Is it wrong to assosciate relative frames of reference with Einstein?

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>>9055231
if portals are treated as perspectives (windows), A
if portals teleport with some kind of mechanism (energy), B

>>9055250
What differentiates windows from portals is that each portal can move independently.
As long as portals do not move relative to one another, which is not the case here, they can be treated as windows

>>9055250
it you assume portals work like in the game it can't be A (momentum is conserved through the portals)

Anyone who thinks its A is either trolling or retarded. No exceptions. Not a single fucking one.

>>9055314
The cube has no momentum. Only the portal. There is no evidence whatsoever that the speed of the portal has an impact on the speed of the object.

>>9055322
Did you just disagree with A and then disagree with B?

good for you dude

>>9055231
Newton would have agreed with B as well because he wasn't a brainlet.

>>9055354
HAHAHAHAHAHAHAHAHAHAHAHAHA

good one

>>9055360
There is not a single good argument for A.

>>9055231
B but both answers would make newton cry.

>>9055231
I guess because Galilean Relativity is in a way "obvious". If you understand Newton's first three laws (which admittedly come from galileo and not the other way around) it makes sense that speeds would just add linearly. Now special relativity is based on the notion that light travels at the same speed for every inertial observer. That already is a pretty hyoog change in understanding but just the beginning really.

The bottom line is that the path to understanding special relativity first involves a deep understanding of Galilean Relativity, or else your understanding will stop at "oh this guy's moving so his time is moving slower" with no way to expand on it. The definitions of observer, time, and many others need to be made significantly more exact, and will often be unintuitive in special cases, such as those that are interesting in the slightest.

>>9055322
It is A you dipshit. When someone swings a hoola hoop around you at max speed does it cause you to gain momentum? No, the portal is exactly like a hoola hoop.

>>9055436
Both the part of the hoop you are entering and the one you are exiting are moving at the same speed you retard.

>>9055436
Exactly

>>9055442
You aren't gaining momentum though. Once your entire mass is outside the portals field you stop immediately because you never had momentum.

It's A.

Imagine stopping the top portal halfway through the cube. Would the cube fly out?
No, obviously

If you argue that the cube will move because of the collision, then why even associate Einstein into this?

>>9055450
Yeah I really don't get what the fuck you're trying to say.

>>9055322
Did you know that you just agreed with A

>>9055450
Also for the fact the matter entering the portal comes out exactly as it goes in tells you there is no energy in the force field. If there was then the matter exiting would be annihilated or destroyed in some manner.

>>9055231
ITS A BECAUSE CONSERVATION OF ENERGY IS THE SINGLE MOST IMPORTANT LAW IN PHYSICS IF YOU THROW THAT AWAY YOU ARE TALKING ABOUT ANOTHER UNIVERSE

REEEEEEEEEEEEEEEEEEEEEEEEEEEEE

>>9055469
>energy conservation
>in a scenario with portals
Are you dumb?

>>9055469
Conservation of energy doesn't work in general relativity

>>9055479
Disprove portals cannot exist.

>>9055479
Then we can talk any shit if universe laws can not apply

>>9055480
Can you elaborate?


Now that I think about it, if portal existed and B happened. Physicists would just define a "potential portal energy" to make conservation of energy fit.

>>9055490
Prove that your statement matters

>>9055493
The ability to accelerate indefinitely without losing potential energy by using a floor and a ceiling portal should have given away that there is no reasonable definition of energy in this setting.

At first sight it's B, but if you decide to use your mind it's A. Are you seriously saying the momentum from the portal is passed to the cube? If the cube was the one moving it would've been B, of course, but the cube doesn't move, it's being transported without it gaining momentum, so it'd fall. Also portals can't move like that but ok.

>>9055496
t.cunt

>>9055453
But wouldn't it fly out?
What if you change your frame of reference so that the other portal is not moving? Then the cube will appear in the second portal at speed and suddenly stop.

>>9055528
The momentum from the portal is passed? No, by entering the other portal the cube changes it's frame of reference. Yeah I'm basically saying that if the portal stopped with the cube halfway through it'd get ripped apart.

