.
Exactly what I thought, it wouldn't flatten, gravity would pull the heavier side of the block, the one leaving portal B, completely out of the portal.
It should fall off the second portal, right?
Kurokami Reaper It should, yes
@@Certrix, it would flatten. Since the tiny bit first teleported stays in the frame of the teleporter, it experiences gravity from the sites of both the entry and exit portals.
@@Sivah_Akash That doesn't make sense. The normal force of the ground pushing on your feet equals the force gravity is pulling you down with. You don't flatten
Physicists: Valve what will you do about moving portals?
Valve: We'll make them disappear if they move.
Physicists: Surprised Pikacu face.
Valve: makes portals move in one level anyway
@@jfb- Valve: **disables special code to do so**
@@thanosattorneyatlaw4062 Its not really special code, its the sv_allow_mobile_portals flag (accessible in console).
@@coolguy284_2 I was making it more dramatic........ It's a joke
..
Maps have a flag for enabling moving portals. In portal 2, you can enable this using the developer console. However, the Valve Developer Community site, this option causes moving portals to be non-traversable for anything but lasers.
‘Depends if you think like a programmer or a physicist’
But when you program video games you have to think like both 😭😭😭
Haaris Qureshi ....isn‘t this another paradox?
Not really only if you want to have realistic physics which you don’t always necessarily do
Ehhhhh not exactly.
Unless you're programming Algodoo, which is arguably a quite accurate 2D physics simulator out there (and used by academics somewhere), you're not putting real life physics equations as is in video games. Even with advanced engines like Bullet, Unreal Engine (and PhysX), or GTA V's RAGE, the physics in 3D game engine can defy real life physics, even if the code got the concept right and believable enough to percieve by our logic outside speedrunning or uncommon situations.
Besides, putting real life physics equations as it is in a game physics engine can ruin a game's fun and charm or even the gameplay itself. And performance wise, it's not good either to do those equation in 16 ms or less.
@@Xezian not really. Even if you don't use real time physics, the game itself runs on a set of rules you as a programmer input and it has to stay consistent and you have to chart your own "imaginary" physics from scratch
Bhanu Vardhan yes but programming a new set of rules is a lot easier than programming an existence that isn’t even possible yet. Physicist don’t even have the proof of concept that a portal can exist except for theories and equations, this is infinitely harder than programming a game to say when X enters A send X to B with equal momentum.
i have watched this video a dozen times in the past 3 years and my answer changes every single time
Answer to the bonus question: If the portals were like 3D printers, the cube would come out slanted.
Oooo I like your thinking! Although if the speed is measured relative to the moving portal then while the part of the portal that prints is moving the object is also moving just the same, lining it back up again.
2+1D printers. 3s dont exist according to valve.
If the portals were like 3d printers, you wouldnt be able to see through them like in the game
There's no paradox.
Your initial premise id's incorrect, there is no movement in relationto the portals, they are the same point in space. It's like asking if you passed a hoola-hoop quickly over a box, the box would shoot up.
The portals in the game don't teleport objects, they link two points in space to make them the same point in space.
Exaaaaaaactly what I've been thinking through the whole video.
That’s what I was thinking. It baffles me when he started talking about it squishing up inside the portal - no, that portion of the cube would just hang out of the other end of the portal, eventually having a greater mass on the blue side than the orange, causing gravity to pull it downwards, “tipping” it out of the portal. No acceleration is required, the cube is just suddenly at a different point in space and is affected differently by gravity on one side of the portal than the other.
Take a look at some of the visuals. Yes they connect two points in space however by what manner do they do the objects exit in relation to the entrance/exit is the question. If you were looking at real life put a box on the ground and take two hula-hoops. Say one hula-hoop is the entrance and the other is the exit. Now set one against a door or wall and drop the other over the box. Will the hula-hoop you dropped over the box be stuck on top of the box, have the box come out with a velocity from the other hoop, come out with no velocity, or come out as a flat object? (You answer is then 3:06, Option B, Option C, or Option A respectively)
Does this make sense as an explanation?
And yet, in the example of a hula hoop, the box would have a velocity relative to the hoop. If the hoop passes over the cube at 5 m/s, then the cube will "enter" one side and "exit" the other at that 5 m/s. The moving side of the hoop would pass over the stationary cube at 5 m/s and the cube would exit the stationary side at 5 m/s relative to the hoop.
Exactly.
I was going crazy when he started talking about boxes "squishing", or portals becoming walls(???) if his own perception of motion became invalid for the object.
Imagine you had a stationary box sitting on a windowsill, and you were able to move the window frame itself laterally from one side of the box to the other. There's no extra movement imparted on the box from this action, the only factor in its movement is friction and center of mass. The fact that it's no longer oriented the same way is irrelevant until the center of mass reaches the other side of the portal and it tips out if there's space for it to do so.
That's all portals are in this case. Two sides of the same "wall" for a window. The difference in movement between the two "halves" of the portal is irrelevant and lost in whatever subspace realm of fantasy they were created in, the connection is not rigid.
"THIS. SENTENCE. IS. FALSE! don't think about it don't think about it"
That's the true Portal Paradox
Ehhh, true. I'll go true.
It's a paradox you moron, there is no answer!!
* confused frankenturret noises *
Yes!
OMG YESSSSS
I think we could measure speed relative to the environment and still have B happen in a game if the teleportation takes both the object and portal's speed relative to each other into account. For instance, if cube and orange are both moving towards each other at a speed of 1, then cube exits blue at a speed of 2, but if both are moving in the same direction, then if orange is faster than cube, then cube would exit blue at the speed of orange - cube. The same thing would then apply to the speed of blue relative to cube. If blue is moving forward, then cube exits at its new velocity plus that of blue.
You just described the option, where the speed is measured relative to the portal. You described what would happen if the speed is measured from the cube in relation to the portal, not in relation to the environment...
If the cube is now has velo of 2 but blue portal still has velo of 1, then the gross momentum of the system is now 3 units where it was 2 units before entering the portal.
@@venomo2868 yes, and that breaks the universe and your cube may become dark matter
Portals do not affect inertia, the cube would not gain speed nor would it move in either scenario.
