What happens, /sci/?

>>9076294
B, Einstein. This thread is over.

>>9076294
A obviously.

File: 1501252398751.jpg (127KB, 1080x1080px) Image search: [Google]

127KB, 1080x1080px

>>9076296
This.

>>9076294
momentum is not conserved under either scenario, exposing the flawed nature of the question. Neither is correct because portals, if they exist, cant have entrances and exists that move relative to one another.

>>9076296
Why?

>>9076301
Portals don't conserve momentum anyway, so that can't be used to evaluate either option.

>>9076305
>Portals don't conserve momentum anyway

take this shit to /vg then since you're not interested in the /sci of it

>>9076323
many physical systems don't obey conservation of momentum, anon

File: dortal.png (9KB, 587x485px) Image search: [Google]

9KB, 587x485px

>>9076323
>implying portals conserve momentum

A. Work is defined as the amount of force necessary to move an object a distance of D. Work = Fd = mad

There isn't any mass acting upon the block thus it moves a distance of zero. Once it pops out of the portal, because the portal acts as a massless object (otherwise it would push the block) the force of gravity causes it to descend, and it can't go back into the portal due to the platform preventing it from doing so.

Due to there being zero work done on the object. it descends due to g and the platform being there in the portal's mechanisms, thus A, it descends at an angle.

>>9076342
No work is done on the object, thus it propels at a distance of 0. A IS THE CORRECT ANSWER GWAH

>>9076340
they also must be oriented spatially the same direction

>>9076342
>>9076345
Energy isn't conserved, so you can't conclude that it doesn't move just because no work is performed on it.

>>9076301
If portals existm, you can see both rooms via your own sight and through the protal. Both rooms are in the reference frame. If the portal exists as a tube, then the propelling force is added to the portal's velocity, the velocity of the portal gets added to the acceleration of the portal's movement, meaning it would propel at v + a. If there is no tube, then it's only v of the portal's descension, at which point it stops descending, v becomes 0, thus A, it doesn't accelerate against gravity because a = 0.

Depends on if portals are tubular or not.

>>9076348
If it isn't conserved then v become zero as the portal's descension becomes zero. A

Just look at it from the reference frame of the orange portal. That should make it obvious that the answer is B, unless portals absolutely destroy our current understanding of all physics.

>>9076362
>unless portals absolutely destroy our current understanding of all physics.

they do.

>>9076362
I agree with this. Unless there's a tube between the portals the answer is A. If there's a tube joining both reference frames, the answer is B. The latter following conventional physics, so B unless there;s no tube between the two portals, in which case, A's correct due to W = mad.

Shouldn't there be very strong tidal forces acting on the cube as it passes through the portal? The top part is trying to fly off, and the bottom part wants to stay still.

>>9076369
A because of 0 f, and there'd be zero distance i n the case of the portals being like a coin. There' however, would be distance if there's a tube between the portals, where the constant velocity of the portal's tube would be added to the acceleration of the orange portal's descension, making it propel.

So, are the portals connected via a tube, or not?

In reality they would have to be, thus B, becuase there'd be a constant velocity of v between the portals' openings.

Realistically, B. Only B. Like a wormhole

>>9076372
I'm drunk, so try to excuse my grammatical errors.

>>9076362
And from an inertial reference frame the cube will have both no velocity & some velocity when it is partially through the portal, which is impossible.

>>9076376
Unless there's a tube between them with a constant velocity of v. In which case, a is conserved.

>>9076380
Because the force of the object, would be ma, the mass accelerating through the portal at the rate of it's descension. Thus that a would be conserved through the constant velocity v of the portal. Does that make sense?

>>9076380
what do you mean by "tube"

>>9076386
I'm so drunk forgive me high IQ

>>9076387
I mean a tube enveloping all space between portals A and B. A tube enveloping ALL the space between portals A and B with an instantaneous velocity of v.

>>9076391
I don't understand, could you draw a diagram illustrating what you mean?

>>9076391
Or a constant gravitational pull of a, which wou;d add to the a of the portal's descension creating a1 + a2, meaning it'd fly out. Again, drunk but if there's gravitational acceleration of a in the portal's tube, the a's' d add up.

>>9076395
If there's a tube between A and B, there's a gravitational acceleration of a betweenm the portals. The acceleration of the portal's descension, a2, would add the acceleration from the tube's a1. creating an acceleration which would, effectively, propel the cube due to a2. Do you get it or not, because I am drunk lol

>>9076404
Basically a1 + a2 = overall a. There'd be an acceleration out of the portal due to overall a. If it's higher than the acceleration of g, it'd propel diagonally out of the portal.

>>9076411
If it's not higher than g, then it'd spurt to the bottom as per option A. How fast is the orange portal moving? Is what we need

>>9076404
What kind of "tube"? I still have absolutely no idea what you're talking about. Draw a picture.

