And now I can report that implicating black holes in our considerations concerning the ultimate laws of physics means progress. I have now concentrated most of my own research towards this subject, asking myself this: suppose you have a tiny black hole and that you insist that it obey both the laws of quantum mechanics and those of gravity. Then how should one describe its behavior?

The shrewdness of this question is that I am assuming that an entire black hole should behave exactly as if it were an atom or molecule obeying the laws of quantum mechanics. Not everybody agrees with me here – not by any means. Some say that black holes are something altogether different. But what is so different about them? Black holes emit particles just like quite a few species of radioactive atoms do. Then why should they not do this by following the same rules? To put it more strongly, I happen to suspect that they absolutely have to obey such laws if you believe in any kind of ‘law and order’ at the Planck length.

One result of my calculations was a total surprise for me. I hit upon practically the same mathematical expressions as the ones in string theory! The formulae for capture and emission of particles by a black hole look exactly like Veneziano's formula. This is odd, since there is no question of strings.