/sci/ - Science & Math

Wouldn't it be a combination of A and B? Wouldn't it make a downward parabola starting at the exit point and ending some distance away from there?

It's A, the block doesn't follow a vector so it'll just fall because off gravity.

initial inertia = 0
no force acting on box (assuming traveling through portals has no resistance)
final inertia = 0

the box would follow scenario A, since the orange portal effectively makes the blue portal a wall the box would sit up against this wall until acted upon by gravity which brings it to is resting position.

It's A.

If you just imagine the orange portal as a hole (which it is) it becomes very obvious.

No matter how violently you smash a cake-cutter around a penny, the penny isn't going to be flying anywhere.

God, it's so nice to see this thread on /sci/ where people actually know their goddamn physics.

Several months ago when I saw this thread on /v/ most retards were screaming it was B citing frame of reference, not realizing that there's no force being applied to the block therefore there will be no acceleration apart from gravity when it exits the portal.

OP here.

>>4794455

I think we can safely assume that gravity still applies in either case; a realistic trajectory is not shown in B. What matters is that, in B, the cube is moving with respect to the blue portal.

>>4794466
> initial inertia = 0
> no force acting on box (assuming traveling through portals has no resistance)
> final inertia = 0

I'm assuming that, by "inertia," you mean momentum. If so, I totally understand what you're saying. However, the problem with using conservation of momentum here is that the portals in Portal do not strictly adhere to this law, even when both portals are stationary. Momentum is a vector, and while the magnitude of this vector is usually conserved (with respect to surroundings) as an object enters one stationary portal and exits through another stationary portal, the direction of this vector may change.

If you were the object going through the portals, an observer would see you change direction if the two portals were on two surfaces which lie along non-parallel planes, but you would not feel any change in direction. So, according to the person going through the portals, momentum is conserved, but an outside observer would disagree.

I think momentum should be conserved relative to the portals -- which can, in a way, be seen as one object, since they connect to points in space. This gets a little weird if one portal is moving with respect to the other, but here's how I see it:

The initial momentum, with respect to the orange portal, is non-zero.
Therefore, the final momentum, with respect to the blue portal, should be non-zero.

A makes no sense. The block couldn't exit with no momentum.

>>4794500

Dubs.

Furthermore, the cube is not being teleported instantaneously across the portal. It must pass through the portal. (At some point, half of the cube will be on the orange side, and half of it will be on the blue side.) When the cube is emerging from the blue portal, the "top" of the cube comes out first, and then the middle, and then the bottom. Super obvious, right? Well, this means the cube is moving as it emerges. (More specifically, it is moving at the same speed at which the orange portal falls.) Consider the implications. If it's moving as it emerges from the blue portal, what could possibly cause it to stop? Unless some force acts on it, the cube should keep on moving once it has completely emerged.

This is a pretty nice way of showing that B is probably correct.

>>4794446
A

>>4794512
See >>4794499

There's no force being applied to the block. The portal is essentially a glorified hole. You could simulate the same thing by simple taking a hula-hoop and pulling down over a block at a high rate of speed. Does the block suddenly launch into space once you pull the hoop down? No. Why? I mean, from the hoop's frame of reference the block is moving at whatever speed the hoop is from an outsider's frame of reference.

The reason is that there's actually no force being applied to the block, and as we know from F=MA, no force = no acceleration = no change in velocity (which in this case is zero). If you were the portal and watching the block, it would appear to be moving towards you but then it would appear to suddenly come to a complete stop once your portal hits the ground.

>>4794512
Correct op. In the shortest way possible, the cube can't leave the blue portal with no velocity. You can't exit a house without moving relative to it.

You've resolved this god awful thread in under 15 posts. That might be a record.

>>4794523
Ugh. You're not addressing the "how can the cube exit if it has no velocity" argument.

Portals can add energy to things. It happens every time you have the exit portal above the entrance portal. You have to allow for portals to apply forces, thereby accelerating things. If you don't allow this, then they fail to make any sense.

In order for the box to move out of the blue portal, it must, like I just said, move. Therefore, it must accelerate in some way. It is at this point Newtonian mechanics cannot explain anything else. Obviously the speed at which the box comes out of the blue portal is a function of how quickly the "smasher" moves over it. So I am saying B is a reasonable choice.

