/sci/ - Science & Math

[TechnoAnon No.5662482]

Which is it?

[Anonymous No.5662489]

Assuming the kinetic energy of the cube is conserved when it goes trough the portal, A.

Assuming the energy og the cube is determined by an observer sitting at the blue portal, seeing the cube come towards him/her, B.

I'd probably go with A.

[TechnoAnon No.5662491]

bump

[TechnoAnon No.5662496]

Personally, i think it's B.
Since the blue portal is stationary, but the orange portal is moving, when the orange portal moves over the cube the cube is going to come out of the portal at the same speed the piston was moving.
So if the piston was moving fast enough, the cube will remain in motion and appear to fly out of the blue portal.

[Anonymous No.5662498]

B

[None !SouFinItEY No.5662502]

>>5662482
It is, has been, and always will be (until Valve decides otherwise) A.

[Anonymous No.5662501]

>>5662498

elaborate, but you're still handwaving the most important point of the question.

the portals defy the laws of physics to being with, so what evidence is there that conservation of momentum would hold for reference frames involving portals?

[None !SouFinItEY No.5662509]

>>5662501
In fact we have unlimited evidence that portals do not conserve momentum, as momentum is a vector and the angles are not preserved for arbitrary portal arrangements (whether moving or not).

Thus any argument for B based on conservation of momentum is trivially dismissed based on evidence.

[Anonymous No.5662513]

https://www.youtube.com/watch?v=S85nudR6D-Y
This is what happens
/thread

[anonymous No.5662514]

dont ever use a fulcrum on a fixed pulley you dumb ass where the fuck is your downward force?? DO YOU EVEN LIFT FAGGOT??!

[Anonymous No.5662515]

>>5662509
portals do preserve the magnitude of momentum.

[Anonymous No.5662510]

>>5662501
What do you mean by "the most important point of the question"? I think I said specifically the answer is B.

Portals could violate many laws of physics, so in a sense it is merely an imaginary device that can displace materials between two locations, like a wormhole of somesort (well it is one). And since the science behind the mechanics behind it is unclear and unsolved IRL, we can only base on the laws we imagine (as provided in the game).


>>5662502
sauce?

[Anonymous No.5662519]

>>5662509
"unlimited evidence that portal do not conserve momentum" <--- I dont see any, can you give an example?

how do you explain the law of "speedy things goes in speedy thing goes out"?

[Anonymous No.5662520]

>>5662515
the real question is whether they take frames of reference into account or not

in real life, we can't test it because they don't exist

in the game, it would definitely be A based on the coding

[Anonymous No.5662521]

>>5662509
We could imagine the portals as connecting an infinite line of worlds (think looking in a mirror with a mirror behind you), so that the box coming in and the box going out are actually two separate objects. Then momentum conservation would dictate that B hold.

[Anonymous No.5662525]

A

zero momentum to begin with,
zero momentum it ends with

piston did not transfer any energy to it

[Anonymous No.5662524]

>>5662520
No
https://www.youtube.com/watch?v=S85nudR6D-Y

[Anonymous No.5662527]

>>5662513
game science =/= game engine

game science is an imaginary science that the game engine merely try to simulates and this the youtube video, it is obvious that the game engine is not made to accommodate such experiement since the game did not have to.

TLDR: a game engine is not good enough for "experiments"

[Anonymous No.5662531]

>>5662525
please see >>5662498

>>5662520
please see >>5662527

[None !SouFinItEY No.5662532]

>>5662519
Any instance where the portals do not share an axis. Angles (direction) change, therefore momentum changes.

[Anonymous No.5662538]

I have a hula-hoop. Moving toward a box at 10 m/s. The box is stationary.

The box passes through the hoop. Box is still stationary.

Answer is A.

[Anonymous No.5662536]

>>5662531

so what you're saying is that since we can't test it and it's not relevant, we shouldn't be talking about it at all?

[None !SouFinItEY No.5662537]

>>5662515
Yes, they do. And the magnitude of the cube's momentum in the picture is 0. Hence A.

[TechnoAnon No.5662540]

>>5662538
Your hula hoop argument is invalid.
In your argument, both the entrance and exit are moving at the same speed and vector.
In the question, the blue portal is stationary and te orange portal is moving

[Anonymous No.5662542]

What are you actually debating? You can't test this in the real world. This doesn't work in the game. So, it is impossible to devise an experiment that would establish who is right. The point of a debate is to get to truth; but, there is no truth. So what exactly are you debating?