>>9076440
It's going in at a rate of a1, a2 is the tube's acceleration, although can be substituted for vp, velocity of the portal. If a1 + vp > g, then the portal accelerates diagonally out of P assuming P has a g dragging the object at a constant velocity vp.The tube's acceleration = vp, a constant velocity with an accleration getting the object to VP. A is conserved in the tube of VP, meaning VP + A. From the reference frame of portal orange, of coursee

File: Untitled.png (17KB, 960x540px) Image search: [Google]

17KB, 960x540px

>>9076440
Forgot the picture, please forgive me and add to the previous post

File: Untitled.png (20KB, 960x540px) Image search: [Google]

20KB, 960x540px

>>9076461

B. Because physics has no preference for frame of reference, and from the point of view of the piston moving downwards, it looks like its the platform shooting upwards.

_____ _____
V
=
______ __^__

The problem is ill-posed; the portals obviously shouldn't be able to move in relation to each other.

File: Frame of reference.jpg (26KB, 1024x768px) Image search: [Google]

26KB, 1024x768px

>>9076556
I was trying to demonstrate with ASCII art, but apparently 4chan gets red of extra spaces, so I drew it instead.

>>9076568
except in B, the box has no kinetic energy, and then it goes through the portal all of a sudden it does. the portals dont do work. B is not possible.

>>9076574
It has kinetic energy relative to the orange portal though

>>9076583
only in the Z direction. when it comes out the other portal it has energy in the x,y, and z directions. something would have to to exert a force to change the momentum

>>9076583
No it doesn't because the object isn't moving. DOES the portal have mass? No, it doesn't; elsewise it would move the cube. No work is done, because the portal has a mass of 0. Work being defined as the amount of force necessary to move an object the distance of d, there is no mass, meaning no force, meaning no distance. The answer is A. No force is propelling the cube a diagonal Acceleration of A.

>>9076599
But the cube is moving relative to the orange portal

>>9076599
No force force is propelling the cube at a diagonal acceleration of A. There's no mass, meaning no force to propel the cube at any distance. The answer is A.

>>9076601
True but there's no mass = no work to MOVE the cube. The object pops up relative to it's location in the first frame. Which is STATIONARY. There's no V giving it momentum (mv) once the portal stops moving, giving it a mass of zero AND a velocity of zero. The momentum, p, of the cube is zero is ZERO due to the velocity of the propellant factor helping zero ONCE the ORANGE PORTAL stops moving. The P Is ZERO once the orange portal stops moving, meaning the object, whose velocity is contingent upon the portal's velocity, IS GOING NOWHERE. IT'S STUCK. IT SLIDES BECAUSE OF G AND THE ANTAGONIZING FORCE OF THE PLATFORM. THE OBJECT WILL, I REPEAT, WILL SLIDE DUE TO THOSE FACTORS. A

>>9076605
THERE'S NO FORCE, MEANING NO WORK, MEABING NO MOTION OF THE OBJECT. A

>>9076622
Work is DEFINED as the amount of force, F, to move an object a distance of d. Of the portal has NO MASS, F = ma, then there is NO FORCE, propelling the object. The answer is A!!

>>9076629
>Work is DEFINED as the amount of force, F, to move an object a distance of d
that's not actually how work is defined.
Work is the energy imparted on an object by some force F, through some distance D.
Answer is A, but you're making us look bad m8

Another easy way to see why its B is because the laws of classical physics should be time symmetric. If A was true then in reverse the portal would suck in the block as it was flying up passed the blue portal.

>>9076642
Alright, sorry. But unless there's a tube with a W of x involved, the answer is A.

>>9076647
>Newton's law of universal gravitation states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

So EVEN IF the blue portal had a mass of X propelling the object CUBE towards it, the acceleration given by portal ORANGE, would become ZERO, after the end of the orange portal's desecension. Meaning no force propelling the CUBE... AWAY from portal blue, meaning NO DIAGONAL, OR OPPOSITIONAL FORCE

>>9076645
>If A was true then in reverse the portal would suck in the block as it was flying up passed the blue portal.
ayy lmao

>>9076645
But B would sick it in, meaning force necessary to propel it away from the force of B. THERE'S NO FORCE, NEGGAA. Or if there is a force it comes solely from portal B. The force of gravity added to the force of the blue portal would pull it towards the direction of gravity, which is down

>>9076678
Suck it in* damn you, autocorrect

>>9076681
Also I'm drunk

>>9076678
>>9076681
No B wouldn't. In reversed B the box has an initial momentum opposite to its final momentum. It flies into the portal in reversed B, no force is applied on it.

>>9076662
>NO DIAGONAL, OR OPPOSITIONAL FORCE

if m of portal B outweighs m of cube.

