/sci/ - Science & Math

>>10763245
>using physics to solve an unphysical problem
Reminder that A is what actually happens in the source engine. Experiment trumps pontification.

>>10763245
I don't know why he said this is not a paradox.
Because... paradox is not always about inconsistency; even Vsauce2 covered about this subject. I guess it is because that is quite a philosophical subject, and someone dealing with this(such as Quine) did not a phenomenal job on defining it. I prefer late wittgenstein's family resemblance on rule of paradox.

Remember when it was /sci/ - Portals and every thread was bound to get 250 replies?

>>10763245
It's A, and i can prove it, go grab a glass or bowl, put something small on a table, then slam the glass or bowl over the object, BAM, the object doesnt shoot straight up through your hand.

>>10763245
IT'S A VIDEO GAME IT DOESN'T APPLY TO REAL LIFE PHYSICS IN ANY WAY

Anyone who unironically says A needs to get off this board because it's 18+.

>>10764027
Now duct tape your bowl to the wall and throw something at it. Holy shit, it doesn't teleport in space? That's because a glass bowl doesn't model a portal.

>>10764091
You're being intentionally retarded, and thats dissapointing. A portal isnt a physical object, its a wormhole, and wormholes down enforce mass on anything going through them, this is why the bowl serves the purpose you stupid asshole, the bowls rim is the portal, drop the bowl from the top of the sears tower onto a grape, the grape wont shot upwards no matter how much you want it.

Have B retards even played Portal? From experiencing the game you know it's A

>>10764101
>bowel suddenly stops when it hits the table
yeah sure that's a great model

portal 2 is on sale right now on stream for 1 buck btw.

>>10763245
It literally is A though

If it's only traveling 3mph
And gravitational acceleration is 100m/s/s
And the cube has a density of 0.01% that of granite
And the cube is 100cm x 100cm x 100cm

>>10763330
It's not a paradox you absolute moronic fucktard. Literally leave /sci/ and never come back. Fuck, you are an incompetent retard. This is not even REMOTELY similar to a paradox. It is just a regular fucking physics problem. You are the most fucktarded person on this entire board, actually on all of 4chan, probably in the entire world, retard.

>>10763245
>>10763245
I just KNEW there was gonna be a thread about this

finally, I've got a moderately influential e-celeb backing me up on /sci/

>>10764091
>Anyone who unironically says A needs to get off this board because it's 18+.
see >>10764259
:^)

>>10763245
A violates the inertial frame of reference of the portals.
B violates conservation of energy.
Supposing that both conservation of energy and inertial frame of references hold true, it's unsolvable.

>>10764287
A violates conservation of energy too.

>>10764302
A already doesn't make sense for the simple reason that a non-moving cube would never leave the portal. But it doesn't violate conservation of energy for the simple reason that there is only one room and the portals simply connect non-adjacent parts of it.

>>10763245

I never understood this. Imagine instead of the top portal you just had a large cylinder coming down at speed towards the motionless cube + motionless platform.
When the cylinder hits the bottom platform, does the cube magically jump up? Of course not.
Now imagine the portal is some "multidimensional" cylinder that ties the orange end to the blue end.
Why is it any different?

>>10764259
>A fags literally need to pull numbers out if their ass to.make some kind of """point"""
what speed was the cube travelling 0.0001 seconds before it finished going through the portal?

I solved it.
Prove me wrong.

>>10764325
>I never understood this
Yea, it's quite obvious you don't.

>>10764396
No, it's not like a large cylinder retard. Because both parts of the cylinder would move at the same speed in your scenario. When in OP's scenario, one part (attached to orange) is moving and the other part (attached to the blue) is not. And you are cunningly trying to weasel out of this fact by calling it a "magic multidimensional wormhole" or some shit. Yeah, nice try.

Listen now. Portals act on their surfaces. Orange scans, blue prints. Since yellow is scanning faster than blue is printing there is accumulation of matter on blue portal's surface causing pressure. This pressure causes force that propels it forward. Therefore it's B.

Your cylinder logic is just shit.

>>10764396
I did consider a similar model but I usually presumed that there was no such thing as space inbetween the two portals. They are just two sides of a single object. Also, how does the cube leave the orange cylinder in A? If it doesn't move, it is probably not supposed to appear at the other end by means of teleportation.

>>10764420
>scans
>prints
Sound like pretty magical non existing properties right there.

If you don't like the cylinder, just imagine this following object in the image and make h go towards 0. That's what you're looking at.

In the game h is just made into some multidimensional fancy magic shit.

>>10764439
>>scans
>>prints
>Sound like pretty magical non existing properties right there.
It's literally the only logical way portals could actually work. Everything else is quirky bullshit.

In your picture, the object doesn't even come out lmao. It's not even touching the portals!

Pic related is what you actually believe.

>>10764396
We always knew this was the case.