[Anonymous No.5662543]

>>5662538

consider this situation:

the portal is stationary and the platform on which the cube is sitting is moving

if the platform moves up to the portal and the cube goes through what happens? it's A

no consider if the moving platform stops right before the cube hits the portal, then it's B

which of these two situations would the moving portal platform see? it depends on the way you've defined the physics of the game

[Anonymous No.5662553]

What if it slams down, and stops abruptly 2/3s of the way onto the cube. Does the cube's momentum throw it through?

Portals are simply unphysical.

[Anonymous No.5662556]

>>5662553
>What if it slams down, and stops abruptly 2/3s of the way onto the cube. Does the cube's momentum throw it through?

Yes.

[Anonymous No.5662560]

For fuck's sake people.

[None !SouFinItEY No.5662559]

>>5662556
I guess B-fans don't mind being wrong, as long as they're consistently wrong.

[Anonymous No.5662566]

>>5662560
That's wrong though, nothing happens.

[Anonymous No.5662564]

>>5662553
>What if it slams down, and stops abruptly 2/3s of the way onto the cube. Does the cube's momentum throw it through?

Yes, at 2/3 the speed the portal was moving.

[Anonymous No.5662569]

>>5662521
Come on guys, I already solved the problem.

[Anonymous No.5662570]

>>5662543
>if the platform moves up to the portal and the cube goes through what happens? it's A

No, it's still B in that case.

[Anonymous No.5662573]

>>5662566
>That's wrong though

Specifically, how is it wrong?

[Anonymous No.5662571]

>>5662553
The moving portal would rip the cube to shreds as it teleports the cube one atomic layer at the time to the other portal and shoots it out at some velocity.

[Anonymous No.5662580]

I honestly can never tell with these threads if people are trolling or not.

[Anonymous No.5662583]

[Anonymous No.5662585]

>>5662571
your "velocity" does not matter because S(in) always = S(out), so the object will always remain intact

the law of conservation of momentum also protects the objects regardless of movements of portals

[None !SouFinItEY No.5662588]

>>5662585
> the law which portals violate will protect them
wut

[Anonymous No.5662589]

>>5662583
no it won't fly, but it will punch out at the same speed the Portal(in) is moving

[Anonymous No.5662593]

>>5662573
https://www.youtube.com/watch?v=S85nudR6D-Y
Nothing happens.

[Anonymous No.5662598]

>>5662593
dude, that's a video game. Do you appeal to mario kart to understand the physics of cars?

[Anonymous No.5662602]

>>5662525

figure one is wrong. zero momentum =/= 10km/s. the portal has no frame of reference, it is a hole. i don't know how to eleborate on it, but just stare at it for long enough and ull see.

[Anonymous No.5662603]

>>5662598
Portals only exist in a video game. If it doesn't work in the game it is a completely irrelevant question.

[Anonymous No.5662606]

one conserves force

the other conserves velocity

it's possible to interpret either to conserve energy

[Anonymous No.5662616]

>>5662606
>it's possible to interpret either to conserve energy

No, it's not. It can't be A because of >>5662560

[Anonymous No.5662617]

>>5662598
>>>Hey guys, what would happen if we did this physically impossible thing in this video game?
>>Nothing. It's also impossible in the video game.
>lol why r u arguing from the video game about physics?
Portals are unphysical. They can't be reconciled with physics.

[Anonymous No.5662624]

>>5662617
They can be reconciled with physics, there's nothing that says conservation of energy is necessarily true, it just happens to more or less be true as far as we know in our universe.

But if you just want to discuss video game mechanics you should be on >>>/v/, as long as this is on /sci/ appeals to reason will win out.

[Anonymous No.5662629]

[Anonymous No.5662636]

>>5662624
>They can be reconciled with physics
No, they really can't, and that you think they can shows that you are extremely ignorant of physics.

They violate the speed of light limit. They violate conservation of momentum, as well as conservation of energy.

Portals are unphysical.

[Anonymous No.5662639]

>>5662629

0/10

[Anonymous No.5662644]

>>5662636
>They violate the speed of light limit.
No they, at no point in space or time does the object possess velocity equal to or greater than the speed of light.


So what if they violate conservation laws? Give me one reason why conservation of either energy or momentum MUST exist, did your Physics God decree it?