>>4794523

I understand your argument but I don't understand why you're quoting >>4794512

What I said in that post was that the cube is in motion with respect to the blue portal as it emerges from the blue portal -- this is a fact which is not up for debate because we know that it does indeed emerge -- and, additionally, that it must be moving at this time with the same speed at which the orange portal falls.

If the cube is moving at this speed as it emerges from the blue portal, your insistence on a lack of any acceleration (aside from gravity) implies only that the cube keeps moving.

Your hula hoop analogy is also fallacious because each side of the hula hoop is stationary with respect to the other side. Here we have one portal moving with respect to the other. That would be like having a magical hula hoop whose "top" side moves at a great velocity with respect to the "bottom" side while, simultaneously, the top and bottom remain connected.

Obvious the physics involved here can be counter-intuitive and does not follow the same rules as real-life examples.

OP is right. It's B

>>4794446
I believe it is mentioned in the game that the portals maintain velocity. fast in = fast out.

This has nothing to do with science and math.

>>4794533

Furthermore, portals imply a discontinuous position function, which is therefore null for rates of change at that discontinuity.

>>4794523
Please see >>4794487

>>4794530
No, there is always conservation of energy and momentum through portals.

The block is not actually moving.

>then they fail to make any sense
>implying portals that spontaneously create energy and exert force on objects that pass through them with no contact make any sense

you know why people are getting tripped up over this, because there is no fucking arrow on the diagram indicating that the entrance portal is moving down to the cube.

the correct answer is A

IMO

>>4794537
>conservation of energy and momentum
You are still ignoring the fact that the block can't pass out of the exit portal and be not moving relative to it. (without becoming a pancake.) So, you can't have conservation of speed AND moving portals. It's one or the other.

(As an aside, when a flying cube undergoes a change of direction by passing through a portal, its momentum changes. Momentum is a vector.)

>>4794530
>Ugh. You're not addressing the "how can the cube exit if it has no velocity" argument.
Yes I did. Let me use another example since you seem to be having trouble with frame of reference:

Let's say you're underneath an arch that's on wheels and attached to a truck. There are two ways to get away from under the arch. Either you could walk away from it (you accelerate) or the truck pulls the arch away from you (the arch accelerates).

Same thing here. The portal is a 2D structure. It's just a doorway that happens to conjoin two different areas of space together into a 2D plane. When you go through it it's no different than going through a hoop.

>>4794534
See above.

A~just fall out
B~Fly out at high velocity.

A pretty much says it would slide across the slanted plane that the blue portal exists on, right? That would only really be logical if the orange portal fully engulfs the cube. But you could also say that once the cube comes through the blue portal it is affected by the gravity and falls at that angle. Then you also have to take friction into account. What is the friction of the surface that the cube exists on? If it has enough friction, it probably won't move, considering that (two) gravitational forces are acting upon the cube (Blue portal and Orange sides). The cube could roll though. Depending on the weight of the cube.
And for the sake of B, once the cube enters the orange portal, and exits the blue, it is traveling through the blue portal, so due to perspective, it would appear to be moving out of the blue portal at a high speed, which would give it that hidden momentum everyone here seems to deem non-existent. Which brings me to this post: >>4794479 It is like its going through a cake cutter when it reaches the orange portal, but when it comes out of the blue portal, it will appear to be moving at high speed, and, depending on the weight, will have momentum when it comes out of the blue portal, because it isn't moving when it goes in, but it is moving when it comes back out, that's where the hidden momentum comes in. So, Assuming that the physics of the portal are possible and logical, it would be B.

>>4794545
>how can portals add energy to particles

This is both plausible and necessary. The portal could be carrying it's own battery with which to accelerate particles. If I put one portal on the roof and another on the floor beneath it, I can drop a cube and have it loop through, accelerating infinitely. Where is the energy coming from? The portals.

>>4794550
its a PORTAL

PORTALS ALREADY ARE AN IMPOSSIBILITY, so you can't directly apply "normal" physics to a clearly impossible situation.

Think of the portal as 2 sides of a hulahoop. If you dropped the hulahoop down on it, does it impart any movement to the block?