Still, many of the common tools fail when you're thinking with portals. Can't use conservation of momentum, energy, or anything that involves a constant frame of reference which is basically all of physics ever.

>>9055250
B portals do use energy, consider two portals on the floor, you jump down into one and fly upwards out the second.

The portals have put energy into the system that has changed your momentum vector twofold.

Even in the "moving window" example it doesn't work because the output of the window somehow "stops" which involves energy exchange.

>inb4 nobody addresses OP's question
You dun' goofed OP. You added a picture more interesting than the topic of your post.

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>>9055528
If the red box moves the green box then B must be true.

you fucking idiots
you ALWAYS treat portals as windows of reference TO ONE ANOTHER
since the orange portal is moving relative to the blue portal, anything that passes through the orange portal will have the relative momentum of the orange portal to the blue portal

If you throw a ball into a moving orange portal that is traveling away from you at 10 m/s, and the ball enters it at 11m/s, the ball's relative momentum will be an added vector out of the blue portal that is 1m/s because the orange portal's momentum is added to the ball traversing it

>>9056065
Replace "momentum" with "velocity" and you're dead-on.

>>9056270
momentum vectors are simply the velocity vector times the mass.

If mass is constant and can be generalized to 1 they're equivalent. People bring up momentum vectors when talking about conservation of momentum.

>>9055436
So what you're saying is that if the yellow portal continued moving, the cube would shoot out of the blue portal?

>>9056316
>If mass is constant and can be generalized to 1 they're equivalent.

True. In this case, however, the object that that the portal is attached to has no guarantee of having the same mass as anything going through it, so velocity should be used instead.

So what is the answer to OP's stated question?

>>9056924
the answer is that Einstein is a fucking meme and gets credit for everything because he's famous.

>Einsteins Law: Famous scientists will be credited with discoveries they didn't make.

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answer is here

>>9055436
Consider this: imagine the portal is going over a long pole, instead of a box

As the yellow portal descended over the pole, it would emerge from the blue portal. Shooting out quickly. The velocity of the pole coming out of the blue portal would be proportional to the velocity of the yellow portal as it engulfed the pole.

Now, let's talk about acceleration. If you were to accellerate the yellow portal, the velocity of the pole coming out of the blue portal would increase. This cannot be done without applying a force to the pole (or box). If we maintain Newton's law, this means that the yellow portal must feel some back-force proportional to the force it is applying to the object going through it.

This means that the portal works a bit like an inductor. It feels a damping force proportional to the change in velocity, just as an inductor emits a back-emf proportional to the change in current.

>>9055364
We've had this exact thread already. Momentum is conserved through a portal (according to the videogame itself, Portal). If the block is not moving and the teleporter does not exert any force on the block, then the block will merely slide down the ramp since it's momentum (of value 0) had to have been conserved since there are no external forces applied to perform work. This is simple stuff guys.

>>9057104
No it won't. As explained in the two posts above yours

>>9057111
The explanations are simply incorrect.
>>9057039
>shooting out quickly
Stopped reading there. This would not happen. Infinitesimal portions of the object being teleported will all maintain their own respective momentum since no external forces are applied and no work is done due to nonconservative forces and thus conserve the momentum of the entire object. In addition, it would not even move until at least its center of mass passed the portal so that a new external force, gravity, will produce a torque which then forces it to slide down the ramp.
>>9057025
What do you even mean by this? This would be if its own displacement is continuous when it is not.

Why do people have the retarded idea that portals conserve momentum of objects?
>inb4 they conserve the magnitude of the momentum of the object
This is not compatible with Galilei invariance.

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>>9057133
Oh wow look it took two seconds to look that up aaaaand

Yeah no new posts for some time that's what I thought y'all niggas know I'm right

>>9055231
there is no reference frame with these kinds of portals
it's inherently unphysical

>>9057144
>the game said so, so it must be true
Are you stupid? If an object comes in moving in one direction and comes out moving in another direction its momentum is clearly not conserved.