>>10764442
Have you ever passed a hoop through an object or thrown an object through a hoop?
Am I speaking to an abstract ayy lmao?

>>10763245
It depends on how that portal works. If it has no resistance to the transmission, than B. If it resists the transfer, then could even be A.
But A is only a special case of the second case, so A is more probable.

>>10763245
ez pz, its A. because the portal is simply a window (so to speak) and if you throw an open window at a fly (that is in flight) the fly simply remains unaffected because there was no transfer of energy (no points of contact between physical objects)

>>10764452
the faster you move your window to that fly, the faster the fly moves relatively to the other side of that very window.

>>10764449
>Have you ever passed a hoop through an object or thrown an object through a hoop?
You're being retarded again, poor Joe. Look at this image again: >>10764420

If both portals are moving, then yes it's like passing an object through a hoop and nothing happens.

But if one is moving with respect to another, then the object experiences pressure because portals act on their surfaces.

>>10764452
You very clearly have no formal education

>>10764452
This literally the hoop argument that other anon proposed. See >>10764462 and then see >>10764420.
Moving portals are like anything you've seen in real life.

>>10764267
Except he was wrong

>>10764465
then explain to me how the fuck option b is viable or how this is a paradox since you are such a fucking brainlet

>>10764478
the cube motion is RELATED to the portal.

>>10764461
Thats nice, but the surrounding environment isn't moving with the window. In the scenario the orange portal is moving relative to the cube while blue portal is stationary. Since the portal (in the game) itself is essentially a 2D plane bounded to another 2D plane, which has no interaction with the objects that cross the boundary, there is no force acted or received on/from objects. An object moving from plane O to B maintains its velocity, which, in this case is zero. The cube should actually look like an "\" upon exiting B since the O is moving "slices" which are affected upon by gravity. Each slice folows another as the slices droop towards the ground.

>>10764490
> the surrounding environment isn't moving with the window.
some of it does, some of it doesn't, but that has nothing to do with it.
>the orange portal is moving relative to the cube while blue portal is stationary
they're the one. thus if one side moves in relation to the cube. so does the other (or so does the cube towards that stationary other side)

>>10764490
>since the O is moving "slices" which are affected upon by gravity
That's neggiligible considering how fast orange piston is moving.

>>10764462
I understand what you're saying but I still think the premise of a commonplace hoop being transformed into a wormhole-like thing is more acceptable and easier to understand than the print-scan wormhole you're proposing.

The hoop model just states that the portals act like normal movement through space. As if those two surfaces where like continuous slices of space, like in a normal situation. This actually explains every behavior you observe in the game. Why wouldn't it explain the case of a moving portal as well? The fact the blue portal remains stationary on the example of the moving platforms is kind of irrelevant here. Whatever stretching of space time or whatever has to happen to allow for those portals to exist in the first place would have to ensure they behave like a commonplace hoop.

The print-scan model seems to require a ton more variables to work.

Imagine you have two static portals (orange/blue) and you pass only half the cube through them, so that you can see half out of each portal. Now you move the blue portal away from the cube with a moving platform. The print-scan model states that somehow the cube on the other side should suffer some kind of deformation/movement, and the hoop model states that nothing special should happen.

I still think the hoop is the best model.

>>10764287
this

its a classic brainlet filter, only the retards think there is an answer.

>>10764353
part of it was going 3mph and part of it was stationary faggot
protip: you literally cannot

>>10764325
frames of reference retard
>what is momentum in exit portal frame of reference
it could be A or B depending on gravitational acceleration, velocity of portal, and block's density.

>>10764503

>>10764503
how fast is orange moving then retard?
>>10764353
>implying it's wrong
>literally provides NO refutation to the post
>>10765233
absolutely
B A S E D
A
S
E
D

>>10763245
huuurr

Why must God continue allowing these threads to exist?

>>10765392
Except it's not moving relative to itself because the portal separates frames of reference, retard

>>10763245
>>10764462
>But if one is moving with respect to another
well we do not know how portals work so they might just be rifts that dynamically redefine which points in space get stitched together as they move around
(with respect to the reference frame of the machine that powers the portals, which I am going to assume is stationed on earth).

>>10765392
>I'm looking at a mirror that is moving towards me so I'm moving towards myself
lmao at ur life kiddo, photons bouncing off the block then going through the portal to your eyes or back to the block doesn't mean fuckall
the block is not moving relative to itself or to you until it passses through the portal
fuck, kids these days

>>10763267
A is correct the only want for it fly out is if the portal adds momentum. Relocate the portal to the otherside of the first portal (as if were a hola hoop) to understand that the cube couldnt possible shoot out.

>>10764264
> litterally retarded
Its not physic problem because you have incomplete information. just invent how these portal work AND the answers is different. its a mater of defining the problem rigorously.

>>10764287
B doesnt have to violate the conservation of energy if moving the portal over an object requires the same energy as moving that object.

