It needs to be 2. Otherwise all the people will materialize inside eachother. In fact, everyone will be deposited onto the 2-dimensional pane of the blue portal itself, like an infinitely thing coat of paint, absolutely smearing them.
Think about it. As your fingertips enter the orange portal, they materialize at the entrance of the blue portal. Then your wrist enters the orange portal, where does it materialize at the blue portal?
- If your fingers shift to make room, then that has imparted momentum and it's option B.
- If you continue to materialize on the other side of the portal like a mirror image, then for all intents and purposes the blue portal is also moving at the same speed as the orange portal, even if orange ring appears still.
- If your fingertips don't have momentum and your wrist materializes at the portal, then your wrist is occupying the same space as your fingertips. Congratulations, you're now a paste.
For whatever reason I feel more willing to break conservation of momentum than I am to
I think it has to be A. You figure that if it were B, the people on the track would suddenly be traveling at a high velocity, but the train's velocity wouldn't be impacted at all, since there was no impact between the train and the people. Wouldn't this mean that the portal had created energy, which is impossible?
Relative to the train, and by extension the portal, the people are moving towards it at the same speed as the train relative to the ground, since the people are tied to the ground. I'm gonna work with the definition of momentum that equals it to the velocity of an object times its mass, and with the assumption that the portals conserve mass and momentum of the objects during teleportation, or with negligible losses. Having found that the momentum stays constant, and given the mass before and after teleportation is constant, the velocities relative to the portal are gonna be constant too. (p1=p2 <=> mv1=mv2 <=> v1=v2). And since the velocity of the people relative to the portal is the velocity is the train relative to the ground, and the velocity of the train relative to the ground is far bigger than the velocity of the people relative to the ground, the answer is gonna be B, where the people shoot out of the portal with great speed.
If the people actually go into the portal and not under it that is.
The train is not moving. The rest of the world is moving underneath it. Therefore, by the principle of "speedy thing go in, speedy thing come out", the people will be launched.
If the train drives slow enough that is takes 3s between when your head gets through and your feed are trough, it also needs to take 3s on the other side or you are ripped to pieces or squashed.
Now if it takes 0.1s, you also have to come out in this time and will have a velocity, the same as the train.
I think B and maybe it's easier to explain my reasoning with a more dramatic example. instead of people on a track, maybe the trolly is heading towards a 50 foot horizontal pole. when the trolly comes to the pole at 90mph, the pole is not moving. but after the trolley's portal has "swallowed" 40 feet of the pole, all 40 feet of that pole are exiting the portal at 90mph, being pushed by the 10 feet of pole that the trolly is still "swallowing", so the momentum of 40feet worth of pole would continue to launch the remaining mass of the pole out of the portal and it would be launched out instead of flopping to the ground.
if we go back to our people on a track example, I think this would also kill them as for people on either side of the portal, it would feel like they're being ran into at 90mph by the people on the other side of the portal.
did that all make sense?
B
Lets say the train is moving with 10 meters per second. That means that the people will enter the portal with 10 meters per second. Therefore, they will leave the other portal with, you guessed it, 10 meters per second. Henceforth, they will be traveling with 10 meters per second after leaving the portal. 10 meters per second.
Discussed this with some friends and the view we came to is that your momentum relative to both the portal and your surroundings is preserved (which explains how you could portal to the moon and not get liquefied by the difference in rotational momentum between earth and the moon). The portal speeds you up or slows you down depending on local conditions on the other side to preserve your relative momentum. This would, logically, indicate that energy is created or destroyed depending on the difference, which (to me) means that 'portals' technically exist outside our universe as a concept and are therefore not subject to conservation of energy.
Unfortunately, this isn't testable in Portal because portals can't be affixed to moving surfaces.
I would assume the people just plop out fine since they would retain their momentum (which is nil), and the portal's own momentum wouldn't be applied to them. But God damn it I wish I could just make a Portal map with a moving portal and see.
A if the trolley is going slow
B if the trolley is going fast.
there's a video with a great explaination about this: https://youtu.be/B19nlhbA7-E
Can someone put this in a lambda function for me so I can kill myself trying to figure it out?
