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If the box enters the portal at a certain rate, it has to exit the portal at the same rate. Unless there’s relatively involved, that has to be true and everything else follows.

How is the portal affixed to the piston? Whatever made up system that affixes the portal to the piston would also allow it to interact with the box.

The box has to exit at the same rate it enters and the law of conservation of mass and energy dictates that no new energy is created and it has to come from somewhere. If there is no way for the energy to be transferred from the portal to the box, then simply, portals cannot exist.

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Bytemeister@lemmy.world ⁨3⁩ ⁨days⁩ ago

How is the portal affixed to the piston?

It’s doesn’t matter really, this is a red herring.

The box has to exit at the same rate it enters…

There is the problem with your logic. The box doesnt move, there is a shortcut in space that moves around it.

the law of conservation of mass and energy dictates that no new energy is created and it has to come from somewhere

EXACTLY!! A is the only scenario where energy (or more accurately, momentum) is conserved in this case. If you want to think about why that is, see my previous post where I extrapolated on a case where a lighter object with a portal on it is moved over the box.

if the portal was put on an object lighter than the box and then quickly moved over the box, the box would be launched at a speed equal to the speed of the lighter object, while it has more mass, this is not a conservation of momentum.

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- Duamerthrax@lemmy.world ⁨3⁩ ⁨days⁩ ago
  
  It’s doesn’t matter really, this is a red herring.
  
  This is not a red herring. A portal can be assumed to be massless and might not interact with anything. In theory, it could have infinite sharpness and cut though the piston when force is applied. But that’s not the hypothetical. The hypothetical has the portal fixed to the piston, interacting with mass. If it can interact with the piston, it can interact with
  
  There is the problem with your logic. The box doesnt move, there is a shortcut in space that moves around it.
  
  The box moves in relation to the portal opening. The reference frame is the portal opening. If, from start to finish, the box takes 1 second to enter the portal, it has to take one second to exit the portal. Everything works backwards from this. If traveling through the portal quickly would cause the box to be launched, then the energy has to come from somewhere and the piston is the only source.
  
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  - Bytemeister@lemmy.world ⁨3⁩ ⁨days⁩ ago
    
    This is not a red herring.
    
    Fine, let’s say it’s held on with elf cum. I’d love to see you explain how that matters.
    
    The box moves in relation to the portal opening. The reference frame is the portal opening. If, from start to finish, the box takes 1 second to enter the portal, it has to take one second to exit the portal.
    
    Whoop, you made an incorrect assumption there. You are only using a frame of reference that includes the box and the portal, any conservation of momentum is only valid for that frame of reference.
    
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