>>10763245
Somehow I thought these threads would be less shitty on /sci/ than on /v/, but this is almost worse.

To be honest I don't really care about the answer to the original problem anymore, because it has been discussed to death, but for what it's worth, it's usually in defense of "A" that people start demonstrating their misunderstanding of the most basic principles of physics — by giving the wrong answer to this alternate problem, for example.

Last time I posted this on /v/, the result was some guy (who thought the correct answer was 7 m/s) trying to convince me that there's a difference between "true" motion and "relative" motion. He even claimed "true motion" was the motion measured relative to the Earth, as if this bitch isn't spinning and flying through space at a billion miles per hour.

>>10765416
woah wtf I think A might be correct now but I'm not sure

>>10766608
7

>>10766608

>What's the final speed of the little box.
Relative to what?
Also most of the posts in this type of thread are just posturing "I can't believe people are so dumb" with 0 content, such as yours.

>>10765984
>momentum
Shit, I just realized that this is an acceleration problem.

The answer is A because the momentum of the platform does not translate any reasonable amount of acceleration onto the object. Even if the platform is moving at incredible velocities, the total acceleration achieved will always be near-to-zero.

If both objects are in motion (as in >>10766608) then you can get a different result, but the motion of an object with zero acceleration will be more or less zero acceleration unless the portal is accelerating at the moment of translation.

TL;DR: Portals can't impart momentum, only acceleration.

(Other notable posts: >>10766014)

>>10763245

the cube materializes the same way people materialized when teleported in star trek

>>10766639
>>What's the final speed of the little box.
>Relative to what?
Are you trying to be clever? It's obviously asking for the speed of the box relative to the frame of reference in which other speeds are given. When the frame of reference of the problem has already been explicitly or implicitly defined, I shouldn't need to tell you which frame of reference to use for your answer.

>>10766629
>7
Incorrect.

In the frame of reference in which the wall moves 3 m/s to the right, the final speed of the little box is 13 m/s to the right.

This isn't even a "paradox" like the original Portal problem shown in the original post. It's just basic math.

>>10766662
Shit, this makes sense. The only reason it didn't occur to me is because I intuitively felt that the area under the blue portal is empty space, when realistically, it's a solid underneath the portal.

We can actually use this method to embed objects into closed (sealed) containers.

>>10766662
That's not how it works in the game though.

>>10765984
>muh hula hoop
The whole point of the problem is that one portal is moving with respect to the other. If you remove that aspect of the problem then it's a fundamentally different problem. Different problems have different answers.

>>10766696
The wall doesn’t increase the speed of the box

>>10766744
>The wall doesn’t increase the speed of the box
The portals don't increase the speed of the box with respect to the wall. However, in the frame of reference in which the wall is moving, the portals do effectively increase the speed of the box.

Here's a slightly better explanation of the solution in case the shitty text in the other one is what has you confused.

13 m/s is the only correct answer to >>10766608.

>>10766757
No, the final speed would still be 7m/s

>>10766757
Riddle me this, what’s the answer when the box is 0m/s and the wall is 10m/s

>>10766760
You can't just respond to mathematical proof with "No". The answer is 13 m/s.

If the answer were 7 m/s in the reference frame of the original problem, then the reference frame in which the wall is stationary would look like this.

>>10766781
20 m/s.

>>10766790
Now I know you’re trolling

>>10766793
What do you think the answer is? 0 m/s? That would put the box on the wrong side of the wall.

You literally don't understand inertial frames of reference so I'll assume you never took a physics course. Maybe you should take one.

>>10766810
Yeah, 0m/s in relation to the wall. Once it gets halfway through on both sides, the portals are moving in the same direction. The box would be trying to go through the blue portal as much as the orange portal

>>10766781
>>10766793
If you don't understand Galilean invariance then you shouldn't be on /sci/.

>>10766781
Going by >>10766662 it'd just be 10m/s because the cube gathers momentum from the movement of the wall as it transposes onto the arrival surface.

>>10766824
What happens when the box is halfway through both the blue and orange portals at rest. And then the wall starts moving at 10m/s

>>10766832
That's a good question. You're introducing acceleration of portals which is absent from the original problem, though, and making things more complicated seems counterproductive when there are still people in this thread who haven't grasped the concept of Galilean invariance.

But to answer your question, I guess the box would accelerate with the portals.

>>10766823
>Yeah, 0m/s in relation to the wall.
Here's that result in the frame of reference in which the wall is stationary.

It doesn't make sense anymore, does it?

>>10766866
No, it would be 0m/s in relation to the wall, but in relation to the ground it would be 10m/s just like >>10766832

real life:

move an object through a window frame, the object exits the window frame with the same speed it entered

move a window frame relative to an object, the object stays stationary because it entered the window frame with no speed and exited the window with no speed

what makes you think it's any different with portals

>>10766902
>No, it would be 0m/s in relation to the wall, but in relation to the ground it would be 10m/s
That's what the image shows. You really REALLY REALLY REALLY do not understand what an inertial frame of reference is, so please ACTUALLY look it up before posting again.