[Anonymous No.5662648]

>>5662624
There is actually something that says conservation must be true. The time invariant property of the Lagrangian makes a very convincing case that conservation of energy must be true.

[Anonymous No.5662646]

>>5662629

In that case the portal exits the block at C while the portal is moving, as it must (it exits at the same rate it enters). When the portal stops, the half that is through already has that momentum, which the block retains. It thus continues at speed C/2.

[Anonymous No.5662651]

>>5662617
You can have them in GR if you allow negative energy densities.

[Anonymous No.5662654]

>>5662644
If information can be transmitted faster than the speed of light and there is no conservation of energy or momentum, then there is nothing you can use from real-world physics to support any arguments about your fantasy video-game physics.

Whatever you want to say happens in your fantasy, happens.

It is pure fantasy, and has nothing to do with the real world or physics.

[Anonymous No.5662655]

>>5662648
The time in-variance assertion is fully equivalent to the conservation assertion. Its a simple re-stating, it doesn't make it any more necessarily true.

[Anonymous No.5662656]

>>5662651
No, you can't. Wormholes and warp drives are not portals. They both behave very differently.

[Anonymous No.5662657]

>>5662648
And it's possible time invariance or quantum mechanics breaks down in some situations.

That said, portal mechanics need no more be a violation of conservation of energy than slingshotting around Jupiter is. The energy can be supplied by the portals.

[Anonymous No.5662661]

i was a believer of A, then i realize it is actually B.

for those who still believes that it is A....

the exit portal is stationary, that means the block has to be "coming out of it" which means it is carrying speed, and thus momentum. and thus it will shoot out.

energy is not conserved. that is an important note

[Anonymous No.5662662]

>>5662656
An appropriately tailored wormhole behaves exactly like a portal.

[Anonymous No.5662664]

>>5662657
Stop talking about conservation of energy as if it was the only problem with portals. Conservation of momentum is a much bigger problem.

[Anonymous No.5662665]

>>5662560

this makes sense, but this is not how it works at any point in either of the games, so why bring it up?

[Anonymous No.5662666]

>>5662662
>I don't know anything about wormholes except what I heard on Star Trek.

[Anonymous No.5662670]

>>5662570

sorry but you're wrong. this is something you can actually test out in the game

[Anonymous No.5662673]

>>5662664
Which can be resolved in exactly the same way as energy.

[Anonymous No.5662686]

>>5662666
Do you need an explicit metric written out? Making a wormhole that looks like a portal is pretty trivial. It's just flat spacetime except at the ring at the edge (unless the portal accelerates, of course, thus this thread).

[Anonymous No.5662689]

>>5662686
where by "making" I mean on paper obviously

[Anonymous No.5662691]

>>5662673
Momentum can't just be stored up somewhere, something has to actually change velocity. And remember that both linear and angular momentum must be conserved PERFECTLY for ALL objects on ALL scales. Teleporting a stationary grain of sand by half an inch changes the angular momentum of the galaxy.

You can't discuss the "physics" of portals unless you specify the mechanism of this, and none is suggested by the game.

[Anonymous No.5662696]

>>5662686
That would actually be pretty cool. But, a portal looks like a discontinuity in space, a metric will be smooth everywhere. Can you make the portal metric one sided? Portals seem to cause problems for spatial derivatives because it depends on what direction you are coming from (discontinuous on the back side, continuous on the front side). I'm not expert in GR, but if you make a wormhole metric isn't it a "3d hole"?

[Anonymous No.5662703]

>>5662686
You obviously have no notion of the proposed physics of wormholes, and the effects necessarily surrounding them.

There is a theory of traversible wormholes, but nothing like a portal which could be placed conveniently on a wall, or produce unlimited energy by letting you drop from one into another above it, accelerating all the time. We're talking about extreme warping of space, here. The energies involved are not small or self-cancelling.

[Anonymous No.5662714]

Answer is B, everyone see >>5662498 for explaination.

"The law of conservation of momentum" is something from the "lore" of Portal, GlaDos explained it very clearly as "speedy thing goes in speedy thing goes out". So when we think about an imaginary problem that involves portals, this law automatically applies because it is part of the "physics" of portals.

The S(in) and S(out) involves not the same portal: the S(in) equates the travelling speed of Object (atoms, stuff, etc) relative to Portal(in), and S(out) equals the speed of Object coming out relative to Portal(out). The two portals are different, and they can move relative to each other (as in the original question), but the S(in) will always S(out).

