Carl sagan — contact. chapter 19 — naked singularity

PART III
THE GALAXY

CHAPTER 19
Naked Singularity

THEY WERE falling. The pentagonal panels of the dodecahedron had become transparent. So had the roof and the floor. Above and below she could make out the organosilicate lacework and the implanted erbium dowels, which seemed to be stirring. All three benzels had disappeared. The dodecahedron plunged, racing down a long dark tunnel just broad enough to permit its passage. The acceleration seemed somewhere around one g. As a result, Ellic, facing forward, was pressed backward in her chair, while Devi, opposite her, was bending slightly at the waist. Perhaps they should have added seat belts.
It was hard not to entertain the thought that they had plunged into the mantle of the Earth, bound for its core of molten iron. Or maybe they were on their way straight to… She tried to imagine this improbable conveyance as a ferryboat upon the River Styx.
There was a texture to the tunnel walls, from which she could sense their speed. The patterns were irregular soft-edged mottlings, nothing with a well-defined form. The walls were not memorable for their appearance, only for their function. Even a few hundred kilometers beneath the Earth's surface the rocks would be glowing with red heat. There was no hint of that. No minor demons were managing the traffic, and no cupboards with jars of marmalade were in evidence.
Every now and then a forward vertex of the dodecahedron would brush the wall, and flakes of an unknown material would be scraped off. The dodec itself seemed unaffected. Soon, quite a cloud of fine particles was following them. Every time the dodecahedron touched the wall, she could sense an undulation, as if something soft had retreated to lessen the impact. The faint yellow lighting was diffuse, uniform.

Occasionally the tunnel would swerve gently, and the dodec would obligingly follow the curvature. Nothing, so far as she could see, was headed towardthem. At these speeds, even a collision with a sparrow would produce a devastating explosion. Or what if this was anendless fall into a bottomless well? She could feel a continuous physical anxiety in the pit of her stomach. Even so, she entertained no second thoughts.
Black hole, she thought. Black hole. I'm falling through the event horizon of a black hole toward the dread singularity. Or maybe this isn't a black hole and I'm headed toward a naked singularity. That's what the physicists called it, a naked singularity. Near a singularity, causality could be violated, effects could precede causes, time could flow backward, and you were unlikely to survive, much less remember the experience. For a rotating black hole, she dredged up from her studies years before, there was not a point but a ring singularity or something still more complex to be avoided. Black holes were nasty. The gravitational tidal forces were so great that you would be stretched into a long thin thread if you were so careless as to fall in. You would also be crushed laterally. Happily, there was no sign of any of this. Through the gray transparent surfaces that were now the ceiling and floor, she could see a great flurry of activity. The organosilicate matrix was collapsing on itself in some places and unfolding in others; the embedded erbium dowels were spinning and tumbling. Everything inside the dodec — including herself and her companions — looked quite ordinary. Well, maybe a bit excited. But they were not yet long thin threads.
These were idle ruminations, she knew. The physics of black holes was not her field.