A physicist working on the math for 30 years claims she has proven them out of existence. I will rework her equation with a bit of quaternion wavelet hypergeometry and see if I can prove once and for all that Blackhole Cities at least can exist. Then if Stephen Hawking has any problem with it we will finally get some press exposure.
Another strong theory. “The Electric Universe” Who needs black holes when just magnetic fields and charged particles will do? Its called plasma. The Aurora Borealis apparently caused by plasma bullets - is an Earthly example.
So if blackholes really don’t exist they will live on in our eternal city imagination. But the proof either way is a long way off.
Here is a good example of Black Holes getting no respect combined with a good round of Tekakak.