S(in) = momentum of object(in) relative to portal(in)
=
S(out) = momentum of object(out) relative to portal(out)

So if you move the portal quickly over the cube, the S(in) will be at a certain speed higher than zero (let's say 10km/s). This is no different that throwing an object into the portal at 10km/s because the S(in) involves only the object and the portal and does not care about the world (literally).

This S(in) will directly translate into S(out)=10km/s which means the atoms will emerge out of the portal at 10km/s.

That means the answer is B.

What I said earlier that "the law of conservation of momentum will also protect the object", what I mean is because the S(in) always equals S(out), there will be no pulling force or pushing force when part of an object emerges at the other side, therefore the object will always remain intact.

To those who argue with "testing with the game": the game is just a game, it is not an experiement simulation, the game cannot be used for anything because it is built for just being a game. It doesn't have the ability to simulate a "moving portal" because it didn't need to.

[Anonymous No.5662721]

>>5662714

speedy things go in speedy things go out

the block isn't speedy, the portal is, so your argument fits in with half of the other posts in this thread. read the whole thread before you post something redundant next time

[Anonymous No.5662724]

>>5662696
Do they actually show the backside of the portal in the game? To do it with a wormhole, you would just connect the backsides as well. If that's inconsistent with the game, I'll have to admit there's a difference.

The only part that needs a nonflat metric is the ring at the edge, which for purposes of smoothness has to have a nonzero size. We can use cylindrical coordinates; then we can set the time and angle parts of the metric to the same as flat space even in the ring. Then transform the z and r parts from rectangular to polar coordinates about the center of the ring, and inside the ring, you can use the metric of the hyperbolic plane.

[Anonymous No.5662726]

>>5662691
There's the wall the portal is attached to.

[Anonymous No.5662732]

This thread is mostly trolling. The proof is the willful ignorance of the fact that nothing actually happens in the game.

[Anonymous No.5662738]

>>5662726
So describe the forces between the portal, the object passing through it, the wall the portal is attached to, the store of energy, and what happens when it runs out.

[Anonymous No.5662734]

>>5662724
the backside of a portal is the other portal. The blue and orange portals are two sides of single object.

[Anonymous No.5662739]

>>5662721
I guess you didnt read...

S(in) = momentum of object(in) relative to portal(in)

"the block isn't speedy, the portal is" confirms there is a S(in), which equals the speed of your "speedy portal" relative to your "not speedy block + the earth"

[Anonymous No.5662745]

>>5662724

There is no "backside" of a portal... you are thinking it in terms of an object. It is not. It is merely a "displacement plane" that is effective from "one side". The "backside" doesn't do anything, so you will not see anything (effectively invisible).

[Anonymous No.5662751]

>>5662732
When you bring up the game (the game program) you are just trolling because we are discussing about science, whether it comes from the story of a game or not

[Anonymous No.5662754]

>>5662703
Of course the energies involved aren't small. Hence the Jupiter analogy.

It's not very realistic, but it's not outright impossible either unless the energy conditions are outright impossible, which is very likely. Although if I were writing a science fiction explanation using GR, I would be more likely to go with some undiscovered coupling of the metric to something other than energy, which would make the tech attainability of wormholes more plausible in general.

[Anonymous No.5662760]

>>5662665
Because it's the most rational answer, and you happen to be on a board discussing science and facts.

[Anonymous No.5662765]

>>5662732
The game doesn't feature anything other than a light beam passing through a moving portal. The game engine has an answer, but it's very glitchy, and it's reasonable to presume that it would be redesigned if it were to be used in actual gameplay. The B answer is consistent with a reasonable simple theory of how moving portals would work if they were actually implemented properly.

[Anonymous No.5662766]

>>5662751
No you aren't. Science is concerned with material things. Restated, science is about experiment. If you don't have an experiment you don't have science. There is no experiment you can do with portals, not even in principle.

[Anonymous No.5662768]

>>5662766
Hey if physics departments can study string theory what's the difference?

[Anonymous No.5662770]

>>5662765
So frame the debate correctly. It's not about what will happen. It's about your *opinion* of what *should* happen. If you have that debate it is more interesting because there are more interesting hypotheticals than just A and B. The framing of this debate is constraining and nothing new ever comes out of it.