>>9076689
I said there was no force...neggaa

Lol

>>9076689
Although now I see what you mean. Still, if there's no m creating a t, then there's still no force. The portal B has to have a mass of m if the cube is at all attracted to it.

>>9076689
no momentum relative to the ground

>>9076701
No m creating a f, force.* autocorrect is my bane

>>9076701
So wait...did we effectively create an option C? Where the cube is stuck non-dimensionally inside of portal B?

So C...is..correct

>>9076706
In reverse B it loses its downwards momentum from the leaving the portal moving upwards at exactly the same speed it entered.

Easier way to see it's B is just to imagine the stand is small enough to go through the portal.

>>9076721
Except the acceleration of portal A adds to the acceleration of portal B. So if the acceleration a < g then A, if a > gtanB then B.

>>9076729
If a of b > gtanb

File: Untitled.png (35KB, 960x540px) Image search: [Google]

35KB, 960x540px

>>9076732

>>9076749
Too drunk. but that should be enough for one to get the geometry (a + ag1)^2 > g2 then B.

>>9076755
>Too drunk. but that should be enough for one to get the trigonometry (a + ag1)^2 > g2^2 then B.

Logically, if a portal is just a hole, then the cube comes out of it just as quickly as it went into it.

People who say it's A because the cube isn't moving are looking at only half of the problem, but in the other half it is the portal that is stationary and therefore the cube that is obviously moving. B therefore perfectly conserves momentum. Furthermore, if you imagine that the orange portal keeps moving past the cube and that the cube is unaffected by wind resistance and gravity, you will see that the cube is moving away from the blue portal at the exact same speed that the orange portal is moving away from the spot where the stationary cube was, meaning that from the perspective of the orange portal, the cube still remains stationary if on the blue side it shoots off.

If anyone still objects that portals can't impart energy, I'd like you to imagine the opposite scenario, where you are standing still next to a stationary portal and step out through a moving one. Maybe just stick your head through. Is your head going to move with the portal, or is it going to be ripped off by mysterious forces as it tries to remain stationary in some objective frame of reference as the moving portal absconds with your likewise stationary body? Either way, you have to admit that some sort of mystery force connected to the portal is imparting some movement on your head.

Really, we've had countless of these threads on /v/ and while I've seen the advocates of B iterate and refine their arguments, the A side seems to be entirely stuck on the mistaken notion that the cube is "objectively" not moving, and an obsession with hula hoops. I think it's pretty thoroughly settled in favour of B.

>>9077885
>If anyone still objects that portals can't impart energy
you assume that portal machines are able to create infinite energy for free and with a strait face you claim that is a reasonable assumption.

don't you think if portals were to be a real thing that they shouldn't have that property?

>>9077953
>don't you think if portals were to be a real thing that they shouldn't have that property?
And how would they exist then? I'm not concerned with where the energy comes from. Just acknowledging that it has to be there.

>>9077960
if we aren't talking about a thing that could exist then shouldn't this conversation be on /v instead of /sci?

>>9077964
Because if we just accept the portals' existence then we're left with just a physics problem which doesn't require us to explain the portals to solve.

>>9077982
what force acts on the cube to cause it to have a velocity?

>>9078140
If you move the portal, you have to move the universe with it. And from both directions. So it's the force of the universe behind the cube.

>>9076294
I think in the game it would be A.
But in real life, where portals would most likely act with mechanisms, it would be B.

B is incorrect, The instantaneous acceleration would, however, cause it to tumble.

File: loop.gif (1MB, 500x280px) Image search: [Google]

1MB, 500x280px

>>9077953

>>9079405
why wouldn't B be correct?

>>9079405
There is no instantaneous acceleration, it will behave as if it was already moving at that speed.

If the bottom platform stays static, then A. Otherwise, B.

>>9080253
No, always B. The cube has to be moving to exit the stationary portal and it's not going to stop for no reason.

Isn't a portal just a hole? If you substitute the portal for a ring that simply falls around the cube, what would cause the cube to move?

>>9080392

According to the game Portal, the magnitude of the momentum is conserved when moving through portals.

Also the cube is moving when it is going through the blue portal so it should keep moving.

>>9078140
portals create a new frame-of-reference problem, nothing in the universe has an absolute velocity, any velocity is always relative to the earth's surface, or the center of the earth, or the sun. In this problem the cube has no energy in the frame of the orange portal but it does have energy in the frame of the blue portal

>>9076294
From my shitty understanding of this, since the orange portal being shot on top of the cube would be the same as the cube being shot through the orange portal, B would happen.

>>9076301
They can't have entrances that move except for that one Portal 2 level.

>>9079658
>>9080247

As the box's center of gravity passes the portal at t=0, the instantaneous shift in normal force will actually generate an infinity spin (theta squared divided by zero would be the angular acceleration value).