In that image, the ground (not shown) would be moving 10 m/s to the left.

>>10766912
>doesn’t write the ground speed
>REEEEEE YOURE JUST SUPPOSED TO ASSUME IT
top kek

>>10766922
YOU WOULDN'T HAVE TO ASSUME IT, IF YOU KNEW HOW THE FUCK INERTIAL FRAMES OF REFERENCE WORK.

I'm just going to settle this now.

>>10766902

>>10766934
No, once it comes out of the blue portal it’s going 29993 toward the blue portal, not away

>>10766941
Sorry for deleting the post to which you replied; I had pasted the wrong numbers into the top half and I've reposted the corrected version here: >>10766943

In any case, I don't know what the fuck you mean. How the fuck is the box moving toward the blue portal after it comes out of it? You think it changes direction after coming out and then goes back in? That's absurd. You never see that happen in the game.

>>10766943
it would be the same as this. the ball would indefinitely go back and fourth

>>10766964
lol

Do you understand this image? >>10766943
Do you know what it's saying?

The bottom half represents what's actually happening, in relative to the solar system, any time you throw an object into a portal placed on a wall. Have you ever, in the game, placed portals on a wall and thrown a box into one portal and watched it oscillate back and forth between them?

>>10766757
>>10766938
>>10766943
Anyone disagreeing with these is literally retarded.

What's the point of a "Science & Math" board if it's inhabited by people who can't even do basic arithmetic?

>>10765984
based ESLposter

>>10766943

>>10766760
are you
are you retarded
or has A just been bait this hole time

>>10767021
A jet doesn't move at 7 m/s. But if we pretend that your speeds are realistic, then your image is correct. The jet would come out of the exit portal backwards. However, the jet is being propelled by its jet engine so I assume it would reverse direction (or just fucking stall and crash in mid-reversal when it reaches Earth-relative 0 m/s).

>>10767028
I don't know about A or B in the original problem, but he is in fact retarded.

The correct answer to >>10766608 is 13 m/s. You can take that fact and use it to interpret >>10763245 however you like.

>>10767039
thats my entire point, it would go back in the hole

>>10767021
Given that you're responding to the image in which the portals (which are stationary on Earth) are moving 30000 m/s due to the speed of the Earth itself with respect to the solar system, I assume your image in which the portals move at 30000 m/s is also drawn in the frame of reference of the solar system.

So this is what you've just drawn, in the frame of reference of the Earth. Why is your jet flying backwards at 7 m/s?

>>10767021
Now that I look at it, the moving portal is creating a pressure wave in the atmosphere. All these answers "in principle" don't capture the reality of how energy is leaving the system in each case.

We can either assume that portals conserve something or we have to assume that any use of them violates conservation. It's a question about what's being conserved in any case.

Should we not assume that any portal of any elevation above its translation counterpart will always result in eventual discovery of the path of least resistance in the atmosphere? Even if the portals are both vertical, air should want to sink from the top one into the bottom. It's an active weather system the moment the portal forms.

>>10767052
cringe

>>10767061
>Now that I look at it, the moving portal is creating a pressure wave in the atmosphere.
Uh. What?

The image is a reply to >>10766943 in which the 30000 m/s speed is actually the speed of the Earth as it moves through the solar system. So it's also the speed of the atmosphere and there is no pressure wave.

Whoever posted >>10767021 is an idiot who drew the jet flying backwards at 7 m/s.

The attached image is what he would have drawn if he weren't an idiot.

>>10767064
You're cringing because you realized how fucking retarded you've been?

It's okay. Everyone has trouble understanding inertial frames of reference, for the first ten minutes of the first day of the most elementary physics course. It just took you a bit longer to understand the concept. You shouldn't feel bad about it because you were just born this way.

>>10766943
>>10767021
there is no difference between these two

>>10767088
You're right. They are the same thing, if you have a jet which flies at 7 m/s through the Earth's atmosphere, fucking backwards, as shown in >>10767052.

>>10767072
A moving portal will necessarily create a pressure wave. The pic was merely the trigger for my thought, not a contingent premise.

>>10767096
It will create a pressure wave if it's moving through the atmosphere. In that particular example, the portal is stationary with respect to the atmosphere. So you can see why I was confused about your post.

>>10767088
What about >>10766943 is incorrect? Please tell me.

>>10767094
no, you're changing the image. the jet is moving at 29993m/s look at the image again. I'm just replacing your box in >>10766943 with a jet moving at 29993m/s

>>10767106
explain to me why the bottom of >>10766943 is ok, but >>10767021 is wrong? It's literally the same image, except changes a box to a jet

>>10767135
The jet is facing the wrong direction! I've said it several times. Subtract 30000 from all speeds to return to the frame of reference in which the Earth is stationary, and you'll see that.