[Anonymous No.5662783]

It's out of the range of physics.

There is no answer.

[Anonymous No.5662788]

>>5662754
You seem to be very confused. Traversable wormholes aren't impossible, as long as we have several impossible things to work with, and as long as GR holds true under conditions not even close to those within which it has been tested.

But a traversable wormhole which looks and acts like a portal from the games Portal and Portal 2 is impossible under all known physics. The thing just wouldn't sit passively, anchored to a wall on a massive, spinning planet, not affecting or being affected by stuff around it or stuff passing through it, regardless of the difference in orientation and gravity at the two ends of the wormhole.

Seriously, stop arguing this bullshit.

[Anonymous No.5662793]

>>5662768
They at least try to come up with experiments. People in this thread can't even be bothered to watch a 4 minute youtube video that answers the question of what happens in the game.

[Anonymous No.5662797]

>>5662768
String theory is more an approach to theorizing than a single theory. It is distinguished by a particular sort of mathematics being used to model the physical universe.

Contrary to common misconception, string theory has produced falsifiable predictions, the problem is that they've been practically untestable, trivially equivalent to other theory, or proven false. Specific string theories have been falsified, while others remain untested, but the overall approach hasn't been, and really, can't be.

String theories are physics, string theory is math.

[Anonymous No.5662798]

>>5662793
The answer in the video is: this feature is not programmed in so nothing happens.

[Anonymous No.5662804]

>>5662788
>The thing just wouldn't sit passively, anchored to a wall on a massive, spinning planet, not affecting or being affected by stuff around it or stuff passing through it, regardless of the difference in orientation and gravity at the two ends of the wormhole.
Why would the energy fields or whatever required to make such a thing be affected more by the shit passing through the portal than Jupiter is affected by a satellite? They wouldn't be. I'll grant that without modifications to the EFE to get the metric we want without the energy densities it says we need, it's like playing with nuclear bombs, multiplied by some number of 10s I won't calculate, and nobody would actually do it on their home planet. And yes, you would need to do more to keep it in the position you wanted than just anchor it to a wall. Keeping the thing from falling would be more of a concern than the fact that it's on a spinning planet, which is almost irrelevant.

[Anonymous No.5662816]

>>5662804
>Why would the energy fields or whatever required to make such a thing be affected more by the shit passing through the portal than Jupiter is affected by a satellite?
Why would the planet you put it on be less affected than if you rubbed Jupiter up against it?

Your whole argument about portals being possible "because wormholes" is extremely stupid.

[Anonymous No.5662818]

>>5662724
I realize I didn't include the gravity in the room, although that's easy to deal with, too. You just have to let the time component of the metric varies a little from place to place. The gravitational potential (by which I mean that time component) has to vary smoothly, but it doesn't have to be the same from one side of the portal to the other. So you can have wormhole-portals from which gravitational energy can be extracted as shown in the game, but a necessary consequence of that is that the time between the two portals gradually drifts out of sync, making the portal eventually a portal to the past/future.

[Anonymous No.5662824]

>>5662816
>Why would the planet you put it on be less affected than if you rubbed Jupiter up against it?
Because the presumption of the wormhole science fiction game is that you can carefully craft the gravitational field generated into whatever you want by carefully choosing the appropriate stress-energy tensor. If you get it slightly wrong, your planet is toast, but I've already said as much.

[Anonymous No.5662829]

Christ, this one has been done to death. I think we can agree this debate is all hypothetical and just for fun. Lets pick a more interesting problem. Try this one.

[Anonymous No.5662831]

>>5662829
Meant to say D>>d, not D>>r

[Anonymous No.5662842]

>>5662824
>the presumption of the wormhole science fiction game
We're not talking about a science fiction game, we're talking about what could be physically possible with real physics.

And no, for wormholes, even traversable ones, to exist in the real world, it is not required that you be able to "carefully craft the gravitational field generated into whatever you want".

I don't believe in wormholes, but that's not all there is to how they work. There are still inescapable limitations and requirements.

No matter what your assumptions about how negative energy density might be achievable, you can't make a man-sized traversable wormhole that won't have major side-effects on its surroundings, just as you can't make a black hole that has an event horizon and no gravitational field beyond it.

[Anonymous No.5662862]

Alright, I'll try to get us started.

[Anonymous No.5662890]

>>5662862
It must be B. So the portals effectively shield the region in between from the electric field.

