But how would the objects get on the other side then? The receiving side isn't moving, so the objects essentially need to be pushed through the portal at the speed at which the train is moving, resulting in B. The only way A could work would be both portals moving at the same relative speed.

[–] MagicPterodactyl@lemmy.ml 1 points 1 year ago (1 children)

I see it like throwing a hoola hoop around something. The object will pass through without having its speed affected.

[–] SuperIce@lemmy.world 6 points 1 year ago (1 children)

But with a hula hoop, both sides of the "portal" are moving at the same speed, so the momentum of the subject is unchanged. That's not the case presented in this post

[–] MagicPterodactyl@lemmy.ml 1 points 1 year ago

That's a good point.