@@Izzmonster until more than half of it is out of the exit portal, then gravity would pull it over onto the ground.
"In the game, the portals pretty much never move relative to the environment."
Boom. Problem solved!
Except in the one part of portal two when they changed it for the sake of a fun mini-puzzle. And also the moon
Well. Only time the portals ever move relative to their surroundings is portal 2, the neurotoxin generator.
@@link_team3855 And how do the portals work? A or B?
@@luken2o223 can't be a you would be smushed like a pancake force on an object causes another to move except in videogames, like Minecraft the speed you go when you tp, you would be dead.
Luke N2O it was moving sideways, not vertically, so some argue “you can’t move them forwards and backwards in the direction they face, so it doesn’t count!”
You could still do the test at the end of the video, however.
Items are locally measured to the environment. As GLaDOS explains in the game, "Speedy thing goes in, speedy thing goes out"
I don't see any reason why that would imply that speeds are measured relative to the environment, rather than relative to the portal.
Non sequitur. "Speedy thing goes in, speedy thing comes out" does not mean it's measured to the environment.
So that would explain that in the HL/Portal universe that there are quantum tunnels but the portal gun shoots teleportation data
@@leonardusl5141 speedy THING goes in though. This implies for the item to go out at a velocity, IT must move.a stationary item would therefore plop out with example A.
@@digitalunity A is impossible. By the time the portal fully covers the box the box is not fully out of portal number 2. then it is in two places at once. The velocity of the box is depending on how fast it went through the portal. The box went through the portal at the speed the portal was moving therefore emerges at the speed of the portal.
All I wanted to do was play portal, not question the exsistance of universe. But I'm glad I did.
i'm glados you did oof
@@jessejordan5658 this comment is just so funny to me and i hate you for it
@@slyceth *They're
*Existence
* Capitalize “I”s
I'm all for option A. Here's why: the object doesn't "move" meaning it has no velocity. The portal is the one moving. So my idea of a portal is one singular object that appears two in three dimension world, but actually is just one in say fourth dimension, allowing the "space" to be connected. hence "object moving into the portal" can be seen as an object moving linear in the space, just skipped a coordinate, which is relative to the portal (the one portal as explained before). However, when the object doesn't move at all, the portal moves relative to the object. The idea is that the object did not came out of the portal, instead the portal moved the object through another dimension and made it appear in the other side. So instead of the object coming out from the portal, imagine the portal moved backwards and showing the object, only the portal didn't move. But consider if the portals are interlinked, if one move, the other should also move accordingly, which if it doesn't it'd looks like the object just appeared. If you consider the concepts of a dimension, option A would be more reasonable.
Because of relativity the answer solely depends on the frame of reference. If the frame of reference is the cube itself or the environment the cube would be crushed because relatively non moving objects can’t exit something also relatively non stationary. If the frame of reference is the moving portal then the cube would fly out because from the moving portals frame of reference it’s the world moving. Motion and velocity is relative, also portals can’t be wormholes if we’re trying to get them to work how they do in the game because wormholes don’t stay attached to surfaces they’re shot on like they do in the game
Bruh you can't place portals on moving platforms. They just disperse.
Besides that one time you could I’m portal 2 (but we don’t talk about that)
You can't place portals because they don't exist...
@@CREEPZOMBEY shut up
Portal 2. When you destroy the Neurotoxin generator. The laser cutting the pipes was moved a portal.
Which is called "Bending and Rupture of an Unstable Harmony". BRUH, for short.
Option D. : When a portal move its just disappear
*cough cough* neurotoxin generator *cough cough*
@@yukkahiro ahem ahem
YuriNone well the neurotoxin emitter part was merely the only possible way to do said part. So you know. How else were you going to shut down the neurotoxin emitters for good
@@ethandavies7608 idk wheatley was screaming at me so i didn't really get to think
also i think i inhaled neurotoxin
@@scritch8833 uncovering the universe is a bit tiring when on neurotoxins. I feel it brutha.
I love that 12 years later were still talking about Portal
Altho there is no portal 3(beside bridge construction portal)
Assuming that portals are only windows as seen in the games, the only force applied on the cube to move him is the gravity force at any speed of the orange portal
the only issue with the doorframe/window/"frame" analogy is that two sides of a portal can have different velocities, as seen in the paradox's beginning itself.
so people think of it as if the portal falling on the cube and the stationary portal have the same velocity when they don't.
so let's start with this bad analogy and rework it so it actually works.
-a wooden frame falls over a cube.
-the frame hits the floor.
-the cube doesn't move.
remove the gravity and the floor
-a frame is given downwards momentum because if it wasn't nothing interesting would happen
-the frame goes over the cube.
-it continues moving downwards.
-the cube doesn't move
move the top and bottom sides of the frame to 2 different positions, such that while inside the frame, it feels like the entire frame. (this is the definition of a portal)
-both the top and bottom parts of the frame are given the same momentum
-the frame goes over the cube.
-the cube is [where the top part of the frame is relative to the bottom part of the frame] relative to the starting cube location was, however it has been given no momentum
only give the bottom frame momentum
-the bottom frame is given momentum while the top frame is stationary
-the bottom frame goes over the cube
-the cube cannot tell whether this is the entire frame or if the top frame is at the same momentum or stationary or going 420m/s west or whatever
-the cube will see the top frame going down at the same speed the bottom frame went over it.
-the top frame is stationary
-therefore the cube must be moving. where the cube's momentum came from? i haven't a clue, but it is moving. portals don't care about the conservation of energy anyways, so it doesn't matter.
The literal term for portal is a doorway or hole between two places, if you have a moving door, your speed relative to it will stay constant
Ok but, doors and doorways aren't the same thing.
@@Doglover745 yes and a doorway is literally a portal
@@Theepic750 yes but, this is about the hypothetical kind. Which is clearly not what you're talking about.
@@Theepic750 I didn't think it was complicated, like the orange one comes down to the cube on the platform, then on the blue one you'd just have the the cube on top of the platform, with just the the cube fully thru, and then it changes to the relative gravity once thru, your literally just tossing a hoolahoop on the cube, and what sposed to go thru pops out of the other hoolahoop
Or what about if the platform the box was on is moving relative the portal speed, but the portal isn’t moving this time. It would shoot out, right?