The jet facing the wrong way is the only problem, except for the fact that 7 m/s relative to the Earth is an unrealistic speed for a jet.

>>10767110
The only difference between >>10767021 and >>10767052 is that I've changed the frame of reference. Is the same as the difference between the top and bottom portions of >>10766943.

I'm really trying to be nice because I know that not everyone is educated in physics but PLEASE go and read about what the fuck an inertial frame of reference is, because if you don't understand why >>10766943 is correct then there's no basis for further discussion between us; you might as well be speaking a different language.

>>10767139
No it's not. This is taking place in space dude.
>the wall is moving 30000m/s to the RIGHT
>the plane/spaceship/USS Enterprise (NCC-1701) is moving to the right at 29993m/s to the RIGHT

>>10767156
If the jet in your image is supposed to be moving at 29993 m/s with respect to the Earth, then the jet diagram has absolutely no similarity to >>10766943 in which the box is moving at 7 m/s with respect to the Earth (and 29993 m/s with respect to the solar system in which the Earth moves).

Did you read the text in >>10766943? Did you read it? Read it. Did you read it yet? Read it. Read the text in that image. Actually, better yet, here's another with more text for you to read.

The whole point is that the bottom half is the frame of reference in which the Earth itself, and the Earth's atmosphere, move at 30000 m/s. What you're telling me is that you completely misunderstood this.

>>10767159
>supposed to be moving at 29993 m/s with respect to the Earth
no, its moving at a fixed point in space, the same as the earth

>>10767164
>moving at a fixed point in space
This is gibberish.

>>10767165
where do you get the 30000m/s for the earth?

>>10767165
just see >>10767156

>>10767171
Okay. Sure. Ignoring the fact that there is no such thing as moving with respect to a "fixed point in space", because there is no absolute frame of reference and you can't measure velocity with respect to space itself, I understand what your diagram is trying to convey. I just hope it's not an attempt to prove >>10766943 wrong because it does not.

>>10767159
literally the same thing

>>10767183
fine, moving with respect to a fixed point in space. Where do you get the 30000m/s from the earth? Use that point in space, count 30000 meters and that's the distance it travels in 1 second.
The jet, moves from the same point at 29993 meters in 1 second.

>>10767183
>I just hope it's not an attempt to prove >>10766943 wrong because it does not.
then why would the jet be moving away from the orange portal. It should be moving toward it.

>>10767185
Sir. Try to read this post in its entirety.

The image in >>10767159 represents the scenario in which there exist two portals, which are stationary with respect to the Earth, and a box, moving 7 m/s with respect to the Earth, which enters one portal and exits the other.

The bottom half of the image is exactly the same scenario as the top half, but viewed from the frame of reference of the solar system through which the Earth moves. Therefore, in the bottom half of >>10767159, the Earth and its atmosphere are also moving at 30000 m/s to the right.

If your image with the jet is equivalent to that, then your jet which moves 29993 m/s to the right is flying above an Earth moving 30000 m/s to the right, and is therefore flying through an atmosphere which is moving 30000 m/s to the right. Therefore, the jet, with respect to the Earth and to the atmosphere, would be moving at 7 m/s to the left. This result is obtained by subtracting 30000 m/s from all velocities, thereby switching back to the frame of reference in which the Earth is considered to be stationary.

If something about this confuses you, let me know and I can try to clarify it.

>>10767200
there is no earth in my drawing, there is only a rogue wall in space flying at 30000m/s

no atmosphere whatsoever. literally a cardboard box with 2 portals on it flying at 30000m/s with a flying craft moving at 29993m/s in the same direction.

>>10767200
the problem isn't that the jet goes toward the blue portal at 7m/s, its that one it passes through, the jet should be moving toward the orange portal

>>10767212
If the jet diagram is not drawn in the frame of reference in which the Earth and its atmosphere are moving at 30000 m/s to the right, then it's not the same as the bottom half of >>10767159 in which the Earth and its atmosphere are moving at 30000 m/s.

My only problem with your jet diagram at this point is that you keep saying it's equivalent to the bottom half of >>10767159 when it's not.

>>10767217
if the earth is moving 30000m/s to the right, and the wall is stationary on the earth, then the wall is moving 30000m/s to the right.

>>10767222
Yes, that's exactly what's shown in the bottom half of >>10767159 which is what I was describing. What's your point?

>>10767224
then the images depict the same exact scenario

>>10767228
Okay. Look. Can we start over? Because I think we're talking past each other. If I understand what you're saying about the jet, then the point you're trying to make is completely unrelated to the point I'm trying to make. I only started replying to you because you, perhaps out of misunderstanding, implied that my totally correct diagram was somehow incorrect.

Let's just go back to the basics.