No. The block is moving in respect to us but it has no momentum

>>4794551
I think its clearly obvious that the portal is moving downwards

Think of the portal as a hole. Or a hula hoop.

>>4794558
But the cube is moving as it come out of the blue portal.

>>4794564
Only in that frame of reference, it has no momentum.

To the block, it is the portal that is moving, it's just standing there.

>>4794558
it is to some. But! I have alot of experience drawing conceptual diagrams, and In my professional opinion (dear god over a fucking video game) there should be an arrow.

It's A.

Imagine dropping a hulahoop on the cube. Same idea.

The only reason it falls is because it's on an incline, so the center of mass changes.

it's B because FROM THE PORTAL"S POINT OF VIEW, the box is MOVING!

Imagine you are looking through the blue portal, while the thing is happening. What do you see? You see the box moving towards you with a velocity. It keeps moving towards you with its velocity, untill BAM, it exits through the portals, and guess what, it has to maintain its velocity, so it goes flying into your face. B it is

Check mate

biotch

lrn2principle of relativity. Seriously, it's one of the oldest principles in physics.

Basically, all that matters is movement RELATIVE TO THE PORTAL.

This is the same reason why you don't factor the rotation of the earth and all of that crap while you do simple projectile problems in your homework. All that matters is movement relative to eachother.

You can just as easily say that the orange portal is stationary, and the box is moving towards it. THere is no right way of looking at it. It is not a fact that something is moving or not. All you can say is that something is moving relative to a point.

>>4794567
But you also have to view it through the perspective of someone only seeing the blue portal, and not seeing the orange portal or the cube or all that. Once the cube comes through the blue portal, it is moving.

>>4794561
The portal isn't adding energy. It's just a warp in space that results in two seemingly disjointed spaces becoming connected. Hence why if you look into a portal it's like looking through a doorway...because it is. It's not a tunnel like you think it is, and if you play the game this is obvious the first time you go through a portal.

>>4794560
The block isn't moving when it comes out. The portal is moving space around it, the block is not actually traveling anywhere.

It would be like if you were in front of a backdrop that was on a conveyor belt and I flipped a control that made the backdrop move at 300,000 MPH. According to your logic you should die of the massive G-force, when in reality you're just standing still.

>>4794551
The reason there is an argument is
>>4794487

>>4794555
I can't say I understand what you're getting at, but it looks like you're making the issue away by changing the scenario to something completely different.

Consider this: The cube is halfway through. If the first half is not moving, then where will the second go? There is no room for it, unless the first half can get out of the way.

>>4794577
But you wouldn't be changing my place in space, in this the cube transfers from one spot to the other, as well as the space around it. You have to be thinking of this through multiple dimensions and perspectives.

>>4794539
>maintain velocity
>maintain a direction

Do you even highschool maths?

>>4794523
>>4794558
>>4794566
>>4794579

Why does everyone always use this hula-hoop analogy? It's been used four times in this thread alone. Who started this crap?

See the end of >>4794534

Two portals, one of which is moving with respect to the other, is not like a hula hoop. There are plenty of reasonable arguments in favor of scenario A, but this is not one of them.

>>4794550
This is dumbbadwrong. Even without imparting velocity on it, it will be pushed out of the orange portal; by itself. The rest of its body is emerging behind it.

But mostly, this entire discussion is pointless. There is no consistent answer. An object does not inherently have velocity, velocity is a property of the relationship between two objects. You mvoe relative to something else.

Before it goes through the portal:
Velocity relative to platform = 0
Velocity relative to orange = X > 0

When it goes through the portal, we want to use blue instead of orange as a reference point, but keep everything else the same.

Velocity relative to platform = 0
Velocity relative to blue = X > 0

There is NO movement from portal B which satisfies those constraints.

Unsurprisingly, immediately transposing yourself from one physical space to another breaks physics like a little bitch. And how it works in the videogame is "magical handwavium." Which is about the only way it really will work.

>>4794590
Because the hula hoop will be moving

>>4794590
the hula hoop analogy is perfect. the portals are like the two sides of the hulahoop, in the game there is no space between portal A and Portal B. goes in one side and out the other.
>>4794588
did you even play the game?

Just made this.

>>4794629
The block is moving without velocity or momentum due to portal magic.