Portals work like doorways, the speed of the door way moving around the object does not effect the speed of the object
I've searched for something like this, I think that is true.
Actually, if you are thinking relative to the door, it will move the object and will align with option B
Xenon from the hula hoops perspective, you will.
And if somehow one end of the hula hoop was stationary (relative to the enviroment) the enviroment would agree with the hoop, and not you.
Of course, counterfactual speculation etc.
Desert Doomer the only way option A seems viable is if the portal somehow doesn’t affect the cube when the portal is moving, though to me it only makes sense that if the cube is moving at any speed through a stationary portal and keep that speed all the way through it, that a portal with speed would be able to move a stationary cube with its speed. i know portals themselves don’t follow conservation of energy but if an object is moving through a moving portal, that energy has to go somewhere.
if a moving portal did indeed have no affect on the cube’s energy, as the video said, why would it gain any speed and come out the other end at all?
that would mean that the cube would consistently come out of the other portal at the exact same rate no matter what’s happening to the first portal.
personally, i don’t see it.
Solveig Lindberg y’know while we’re at it what do you think about his final question at the end of the video? straight or at an angle?
Who feels like he wants to go and play portal again after watching this video
been a while might as well
I feel like I should play it for the first time!
@@PydraxAlpta me too
@@PydraxAlpta It's 90% off in the summer Steam sale right now.
YES
In my opinion, Scenario A seems the less plausible.
Portals connect two points in space without creating any new space. Therefore, the time it takes for an object to enter one portal should be identical to the time it takes for the object to exit the other portal.
So, if an orange portal moves slowly towards an object, than that object should also emerge slowly from the blue portal. Similarly, if the orange portal moves toward an object at like Mach 10, then that object should theoretically exit the blue portal at an equivalent velocity. The velocity of the object relative to the portal has to be preserved so that the time between entering and exiting the portal stays consistent. If it doesn't, then where would the object momentarily exist?
Given that portals don't create new space, just connect existing spaces, the relative velocity at which an object enters a portal should dictate the velocity at which it exits. Since the object exits with a certain velocity and has mass, it would also possess momentum, thus it would result in Scenario B (or maybe C).
The only way Scenario A could work is if the portals somehow momentarily changed the mass of objects as they passed through, but that just feels like making up rules.
Thoughts?
(note i am not an expert in physics or anything so my reasoning could be wrong.)
@@kickthattable this is completely logical and I feel this should be the explanation everyone uses
2:40 the ground gets closer to the portal
The cube on the other end is affected by gravity
I imagine it like a box going through a hoop
If I drop the hoop onto the ground the cube is just in the middle and therefore on the other side of this hoop (other portal)
Actually, gravity would also be transported by the portal, so if you put one end on earth and one end in space, you would be pulled towards the portal as if it were the earth's surface.
fghsgh
To be really technical in that situation, (to the point of being a dick) wouldn’t the jet of air coming through the portal into the vacuum outweigh that of the earths gravity?
(A bit like the end of portal 2, the jet of air was greater than that of earth’s gravity and moon’s gravity combined. Enough to launch Wheatley & Space core into space)
fghsgh
Another question would be how the portal would project the gravity of the earth?
@@coolguysbro101 The air may push you through the portal, but you'd still feel the gravity as only your skin gets pushed up but everything gets pulled down. So you can still feel the gravity, but you may be vacuumed through. If, however, you keep the portal open for long enough and the pressure evens out, gravity will have its influence back.
@@fghsgh Following the premise that portals do exist, they could not allow to gravity to pass through them because if they did their own existence would not be possible, since the implications of the bent of space time caused by gravity would affect the meter around the other portal leading to a massive tidal affects in the earth what would most likely tear apart the planet.
Don't look at it like a portal, but like a hole in a wall with the possibility of changed gravity in the other room.
This guy gets it
@Gooey Prickles Sounds like you're overanalyzing it a bit. The way the portals function in the game is essentially like a hole and you can even put objects mid way in them. Applying real life laws to game logic is not wrong though and I'm sure you'd be right if it were real life circumstances because I won't deny that physics and motion aren't my forté, but game logic wise... It's just a hole and option A was the more reasonable explanation for the way the way portals function here. Though, real life circumstances are probably option B, if not something similar.
I get both sides but listen to this. Say that a door that transports you to another one is dropped on you and you go through, but gravity forces you to go back through. since the portal is there you go back through but you ganed no energy so it doesn't push you out. You will get stuck between them
@Gooey Prickles that is why I compare it to a magic door and you would get stuck
@@RemedieX I get what you are trying to say but it is wrong. Option b would have to have force applied to the cube in order to whoosh. But since the only force is the smasher which isn't affecting the cube it would just go through because the "portal" has no mass and doesn't realy have anything to push
Too many people use the word "paradox" when what they're talking about is a "conundrum" …
Thank you for this comment. I finally decided to watch this video because I had never heard of the “portal paradox”. Then I was like, where is the paradox?
They don't even solve the conundrum , just giving wrong answers.
Paradox gets more clicks tbf
@@scalpingsnake That would be a sad commentary on a channel that purports to set people's thinking straight about complex topics....
@@martinconrad9260 I prefer to blame RUclips. RUclips make it necessary for clickbait in order to get the views you 'deserve'. Of course there are also the videos that don't deserve them and clickbait purely to trick people into watching and maximise views I am referring to the fact that respectable channels also do this because otherwise they simply won't get the views they probably should get.
another option is that if an entry portal moves then the exist portal has to move at the same speed. So the speed should be relative from the portal to the object itself, I think of portals like tubes or rings which are the same, the only difference is what is bigger the length or the diameter.
2:17 and considering Valve themselves have referred to the portals as “quantum space holes” in some promos for Portal 2, this is _the way_ the portals work.