[None !SouFinItEY No.5662894]

the depths to which b-fans sink in twisting the thread away from the game is really depressing

in the end they basically just assert "in this made up model of what I think portals should be like what I think happens happens"

the threads all need to be banned

[Anonymous No.5662905]

>>5662890
No one else? Where did all these opinionated posters go? I guess everyone is still thinking about it.

[Anonymous No.5662906]

the answer completely depends on when you think the cube's frame of reference changes.

if you think the cube's frame of reference changes at the moment it starts going through the portal, then its B. if you think the frame of reference changes as soon as the cube has passed all the way through the portal, then its A. If you assume anything midway, then the cube will most likely break due to the forces acting upon it.

[Anonymous No.5662912]

>>5662906

No, it's simpler than that. If the cube exits the portal at the same rate it enters, then it's B.

[Anonymous No.5662931]

the edge of the portal stamp would stop the portal once it touched the surface of the thing the portal lying on
other thats why it is A
if the surface the cube was standing on would fit completly into the portal/ was as small as the cube itself it would be B

thank you hold your applause

[Anonymous No.5662936]

>>5662842
That is exactly how people come up with shit like the Alcubierre drive. They pick the metric they want, and the EFE tell you what energy densities you need to achieve it. All I'm saying is that you can do precisely the same thing to make wormhole-portals. The metric that does what I want exists. It does not have the "major side-effects" you describe. There's nothing more to argue about.

[Anonymous No.5662949]

>>5662931

No.

[Anonymous No.5662947]

It's B.
When the cube is 99.9% out of the blue portal it's moving at the velocity of the orange portal. Why would it suddenly stop when it’s 100% out?

[Anonymous No.5662948]

wouldn't the earth absorb the force of the piston and not the cube?

[Anonymous No.5662951]

>>5662949
yes.

[Anonymous No.5662959]

>>5662513
This is the answer. If you disagree with this as the answer please make a portal IN THE MOTHERFUCKING REAL WORLD and test it.

Can't? THAT'S BECAUSE PORTALS AREN'T REAL FAGGOT.

Stop bringing this stupid unscientific shit to the science board.

[None !SouFinItEY No.5662964]

>>5662947
The orange portal stops when it hits the platform. If it didn't, and the platform also went through the portal, then of course the cube (and the platform it is on) would continue to come out of the blue portal.

[Anonymous No.5662966]

>>5662959
thought experiments are a classic part of science. Just because you don't have two brain cells to rub together and think for yourself doesn't mean everyone else is a "faggot"

[Anonymous No.5662977]

>>5662964
I ment the cube, not the portal. If the cube is moving at some velocity what suddenly stops it when it's fully out of the blue portal?

[Anonymous No.5662981]

>>5662890
If it's B then that would create an infinitely strong magnetic field around the region connecting the portals. Where would the energy come from to sustain it?

[Anonymous No.5662990]

Stop making these pseudo-science threads.

[None !SouFinItEY No.5662991]

>>5662977
> what makes it stop
the orange portal stops. The cube is sitting on a platform. The orange portal approaches this platform, passing over the cube, so the cube emerges from the blue portal as the orange portal passes over it.

When you ask, "What makes it stop" I feel like you are changing reference frames. First, you want the orange portal('s platform) to be the reference frame. Then, once the cube starts leaving the blue portal, you want the blue portal('s platform) to be the reference frame. If you change reference frames willy-nilly like that, you will only confuse yourself. Instead pick one and stick to it.

I recommend picking the reference frame of the eye watching this happen for the sake of expediency (since it is already conveniently drawn for us). You can see that the cube has no momentum, and isn't given any by the orange portal, until---having exited the blue portal---gravitational acceleration drags it down the slope with a slight "plop."

The situation is not different if we see pick the reference frame of the orange portal. It sees a cube rushing at it. Then the cube "suddenly" stops. But that's the same as us watching the orange portal approach the cube, then stop when the platforms come together.

B never comes close to happening.

[Anonymous No.5663006]

>>5662981
The electric field isn't going to be straight up and down. There are going to be edge effects.

That said, a Gaussian surface argument isn't sufficient to tell you what the field between the portals is. If we're using wormhole portals, then since a wormhole can carry a fixed electric flux from one mouth to another, I don't think we can say what the answer is unless we specify what that flux is. If we presume the flux was fixed when the wormhole was created and that the portal backsides are connected, then the portal should not act as an electric field shield because the amount that flows in the back has to equal what flows out the front.