>>9078342
>If you move the portal, you have to move the universe with it
no, the pedestal the cube was resting on is still there, and now the cube suddenly has velocity relative to the pedestal? not happening.

>>9079658
B is correct

>>9076583
>you standing still, watch a train pass by
Do you have kinetic energy from the perspective of the train passengers? Obviously not.

>>9081223
Of course you do, what are you talking about?

>>9081234
wrong, kinetic energy doesn't work that way

>>9081239
It's mass times velocity squared, and obviously I have velocity relative to the passengers.

>>9081242
try to convert that energy to another form and see how that works out lol

>>9081259
Obviously you could convert it to another form of energy on the train. Are you thinking of the Earth's surface being an objective frame of reference here?

File: thonkong.jpg (55KB, 636x424px) Image search: [Google]

55KB, 636x424px

>>9076294

>>9081321
checkmate

>>9080970
Only the cube crosses the threshold. The pedestal is still in its old frame of reference.

>>9076348
Another way of looking at it is to imagine the block is your extended arm. If you think B is right, then it means your arm would seem to spontaneously rip itself off your body and go flying because the motion of the yellow portal (which is nothing more than a portal somehow transferred to your stationary arm.

>>9081321
Would be B if it's moving fast enough

>>9082611
that would imply jumping into portals rips you apart for no reason

which does not happen in the games

>>9083091
You don't ever move fast enough in the games to overcome your character's tensile strength.
It would probably have to be faster than a human's terminal velocity.

>>9082282
the pedestal does not move. you can use the pedestal as the reference point by which you assess the velocity of the block. so B cannot be correct because the block suddenly accelerates wrt the pedestal atop which the cube was previously motionless

>>9083307
>the pedestal does not move.
If you look at the blue portal it obviously does. It just doesn't actually pass the portal so this movement is never actualised. similarly, the cube was also not previously motionless, from the perspective of the reality which it enters.

>>9082526
That is unfortunately exactly what would happen. Don't worry, though, A also leaves plenty of opportunities to inexplicably rip your arm off with a moving portal.

>>9082981
>>9083234
Always and forever B

>>9084333
you can't have two difference reference frames that yield two different results. B is not consistent.
block is motionless wrt the pedestal holding it, then spontaneously accelerated wrt pedestal upon exiting portal.
A is the only possibility that yields consistent results when looking at the scenario from different reference frames.

>>9076294
A
The logic behind portals is "speedy things go in, speedy things go out". Since the cube isn't a speedy thing which goes in, it isn't a speedy thing which goes out.

>>9082060
>>9083091
dum dums

>>9084419
>The logic behind portals is "speedy things go in, speedy things go out"
That's the same logic that gives you B

>portal
2008 called. They want their cake back.

>>9076340
Isn't the idea of a portal that you get instantly displaced to another location and the orientation of your velocity would be relative to the orientation of the exit portal? Portals are science fiction right? So wouldn't they obey the laws of physics defined by the science fiction worlds they were invented in?

>>9084562
No, because the Portal is the speedy thing not the object going throught the poratl.

>>9084596
retard

What if the moving portal instantly stopped moving halfway through the cube. Then what would happen?

>>9084635
cube sticks half way thru portals

I'm convinced people saying "B" are literally trying to troll the thread on purpose

>>9085725
I'm convinced you are a brainlet

>>9085725
/sci/ is mostly populated by highschool popsci lovers and braindead undergrads just finishing up their first calc based physics class.
These people post online iq test results to validate their false sense of superiority. They're likely not trolling, just very stupid.

>>9085734
Found one of them --> >>9085731

>>9085734
Why don't you post your argument or refute some of the arguments for B then, Professor.

>>9085760
They're located ITT.
The block initially has 0 velocity relative to the pedestal atop which it is sitting.
Are you suggesting that upon entering the orange portal, and exiting the blue portal, that it is instantaneously accelerated wrt the pedestal it was once sitting on stationary?

>>9085782
>relative to the pedestal
But the pedestal's frame of reference has nothing to do with anything.
It's the portals' that matter.

>>9085814
>But the pedestal's frame of reference has nothing to do with anything.
>violating relativity in one reference frame is fine, but violating it in another is not ok

>>9085823
So you are admitting that A violates relativity.

>>9085829
Only wrt the portal, wheras in case B, the portals reference frame is the only frame that does not violate relativity. Case B violates relativity in every other reference plane, even the case where we take the blue portal as the reference plane (everyone is treating the blue portal as an extension of the orange portal, when it is it's own separate entity, and can exist on its own without the orange portal).

>>9085843
Wouldn't you say it makes more sense that the portals can cause objects to violate relativity in relation to the rest of the environment, which already happens in the game, than for the portals' reference frames to be violated?