>>9057182
This portal is from the game Portal so of course it's valid evidence. Even if I didn't use the game itself, momentum would still be conserved on the foundations that NO (read again: NO ) net external forces are acting on it. In addition, reference frames don't matter for this since different frames of reference which are made noninertial only make it SEEM like classical mechanics do not work. If you need me to spoon feed you further, the vectors I am considering are relative to the ground. Give me some reasons why it would accelerate despite the fact that there aren't any agents for forces to be applied prior to the teleporting. I'm honestly open to listening.

>>9057182
Also I don't know why it hit me just now but, what do you mean when you say the direction changed? If we're to discuss the OP then it is at the bottom of the ramp due to torque produced by gravity upon the objects center of mass. I promise you, the object is only teleported, and not accelerated. My apologies for reading over that.

>>9057200
The momentum is clearly not conserved so either there are external forces or portals do not observe the laws of classical mechanics (tip: they don't).
>different frames of reference which are made noninertial
Who ever mentioned anything like that?

>>9057204
I was not discussing the OP problem in particular, just noting that arguing with conservation of momentum is asinine in general.

>>9057209
>who said
Other guys in the thread? Wasn't exactly saying you I was just saying.
And why do you say it's clearly not conserved when I feel that it clearly is conserved and can even tell you only the force of gravity and the force normal are acting on the object before, during, and after. Portals are directly from the game Portal and the game itself even said that momentum is conserved. There is no other way to look at it. It is A.

>>9057121
>no work is done due to nonconservative forces
But it's not a conservative system

Mate, in the portal universe you can teleport yourself to a higher position doing 0 work. This is not some kind of conservative vector field that will respect your conservation laws

>What do you even mean by this?
Can't you tell? The box emerges from the blue portal in a certain period of time. This means that the velocity of the box must be h/T where h is the length of one side, and T is the amount of time it took to emerge.

This doesn't fall back on any hitherto conservation laws. It's just sort of a logic thing.

>>9055231
A

B.

>>9055231
both classical newtonian physics and relativity will lead to B

>>9055231
portals can't move on surfaces, so both answers are wrong because they can't exist

where's my prize

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>>9055231
There is already a published proof for B found online.

http://journalofsci.weebly.com/home/sterling-relativity-and-sterling-transformations-in-portal-math

>>9057848

The planet is moving you dopey prick. All portals are on moving surfaces.

>>9057874
this + there is at least one place in the game where a portal moves relative to the earth

https://www.youtube.com/watch?v=mCQiwhik8nc

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>>9057871
>posting your own retarded blog

>>9057751
>Zero work
Okay, but that doesn't change the fact that momentum is conserved. Also, work that correlates with raising something would be a conservative type of work. Albeit it isn't done, energy is put into the system but not in any kinetic form when you teleport to a higher location, it's potential energy.
>>9057751
>Can't you tell about its velocity?
I disagree with this. For example, if I have portal side A in New York and merely walk through it to be teleported to side B all the way in Taichung, I would not come flying out at some arbitrarily retarded fast speed.
I suppose this is a way of measuring its pace of emergence, but this does not give reason to why it should fly. If objects did do this when passing through portals, I imagine putting a mere limb into a portal would consequently either rip that limb off or drag the rest of your body in.

>>9055453
>Imagine stopping the top portal halfway through the cube. Would the cube fall out? No,obviously

>What is energy transfer?
I could walk you through the calculations required, but its pretty clear that yes, the cube will move if enough energy is imparted through it
>but muh conservation of energy
Thats not how portals work, retard.

>>9057894
ok, now show us a portal moving perpendicular to its host surface

Alright A fags, listen up.

The moving portal is moving at some speed, for the sake of argument lets call it 1m/s. Therefore, cube enters the portal at 1m/s. Therefore the cube exits the other portal at 1m/s.

