Without doubt Kurt's big claim to fame were his "undecidability" theorems about how some mathematical statements have no proof, but are nonetheless true. But high level sci-fi fans might prefer his equations where the universe rotates in time so the future eventually returns to the past. How about that! Kurt proved time travel is possible!

Alas, others, a bit more mundane, simply point out that this "forward to the past" universe is only one possible solution to the equation, and it may have no real meaning. In fact, there is another solution to Kurt's cosmology where time proceeds forward normally, and the universe physically rotates back to it's origin. That's probably the more meaningful solution.

Kurt, like many famous mathematicians, had a mystical streak. Using modal logic, a logic that includes the concept of necessity and possibility, he worked out an ontological proof for the existence of God. The proof is quite short and not particularly difficult to understand. But it does require some new and not quite self evident axioms and Kurt also had to invent a completely new property for God (and everyone else who had it) called positivity. Empiricists snort that all this is simply reverse engineering. Find the answer you want, and work backwards until you come up with a system and axioms which are not self evident (and possibly nonsensical) that give you what you're trying to prove.

When Kurt fled Austria after the Anschluss, he became an American citizen. When he was studying for his citizenship exam, he was aghast when his quick grasp of logic allowed him to deduced that the Constitution would permit American democracy to be legally and easily transformed into totalitarianism. That caused him a bit of trouble when the examining judge asked him why he had wished to become an American citizen. Kurt said he wanted to live in a free society, and his own country had been transformed into a dictatorship. "Which of course," the judge said, "can't happen here." Kurt leapt up and cried, "Oh, but you're wrong!" His sponsor was able to divert Kurt from going further into the matter.

Although considered probably the greatest logician in history, toward the end of his life Kurt somehow deduced someone was poisoning his food. He refused to eat and eventually died of starvation.