>>9085847
>violate relativity in relation to the rest of the environment, which already happens in the game
No, and where does that happen?
The portals can't just cause physics to be inconsistent, it would make more sense for the portals to be a local exception, rather than for relativity to fail globally with the introduction of portals.

>>9085852
>The portals can't just cause physics to be inconsistent
It's going to be inconsistent either way.

>it would make more sense for the portals to be a local exception
It depends how you look at it. Is going through the portals the exception, or does going through the portals cause the exception?

>>9085858
>Is going through the portals the exception, or does going through the portals cause the exception?
Either way the exception should not be everything that exists except for the portals. That's not an exception anymore.
If the portals cause relativity to fail in every case except with respect to their own reference planes, they blatantly violate relativity.

>>9085867
>Either way the exception should not be everything that exists except for the portals
Why not?
The portals are the 'magical' objects here. It seems to me that their reference frames should be prioritised.

>they blatantly violate relativity.
Relativity is violated either way.

>>9085878
>The portals are the 'magical' objects here
Exactly why they are the exception.
>Relativity is violated either way.
But only in the case of the portals' reference frames. In case A, relativity is satisfied in all cases globally other than the portals' local exception.
It's like how Ohm's law is a (almost) a universal law, except in the case where you have to use the Child-Langmuir law to appropriately describe the current-voltage relationship of a system. A bit of a faulty analogy, but you see what I'm saying with the (almost) globally consistent law (relativity) and the one exception where it does not apply (the portals).

A because there is only one hole

>>9085892
>why they are the exception.
This statement doesn't mean anything.
"Being the exception" can apply to both A and B depending on how you look at it.

>>9085892
But portals already violate relativity the same way as in B. Whenever you go through a portal you change your relative direction and/or position, just not velocity.

>>9085916
>"Being the exception" can apply to both A and B depending on how you look at it.
No because "being the exception" implies a deviation from typical behavior, or an isolated example. The portals are an isolated example, whereas every other case behaving in the same manner, consistent with one another, is not an abnormality, nor a deviation, but the standard.

>>9085933
The portals can be the exception in that they cause relativity to fail for objects passing through them, or they can be the exception in that relativity fails for the portals when something passes through them.

I think the portals' reference frames being prioritized makes the most sense, since otherwise an object travelling through the portals while the two portals have a relative motion would have to be somehow compressed as it passes through.

>>9085974
>I think the portals' reference frames being prioritized makes the most sense
Why would relativity even apply to portals when it doesn't apply to anything else?

>>9086039
Because otherwise objects either have to be compressed in the portal, or abruptly lose momentum while not even inside the portal.

>>9085847

>>9083234

>>9083234
>>9086057
Doesn't change anything. If you think OP is B, then this would still be B

>>9086067
But B is not correct in either case though..

>>9086073
There is no absolute correct answer

>>9076294
B, if you imagine you are looking through the blue portal, you will see its stand moving towards you, much like the piston with the orange portal on it.

>>9076294
Can't you just imagine there's a hole where the orange portal is? If so it would obviously be A, assuming the stand is immovable and doesn't recoil.

File: 1439662180600.jpg (52KB, 646x431px) Image search: [Google]

52KB, 646x431px

>>9086109
>looking in blue portal
>object coming at you through hole at 100 mph
>abruptly stops and falls to the ground

>>9086116
>running at object with hula hoop at 100 mph
>shoots out the other side once you pass the hula hoop over it

>>9086116
But what if you are looking at the orange hole coming at you?

>>9086129
>Looking up
>Guy standing horizontally in hole
>Guy and hole start coming towards you at 100 mph
>Hole goes over you
>You fall sideways onto the floor/wall

>>9086122
moving portals aren't analogous to hula hoops

>>9086136
>>Looking up
>>Guy standing horizontally in hole
>>Guy and hole start coming towards you at 100 mph
>>Hole goes over you
>you become superman and fly past guy and hole

>>9086137
they literally are tho. one side of the hula hoop is the orange portal, and the opposite side is the blue portal. if you split the hula hoop in half and separated them, that would be exactly like having two portals

>>9086141
>>you all of a sudden instantly accelerate to 100mph
>>The g-forces kill you

>>9086116
If the object is completely through the portal before the orange portal comes to a stop, I suppose B would apply. But that completely violates the laws of physics because the object has no momentum before and no force is applied, so how can it have momentum after? The problem comes from the idea of a moving portal, which makes even less sense than a normal portal.

>>9086153
But relative to the blue portal the orange portal is stationary and everything else except the orange portal is moving, so the same thing would happen as when the box is being thrown into the orange portal. The answer is B

>>9086144
Try moving the the two regions of space on each side of a hula hoop relative to each other... Oh wait, you can't, because a hula hoop is not a portal.

>>9086162
No it is, it just a portal that only exist in a single point of time and space.