They do obey conservation of momentum like he said yet he is still drawing the conclusion b that "if fast go in fast go out"
If the cube was on a pillar, the pillar wouldnt be send flying just because a hole slammed into it. And the cube would rest on top of the pillar until the gravity on the blue side would pull harder than the gravity on the orange side
Shoots out the portal at an angle, again it's relative speed so it's equivalent to it travelling at a angle towards the portal
damn i want this as a real level to play, pretty sure it won't work with the engine or something tho
Or equally, goes straight up if we're considering portals to work using option A
not really, because the other end of the portal is not moving also the portal has to interact with the object in some way and also had to deaccelarate due to the conversion of energy and impulse. Also your relative speed argument works against you, because if the cube shoots out at an angle you are changing the relative speed. Before it was moving downwards and "sideways" relative to the orange portal and afterwards it would move "sideways" and up relative to the blue portal. You can not just change the frame of reference, when looking at relative speed once you picked one you have to work with it.
@@jantemili I really think it could be made to work.
But what if it is As hypothesis... It would go straight up but the cube would be morphed as each "slice" of cube will be more off set as the entering portal moves. ... I still like B more but just thinking of A is still interesting
Portal developers were so advanced in that time that no one really understood how portals worked except them.
portals in portal were like doorframes, nothing else
@@TheWorldEnd2 Never seen a doorframe the allows you to teleport though...
@@haleph9605 Well, of course they do. You teleport from one room to another.
@@haleph9605 it is extremely localized teleportation
Jules Fontvielle
They mean that’s essentially how the portals functioned in game. You could look through them and see what was in next “room” without actually having to walk through, much like a doorway
Proof portals aren't wormholes:
- portals exist
- wormholes don't exist
- it's called a quantum tunneling device for a reason
you can do this test in portal 2 map creator if you really want to know the answer
just dont forget to use "sv_allow_mobile_portals 1" or the portal will disappear when the platform starts to move
There is another option. Both portals are spatially linked to each other and if one moves so must the other. That way if one moves causing an object to pass through it, the other moves as well with the object exiting it while maintaining it's stationary property.
Makes sense.
The issue then is that since portals can only be placed on a surface, the exit portal would have to move in towards the wall and the object would appear fused inside the wall.
@@GIRGHGH Or the original moving portal will just spew out a huge tube of ground/wall/whatever
Then the issue is that the wall can't move either.
That's just the case where both are moving - but not relative to each other.
In the game, GLaDOS explicitly points out "how the momentum is changed [when going through the portal], or more precisely how it is not" in a situation where portals are perpendicular to each other.
I find that difficult to interpret in any way other than "B", that is, momentum is maintained, but frame of reference is shifted (and rotated) from one portal to the other
true , all these terms are relative and we can only determine in one frame possible , thats how our physical world works and portals are (as of now LOL) not possible . It doesn't satisfy space-time laws we have .
If you take a piece of cardboard and put a hole through it and drop it onto a ball, the ball doesn't go flying out the other end. I think portals are like a hole in that cardboard, but the cardboard has no width and the ends can be anywhere. That would make A be the correct answer.
@@Purely_Andy Yeah, but relative to the cardboard hole, the ball *is* flying out the other end, so option A would no longer work.
@@Guinea.Pig-Gaming so if for some unexplainable reason, if a hula hoop drops around me at lets say 20 mph and I jump through it while its still falling, then I should gain enough energy to jump much higher and much faster then normal.
LazyKirby57 Not relative to you, but relative to the hula hoop.
А вы преставьте порталы в качестве дверной рамки.
По сути портал это и есть дверь.
И вот представим: лежит объект на поле и на него падает дверная рамка, что произойдёт?
Дверная рамка упадёт на объект, а объект продолжит стоять на месте как не в чём не бывало.
Так почему если бросить на обьект портал, он должен вдруг из не откуда получить скорость?
Портал это дверь ведущая из одной точки в другую, ваша дверь в комнате, ведёт из комнаты в коридор, а падающая рамка на объект ведёт объект в одно и тоже место.
Но портал позволяет вам появится а другом месте с теми же характеристиками.
Если бы портал имел какое-нибудь гравитационное поле, то да, я бы поверил что вылетить из портала будет возможно, так как он вас своей гравитацией вытолкнет, но без гравитации, там нечему вас выталкивать.
3:43 when someone tells me the creator of GIF pronounces it "jif"
Jif Peanut Butter
One day god will come down to earth and will say: „ its called Jod“
and will leave
I'll be there in a giffy
The Graphics Interchange Format was a GIFt to the world.
The creator is wrong bc its "graphics" not "Jraphics"
Yes, but consider this:
*PERPENDICULAR UNIVERSES*
"Now, you're probably going to wonder what I'll need all this speed for. After all, I do build up speed for 12 hours. But to answer that, we need to talk about *PERPENDICULAR UNIVERSES."*
You've broken my mind. Thank you sir
oh no
this is beyond references
Wel this sure made me nostalgic.
Time to go test with Glados again.
yeah same
Let's put our differences aside... for science... you monster.
I think I have a solution to the portal paradox, but its all relative to the conditions you set, mainly, is the portal moving at a constant velocity, or is it accelerating, and is gravity present, or is it not, and what about both at the same time. in theory, option B could work if gravity is only present on the slope side, or the piston is accelerating towards the cube. Realistically, with the problem we have though, gravity is present, so in reality, it would kinda be like a sloped magnet. Since the cube is only affected by what part is in what, that would apply to gravity as well (ex. .5g of the object is on the platform side, and .5g of the object is on the sloped side, so both of their respective gravities would apply to that amount). So in essence, like with the sloped magnet scenario, the closer to the platform the portal is, the weaker the pull (magnet) would get, but until the object is pulled completely through the portal, that pull is still present. So I think realistically, given a constant velocity, we'd see the cube slide down in the same orientation.
This is why you can't place portals on moving surfaces
But moving in relation to what? Lol. The earth itself is moving.
@@eduardofreitas8336 it's impossible to feel the movement of earth. A car sits on earth but the car itself isnt moving on its own.
@@mojmov6128 You totally missed the point.
@@eduardofreitas8336 how? I'm saying that u can't place portals on a surface that is moving by itself through it's own mechanism
Neurotoxin generator: *laughs in portals on moving surfaces*
Speedy thing goes in, speedy thing comes out.
Nothing speedy is going in, so it's A I assume.
@@happyh0ur888 it's speedy relative to the portal. Running into the wall at 1m/s is the same as the wall being chucked at you at 1 m/s, in the walls reference frame.