TO THE HOLE/HULA HOOP ANALOGY:

you can't do it. Either an entire hoola hoop is moving or entire hula hoop is stationary. You can't have the entrance side moving and the exit side stationary, or vice versa. BUT GUESS WHAT, in this scenario, one side is moving and the other isn't. So therefore the analogy doesn't work

>>4794637
Why cant you?

you know what it is, you guys can't think outside of the box. people are getting tripped up because they can't throw out physics and think in imaginary land, which is 100 percent necessary in this case.

The answer is A. I imagine /v/ had already sorted this out seeing as how the only way to come to the correct answer is to have played the game.

>>4794640
Such a hula hoop is just broken hula hoop. Op's scenario require the portals to moving relative to each other, and using the hula hoop analogy removes this, leaving you with an inapplicable scenario.

Don't bother arguing against the above point. Focus on this:
>>4794629

>>4794629
You are fucking retarded. I answered this already.

Imagine this. You are standing on a platform with a hula hoop (there it is again) around your waist. The platform raises, pushing your legs up and through the hoop. Does the rest of your body deform, or do the forces exerted on your legs, and the tension in your legs, push the rest up?

There are arguments for A and B and I don't really care because it's portals and neither makes sense from a physics standpoint; but that argument is very, very crap.

>>4794640

Eithe
r an entire hoola hoop is moving or entire hula hoop is stationary. You can't have the entrance side moving and the exit side stationary, or vice versa. BUT GUESS WHAT, in this scenario, the entrance side is moving and the exit side is stationary. Therefore it is unlike a hula hoop

>>4794629
this guy is right and you should all applaud him and suck his dick or something idk. During the moment when the block is passing through the portal on the Blue side, it is moving. THEREFORE IT HAS VELOCITY BOOM BITCH WADDUP

>>4794581
>>4794581
>>4794581
>>4794581
>>4794581
>>4794581
>>4794581
>>4794581
>>4794581
>>4794581
I strongly recomend you guys look here

Portals do not exist so there is no method in which to test this hypothesis.

- Theoretically, if you were to take a hoop of some sort and slap/drop it over a ball, would it shoot out of the hoop?

- Is the hoop coming in contact with the ball or exerting some form of action? No.

- Do objects in portal have to gain velocity before they can actually maintain momentum when flying through a given portal? Yes.

- Once again, what is the portal transporting objects through?

SPACE, MOTHERFUCKER. There might be air there! But there's nothing significant enough to actually interact with the cube. So please, for the love of everything sacred, shut the fuck up about the stupid, fucking cube going through the stupid, fucking portal

>>4794658
You've changed the scenario into a different one. Answer this: Where does the orange half go?

>>4794658
You are fucking retarded. You can't compare this to a hula hoop. See my post >>4794662

Speedy thing goes in, speedy thing comes out.

No momentum on the block, it won't come flying out. As for anything else, fuck me.

PHYSICS DOES NOT APPLY

PORTAL FUCKING MAGIC

THE HULA HOOP ANALOGY WORKS

THE ANSWER IS A.

>>4794662
>I strongly recomend you guys look here
That guy's not very bright. Relative motion is important, but he picks one frame of reference and ignores every other. The fact is, the cube suddenly having velocity on the far end (relative to the environment) would make no sense in the context of its previous relative velocities to the environment around it, and make sense to the portal. But why choose the portal as the One True Reference? Why not choose... the ground?

And then everything falls apart. Again: there is no consistent answer. Portals don't actually work unless you introduce additional bullshit rules above and beyond physics.

>>4794674
see this post

>>4794581

>>4794658
>it's all fake physics so there is no answer

Physics is about creating models that make predictions. ITT we have no actual portals to test our models' predictions, but we can see which model is the most coherent, consistent, simple, elegant, or whatever. I vote B.

>>4794581
>This is the same reason why you don't factor the rotation of the earth and all of that crap while you do simple projectile problems in your homework

Uh its called the coriolis effect and you DO take it into account when you are plotting projectile movement on the earth, etc.
So your whole point is bullshit.

>>4794689
>I vote B.

How is B consistent or elegant or coherent?

