Here's the deal: There are actually four portals. Two of them facing to a black hole and their linked portals are facing each otherthe whole system looks like this

  1. In image BH is black hole
  2. P1 is portal number one similarly P2,P3,P4
  3. P1 is linked with P3
  4. P2 is linked with P4
  5. r is distance at which portals are revolving around black hole. r is equal for P1 and P2 Now the question is what will happen in between P3 and P4? Can an object be safe enough get advantage of time dilation , between P3 and p4? I haven't thought about distance 'r' (And what happens if black hole's gravity acts on itself and forms wierd loop?)
  • 3
    $\begingroup$ What are the physics of a “portal” and how's that differ from GR wormholes? How are these “special”? $\endgroup$
    – JDługosz
    May 6, 2017 at 13:06
  • $\begingroup$ Do you mean that P1 is linked to P3 and P2 to P4 ? Else I don't understand the question. $\endgroup$ May 6, 2017 at 13:41
  • $\begingroup$ @JDługosz read description without it they're not special $\endgroup$
    – McGucket
    May 6, 2017 at 14:05
  • $\begingroup$ @EngelOfChipolata actually I typed question on mobile stackexchange app and I'm not good at cellphones $\endgroup$
    – McGucket
    May 6, 2017 at 14:07
  • $\begingroup$ Have you ever been the rope in tug-of-war? That's what standing between P3 and P4 would be like. $\endgroup$ May 6, 2017 at 15:53

1 Answer 1


The equilibrium point between P3 and P4 is unstable. It also is a three body system which is needlessly difficult to model.

Just use a single pair of portals one of which, P1, orbits the black hole and the other, P2, is some distance away and is orbited by your object at the correct distance for your desired gravitic potential. I am not entirely certain if that would be stable either because black holes have some weird things well beyond my competence close to them. But reducing the number of objects can only help.

Since we are already assume gate technology you might want to make them spherical instead of circular. If you connect a spherical gate surrounding the black hole to another the spherical gate surrounding a volume of space. The entire surrounded volume would have a stable and constant gravitic potential, which is what you probably wanted. Constructing the machinery for the gates seems like a pain, but that is what engineers are for, right?

  • $\begingroup$ The second spherical gate will act like a black hole then? $\endgroup$
    – McGucket
    May 6, 2017 at 12:48
  • $\begingroup$ @McGucket No, the geometry will still be different. Inside the first gate will be a singularity and the gravity well of the black hole. Inside the second gate should be a flat space-time with your desired "rate of time". What the gates would look like from the outside is a different question that depends on how you decide the gates should work. You probably should ask a separate question if you decide to with this option. $\endgroup$ May 7, 2017 at 7:20

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