Prove me wrong (you can't)

>portals don't conserve momentum

Portals conserve speed
Portals conserve mass

Momentum is a function of speed and mass

If you think the answer is A, you are actually mentally impared

>>9058059
>if I have portal side A in New York and merely walk through it to be teleported to side B all the way in Taichung, I would not come flying out at some arbitrarily retarded fast speed.
Is th portal moving relative to the room in either case? If not, I don't understand your objection.

>If objects did do this when passing through portals, I imagine putting a mere limb into a portal would consequently either rip that limb off or drag the rest of your body in.
I really think you have a bad understanding of this whole scenario

>>9059030
bingo

If it were A, that means the second the object cleared the portal, it would arbitrarily decelerate. And since it's no longer in contact with the portal, it's difficult to picture how this would work

>>9059111
Yeah okay you're probably just trolling. I'll continue. As in the last thread, which also came to the conclusion of A, I shall quote the counterargument Anon made
>So if an open door comes flying at me and I jump through it, I'll bolt out like a fucking rocket?
Consider calling your university to get a refund for your degree. Good day.

>>9059209
Hey, if nothing stops the door, you will continue moving relative to it. That's how basic relativity works.

>>9055344
Top lel

>>9059229
Yeah but what about to the ground? My ass wouldn't be called SpaceX, I can tell you that.
I feel like everybody here is treating this as a complicated problem. It honestly almost upset me so many people now said B and I thought I was going nuts. Googled that shit at least four other sites and nope every serious reply stated that A as correct. I'm leaving this cancer.

>>9059243
But what if the ground isn't there? What if the yellow portal continues moving after the cube clears it? Would that make the cube move the same distance past the blue portal? What if the yellow portal started moving backwards afterwards? Would that suck the cube back in into the blue portal? For A to be true, you have to assume that whatever force is acting upon the yellow portal also acts upon the cube on the other side of it.

>>9059250
>For A to be true, you have to assume that whatever force is acting upon the yellow portal also acts upon the cube on the other side of it.
There aren't any forces acting on it. The portal doesn't ever touch the object it's teleporting and it doesn't emit any field so there isn't even an agent for any force to be exerted through. That is why I believe and have evidence to say that A is correct due to the conservation of momentum.

>>9059365
The problem is, the cube has momentum, since it's moving out of the blue portal. You'd need some force to stop it from continuing that motion.

>>9059250
It doesn't matter what the first portal does or where it is once the object has been teleported. Also, if the yellow portal stops and goes back up, it really only matters if the center of mass of the object has passed or not since that point passing will be vulnerable to torque produced by gravity which will then pull it down the ramp. Don't know why I didn't include this in one reply. My bad.

>>9059369
But it's not *moving* out of the portal, it's really just emerging into another line of sight if that makes sense. The cube has no momentum simply resting, and momentum is conserved through portals, as stated by the videogame itself and the absence of external forces.

>>9059373
>But it's not *moving* out of the portal, it's really just emerging into another line of sight if that makes sense
No, it doesn't. All relative motion would continue with no forces acting upon the cube or the blue portal's frame of reference.

did einstein steal relativity from galileo?

>>9057121
Infinitesimal portions of the object must me moved out of the way at a rapid rate to allow the next "slice" of the object to appear through the portal. These slices push against each other.

If you squeeze a toothpaste tube hard it will shoot out even though the toothpaste "had no momentum" when you started. The moving portal imparts this momentum.

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>>9058059
>Okay, but that doesn't change the fact that momentum is conserved.
momentum is not conserved. The only way momentum can possibly be conserved is if the blue and orange portals are literally a hula hoop.

>>9055231
portals that aren't stationary relative to one another and aren't oriented the same direction spatially can not exist because conservation of momentum.

that game is cancer

>>9059722
Aside from the fantasy physics or teleportation part, why couldn't the portals impart momentum changes to the walls they are attached to?

Why wouldn't the portals require energy to work?