...
You guys realize that you can easily derive contradictions with these portals when they're accelerating with respect to each other, right? In other words, IT IS NOT POSSIBLE TO COME UP WITH A SELF-CONSISTENT THEORY TO DESCRIBE THESE FUCKING PORTALS! (i.e. the entire question is just a troll)

Finding examples of these contradictions is left as an exercise for the reader (hint: it's really trivial - just consider a meter stick that's sticking halfway through the portals, and try to figure out what happens when one of the portals is accelerated. There's no self-consistent answer, unless you start assuming the two portals are not identical)

>>4794694
ok that was bad choice of words. What I meant was that when you do those simple physics problems you get in intro to physics that are calculating how far a racecar goes or something like that, you don't factor the rotation of the earth and movement of the galaxies and waht not.


guys, this is the reason why when you're in a car going at constant velocity, although you are moving, it doesn't feel like you are. The reason is because technically, you could say that you are stationary, and the earth is moving at 60mph under you.

Things can only move relative to eachother. They don't just "move"

>>4794701
>how is B coherent
A is incoherent, because of the image that is posted shortly above. B is fine, if you allow portals to impart kinetic energy into particles.

>>4794709
Interesting. I suppose you can't have accelerating portals. But you can have moving portals if you want.

>>4794675
Of course the portal is the one true reference. It is the thing the object is passing through.

Ready for this? Ready for me to blow your mind??

guess what...

THE ORANGE PORTAL = THE ENVIRONMENT IN THE AREA OF THE BLUE PORTAL

aka if the orange portal is moving, the environment of the blue portal is moving with it.

WOOOOOOOOOAAAAAAAHHHHHH

yes I understand if this is hard to understand. Just imagine you are the box and you are looking through the orange portal as it is plummeting towards you. What do you see when you look inside it? The environment of the blue portal crashing towards you as well.

TRIPPIN BALLZ MAN

why are you guys trying to use real physics and logic to derive an answer, the ONLY WAY is to know how the portals from the game portal act via having played the games, the physics in the game do not make sense. In the game the distance between portal A and portal B is ALWAYS CONSTANT.

IT IS NONSENSICAL

THE CORRECT ANSWER IS A.

>>4794723
>can't have accelerating portals
Scratch that, changed my mind. You could, you would merely have to have portals that are able to accelerate the meter stick.

Portals are perfectly possible if you just imagine them as matter transmitters.

>>4794729

>In the game the distance between portal A and portal B is ALWAYS CONSTANT.

But its not in this case.

>IT IS NONSENSICAL
>(therefore)
>THE CORRECT ANSWER IS A

Cool non-sequitur, bro.

It's B, but you must remember that gravity force and inertial force are locally indistinguishable.

>>4794711
>you don't factor the rotation of the earth and movement of the galaxies and waht not.

You leave it out because it's negligible, not because it doesn't effect you.

>>4794742
how is it not in this case, OP specifically states
>more logical given the fictional laws of physics used in the game
and in the game the distance between portal a and portal b is always constant.

the rest of what you said is just stupid so my acknowledgement of it ends here.

>>4794560

I like where you're thinking with this, but one thing I haven't seen any mention of here is how a portal is created. In order to make space-time join two either distantly related or completely unrelated parts of space-time you would require a massive amount of negative energy.

Simply put, any positive energy (which is most of our universe by an unimaginable majority) has a positive gravitational effect. To make a hole in it is somewhat (although this analogy falls much short) like trying to dig a hole in the very loose, watery sand along a shoreline. Since our universe is made of, for all intents and purposes, positive matter, in order to make a portal and keep it open, it would require a rather large amount of negative energy.

Then there are also the quantum gravitational effects to think about. Seeing as there's really no unifying theory between QCD and General Relativity (or rather, there is no ONE theory, just a jumble of competing theories with related equations) there are lot of questions still not answered. This is normally not a problem in problems of much lower concentrations of energy, but as the physics dictates, there can be a lot of random things that happen. If the boundary between the two space-times is "jagged", there can be a high amount of quantum randomness from the highly discontinuous border. However, if it is "smooth" or roughly parallel, then the hula hoop analogy might actually hold.

TL;DR God most definitely rolls the d20 on this one

the easiest solution is to imagine you are the portal.

The portal moving is the same as the object moving into the portal.