[Anonymous No.5663023]

>>5662991
The part of the object that already came out is pushed by the incoming part of that object.
It makes sense that once it completely passed through, the velocity of the cube doesn't suddenly become null.

[None !SouFinItEY No.5663061]

>>5663023
It doesn't have a velocity. It's just sitting there on a platform. Deal with it.

[Anonymous No.5663085]

Hmm... instead of having the backsides connected to each other, maybe they're both connected to the secret facility that provides energy to the portals. That would also explain how you can open one portal before opening the other. What you actually have is TWO portals to the facility. When you traverse what appears to be a single portal, what you are actually doing is traveling to the secret facility and back.

[Anonymous No.5663198]

>>5663023

an object at rest stays at rest until acted upon by an outside force.

Now, what force is acting on the cube when the portal moves over it? What energy is being transferred to the cube to overcome it's inertia and cause it to move?

[Anonymous No.5663201]

>>5663198
you cant explain unphysical phenomena with physics.

[Anonymous No.5663205]

>>5663201

Then delete the thread.

There is no energy transfer to the cube. It has to have its inertia overcome in order to move. Special pleading is not an answer.

[Anonymous No.5663210]

>>5663205
space time distorted. It didn't move but it gained momentum. Nothing wrong with that.

[Anonymous No.5663214]

>>5663210

Since when do portals have an attractive force?

Stop making things up. Speedy thing goes in, speedy thing comes out. Conversely, stopped thing goes in, stopped thing comes out.

You need a force to overcome the inertia of the block or it's just going to plop out from gravity alone.

[Anonymous No.5663215]

Kind of both...

if you were a spectator to this, you would see the cube moving fast towards you through the portal, but if you stare at the cube directly it is still the same place

[Anonymous No.5663216]

>>5663214
portals are the epitome of attractive force, they're a fucking sharp discontinuity in space and time, its the extreme limiting case of warping space-tiem.

[Anonymous No.5663218]

>>5663215

yeah. it would appear to move very fast as it came out of the portal due to the motion of the other portal, but the block would not have any of the energy of this motion and would simply drop to the ground from gravity.

It would look weird. But that's how it would be.

[Anonymous No.5663219]

>>5663214
your problem is that you think the cube has to accelerate. it doesn't. Its always in an inertial reference frame, that reference frame however is different on each side of the portal. Relative to an observer, it goes from rest to motion without intervening acceleration.

Its momentum space teleportation, I can't see why you'd have a problem with that given that you've already accepted real space teleportation.

[Anonymous No.5663226]

>>5663219

Cite where you are deriving the fact that conservation of energy is violated by portals.

You are saying that the act of passing through the portal imparts all the kinetic energy of that portal. This never happens in the game. You are making assumptions based on nothing.

[Anonymous No.5663233]

>>5663216

Demonstrate an example of the portals imparting energy to an object in the games.

Otherwise you are just making shit up to fit your hypothesis.

[Anonymous No.5663238]

>>5663233
objects fall infinitely gaining speed.

[Anonymous No.5663244]

>>5663238

From gravitational attraction as they are outside of the portal. Not from the portals themselves. The mechanics are similar to but not exactly like orbiting.

[Anonymous No.5663242]

>>5663226
when is conservation of energy not violated by portals? You simply move an object to a higher point with a portal and you've violated conservation.

[Anonymous No.5663247]

>>5663244
Its like orbit, except it violates conservation of energy.

[Anonymous No.5663245]

I rest it

[Anonymous No.5663252]

>>5663242

You moved the block. That adds the energy. The opposite side of the portal is in a slightly less gravity field if it's higher up.

This is the major difference. If you impart energy onto it, it's fair. It's when you're not imparting energy and still getting motion, like Example B, that's cheating.

[Anonymous No.5663257]

>>5663247

No. It doesn't. The thing falls from one portal to another, each time it's in freefall it accelerates according to the gravitational constant if we assume no air resistance.

[Anonymous No.5663262]

>>5663257
where does the energy come from? without portals an objects gravitational potential is turned into kinetic energy as it falls. With portals, and object suddenly gains gravitational potential, then turns it into kinetic, then suddenly gains more gravitational potential while preservering its kinetic energy, then gets more kinetic energy as it falls again, and then suddenly gets more potential energy , while still preserving its kinetic energy.