@@black1blade74 Lol nope. Not quite.
@@black1blade74 Relative to which portal?
You can't specify that Blue is the end all be all to the relativity paradox when orange clearly also exists.
And even besides that, Blue is moving 1600 km/hr in relation to space around it.
Thanks GLaDOS
Fun fact: the portal gun is also called the handheld quantum tunneling device
In the old test areas sure
@@beachchaos1863 still cannon
@@beachchaos1863 in portal 1 im almost sure that glados calls the portal gun like that when you first find it
@@Just-An-Average-Guy Even in Portal 2 there are posters on the wall with quantum tunneling device written on it
let's face it, if you want something to sound sci-fi, just add "quantum" to it.
Like my quantum toaster, and quantum pogo stick.
Quantum jellybeans. Perfect name for a sci-fi noodle shop would be "The Quantum Wanton."
Quntum stippling. Quantum localization unit. Quantum powder. Quantum axle.
You get the idea.
I have no idea how B is more logical, you're adding energy to the cube and the portal loses 0 energy in the process. Where does the cubes new energy come from? What losses were induced on the portal? I understand it's moving relative to the portal, but even when you include relative motion you don't answer where the energy comes from unless the portal is slowed by the cube traveling through.
That breaks physics more than the portals themselves.
Edit: talked with a friend about it for a bit and B is only possible if the extra relative velocity is added by whatever powers the portal gun, and if you consider the portals to be a part of a 4th spatial dimension, so they're stationary relative to each other no matter what their relative motion is to the 3 spatial dimensions we can observe. If you don't include a 4th spatial dimension and the energy from the portal gun itself, answer B can generate infinite energy.
Portals have basically never abided by conservation of energy laws. Most obvious example is something falling indefinitely through two portals, not only is the GPE of the object constantly increasing, but you've fulfilled the definition of a perpetual motion device which inherently breaks conservation of energy.
Also portals being able to change the direction something moves means its speed and kinetic energy has changed in most reference frames. It in fact only stays the same in the reference frame where both the portals are motionless, which isn't the case in the reference frame the problem is presented in.
@J4hk3 that's not true, it wouldn't Technically be a perpetual motion machine, because if it were, then any object in a perfect orbit around earth would itself be a purpetual motion machine. Purpetual Motion machines have to magically generate energy. Now it may be possible to make portals do this but you'd have to create some sort of device that can convert the energy from a falling object into some usable form of energy. Its probably possible to do this with portals though.
@@calebmon in a perfect orbit (imagine the earth is the centre of the universe and not moving relative to a finite universe), the moon perfectly orbiting the earth would be neither gaining or losing energy.
In the portal game how ever putting something to fall between two portals below and above one another has the object perpetually accelerate until the source engine decides it's as fast as we can let it without causing too many bugs.
In a "real" scenario this would not only be a perpetual motion machine, it would be accelerating infinitely creating energy out of nothing. If we assume it draws energy from nowhere to work.
But alas it's a videogame and debating how it works in an universe where sentries shoot 65% more bullet per bullet and the CEO turns lemons into combustible lemons is somewhat fruitless. The fruit would combust how ever.
@lemons1559 @lemons1559 "Imagine the earth is the centre of the universe" there is no center to the universe, why would the position of the earth cause the moon orbiting around it to not gain or lose energy? Wtf do you even mean?
"until the source engine decides its as fast as we can let it without causing too many bugs" it's called terminal velocity, an object falling can only go so fast in real life too. Objects don't keep increasing speed indefinitely in real life either. Likewise in real life this falling wouldn't be perpetual motion as it does not in fact generate any energy, how would you go about storing that energy? 🤔 you can't. In much the same way that you cannot gain any energy from the moon rotating around the earth, because gravity is not a source of energy, it is a force, any way that you could gain energy from this would slow the object down or move it out of line with the portal either of which would stop energy from being gained eventually meaning it isn't any more of a perpetual motion machine than the moon is.
@@calebmon keep in mind the portal games are games, they aren't real, make no attempt to be realistic and are silly on purpose.
Terminal velocity is air drag pushing against you which you can mostly ignore by falling in a vacuum. Please locate to me an atmosphere or terminal velocity in the source engine. It doesn't exist. It's just an arbitrary cap for how fast you can move.
If you wish to some how harness the energy of some falling mass you can use a water wheel or something like that or make it a magnet falling through a coil.
You say making energy with gravity is impossible in real life. Portals don't exist in real life. Are we on the topic of portals or reality? As to how to store that energy: the mass is moving. It's full of kinetic energy stored in that mass. Call it a kinetix battery.
The moon around earth moves at a constantish velocity around the earth. If you put portals over and under each other, anything that you make fall from the above portal to the bottom one will have some meters of potential energy, become kinetic energy, go through the portal to move above where it was ad infinitum and tada, you have infinite energy. This is in no way comparable to an object orbiting another, it's purely a fiction that would break the laws of physics was it to occur.
You exploit this infinite (if not for the game's velocity cap) energy you can make up in the portal games on several occasions by using it to launch yourself across the map.
It's very simple actually. Speedy thing goes in, speedy thing comes out
Speedy thing is not speedy when it goes in so its not speedy when it goes out
I'm Cave Johnson. We're done here 😂
This guy is treating the portals as if they're two separate portals, but in reality, it's one portal, they're both an entrance and an exit to one another. It's not rocket science.
that's the whole argument, and as others have stated, what are you measuring speed against?
So... B then.
2:45
"How could a stationary object exit a stationary portal without moving?"
The orange part of the Portal moves.
You think of portals like two ends of a teleporter with no space in between when in the game its much more like a portable hole.
At somewhere around ~3:00 you say the Cube would get squished up between dimensions while entering orange but a portal isnt a physical object.
Think of it the same way as if the moving platform just had a hole in it. Only this time the exit of the hole isnt on top of the platform but somewhere else.
The cube is still laying on top of a flat surface while exiting blue. Just because from blues perspective it looks like a hydraulic press is pushing the cube through doesnt mean it goes flying, the rest of the platform orange is attached to still blocks the ground from passing through.
Imagine if the cube was on an elevated position like a pillar. The cube + pillar would pass through the portal, then the cube would tip over due to gravity.