The momentum of the object relative to the portal (not whatever other refrence you want) is always conserved, thus it shoots out of the other end.

OP here. I'm only going to sage because I'm not actually contributing to the discussion, but simply commenting on it.

I just want to say that I'm still reading replies, but I'm disappointed that you people are so obviously failing to understand each other. Just talking past each other without actually understanding each other's arguments. I know this question represents a paradox, if you follow the actual laws of physics, since portals don't exist at all, but I hate to see you guys repeatedly using the "hula hoop" example after it has been pointed out numerous times that the analogy doesn't work because one side of a hula hoop cannot move with respect to the other. Stop it.

>how is it not in this case, OP specifically states

No. he does not state that. He asks if we can agree given (assuming) the fictional laws of physics in the game. The laws of physics of the game are not an explicitly stated assumption for this problem in the picture.

Also, cool non-sequitur, bro still stands. Nonsense does not lead to a definitive conclusion.

>>4794751

"I'm going to say that everyone here is wrong without actually comprehending a damn thing that anyone has said, then do the same exact thing.

Boy, aren't I right!"

>>4794746
>require a massive amount of negative energy.

stopped right there.

I hate these threads so I'm going to use a dumbed down analogy to appease everyone who is stupid enough to think it's B. Imagine you're standing in a room, in front of you is a wall and on the other side is a another room. You fire the orange portal on one side of the wall and the blue one on the other. The wall moves towards you at whatever speed you want, you go through the portal and guess what? You're standing fucking still on the other side of the wall, you were not launched at the speed of the portal, there is no fucking movement.

>>4794757
go out and get the game, play it. assuming you are intelligent enough to do so, devise a simple method for testing whether or not the distance between portal a and portal b is always constant.

>>4794760

"B-b-bu-but you're wrong, retard!" are what these threads basically boil down to.

No one actually agrees on an answer and overly thinks these scenarios way too often to the point when we are contradicting ourselves with each post.

In other words, monkeys in a cage flinging bullshit at each other: The Thread.

>>4794760
Actually, you're not, The portal moved to you. let's say it's at a speed of "one human width" per second

That means at .1 seconds, 10% of you has moved through the portal. At .5, you're 50% the way through the stationary portal. At .9, you're 90% the way.

Can you see that in order to move through a stationary portal, you must be moving with respect to that portal? Infact, when you exit the portal, you're moving at "one human width" per second.

>>4794743
Actually, you do leave it out because it doesn't effect you.

The reason why you factor rotation of the earth in projectiles is because the rotation of the earth is not constant velocity. There is centripetal acceleration. So if there is any other CURVED MOVEMENT in the universe that I'm not thinking of, like how we are rotating in the galaxy or something, then yeah, sure, regard that too. But constant velocity does NOT effect us. Let's say, the entire universe was actually moving 5m/s in a certain direction this whole time without anybody knowing it, it wouldn't matter for anything. Nothing would be any different than if it were stationary. But anyway, again, you could say that the universe is stationary or that it is moving a million miles per hour, and you wouldn't be wrong either way. It is not a fact if something is moving or not! You can only say something is moving relative to something else!

Imagine you are floating in empty black space. You see a ball in front of you. It moves towards you. Would there really be any way to tell if you are moving towards it, or it is moving towards you? No, there's no way. Exactly.

Are you really trying to deny Galileo's principle of relativity? Are you really trying to deny one of the most basic and fundamental laws of physics?

>>4794760

No real life example or dumbed down analogy represents the problem in the picture, that is why so many people are having problems with it. The situation in the picture cannot be replicated in real life. In your example, the in and out portals are not moving relative to each other. In the picture, they are. This is significant to the problem.

>>4794767
The galaxies moves, the solar system moves, the earth orbits the sun and the gravity of the sun/moon/other objects is applied differently to the person then to the earth as a whole, look at tides for an example of that.

Sounds like you are the one who doesn't understand physics.

>>4794768
>>4794767
>>4794760


See

>>4794766

>>4794765

Are we able to agree that something like OP's pic cant be tested? If so, we have nothing further to discuss. If not, we are at am impasse.

>>4794774

Yes, the situation is a paradox. But no one will agree on that since one of us has to be correct about a concept that we're not even capable of theorizing.