>>9059719
lmao. The exact same problem with momentum you describe has been solved here:

>>9057871

>>9057104
>This is simple stuff guys.
If you ever find yourself saying this, realize that it's probably nowhere near as simple as you say it is. Like in this case, momentum for the cube is only zero from the reference point of the pole it's on. Let's back out and use the center of the earth as a reference point. Holy shit, that fucker now has an angular velocity of around 1600 km/h that's aligned with the rotation of the earth. For shits and giggles, imagine that the exit portal is on the opposite side of the planet, then imagine it's at one of the poles...and hell, we're not even talking about how the gravity and normal vectors are changing and acting on the body as it goes through the portal...and god help we think about oh, I don't know, a portal being on the moon with this conservation of momentum...

>>9055231
Did you play the game? Portals disappear from moving surfaces.
>inb4 earth spinning, moving around the sun, around the galaxy, etc

>>9061587
Did you play the games?
Two 'puzzles' involved portals on moving surfaces.

are A fags actually retarded or just trolling?

the cube's or any object's velocity is a product of the reference frame. The two portals have different reference frames, changing the reference frame of any object that passes through. Not to mention the part whee the cube's momentum is not conserved or the part where h/T.

I don't care about the topic but want to explain something pertaining to the image.

As the mechanism in the first diagram moves downward at a velocity of x, the cube, at its top during the moment of penetration, would be moving at the same velocity out of the portal as the mechanism's velocity moving downward; however, since there is no propelling force having been exerted on the mass of the cube, it'd come out and fall.

ENFP A's correct.

Also because of there being a gradient and flat surface of which diagram A's mechanism lands upon, the cube wouldn't be able to fall back into the portal, thus it's "plop."

Ye

>>9062005
There's no m in the force of the falling component. It wouldn't the propel the cube. Can't move shit without mass bozo. YOU MAD CUZZA MY WORK

cwutididtherehoho

>>9062011
The force propelling the cube is its own inertia and the unmoving platform underneath it. The cube is squeezed through the rapidly descending portal, emerging at a velocity of h/T, meaning the cube has velocity.

Portals are nonconservitive in both angular and transnational momentum for objects that pass through them. Either the momentum is not conserved in the larger system or the portals must exert equal and opposite forces at both the entrance and exit portals.

I have a machine, an object enters the machine at one end, I record the object's orientation, rotational and transnational state. Then my machine grabs the object, transports it through an elon musk hyperloop to the ejector which imparts the same orientation and rotational and transnational momentum, but rotated to my desired exit angle.

Functionally my machine is identical to a portal except the object doesn't enter and exit simultaneously. My entrance must absorb the difference in momentum between the grabber and cube, either the grabber or cube could be moving. The exit must also conserve momentum as it accelerates the cube for ejection.

From the moving portal's reference frame the cube is moving and has momentum.

>>9062015
>meaning the cube has velocity.
Right, but the force moving it has no mass. Without force exerted upon something, there's 0 work done to the object, thus there's no distance. W = fd

>From the moving portal's reference frame the cube is moving and has momentum.

Tricky. You're right. I'll give it to ya, man. Thanks for clarifying

>>9062021
>>9062015
Actually, wait. If there's no work being done on the object, then it can't move. There's no acceleration, but only a velocity which stops once the descending platform hits the pedestal.

PLOP :D

ilu

>>9062028
The acceleration stops once the portal stops moving, no force = no distance.

>>9062028
why would the cube's velocity change? you need work for that to happen, and there's nothing acting upon it.

>nobody taking into account that gravity pulling it down in A is going against gravity keeping it on the platform

Sigh brainlets....

>>9062015
>>9062021
>>9062028
>>9062034
With zero velocity at the end of the portal's descension, the momentum of the block would also become 0.

A

>>9062051
what force is stopping the cube? is it the same one that's stopping the orange portal?

>>9062109
The cube only gains velocity congruent to the falling portal. Once the portal stops moving, the cube also does..

>>9062114
the problem is, that only happens once the cube is on the other side, and the same force is not acting on the blue portal, so there's no reason why it should change it's velocity relative to the cube.

>>9062109
>>9062114
There isn't a force "stopping" the cube, per se, because there isn't any acting force once the portal stops accelerating. It's the nullifcation of force which stops the cube's motion. Remember W = mad, if a = 0, m and d also become 0, meaning no distance. So the nullification of the force is yeah A.