>>9086162
>a hula hoop is not a portal.
literally any two shapes can be a fucking portal if you give them the made up properties of a portal you retard. my computer screen and my tv screen could be portals if we lived in a fucking video game

>>9086153
We already know portals violate conservation of momentum.
The difference is B violates conservation of momentum as the object goes through the portal, while A violates conservation of momentum after the object has completely exited the portal.

>>9086168
>x is just y if x had the properties of y

wow really makes you think

>>9086161
But I'm saying for that to be the case you must violate the laws of physics. You can't pick an answer that violates the laws of physics. The problem comes from having 1 portal moving and the other portal stationary. They must either both be stationary or both moving in the same relative direction at the same speed.

>>9086169
Pretty much, except I think it's that the portals aren't both stationary or both moving in the same relative direction at the same speed, that causes the violation of conservation of momentum. Portals themselves don't violate it, as long as they're properly anchored to each other in space.

>>9086175
Portals always violate conservation of momentum, it's relativity that is only violated when they are moving relative to each other.

>>9086177
Explain how throwing an object through a stationary portal and it coming out another stationary portal 10 metres away violates the conservation of momentum. Not saying you're wrong, just don't understand.

>>9086180
>Explain how throwing an object through a stationary portal and it coming out another stationary portal 10 metres away violates the conservation of momentum
Are you literally retarded?

>>9086183
I guess so. But you still haven't explained.

>>9086187
If you put a portal on the ceiling and one on the floor, you can jump into a loop and accelerate forever.
Is momentum being conserved?

>>9086191
yes, in the you exit the portal with the same momentum as when you entered it. you gain kinetic energy in the distance between the portals, but you dont change your momentum upon interacting with a portal.
the only time your momentum would change is if the direction changed. the magnitude of your momentum is conserved.

>>9086195
>in the you exit the portal with the same momentum as when you entered it. you gain kinetic energy in the distance between the portals

Ok, but it is still the portals tcausing the violation.
You are just arguing semantics.

>>9086191
>What is twrminal velocity
Also, if its the same if you jump off an infinitely tall cliff. Its not your momentum moving you, its gravity.

>>9086199
>Ok, but it is still the portals tcausing the violation.
no, the portals are just extending the range that you can fall.
Instead of falling the distance from the ceiling to the floor, you can fall two times that distance effectively by falling down and through the portal once. Now you have built up exactly the same amount of momentum as if the ceiling to floor distance was doubled.
It's still gravity accelerating you, the portal is just extending the range through witch gravity has the opportunity to act.

>>9086191
You're right in that example. I was thinking in an isolated experiment with no outside forces, but I suppose that would be impossible considering gravity has infinite range.

>>9086202
Do the experiment in a vacuum.

>if its the same if you jump off an infinitely tall cliff. Its not your momentum moving you, its gravity.
Yes. A portal loop is the same as having an infinite gravitational potential. Thank you for agreeing with me.

>>9086205
>You're right in that example
except he's wrong though

>>9086204
The portal isn't imparting a force on you, but I never said that. The portal is still causing a conservation violation though.

>>9086209
It's creating momentum out of nothing. How is that not a violation of the conservation of momentum?

>>9086208
You still haven't mentioned how portals supposedly fail to conserve momentum though

>>9086208
Then it'll just be the same as moving in a vacuum, no air resistance mo fucker. The portals dont take away momentum, theyre 2 dimensional faggit.

>>9086211
>The portal isn't imparting a force on you
>The portal is still causing a conservation violation though.
the only way to cause a violation (barring the direction) is to apply a force. that's how you increase momentum..

>>9086213
>It's creating momentum out of nothing
what force is the portal imparting on things that enter or exit it?

>>9086220
>the only way to cause a violation (barring the direction) is to apply a force. that's how you increase momentum..
well I'm just going to have to violate that rule
nothin personell kiddo

>>9086214
>>9086220
>what force is the portal imparting on things that enter or exit it?
In his example the portals are adding gravitational potential to the object. Which I suppose would technically be violating the conservation of energy, but by violating that, the conservation of momentum is also simultaneously violated.

>>9086223
Finally a answer.

>>9086223
>In his example the portals are adding gravitational potential to the object.
no, gravity is doing that. the portals just position the object so that it can continue falling.
the portal does not impart any force on the object. the object only accelerated under the force of gravity.
There is no violation, if there were, you would have to claim that gravity violates the conservation laws.

>>9086214
Take a closed space full of particles with net momentum of zero and do Maxwell's demon with the portals.
Pick a direction, and whenever a particle comes along moving in that direction you open the portals and reverse its momentum then close the portal. You've just changed the net momentum of the system.

>>9086227
>no, gravity is doing that
If I lift an apple, I am giving it potential energy, not gravity.