>>4794760
>>4794760
Wow, way to read the thread before you post.

First of all, if you've studied physics at all, you'd know that things often defy intuition.

Second of all, read this:
>>4794581
and if you're still having doubts, try this
>>4794629

>>4794768
quite frankly I imagine /v/ came to the conclusion A.(correctly) due to the experience they had with actually playing the game. then OP either wanted to troll /sci/ (successfully), or felt retarded because he thought it was B. and wanted to get that answer form somebody to make himself feel better.

>>4794785
you are aware this image is old shit and probably been posted here 100 times?

>>4794788
Yes I am.

TO EVERYONE WHO"S SAYING IT"S A PARADOX:

how is it a paradox?

Just because portal's cant exist doesn't mean it's a paradox

and just because we can't agree on an answer doesn't mean it's a paradox. We never agree on anything anyway

>>4794629
>how long will the orange half have enough gravity holding it down such that the object is able to maintain a relative upright position (perpendicular to the blue portal surface)?

>>4794785

This concept has been posted on every board nearly, sometimes altered for further arguments that spanned until the post count.

The thing is that nobody is wrong and nobody is right. Yes, people are misunderstanding the rules of physics here. Yes, this is an impossible situation to replicate.

I'd appreciate it if we could at least mindlessly argue about something productive, like why most of the other boards have begun flooding over to /sci/ with their ancient troll threads.

>>4794773
>The galaxies moves, the solar system moves, the earth orbits the sun

so?

>he gravity of the sun/moon/other objects is applied differently to the person then to the earth as a whole, look at tides for an example of that.

how are they applied differently and how are tides an example of that?

Plus what does that have to do with anything?

Now you're just stating random things without explaining them

You know what's the best way to test this? Boot up Portal 2 and make it. There, problem solved.

>>4794800
>how are they applied differently and how are tides an example of that?

da fuq are you serious about this?

>>4794803
yes. Explain

>>4794801
do it

>>4794791
>>4794791
>>4794791
>>4794791
>>4794791
>>4794791
>>4794791
>>4794791
>>4794791
>>4794791
>>4794791

>>4794785

OP here, I didn't create the image and there's no evidence in the game to suggest that A is the correct answer since the game only has moving portals in "scripted" sequences which don't resemble the pictured scenario.

I also don't see what's so "retarded" about option B, since, like I said before:

Initially, the cube is moving with respect to the orange portal.
At the end, the cube is moving with respect to the blue portal.

To me, this seems consistent with what we do know about the portals shown in the game. Please don't reply to this telling me that the cube is not moving at the beginning; I wrote that it moves with respect to the orange portal, and that is correct.

Yes, the cube is initially stationary with respect to the room itself, and this might suggest that it should be stationary with respect to the room at the end. However, in the game, momentum is conserved with respect to the portals, not with respect to the room. We know this because an object passing through two portals will often "change direction" in the eyes of an outside observer. In other words, the momentum with respect to the room is not conserved. But if that observer jumps through the portals himself, he feels no change in direction. From this you might conclude that momentum is conserved with respect to the portals.

I'm not dumb enough to think there's a real "right answer" here, and I completely understand the arguments in favor of A, but B makes sense to me. That's my opinion. If you think my reasoning is "retarded" then you probably need to work on your reading comprehension.

>>4794805
http://en.wikipedia.org/wiki/Tide

Tidal phenomena are not limited to the oceans, but can occur in other systems whenever a gravitational field that varies in time and space is present. For example, the solid part of the Earth is affected by tides, though this is not as easily seen as the water tidal movements.

The tidal force produced by a massive object (Moon, hereafter) on a small particle located on or in an extensive body (Earth, hereafter) is the vector difference between the gravitational force exerted by the Moon on the particle, and the gravitational force that would be exerted on the particle if it were located at the Earth's center of mass.

>>4794801

Portals can't move in Portal. The engine isn't built for that apparently.

>>4794791
see
>>4794487

>>4794810
why can't there be a right answer? Just because they don't exist irl doesn't mean there can't be an answer

>>4794801
http://www.youtube.com/watch?v=S85nudR6D-Y

>>4794810

That's great. I like that you're actually trying to reason with the situation at hand, but nobody is going to agree if that's what you're expecting.

