Researchers previously thought that any spacecraft attempting to use a black hole as a portal of this type would have to reckon with nature at its worst.
The hot and dense singularity would cause the spacecraft to endure a sequence of increasingly uncomfortable tidal stretching and squeezing before being completely vaporized.
Flying through a black hole
My team at the University of Massachusetts Dartmouth and a colleague at Georgia Gwinnett College have shown that all black holes are not created equal.
If the black hole like Sagittarius A*, located at the center of our own galaxy, is large and rotating, then the outlook for a spacecraft changes dramatically.
That's because the singularity that a spacecraft would have to contend with is very gentle and could allow for a very peaceful passage.
The reason that this is possible is that the relevant singularity inside a rotating black hole is technically "weak", and thus does not damage objects that interact with it.
In 2016, my PhD student, Caroline Mallary, inspired by Christopher Nolan's blockbuster film
Interstellar, set out to test if Cooper (Matthew McConaughey's character), could survive his fall deep into Gargantua – a fictional, supermassive, rapidly rotating black hole some 100 million times the mass of our sun.
Interstellar was based on a book written by Nobel Prize-winning astrophysicist
Kip Thorne and Gargantua's physical properties are central to the plot of this Hollywood movie.
Building on work done by physicist
Amos Ori two decades prior, and armed with her strong computational skills,
Mallary built a computer model that would capture most of the essential physical effects on a spacecraft, or any large object, falling into a large, rotating black hole like Sagittarius A*.
Not even a bumpy ride?
What she discovered is that under all conditions an object falling into a rotating black hole would not experience infinitely large effects upon passage through the hole's so-called inner horizon singularity.
This is the singularity that an object entering a rotating black hole cannot maneuver around or avoid.
Not only that, under the right circumstances, these effects may be negligibly small, allowing for a rather comfortable passage through the singularity.
Mallary also discovered a feature that was not fully appreciated before: the fact that the effects of the singularity in the context of a rotating black hole would result in rapidly increasing cycles of stretching and squeezing on the spacecraft.
But for very large black holes like Gargantua, the strength of this effect would be very small. So, the spacecraft and any individuals on board would not detect it.