Dont they need to be hovering mid air for either to happen? I am trying to imagine how would a moving portal teleport a person laying down without teleporting the ground beneath him. I think neither a or b would happen, I think they would be draggen on the ground and splattered, but if I HAVE to choose, I say A is more likely. Because they are laying and not hovering I dont think they will be launched.
This reminds me of when somebody set up the Trolley Problem for their toddler with those little wooden toy trains. The kid put the one guy on the track with the several guys and then plowed through all of them with glee.
B, but only their bellies; the portal is above most of their bodies, and their heads and ankles will get cut off for being off even the track.
C. A train flies out of the blue portal
I think it's A because I assume a portal stitches two points in space to each other.
So if I have a surface A and B with a portal ']' in the middle A0 A1 ] A2 A3. B0 B1 [ B2 B3
A portal creates a new surface
A0 A1 ][ B2 B3
And if you move the portal the new surface changes.
A0 A1 A2 ][ B3
Speed is distance over time. When a portal moves the object that passed through the portal stays stationary. Let's say I am standing on B2. When the portal advances I find myself standing on A2 , have i moved? No the environment has changed but i am still in the same relative position with respect to the portal surface. No distance travelled so no speed.
I love this comment section. Perfect balance of people actually trying to discuss and people getting pissy because their answer can be the only right one.
I don't know shit but when I try and picture it happening in my head I can only see A being correct, think Doctor Strange portals. When he moves a portal the person comes out stationary
This comment section reminds me a bit of these cringe powerscalers, discussing Saitama vs Son Goku in the comments of a YouTube video.
I've seen this debate about the outcome of the moving portal. I'm pretty certain that because of inertia, and the people aren't moving, they will just plop out the other side. Think of it like moving a hoola hoop through the people. That's basically what the portal is.
The hoola hoop has inertia and is moving, but it doesn't actually come in contact with the people, so it passes right around them. There's no way for the people to have instant acceleration because the porta did, otherwise it'd be like them hitting a brick wall and they would probably explode
If it's A, then it figures to me that the blue portal would enact some force on the structure on which it's placed when the tied up people plop out
A, the people are traveling towards the portal, not the other way around.
If they were falling/running at the portal it would be different.
Here the portal is moving forward towards them, they have no momentum.tk travel through the portal.
The Portal can't move front or back, only "to it's sides"
Suppose the blue portal is instead aligned parallel to and facing the ground. Maybe a 18" off the ground, a little higher than a person is wide. Additionally, the person is standing upright on the track.
In the above scenario, with the ground rushing at the person, does it suddenly "stop," with the person gently falling onto the ground? This is the same problem, I suppose, but from a different perspective.
Now, what if that blue portal is instead only 6" off the ground? Is the person embedded in the ground, or does the universe crash?
Suppose the blue portal is sitting upright on the tracks facing directly into the orange portal (parallel to it) from some distance. We will of course neglect gravity and most physical laws.
Option B: The people shoot out of the blue portal, eventually reaching the orange portal again after a finite time (exactly halfway between the portals). At which point, their velocity relative to the train is double what it originally was, and they shoot out of the orange portal again twice as fast. Since the people are faster than the train, they will hit the train before it covers half of the remaining distance; and so this all happens again, with the people's velocity now increasing to triple the initial value. And it happens again, and again, until relativistic effects take over and the velocity is no longer approximately additive. In other words, the people accelerate to an appreciable fraction of the speed of light, regardless of the starting velocity.
Option A: The people plop out of the portal and eventually get smashed between the train and the portal wall in a satisfying and physically plausible fashion.
Bonus Option C: In option B, it is unspecified if the resultant velocity of the people is equal to the velocity of the people relative to the train, or equal and opposite to the velocity of the train relative to the people. This difference becomes meaningful at the relativistic speeds we achieved, and I implicitly assumed the latter. In the former case, the people are eventually carrying ~100% of the energy of the system and therefore doubling it every time they pass through the portal, and time dilation be damned, for an instant they achieve infinite energy.
Now suppose the blue portal is just a centimeter behind the orange portal, opening the other direction, so anything that goes in one almost doesn't even seem to have teleported. When the people pass through the orange portal, they appear on the other side; inside the train.
Option B: As the people pass into the portal, they instantly shoot backward, as if the train grabbed and threw them behind itself.
Option A: The people simply pass through the portal, as if it weren't there at all.