"To me, this seems consistent with what we do know about the portals shown in the GAME. Please don't reply to this telling me that the cube is not moving at the beginning; I wrote that it moves with respect to the orange portal, and that is correct."

That's the issue, it's a GAME, a simulation on an engine designed for video games! This is like seeing somebody walking around in space on television before 1957 and then arguing to everyone about how this is actually possible. We only end up trying to explain our beliefs while completely becoming detached from reality and anything sensible.

>>4794822
So basically even the guys at portal hq don't know what happens or don't have the physics know-how to put into the game for this scenario. great

>>4794838
In the game, there never exist two portals which are moving with respect to eachother. So, who the fuck cares? The concept of a moving portal is not defined in the context of the game.

We can jerk eachother off and make shit up all we want, but it's pointless because classical physics does not have an answer and the game does not have an answer, so there is no answer you can give which is consistent with any observations at all.

This conversation really is totally pointless. There is no answer that can be consistently correct without additional assumptions that are not present in reality or the game.

>>4794810
lets break this down.

>/sci/ is probably smarter than /v/
>Can we just agree that scenario B is more logical
>I'm not even trolling.

So, You think the answer is B.
You also think that /sci/ is smarter the /v/ whatever that means.
which of course leads us to believe that the answer you received from /v/ was to you unsatisfactory meaning it was contrary to your own personal beliefs making their answer A.
and last but not least you are "not even trolling" which leads us to believe that you are trolling.

I didnt suggest that you are retarded, I suggested that you either are trolling or felt retarded for coming to a conclusion that was contrary to the "video game experts" opinions

>>4794845

>/sci/ is probably smarter than /v/

We're not a hivemind, asshole.

>>4794849
Tell it to OP dumbass

>>4794861

He has likely read it. Also, do I sense a bit of hostility?

>>4794864
no hostility, just some irritability I suppose. I assumed he was calling me the asshole, that is how it seemed to me.

>>4794871

That was me, I'm sorry if I offended you.

>>4794876
it is quite alright. apparently emotions run high on /sci/ when it comes to hypothetical arguments regarding video games.

The question, as posed, is a paradox. Niether answer can be correct without positing new laws of physics on top of the big problem you already have with allowing portals to exist. The solution to the paradox is that portals should not be permitted to move relative to one another. They can both move together with exactly the same velocity as if they were locked together. In that case the situation in the original problem isn't even allowed.

>>4794885
But you can test and verify that the distance between portal a and portal b is always constant. due to this the portals moving relative to each other is not a problem, it will not effect how they act.

This is at the very least my personal opinion on the matter.

>>4794845

I haven't seen this discussion on /v/ in a while. I only remember that they couldn't agree on anything. Obviously, we can't either; that's what I was expecting.

So yes, although I did hope that some of you would agree with me (and some of you did), I was trying to start a debate. The whole "can we just agree" thing wasn't serious, because I knew there would be disagreement. But I wasn't trolling in the sense that I'm only here to make people mad. If this thread makes you mad, that's unfortunate. I think it's an interesting thing to discuss, as long as people don't resort to ad hominem attacks.

I think the major confusion here is that we simply don't have this technology. We don't HAVE portals. We dont know HOW they work, or WHAT they will do in this scenario. The only correct way for this to be *truly* answered is to simply look at the games own physic engine and base the answer off that. Since the game doesnt even allow portals on moving objects, the answer is simply nothing. Nothing would happen because its not possible. It's an incredible paradox.

>>4794889
i think its more of a coordination problem.

didn't we have this fucking thread last week?

>>4794888
I'm not clear on what you are saying. Perhaps indicate on the rod version of the problem what you are talking about.

>>4794943
in the game portal you can very easily demonstrate that regardless of how far apart the two portals are placed, there is no distance between them hence why I say that the distance between portal a and portal b is constant.

people are claiming that this becomes paradoxical because the game does not account for portals moving relative to each other, but we can safely assume that the distance between portal a and portal b would still be constant

>>4794972
I'm still confused at what you are getting at. Indicate on the diagram to clarify.

If you measure a distance between two points through the portal, yes it is always constant. For portals to be consistent all paths must be invariant, not just the paths through the portal.

>>4795072
No