Otherwise you could try to look at this problem from the blue portals perspective. If you look at it while the orange portal moves quickly down on the cube and the pillar, you would basically see how a pillar is pushing the cube really fast out of the portal, like when you throw a basketball the wrong way into the basket. It that case the ball doesn't just fall flat out of the ring but keeps its initial speed aswell until gravity pulls it back down.
With the portals it's just a _bit_ different. While the cube is stationary, the portal moves and since it connects it to another point of the room, the moment the cube itself would still be 0 to its relative position of the pillar, but the room the cube enters moves instead very quickly. And relatively speaking it's the exact same thing as when the cube would move quickly while the room is stationary.
@@kartoffelwillipeter3067 While relativly speaking it _looks_ the same, there is a diffrence between launching a stone into a wall with a catapult and moving the wall forward and the catapult backwards. While the stone does again collide with the wall this time the reaction is completely diffrent.
Another example would be if you put a water glass over the cube. No matter how fast you put the glass down the cube won't move even tho from the glasses perspective it looks like a cube is ramming into it.
While they close in in relativ distance the kinetic energy a hole or "nothing" exerts while beeing flung at high speeds is not equal to an object like the cube beeing flung into the hole, even tho their relativ distance is the same in both cases.
If you throw a ring (portal) on a stick (cube) the stick wont move afterwards. If you throw the stick through the ring the stick will move.
Why? Because if you throw the ring there is ground below it preventing it from going further. No kinetic force is applied to the stick. (Cube)
No matter how fast the portal is, the cube is stationary. From the cubes perspective only gravity changes after passing through.
I think that the theory of portals is missing a fundamental idea or explanation. They're essentially a hole in the fabric of the universe, space-time if you will. It folds it together and creates a hole to step through. I don't believe an object without it's own momentum can exit a portal that also has no momentum.
I believe if you make portals of any size but especially as small as these examples would take astronomical technology and calculations. The universe is always moving, expanding in it's own various ebbs and flows. Planets move and turn, whole galaxies and even black holes scream across the universe. Not being able to make those calculations and adjustments would make any sort of portal unstable. If you're able to make these adjustments it would account for your lack of momentum and give you the momentum you need by closing the gap between portals constantly and at an insane rate. That would give momentum to pass through. (The gap that I believe forms between the portals when they're unstable and take things in. One that's imperceptible in a stable functioning portal.)
You can't theoretically exit a stationary portal without momentum without moving yourself or without help. Think of it this way: you have to vertical walls, one is moving at you and one is stationary. The moving one envelopes you but how do you move forward in the stationary one at all. To further this question and answer... what do you think would happen if both of the portals were moving in opposite directions and you jumped in with no momentum? I think a space grows between. You can't really exit either of them and whatever space is between the two holes just keeps getting bigger without help and more science.
My best theory for this is black holes are natural portals. A star died and violently blew a hole from one end of the fabric to the other. It's just that is dangerous and as unstable as hell. If it poked a hole that way there's probably an equal hole elsewhere. Except they're not stable, traveling at some of the highest speeds and traveling great distances away from eachother or literally any direction except closer or more stable.
Creating such a space with enough suction to trap light itself. It also ties into the theory of white holes that expel instead of suck in everything. It could be that dimensional space between portals closing and dissipating due to some universal hole-pocket size in reality law or the holes converged together somehow and end up closing, ejecting everything. Which given the astronomical size of the universe and the portals themselves this could take trillions of years or maybe never even happened yet.
Black holes have been theorized to lead somewhere but of course they crush everything in existence. Maybe they're thought to be so dense because of a gravitational pull that's actually caused because of what's behind that portal and how mind bendingly huge it could be.
I could've tried to explain this better and more sciencey but it's 2am and I don't care enough.
@@hinamiravenroot7162 There is one key difference in your analogy with the ring and the stick.
If I understand you correctly, the ring represents both portals, though in the game, the exit portal has no mementum relative to its world. Your ring does. By not moving the blue portal you create a path through which the cube travels from a place where it has no relative momentum into a room with to which it has a big relative momentum. Basically by accilerating the red portal while the blue one is stationary you accilerate the world behind its exit towards the cube. So relatively speaking the blue portal and the
cube must a great difference in momentum.
@@kartoffelwillipeter3067 oh you are right I didnt think about that
Regarding the final question, My intuition tells me the block should come out at an angle.
Unless you drop it at an angle it would still be straight.
But if you were too drop it through the blue while the orange is moving I think that would have a different result.
@Globin347 I agree with you. Assuming the B approach to how the portals work, you add the velocities of the portal and the item passing through it together to reach a net velocity when it comes out of the second portal. Comparatively it is like the experiment where you have the rolling cart and a ball launcher that shoots the ball into the air. The only difference is that with the cart you add in the vertical velocity after it moving horizontally, while with the portal you add in the horizontal velocity after it is moving vertically.
*Side Note*: If you believe option C (from video 1:59) then it would move straight out of the portal and ignore the horizontal movement.
I agree with birb
@@datapack122re8 well i consider the fact that the portals moving and the object is you know going in straight but the portal sees it as moving at an angle relative to its top and bottom
I concur.
From a relativistic perspective: in the reference frame of the entry portal, the box is approaching the portal at an angle, and therefore it should be ejected from the exit portal at an angle. Or, alternatively, from the reference frame of the box, the portal approaches the box at an angle (the combined velocities of the box and the portal) and therefore, once the portal passes over the box, the exit portal should recede from the box at an angle.
From the reference frame of the environment, conservation of momentum seems to have been violated (since the box has changed direction), but that apparent violation might get absorbed by the portal somehow.
For option B, what happens if the portal stops moving halfway across the object? Does the object get pulled through since half of it now has a velocity but the other half doesn't? Would objects get ripped apart if the speed is too high?
this is what makes me think that it'd be more like option A, it's simply a window onto another point in space, think "hole in the wall" the american game show. And regarding the issue where only part of the object goes through, then what happens to it would depend on the center of mass of the object. if the center of mass has gone through the portal, then the object is under influence of gravity at the other side of the portal, wherever that is in space.