The diagram in >>10767159 illustrates a scenario in which there is a pair of portals (which are stationary with respect to the Earth) and a box which (moving at 7 m/s with respect to the Earth) enters one portal and exits the other portal. The top portion of the image illustrates this scenario from the frame of reference in which the Earth is stationary. Can we agree that the top half of the image correctly illustrates how portals behave in the video game called Portal? Yes? Good.

Now, the bottom portion of the image conveys the fact that, if you view the Earth from the perspective of the solar system as a whole, the Earth itself is actually moving through space at (very roughly) 30000 m/s, which means that the portals are also moving at 30000 m/s in the same direction as the Earth. Before entering the portal, the box is moving left with respect to the Earth, but the Earth is moving much faster to the right with respect to the solar system, so the box is therefore moving to the right with respect to the solar system. This is why the box is shown moving to the right at 29993 m/s to the right instead of 7 m/s to the left. Numerically, in order to translate from the Earth frame to the solar-system frame, you basically just add the velocity of the Earth to all velocities.

Does that make sense? Good.

Now the diagram in >>10767156 depicts the scenario in which an obscenely fast jet is moving 29993 m/s to the right, but the portal wall is moving 30000 m/s to the right, and therefore catches up to the jet. Right? Okay. But it doesn't mean the Earth diagram is wrong.

>>10767228
I ran out of fucking characters in >>10767257.

In the jet diagram, if the portals moving at 30000 m/s caught up to the jet moving at 29993 m/s, then the jet would enter the entrance portal at a relative speed of 7 m/s, because that's how much faster the portals are moving. So yes, the jet would come out of the exit portal at a relative speed of 7 m/s, which is why it initially comes out at 30007 m/s.

If the jet is being propelled by its engines (as implied by the fire in the image) then I assume it would quickly change direction and start heading back towards the portal from which it just emerged. However, this doesn't mean the box (which doesn't have jet engines) should magically change direction in the Earth diagram.

>>10767257
>>10767271
I agree with these posts now

except for
>But it doesn't mean the Earth diagram is wrong.
I never said your earth diagram was wrong. I was asking why the plane wouldn't move back toward the portal.

but I agree with these
>which is why it initially comes out at 30007 m/s.
>If the jet is being propelled by its engines (as implied by the fire in the image) then I assume it would quickly change direction and start heading back towards the portal from which it just emerged

>>10767290
>wouldn't move back toward the portal
It would because it can use its rockets to accelerate. If it doesn't change thrust, no acceleration occurs and >>10767257
>>10767271
Stop being a faggot. You were the only one talking past anyone. When you elevate the level of dialogue, do so. Don't just repeat it and let the dialogue stagnate.

We should have started talking about acceleration 20 posts ago.

>>10767301
based

>applying physical equations to a problem that involves imaginary physics

2019 and we're still talking about this this shit?

>>10764016
The pic is so accurate it hurts. [B is unironically correct for the record)

>>10767301
>You were the only one talking past anyone.
That wasn't my intention at all.

I posted >>10766943, and defended it. People kept replying to my defenses of it with "what about ________?" and other things that implied >>10766943 was wrong, so I kept defending it. It's correct, by the way.

>>10767474
>wasn't my intent
I know your intent. Your intent stops mattering the moment you're talking past someone, because the intent ends up meaning nothing in that case.

Here, you THOUGHT others were implying you were wrong, but it was just one anon, and they weren't implying that. They were asking a question, and you eventually answered (on accident). It was painful for me to watch, and I have only the slimmest of justifications for why I let it play out the way it did despite my intense understanding of exactly what each party was misunderstanding about the other party's intended meaning.

>>10764016
>you can absolutely use intuition, yours is just shit
lost

>MUH HOOPS
>MUH DOORFRAME
STOP REPLYING TO A-FAGS THEY ARE LITERALLY TROLLING.

>>10766757
I don't get it.
Like, I understand you managed the final solution by applying a different frame, but how does that one make sense?
I imagine that the box enters the orange portal, and since the orange portal is moving towards it then it gains extra speed. But shouldn't that speed be only 3m/s? Where is the extra 3 coming from?

>>10765398
The portals connect the 2 frames of reference seamlessly

>>10767521
>you THOUGHT others were implying you were wrong
That was part of it.

The other part of it, actually, was that the other person was claiming that (explicitly, not just implying) that >>10766943 and >>10767021 are the "same thing" (see >>10767185), which is not the case. If the diagram with the jet were the "same thing" as the diagram with the little box, then the jet diagram would be depicting a frame of reference in which the Earth and its atmosphere are moving 30000 m/s to the right along with the portals, which would mean that the jet is flying, with respect to the Earth, 7 m/s backwards. If that's not what the jet diagram was meant to show, then it's not the same as the diagram with the little cube.

A shitload of what I wrote in this thread was just trying to make that totally point, and I was being met with disagreement because the other guy didn't understand the point I was making. I wasn't trying to say his jet had to be moving backwards; I was saying it would be moving backwards if his diagram were truly analogous to the one I had originally posted.