THAT IS NOT CONSERVATION. THAT IS MAGIC.

[Anonymous No.5663264]

>>5663252
energy is not added unless you do work. You do not do work unless you move it against a force. Portal bypasses gravitational force to raise block. Energy was dun created.

[Anonymous No.5663273]

>>5663262
The energy is added by gravity acting on the object. Are you rere?

[Anonymous No.5663275]

>>5663273
gravity is a conservative field. I don't think you know physics... at all.

[Anonymous No.5663303]

I can't believe this is on sci

It can't be solved with real world physics

It depends on how you think of a portal. if it is just a ring that connects two points in space, it is A since space has no inertial reference frame.

if the portal is some sort of "object" like a field of energy, it s B

[LeX !i68/3eKYfU No.5663311]

Holy shit you retards.

Its A.

[Anonymous No.5663323]

>>5663303

this solution has already been posted, and it's also been posted that people like to ignore this. i've saged this thread many times already

[Anonymous No.5663327]

Neither

[LeX !i68/3eKYfU No.5663333]

I just texted this shit to my cousin who is about to complete his physics bachlors and surrounded with his physics major classmates all say its A.

[Anonymous No.5663354]

>>5663333

good, at least some people arent' retarded

[Teacup !obkpuSWh5M No.5663358]

The cube would probably start accelarating infinitely into itself and rotate perpertually into the other dimension outside the blue portal because of the momentum imparted into it by the orange portal.

[Anonymous No.5663360]

>>5663303
>I can't believe this is on sci
it gets posted all to often

[Anonymous No.5663389]

>>5663333
I have completed a physics masters and I can tell you with absolute certainty it is B, I then showed it to a lecture hall filled with esteemed personages attending a conference and Stephen Hawking himself stood up and yelled, "B! B!, a thousand times B!."

[Anonymous No.5663397]

what about gravity?

wouldnt earths gravity affect the earth through both portals, pulling itself arround both until they are at the center of gravity? an interesting doomsday device.

[Anonymous No.5663402]

>>5663397
nah, because the portals subtend a very small solid angle from the earth. It would be very inconsequential.

[LeX !i68/3eKYfU No.5663408]

>>5663389

[Anonymous No.5663415]

This is a better question that gets to the fundamentals of the problems portals cause for the continuity of space. This thread is pleb tier though, so only a few people are capable of speculating on a hypothetical boundary condition that would give some kind of consistent solution to the Laplace equation, just for suits and giggles. This stuff isn't real of course.

[Anonymous No.5663417]

>>5663408
Oh, but Albert Einstein, just descended from Heaven with Nikola Tesla at his right hand and Newton on his left. They all concur that it is B.

[LeX !i68/3eKYfU No.5663434]

>>5663417
This made me lol

[Anonymous No.5663435]

disregard

[Anonymous No.5663442]

>>5663408

v is not zero relative to the moving portal

for our purposes the cube is NOT standing still. it is in motion and it has momentum relative tot he portal.

[Anonymous No.5663445]

>>5662966
But it's just circle jerking mental masturbation that accomplishes nothing.

No theory is correct so you'll argue this endlessly. Put the fucking thing to rest already

[LeX !i68/3eKYfU No.5663458]

>>5663445
Youre trolling.

Stop.

[LeX !i68/3eKYfU No.5663462]

>>5663445

[LeX !i68/3eKYfU No.5663469]

>>5663462
Meant for >>5663442

[Anonymous No.5663518]

I did an experiment and recorded the results

Answer is B

The box is still flying at 10m/s

[Anonymous No.5663529]

>>5663462

>what does that even mean, am I being trolled?

even in his example, with the hole dropped over the box, the box has motion relative to the hole

in all probability YOU'RE trolling me. it's just relative motion, middle school physics. when you're in an airplane do you have momentum? when you're sitting in your desk do you have relative momentum? in both cases the answer is, it depends on what your velocity is relative to. in this case the relevant point of reference is the portal, not the ground. it has v going into the portal and it must have v coming out.

[Anonymous No.5663558]

>>5663518
I would be delighted to hear your experiment, as we don't have portals.

[TechnoAnon No.5663852]

...

[Anonymous No.5663873]

>>5663558
.

[Anonymous No.5663945]

>>5663518
wrong