He did a video on this and it would shoot out with half the speed or break depending on the durability of the action
I thought “A” because if you put a cube on a table and slam a piece of paper with a hole on it then it wouldn’t move
It kinda would though.
From the frame of reference of the hole in the paper, the cube will be moving through it, up until the hole violently accelerates to then keep pace with the cube (that is, it hit the table).
@@ShadowFalcon But that's from the reference of the hole. In portal you dont play as a portal, you play as a viewer.
@@Quaz-jinx
Maybe, but according to relativity, both frames of reference are equally valid.
Consider this.
If you're in a void, with a doorway, how would you know if it was you moving towards the doorway, or the doorway moving towards you?
Or in the case of these portals, how would you know if it was you moving toward the portal opening, or the portal opening with an entire universe on the other side moving towards you?
What you're doing (which came instinctual to most, since it's a good approximation) is assuming an absolute reference with witch everything can be measured against.
I used the same logical example when I tried to explain the answer.
I thought of the portals as doorways. If a doorway/hole in wall was moving towards you, you don't move.
Since I'm colourblind neither answer is correct relative to me.
But you still see the difference :)
Red n yellow portals for me
@@Fyuri Not every colorblindness is the same. Some people don´t see any colors.
buryitdeep So if I wear all orange or all blue clothes You'll just see a floating head??
@@Fyuri Yes but if a orange portal and a blue portal have the exact same contrast, some people won´t be able to tell the difference.
You can't "port" onto a moving surface, anyway, so the whole question is moot
The exit speed relative to the exit portal is necessarily equal to the entry speed relative to the entry portal. An object 2 meters long, moving at 2 meters per second relative to the entry portal, takes 1 second to pass entirely through the portal. Unless there is some kind of buffer to store the matter until it exits, that object will take the same time to exit, and therefore has the same speed relative to the exit portal.
In relativity, there is no absolute motion (as was mentioned) which means the notion that the portal is moving is exactly as valid as saying the cube is moving and the portal is stationary. Thus the behavior of a cube moving into the portal is EXACTLY the same as the portal moving towards the cube. Since we know the effect of a cube moving into a portal, we know the effect in a hypothetical 'real' world where the portal is 'in motion' would be identical.
Consider a portal that is stationary and a cube passes into it... We know the effect. Now consider that the portal is sitting on the back of a truck that is in motion and cube is stationary.... Then consider that the truck is on a rotating planet.... and so on and so on. At no point will you ever discover a fixed point. Motion is relative. The only thing that matters is the motion within the frame of reference.
This was a triumph. I'm making a note here: HUGE SUCCESS.
For the good of all of us, except the ones who are dead
It's hard to overstate my satisfaction
@@aidenhanson884
Aperture Science
“We do what we Must Because we can”
For the good of all of us
Except the one who are dead
@@Fur4all but there's no sense crying after every mistake, you just keep on trying 'til you run out of cake
KingCraft Aiden and the science gets done, and you make a neat gun, for the people who are...
It's about the inertia of the object entering the portal that gives it it's speed. A portal doesn't imbue inertia onto an object. Option A.
The portal acts as a window, and if the window (and everything beyond it) is moving relative to the cube, then the other side of the portal (the exit of the cube) would show the cube moving relative to the window. Much of the problem may actually have to do then with how much energy it would cost to actually be able to move a portal.
Exactly
I think you're confusing inertia with momentum. Inertia is simply the empirical fact that all objects remain the way they are if no force is exerted on them. Your comment makes no sense.
I'll assume that you mean momentum. In this case, you are simply wrong. Momentum is mass times velocity. And if you watched the video, you'd know that velocity is dependent on your frame of reference. Yes, momentum is also dependent on your frame of reference. In the frame of the environment, the object has no momentum, but in the frame of the orange portal, it does.
@@PlasticBro no
@@PlasticBro I don't think you've studied any real physics if you don't understand what I'm saying. I understand mechanics and energy conservation. It may hypothetically be impossible to move a portal relative to another portal in the same dimension due to the energy required for a portal to move the entirety of space for an object going through it, generating momentum for that object. Then again, the energy input required may just need to be enough to move the object through the portal at velocity V. Honest to God it's not that hard to imagine. If you're at the edge of the entrance portal and you are moving towards the block, the velocity of the block relative to the space through the portal is the same as the velocity of the portal entrance. The reason the block would just fly through is because the exit portal is static. But the problem is that it's all in the same dimension..... And that's why I postulate that the only reason any of this would work in the first place is if energy is input to the portal in some way to generate momentum for the cube relative to you. It's all very sticky stuff. But your dismissal of my ideas because you lack the capacity to heft a single braincell is insolent and insulting.
For the last question, If the portal scans the box bit by bit then would the box come out of the other portal slanted?
it would hit at different areas of the sliding portal and come out 3rd printed shifted
Gooey Prickles but theoretically portals are not stationary due to rotation of the Earth and it’s orbit.
@@gandalftheantlion hey, thats relativity!
I think the real lesson the video is trying to teach is "How the fuck are any of us supposed to know, we dont know how Portals actually work, let alone what they are relative to"
??? My English is bad, i think the cube will "fallout" (hehe) #gravity and reconstruct correctly
@Gooey Prickles -- We already have the "instantaneous acceleration" problem. If the portals are facing the same direction, any object thrown into them must instantaneous reverse it's momentum. Rather, momentum is conserved *relative to the portals* and any excess/deficit is applied to the surface the portal is mounted on.
for me, option A is more correct. In one of the "Aperture Investment Opportunity" it was said that the portal gun creates a hole in space, which means teleportation works on creating a hole in a curved space. Such portals should be treated as doorways, and if the doorway is flying at you, then you will not get its speed when you pass through it.
You would if the exit of said doorway was in a fixed location. Leaving a stationary exit entails movement by default.
(3:50) Video: There is no paradox!
(3:55) Also Video: You decide what the answer for the paradox is!
Me: So which one?
*Paradox formed*
Uh, I'm going to go with true, although to be fair I may have heard that one before
@@jakeread9668 The paradox is still a paradox because since we have no way of knowing how portals actually work, we're still in the search for answer, thus, it's a veridical paradox because his earlier statement was false and he made it clear 5 seconds afterward that there is a paradox about the portals (which is btw an antinomy). Anyway, this video has perhaps the wrong idea of the right answer.
