dd637b1b_Particles_vs__strings__particles
[topic] black holes [strings] Some advantages are found in the description of black holes, but the situation is unclear. [particles] 
A black hole is defined by an "event horizon", which is the border of the part of space where even light must hit the singularity, which is in turn defined as the region where the theory breaks down. Thus the very existence of black holes in a theory of gravity indicates its inadequacy. (However, black hole singularities might be avoided by formulations in "Euclidean space", with imaginary time.) Black hole solutions are not expected in a composite-state theory of gravity.
Particles vs. strings
particles