>>9086232
you're doing work on the apple by applying a force through some distance.
Draw a fbd of the application of force on an object by the portal. also draw the path that the portal applied the force through

>>9086233
Exactly, but the portal is skipping the part where it does work to move it through a field/force. You can't just skip that part. Hence violating conservation of energy.

>>9086240
>>9086233
>>9086232
Listen fags, GPE = mgh. m and g dont change with the portals, but h does. Seeing as you now have infinite hieght, you now have infinite gpe.

>>9086240
You also can't move things through space and time instantaneously, but this is a video game.
And the portal still is not doing any work, it's not imparting any force, and it's not changing the magnitude of an object's momentum

>>9086246
>it's not imparting any force
That's exactly the problem. It's getting results without doing the work. That's just the same as doing the work and not getting the results. Either way their is an energy disparity before and after, so it's violating the conservation of energy.

>>9086231
If you understood maxwell's demon, you'd realize your claim is less an attack on the ability of portals to conserve momentum and more of an attack on the validity of conservation of momentum

>>9086250
Ut the portal isnt providing the force to move an object, the object itself is. The portal is only providing infinite distance/height which is where the problem comes from.

>>9086255
Where did I say it provided a force? What I'm saying is it doesn't have to impart a force to violate conservation.

>>9086251
Portals only violate conservation of momentum if you can open and close them.

>>9086257
I think we are looking at this wrong, The infinite GPE is what really bugs me.

>>9086257
The original argument was concervation of momentum, which could only be violated with the addition of an external force (not counting any change in direction)
You're changing the initial argument to conservation of energy which it technically violates in that it can be used to increase an objects potential energy, but it still maintains the objects momentum

>>9086263
It's only infinite because you've got it in a loop. The real issue is simply that it's adding GPE each time, the fact that you can infinitely loop that addition is pretty irrelevant.

>>9086262
>Portals violate momentum conservation in that they dont preserve direction.
The objects momentum is maintained at the same magnitude though

IT DOESNT VIOLATE CONSERVATION OF MOMENTUM!!!!

>>9086268
ok.....
that still violates conservation of momentum

Do you have any clue what you are talking about or are you here from /v/ or something?

>>9086264
But the moment it violates CoE by adding potential, that potential becomes kinetic and violates CoM. So you can argue it doesn't directly violate CoM, but it definitely does indirectly.

>>9086277
the portal isn't causing any increase in momentum. it's causing an increase in potential energy.
in order to strictly violate momentum conservation, it would have to do work on the object. that's it, that's what would have to happen.
>>9086276
have you not been paying attention? portals do not strictly conserve momentum, but they maintain the magnitude of an object's momentum. i literally have not made any argument counter to that

>>9086287
>the portal isn't causing any increase in momentum. it's causing an increase in potential energy.
Which is exactly what I said, or at least is what I'm trying to say. It creates a system that subsequently violates CoM, but doesn't do it directly. But CoM is violated as a result of what the portals have done.

>>9086287
>portals do not strictly conserve momentum, but they maintain the magnitude of an object's momentum.
And we're back to square one >>9086177

Thanks for that productive argument

File: 1439753928515.jpg (261KB, 900x900px) Image search: [Google]

261KB, 900x900px

>>9086287
>but they maintain the magnitude of an object's momentum
NO ONE HAS DISPUTED THIS

>>9086299
But >>9086177 is wrong because portals don't "always" violate CoM

>>9086310
Depends on the topology of the universe, but the only case where they definitely wouldn't is if they are back to back. AKA the hula hoop case.

You should see the velocity of the of the object in relation to the yellow portal. When the object crosses the portal that speed is conserved...

>>9086320
>but the only case where they definitely wouldn't is if they are back to back. AKA the hula hoop case.
>one portal on the side of a wall in a room
>another portal on the opposite side of the wall in the room
>walk through portal
>momentum conserved

>>9086333
depends on the topology

>>9086320
So you're saying the only time CoM isn't violated is when they're positioned to essentially not be there/be pointless? Is that because the forces acting on the object must be exactly the same before and after, and there are no two places in the universe where the forces acting on both points are the same?

>>9086333
No, because gravity is different in those two places.

>>9086341
>No, because gravity is different in those two places.
>gravity is different acting at the same height
its like walking into a room through the back, walking through to the front door, and coming out through the back door again in a straight path. momentum conserved

>>9086347
But absolutely everything in the universe has gravity that is affecting you as you walk through. The direction/magnitude of those forces changes as you change position.

>>9086338
I'm completely ignoring any fields.
Adding fields just makes the momentum violation worse.

Just strictly looking at through a Newtonian motion perspective it already violates CoM.

>>9086350
if the differences cannot be measured to a degree that would determine them to be statistically significant it can be argued that they don't exist

>>9086353
>through a Newtonian motion perspective it already violates CoM
Care to elaborate? Not sure what you mean.