@@boputime4130 was quoting Wheatley actually but ok
Slime Duck
That’s not a paradox. That’s a choice.
@@jakeread9668 Nice one, Wheatley is still a gaming gem
Now you're thinking with portals.
This comment deserves some cake
Mildly Aggressive Desk I think you meant a lie.
Mr. Bodymassagemachine
Sshhhhhhhhh
I've played Portal 2 way too much, and I know that if you turn on cheats (sv_cheats 1) then you can turn on moving portals (sv_allow_moving_portals 1, iirc). I wonder.
I'd imagine they would work like windows
No actualy with windows both sides are moving
Yeah, when I throw my baseballs at old men.
You like them to have blue screens? Odd ...
I think of it more like a door way.
I like to think about it like cutting a hole in the panel and the other side of the hole is just in a different place so option a would work
The way it would work is option B. The portals canonically are trans-dimensional, so they open up holes to other dimensions, not the same dimension. It's just lucky there's an infinite number of imperceptibly near-identical dimensions. It's important to note that the way the game is programmed and the way the portals function canonically are not the same thing. In fact, it might've been even easier to code if they'd thought about the way option B explains the mechanics of trans-dimensional gateways.
What the portals actually do is as follows: The entry portal changes your velocity relative to the exit portal. That is the simplest way to think of it. The way to imagine this in practice is to imagine a cube (say, a companion cube) is sitting perfectly balanced on top of a long, thin, metal pole. The entry portal flies down over the cube, and because the pole is thinner than the cube, the portal slides down some of the pole, too, before suddenly stopping. If you were observing the exit portal, you would see the metal pole spear out of it with the cube at its tip. The pole would appear to be thrusting the cube through the air until the pole stopped moving (at the same time the entry portal stopped), but because the cube isn't attached to the pole it would fly off, maintaining the velocity the entry portal gave it relative to the exit portal. The only reason the pole doesn't fly off, too, is because it's firmly attached to something that can't fit inside the entry portal (i.e.: the ground) And the velocity achieved by the entry portal isn't fast enough for the mass of the pole to tear/break itself when the portal stops. (Theoretically, if the portal moved fast enough and stopped fast enough (read: instantaneously), there is a speed at which an object would simply rip itself apart and fly away from the exit portal with its newly-imparted velocity.)
If you think it's option A, your brain doesn't work right. And option C or any other option ignores how the portals canonically function. Option B is the only result that makes any sense.
I think the more interesting question to all of this is: How could you utilize the imparted velocity to do fun and interesting things? For example, if the entry portal only moved partway down the cube and then suddenly stopped, how fast would it need to move and how much of the cube would it need to transport before the mass and velocity of the cube on the exit side were enough to lift the cube off of its platform on the entry side?
For the last puzzle, option D: the portal stops being a cube as each infinitely small layer of it is slightly displaced, thus causing it to emerge from the other end as a deformed prism.
Not if the rest of the cube follows the displacement, causing it to emerge as a cube but going sideways. Basically it would only emerge as a deformed prism if the inertia doesn't translate from one portal to another, exactly like the cube emerging squished in the first problem. It actually is the same problem as the other one.
@@WallySketch I was thinking that while falling through the moving portal, the coordinates to which the sections are "scanned" are moving along a horizontal axis printing it slanted on the way out, after that I'm guessing it should have to shoot straight out. I guess someone who would have to program it would simply not allow portals carrying velocity to operate normally haha
@@scottausor The coordinates which the sections are scanned are moving along a horizontal axis at the same speed the rest of the object is moving due to inertia, so if inertia is conserved the object won't be deformed. It will just have a lateral speed.
If the inertia is NOT conserved, then yes the object will come out as you said, as a deformed parallelepiped.
Perhaps the cube would have a rotational force applied to it?
Answer is :
_
_
_
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portal
Cube gonna exit sliced in layers, or recombinated in stairs like form. Portals have corelated coordinates themself.
I think the idea that makes sense is to view the portals as a metal ring. If you move the ring over something the object comes out the other side. View each side of the one ring as a separate portal. It’s instant transmission through a two dimensional space (the flat surface of the portal) the idea of thinking of the portal as a hoop or ring that has been split in half is I think the easiest way to visualize it.
Right, but as soon as it exits the other side (in the case in the video) it's subject to totally different forces. There's gravity, AND there's the fact there's nothing behind it (no floor) anymore.
The speed of the cube edge emerging from the portal has to be fast enough to allow the rest of the cube room to come through behind it. Otherwise it's somehow being compressed in "portal space" (which doesn't exist). The cube has to "get out the way" of itself - therefore, it emerges from the portal at a fast speed. Therefore it's moving (fast) as it exits the portal. That momentum can't just disappear.
your answer would make even more sense if the two ends of the portal are always moving at the same speed. then stationary objects would not be squished
@@OhSoUnicornly wouldn't it just be like to people pushing a box from opposit sides?
The stronger force makes the box accelerate and in case of equal force the box doesn't move.
The cube going into the portal doesn't mean it has to fully go through or else go back. Or at least that seems most logical to me
Thing is that each individual atom that passes would see the sudden change of gravity individually, that much is true, but the thing about the momentum not being able to disappear I disagree with, if you think about absolute momentum, it had none, so it doesn't disappear it never had it. The only absolute things that the object has is mass, that mass is being subject to gravity, what happens between portals is a change of the direction of said gravity and the speed of the portal is just the speed with which the gravity direction changes on the cube. Think of it this way, if you had a chamber in which gravity could be reversed entirely instantly, would an object sitting there just free fall or would it fall at the speed of light?...
I don't know why people keep talking about gravity.
Yes it _does_ affect the speed of the cube. But it does _not_ relate _at all_ with what is being talked about here.
An object coming out of a portal is _moving_
_Stationary objects don't come out of portals_
Me: Looks at thumbnail and title.
oh pretty cool
My Brain in five minutes: What no how
Me looking at the thumbnail and title:"It's obviously A. Play the game moron."
Me after watching the video:"this guy is a fucking moron who hasn't played Portal."
Another possibility: the portals can move but must stay stationary relative to each other.