>>10766909
The relative velocity between the two openings of the window is 0, while for portals this doesn't need to be true

>>10767521
>you THOUGHT others were implying you were wrong
That was part of it.

The other part of it, actually, was that the other person was claiming (explicitly, not just implying) that >>10766943 (You) and >>10767021 are the "same thing" (see >>10767185), which is not the case. If the diagram with the jet were the "same thing" as the diagram with the little box, then the jet diagram would be depicting a frame of reference in which the Earth and its atmosphere are moving 30000 m/s to the right along with the portals, which would mean that the jet is flying, with respect to the Earth, 7 m/s backwards. If that's not what the jet diagram was meant to show -- and it's obviously not -- then it's not the same as the diagram with the little box.

A shitload of what I wrote in this thread was just trying to make that totally valid point, and I was being met with disagreement because the other guy didn't understand the point I was making. I wasn't trying to say his jet had to be moving backwards; I was saying it would be moving backwards if his diagram were truly analogous to the one I had originally posted.

>>10767561
Both the top and the bottom portal are moving. It would lead to acceleration post-reference-frame, if we knew how acceleration worked.

>>10763245
What a dumb retard. Did the nu-male youtuber fail basic physisc? Its obviously A. Frame of reference only matters when there's two solid object. A portal is not a solid object its a vacuum, thus the direct frame of reference isn't available, so the global frame of reference is of 0 m/s for the cube.

>>10767593
Literally nobody gives a shit how accurate your analogy is. This is a thread about portal physics, not relativistic wormholes. You're (still) beating a dead horse, that you killed, so you could beat it.

>>10767561
Don't think of it as the portals adding speed to the box.

It's just this: The speed going in, relative to the entrance portal, must be equal to the speed going out, relative to the exit portal. That's just how portals need to work, if portal interactions are to make sense in every inertial frame of reference.

If the portals are moving 3 m/s to the right and the box is moving 7 m/s to the left, then the relative speed with which the box enters the orange portal is 10 m/s, and so it must exit the blue portal with a relative speed of 10 m/s, which means it's going 10 m/s faster than the blue portal, which means it's going 13 m/s to the right.

It really is just "speedy thing goes in, speedy thing comes out" generalized to work in every inertial frame of reference.

>>10767605
what about in this situation, if the portals come down on the cube at 10m/s, will the cube jump up at 10m/s or will it act like a hula hoop?

>>10767605
>>10767636
This is why I've been telling you fuckers to start factoring in acceleration, because the acceleration due to gravity is the main factor in determining how portals actually interact and if conservation laws can mean anything in a portal world.

>>10767643
SO WHATS THE ANSWER

>>10767636

Take the rule stated in my previous post (>>10767605):
>The speed going in, relative to the entrance portal, must be equal to the speed going out, relative to the exit portal.
Now apply it here.

The cube's speed going in, relative to the entrance portal, is 10 m/s. The cube's speed going out must then be 10 m/s with respect to the exit portal.

Like the entrance portal, the exit portal is moving 10 m/s downwards relative to the ground. Therefore, an exit speed of 10 m/s with respect to the upward-facing exit portal is actually 0 m/s with respect to the ground. In other words, the cube basically remains stationary. So yes, when you put two portals on opposites sides of a platform, it basically acts as a "hula hoop" or a simple window. This is the simplest possible problem involving portals, though, so it's not very interesting.

If you want to have fun, take what I said in my previous post again:
>The speed going in, relative to the entrance portal, must be equal to the speed going out, relative to the exit portal.
Now apply it to the problem in the original post, assuming the orange portal's downward speed with respect to the ground is 10 m/s.

The cube's speed going in, relative to the entrance portal, is 10 m/s. The cube's speed going out must then be 10 m/s with respect to the exit portal.

But the exit portal is stationary with respect to the ground, this time. Therefore, an exit speed of 10 m/s with respect to the diagonally-facing exit portal is actually 10 m/s with respect to the ground.

This result is a bit counter-intuitive, which is why the original problem is controversial. However, as I explained in my previous post, the only way for portal interactions to make sense in every inertial frame of reference is for this rule to be true:
>The speed going in, relative to the entrance portal, must be equal to the speed going out, relative to the exit portal.

>>10767685
so the answer actually is B?

>>10767692
Anon's just BS'ing about inertial reference frames because they don't know how to calculate the transit of acceleration. Yes, the instantaneous velocity upon completion of the apparatus is 10m/s, but without acceleration we have no way of knowing how long it will remain in at that velocity.

>>10767692
Well, that's one possible argument in favor of B.

>>10767715
>just BS'ing
Find a specific flaw in my argument or you have no argument.

>>10767653
>>10767692
Depends on gravitational acceleration, velocity of portal, and density of block. The 'correct' answer is B, but it would be A given great enough gravitational acceleration, slow enough velocity of portal, and great enough density of block.

