Remember, in the story of the Strugatsky brothers "A beetle in an anthill" there is a mention of the flight of a unique spaceship "Darkness" inside the black hole EN 200056 … If one day mankind grows to try to carry out such an experiment, what will be its results?
Let us assume that the hole to be penetrated is static and therefore does not twist the surrounding space (the Strugatskys do not mention whether the hole had a rotational moment). In this case, the boundary of the hole (aka the event horizon) is the correct sphere. The spacecraft after entering this sphere is doomed to fall into the center of the hole, and no maneuvers can prevent this. Immobile objects inside such a hole cannot exist, and the slightest movement will inevitably lead to its center, to the point of singularity, near which the force of gravity tends to infinity. The space inside the hole behaves like time - reverse movements are impossible there (this rule applies not only to material bodies, but also to quanta of light). There is no point in jumping into such a holesince the reconnaissance starship will not be able to transmit any information from there, and upon approaching the point of singularity, it will be torn apart by tidal forces.
Space spinning top
The situation inside the spinning hole is much more interesting. The fact is that it has two different external boundaries: the event horizon and the static limit. The static limit is the boundary of the region, within which any body can no longer be at rest with respect to a distant observer, but must rotate around a black hole to keep from falling. For a non-rotating hole, the event horizon and the limit of staticity coincide, while for a rotating hole they touch only at the poles (they are not spherical, but flattened along the axis of rotation of the hole). While flying through the cavity (ergosphere) lying between them, the captain of "Darkness" can still turn back and return to our Universe.
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The insides of the hole
What happens if "Darkness" does dive into the hole? After crossing the event horizon, the starship will first be pulled uncontrollably inward, as happens when falling into a hole with zero angular momentum. This means that just below the event horizon is the same "timelike" space as in a non-rotating hole, but now it does not reach the center of the hole. From the inside, this space is limited by the second horizon, and it contains the usual space (albeit strongly curved), where movement in different directions is possible.
However, caution is needed here. In this area, more precisely in its equatorial plane, there is a zone where the curvature of space, and hence gravity tends to infinity, is a singularity. But in this case it is not a point, as in the case of a non-rotating hole, but a closed ring. It is not worth approaching it - again because of the catastrophic tidal forces. Nevertheless, the spaceship may enter a trajectory that will forever leave it inside the second horizon, preventing it from falling onto the annular singularity. But the ship will never cross this horizon and return to "timelike" space.
Flying right through
Let's assume that "Darkness" flies "over" the singularity in the "northern region" of the inner space. The captain can steer the ship southward by either circling the singularity or flying through a hole in the singularity ring. Both routes are possible, but lead to different spaces without a single common point! The roundabout movement will leave the ship inside the second horizon of the same hole. A jump through the ring promises much more - the starship can enter a trajectory that crosses both horizons and brings it into normal space outside the hole. True, this will be the space of another Universe - negative.
Since weightless starships are unlikely to appear in the distant future, the brave astronauts, most likely, will do nothing good. There is reason to believe that immediately after the ship crosses the outer horizon, "beats" of the internal geometry of the hole will begin, which will turn into a source of powerful gravitational radiation. Gravitational convulsions will irreversibly destroy the previous symmetry of the intra-hole space, which will completely exclude the possibility of a breakthrough into another Universe.
Alexey Levin