Spyke

It's the scene with the lasers innit? So many "paradoxes" are solved with the answer of "portals cannot move relative to one another," and then they do the bit with the laser. -_-

30
hikaru755reply
lemmy.world

The thing is, movement is relative. Everything on earth is constantly in motion if you're observing from any other celestial body, so motion itself can't be what breaks portals. What it might be, though, is acceleration. Those panels in the video seem to be moving at a constant speed, so aren't experiencing any substantial acceleration, making a portal on them possible

7
lseifreply
sopuli.xyz

you can say they cant move 'relative to each other', but what about the universe supposedly expanding?

3

The same reason the Earth or your body isn't expanding along with the universe - gravity is stronger than the expansion rate

3

They can move at a constant speed in a constant direction, but the acceleration would break them.

1
hikaru755reply
lemmy.world

You can pass two 2d ovals through each other in a 3D space no problem if they're exactly the same size.

5
lolcatnipreply
reddthat.com

Yes, but can you maintain the property that each point on the orange portal is connected to a point on the blue portal and vice versa? My intuition is that you'd end up with a paradox because you'd end up with a point on one portal connected to two different points on the other, but my analytic geometry skills aren't good enough for me to attempt a proof.

0

Not sure I'm following. If the portals are exactly the same size, and stay that size, then why would you have to connect one point on one to two points on the other?

2
Spzireply

Consider these two pixel-oval portals:

  xx         oo
x    x     o    o
x    x     o    o
x    x     o    o
x    x     o    o
  xx         oo

They are the same size, and you can easily make a bijective mapping for each of their pixels.

Rotate one two times in 3D space by 90°, and it fits through the other. If you want more wiggle room, make them taller.

1

Just came here to check whether someone already posted the minutephysics video.

I think their explanation is rather good for passing portals through themselves. The box doesn't add much to the equation: it is just physical objects smashed into eachother...

2
lolcatnipreply
reddthat.com

You can't place a portal on anything the game physics would allow to go through another portal.

5
Laticaudareply
lemmy.ca

Theoretically you can if they're moving in a constant direction at a constant speed a la an inertial frame.

6

That doesn't work because gravity makes the game's reference frame non-inertial. One of the big takeaways of general relativity is that idea a reference frame that's inertial except for gravity is meaningless. Even ignoring relativity, everything is subjected to centripetal acceleration due to the Earth's rotation (and the story canonically takes place on Earth).

I think the real answer is probably the least satisfying: the game's physics just don't correspond to real physics. Most portals appear to exist in a privileged reference frame that can be said to be motionless, but even that isn't the real rule; the real rule is that portals can exist where the level designers want to allow them to exist. They try to make it feel like there's a certain logic behind it, but they'll bend the rules as necessary to make a cool puzzle work, and they keep the everything consistent within a single puzzle, but some subtleties of how portals appear to work are subject to change between puzzles.

2

Except that one time in Portal 2.

When you cut the tubes to the big gas chambery thing.

3
lemmy.world

Box moves 1 inch and the portal poofs due to an unstable surface.

22

This always bothers me when people argue what would happen if you pushed Portal portals into each other. You can't. The moment the surface moves, it's unstable and the portal pops. They're quite specific about this in the games.

-2
LinyosTreply
sopuli.xyz

They have a flag to disable that specific behaviour for that specific scene IIRC.

1

In this case, the portals are only moving in planes parallel to each other, so there is no stability introduced.

-1

Portal surfaces can move. By nature everything is moving, we just happen to be in the same frame of reference.

Regardless, here is a video of a portal on a moving surface from portal 2. https://youtu.be/OrAHvenjZpA?si=VY5dRvUP8_LPgOPO (around the 1 minute mark)

Additionally shooting a portal on the moon also demonstrates that movement is allowed (since the moon is in a non synchronous orbit)

1
lemmy.world

So how do you find a box that can fit a blue portal inside, but also itself fits through the orange portal; given that both portals are equal in size?

11

That's only in direction of motion. The height still won't fit. Of course, all hell breaks loose if they touch even if they don't pass all the way through.

1
lemmy.world

Is their anything that can escape the "self referential" paradox?

9

Gödel and Russell would be very pleased. Or maybe dismayed. I'm not sure how they felt about their discoveries.

3

I just assume as soon as one touches the other they fizzle out. I guess the top of the box gets cut a bit.

It's like folding space. They basically occupy the same location. Its just two "sides" of a 2D plane. The portal can't go into itself.

Worst case if it can it's like bottle so they just flip positions and the whole thing reverses and the box just comes right out and the colors swap.

Nothing crazy.

8

The result is a box with a portal in it, in a box with an portal in it, in a box with an portal in it, in a box with an portal in it........∞

3

In the game, the portals are always the same size. If that's true here, then the box just won't fit into the portal on the wall.

If it isn't true here, then the box will push on the inside of itself. If the lid were open, the box coming out of itself would have to be smaller than the original box since the blue portal is smaller (but that's not a mechanic seen anywhere in the Portal series).

1

The real question is what would happen if you tossed a normal size gate into an Ori supergate that were connected.

We know they CAN connect, since that's how they block the supergate from this side. And they never established whether a connected gate can move through space without losing a connection, just that you have to know where you are in space to dial out, and two gates can't activate when close together.

2
fishosreply
lemmy.world

Didn't they establish that a ship has to stop to connect? Wasn't that a thing with Universe and the gate being ON the ship? So a gate can't be actively moving while connected, I think. My memory is a bit fuzzy. And I feel like there's still one time an exception is made, but it involves some one time use trickery.

0

Gates can be moving, but not at faster than light. SG1 had the bit where they tossed an active gate into a sun to blow it up, and Atlantis had straight up orbital space gates with stabilizer rockets on them

There was some explanation about how the gates had to be calibrated to a general part of space in order to participate in the gate network which is why they couldn't use it in hyperspace. That, and probably some physics mumbo jumbo about why wormholes can't connect from within subspace or whatever

1

THIS is what happens when you succeed in making an AI ( or Hoomin ) that can create MODERN KOANS.

You Bastard!!

: P

_ /\ _

0
mander.xyz

Both portals should the same size. Fitting one in a box, means the box should be too big to fit in the other portal.

-1

They're ellipses. You put one on its side and it fits through.

11
nxdefiantreply
startrek.website

The box contains the oval, and by definition cannot fit inside the thing it contains.

-2

It isn't shown explicitly, but notice in the last panel with the box, the box is much wider and much shorter. It was rotated 90°.

2