>>10767536

>WAAAH STOP REPLYING TO A-FAGS, THEY ARE RIGHT.

>>10767584
they also separate them

>>10767604
Yes a thread about portal physics which is a discipline that does not exist. In the game which is the only place portals do exist the answer is A. If you tried to apply this to real life then you would have to make an entirely new field of science math by inventing portals. This is all good food for thought and a fun way for people to apply their real knowledge to a hypothetical experiment but people getting nasty about it is ridiculous.

There is currently no answer that can be applied to our natural world because portals do not exist in it. This is the only true answer. You can have fun thinking about it, but remember you are arguing about a phenomenon that there is absolutely no reference for or literature about in physics.

Sigh

imma post this once again in hopes that someone replays me with a liger answer. Please bare with me.

If you are standing there n a long hallway and at the end of that hallway is a huge piston pointing at you with a portal on it. You can see through it to the other side of the world there someone else is stand. There portal is fixed on a wall....

Ok....So the piston turns on and starts coming at you at 50mph...You see this as the portal and everything on the other end of it coming at you at 50mph...The whole universe is coming at you at that speed on that end. On the other end where the other person is standing looking at there portal on the wall they see you and everything on your end coming at them at 50 mph.

Since the piston stops at the base as one would assume in OP pic, then wouldn’t just a quick hope right as it passes you would just fine?

Let’s say you are being held over a huge moving treadmill moving at 50mph. The second they drop you the treadmill stops so your ok. Same idea.

The only way this works is if the two ends are from different dimensions. otherwise you would have one Whole universe coming at each other from different angles which makes no sense (I mean neither does any of this)

Portal gun is a dimensional hopper and every time you jumps it’s just to a completely different universe basically the same as the one you left.

This is my head canon and you can’t change my mind.

>>10767775
>If you tried to apply this to real life then you would have to make an entirely new field of science math by inventing portals

The math for portals already exists dummy.

>>10764027
This. You'd have to be a retard to believe in B.

>>10764027
>>10767842
This is just the "hula hoop" analogy again.

>>10763245
In before, during, and after retards assume there exists a privileged reference frame and/or an "absolute" velocity.

None of you fags have ever taken a real physics course in your lives.

>>10767877
> Wrong
Drop a hoop over an object. Both ends are moving. But on the completion both ends its not moving. When both ends are not moving it has the properties of the initial portal. When both ends are not moving it has the propeties of the second portal. The cube may appears to shoot out because of its relative velocity but never does. The portals impart no momentum. A point a and point B it has the same characteristics as the experiment.

>>10767910
>believing there is NOT a privileged frame of reference
>not believing in the ether
>believing in Einsteinian relativity
You just went full retard. Even Einstein himself admitted later in life that absolute relativity is false and that the ether exists.

>>10767956
> source: your ass

>>10767973
Try reading an Einstein biography and you'll know what I am right, retard. Pic related literally explicitly says that later in life Einstein returned to believing in the ether.

>>10767939
So the only reason B is wrong is that the orange portal stops?

If the pedestal on which the cube stands isn't there, and the cube is just floating below the orange portal because there is no gravity, and the orange portal eats the cube and keeps going, then does the cube shoot out of the blue portal?

>>10767939
>avatar fags

a tards will never be able to explain how a stationary cube exits a stationary portal

>>10764396
This hypothetical cylinder has a height of 0 and the cube moves relative to it. Thanks for proving (once again) that it is B.

>>10764016
dumbass

>>10764420
Nice inventing of portal science, dickhead. And you're arrogant about it as well. kys

>>10770645
>>10770668
you talk like a fag and should return to reddit immediately.

>>10763245
You're all wrong

>>10763245
/sci/ is literally brainlets

Wait guys I have been B all my life but now I thought about it as 2 sections of the room instantly connecting.with each other and now I Think it's A

WAIT I HAVE FIGURED IT OUT GUYS I KNOW THE SOURCE OF THE ARGUEMENT.

>If you believe that the portals simply connect two parts of the room that were not connected before you think the answer is A
>If you think the portal teleports infinitely many 2d slices of the object than you should support opinion B.

>>10764287
What conservation of energy? I think you should pass high school physics before discussing this problem. That's assuming there's no outside potential acting on the cube. Doesn't having a fucking portal nearby cause some kind of interaction that potentially makes conservation of energy not a required law?

Your argument for A makes sense because that's the definition of a portal, momentum has to be conserved, plus there's the more physical wormholes, otherwise it could be A as well

Continuation of
>>10771742

If you drop down a demension and think of portals as two 1d objects on the edges of a 2d surface. then bend the surface into the third demension in order to connect the two points. you then squish the surface so that another random spot on the edge slams into the a side of the portal. This connects the end of the other portal to the edge of the sphere. Using that simplification that the argument in my previous post was correct.

>>10771742
good thinking.