>>9086354
What? You can't violate the laws of physics and then say it doesn't count because it was only slightly lmao

>>9086358
>Care to elaborate? Not sure what you mean.
https://www.youtube.com/watch?v=cMDdOH9K7mE

>>9086358
>What? You can't violate the laws of physics and then say it doesn't count because it was only slightly lmao
you can't say a difference of .00005 exists if your equipment can only measure to the nearest .00001 and has implicit uncertainty of +/- .00002
Your readings are not statistically significantly differing enough to say such a difference exists with any certainty

>>9086371
I assume you're trolling because otherwise you're legit retarded.

>>9086367
Well that's not helpful.

>>9086374
>Well that's not helpful.
sorry

The speed is conserved, not the velocity cause it changes the vector. So in relation to the upper platform the cube travels at some speed, then the platform stops but the cube is in an other frame of reference. So it keeps the freaking speed.
https://youtu.be/ASUUN0W4_JY

>>9086374
>I assume you're trolling because otherwise you're legit retarded.
>I don't understand statistics.
>I don't understand uncertainty
Welcome to physics m8, when you have a job and do work, gimme a call to explain this shit to you before you get immediately fired for being incompetent.
>hey boss i think i'm on to something. the difference in the force on this object caused by gravitational variances is 0.001 +/- 0.001 Newton

>>9086392
We have never measured something moving at exactly c, but we still know the exact value of c. Things can be proven mathematically, without actual measurements, you dingdong.

>>9086401
LEL we know the exact value of c because of the definition of the meter, which fixes the value of c exactly. nice try though

>>9086385
Threads over.

>>9086412
>we know the exact value of c because of the definition of the meter, which fixes the value of c exactly
Other way around, mongo. Although I admit I am an idiot for still entertaining you.

>>9086419
We know the value of a meter because we have the speed of light?

>>9086424
Yes, obviously. The reverse makes zero sense.

File: wrong nigger.png (279KB, 1147x603px) Image search: [Google]

279KB, 1147x603px

>>9086419
you could not be more wrong.
pic related, i even highlighted all the specific references to measurement uncertainty as a limiting factor in data collection

File: Wrong, negro.png (169KB, 1598x754px) Image search: [Google]

169KB, 1598x754px

>>9086428

>>9086433
not sure what you're trying to tell me but
>This definition fixed the speed of light in vacuum at exactly 299792458 metres per second

>>9084353
Wrong, because if you look at both frames of reference then the result of A is a block that's moving quickly towards the blue portal and then suddenly stopping for no reason. On the other hand, if you imagine the orange portal continuing as if the pedestal wasn't there, you'll see that it is actually B that is entirely consistent.

>>9085725
Then you should be able to refute their arguments, which you can't. Meanwhile every argument for A has been refuted by now.

>>9086945
Both scenarios violate the laws of physics. It is neither.

>>9087325
The whole game of Portal violates the laws of physics

>>9087351
So what would happen in this scenario would be completely up to the game makers, and would have no bearing on logic or reality. So why is this even a question on /sci/?

>>9076340

But, that is from the rooms point of view.

Wouldn't a more appropriate drawing be similar to the scenario where someone was able to jump down a hole that went through a hollow Earth?

>>9087382
Yes it would be up to the game makers, but one scenario still makes more sense than the other.

>>9089236
Still A

File: 1499878303187.png (131KB, 396x385px) Image search: [Google]

131KB, 396x385px

>>9076294
A, because gravity polls it down

>>9087382
That's wrong. Just because we're dealing with a hypothetical scenario that doesn't mean logic doesn't apply. Just because something isn't real that doesn't mean we can't speculate about it, knowing its properties. And that is why the answer is B.

File: image.gif (946KB, 301x308px) Image search: [Google]

946KB, 301x308px

A

>>9076294
The fact that both are pretty close to nonsensical is in itself a proof that portals should not move relative to each other.

>>9090180
>Bfags think of a thousand ways to explain how the difference between this problem and a hula hoop are precisely what makes it interesting
>Afags think of a thousand ways to reinvent the hula hoop
Brilliant use of brainpower there.

>>9076294
Easy, just take a wooden plane (or metal) make a hole. place a cube on your table. plade de plane through the cube with a 'high' velocity. See what happens. (can also ve done with a cup.
Lo and behold: NOT happens, if you smash your plane/cup hard enough the cube bounces up but that is because of the vibration of the surface where the cube is resting on.

>>9076294
A relative to the platform but B relative to the piston.
In this way, moving portals would in some cases cause relativistic inconsistencies due to distortion of space.

>>9090191
Case in point >>9091299

File: trash.jpg (125KB, 1596x714px) Image search: [Google]

125KB, 1596x714px

>>9076296
B. Newton. Einstein has nothing to do with it.