>>9062121
Right, but it's exiting at the same rate of which it's entering. Once the entrance velocity becomes 0, same thing happens with its exit velocity. Without acceleration, there's no distance.

>>9062128
so does that mean if the entrance continued moving for, say, 1 metre more, the cube would stop 1 metre away from the exit portal?

>>9062128
Because Work = mad

if a = 0 d =0 the cube after the falling portal's acceleration becomes 0 won't move any further.

>>9062133
You're making the portal three dimensional, it's 2 dimensional meaning the z axis isn't there.

>>9062142
what? i'm not introducing any new dimensions here, everything's moving in the same direction it was already moving.

If you slammed a portal down, but stop right when the box is half in and half out, would it get sucked through the portal? If not then A.

I'm not making an assertion of one or the other, but could someone adress this thought experiment?

>>9062150
it would get launched out of the exit at half the speed

>>9062148
If there's enough force to move the block it'll move, but the displaced air mass wouldn't generate enough joules move it.

Ok if it's B where is the energy coming from?

Would the portal moving down meet resistance when something goes through it? Where does the momentum come from that the box gains?

>>9062162
what energy? you don't need energy for objects to continue moving.

Does /sci/ actually believe that holes can transfer momentum to an object passing through them?

>>9062184
but you need energy to accelerate them. The cube was static

>>9062192
and it always moved at a constant speed from the exit's point of view. no acceleration occurred.

>>9062164
the portals are mounted on objects that have mass. So they could transfer the forces to the wall/piston they are mounted on.

>>9062197
before the cube entered the portal it didnt move. After the portal it was moving, which means he got kinetic energy out of somewhere. It's simple physics dude

>>9062228
This makes some sense to be.

>>9062197
Not if both portals are in the same reframe with v=0 being defined by the surroundings

>>9055231
Because special relativity had a lot of meme magic with it. From that time we even still have this retarded meme that the whole "relativity" word is reserved for light speed effects, and when you want to say that some effect is relativistic (as in due to different viewpoints) you need to clarify that you use Galilean term.

>>9055480
6/10

>>9055231
Dependeth on the force applied. Even in Newtonian physics, this would be true.

>>9064260
>>9062613
>>9062251
>>9062246
>>9062191
>>9062162
>>9062051
>>9062008
THIS PROBLEM ALREADY HAS A NAME.

Galilean relativity/invariance is only true in a FLAT, UNBROKEN SPACE.

Since with portals, space is NOT flat and unbroken, you can't use Galilean Relativity. A Galilean transformation in this space will break Newton's laws. You have to use Sterling Relativity.

When you apply a Sterling Transformation, you will see that ALL OF NETWON's LAWS OF MOTION hold. Applying the Sterling Relativity to this question, we see the answer is B.

>>9055231
The real question is what will happen if BOTH portals are moving?

>>9055781
That's not momentum, though. That's the change of space. Like our universe. It's not "flying apart" so much as the space in between particles is changing.

There's already an established theory on this, even if roundabout. Please stop shit posting.

>>9064330
>Thats not velocity, thats just an object moving a distance over time

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>>9055231
FTFY

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>>9065514
better version

>>9064330
>That's not momentum, the cube is just moving

>>9067182
>>9065492
>portals
>distance
You tried.

>>9067213
this. yall autists never learn that the portals aren't translating anything continuously through space to get it to another location. it's at point A, then it's at point B. there is not path from A to B, and nothing going through it is given energy to move through space by the portal

>>9062246
>before the cube entered the portal it didnt move.
Yes it did, relative to the room on the other side of the portal.

>>9064318
Alright, what the fuck is Sterling relativity. When I search for it all that comes up is your retarded blog

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>>9055231

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>>9068910
It depends though doesn't it, the portal could be turning matter into energy, transporting the energy and reassembling it to matter again or point A could simply be the same as point B. If the latter one is right then my guess would be that the cube wouldn't gain any momentum at all, it would just stick awkwardly out of the portal.