What distinguishes a mathematical model from, say, a poem, a song, a portrait or any other kind of "model," is that the mathematical model is an image or picture of reality painted with logical symbols instead of with words, sounds or watercolors.

In fact, the very nature of an X-event is that it is both rare and surprising. So I would not say that any specific X-event is likely. What I would say, though, is that some X-event is not only plausible, but very likely in a time scale of a few years.

Once the reality sets in of a superhuman intelligence being in control of every aspect of the infrastructures we rely upon for everyday life, we will simply have to try to come to an accommodation with that entity.

A good analogy is stretching a rubber band. You can stretch and stretch and even feel the tension increase in the muscles in your hands and arms as the gap from one end of the band to the other widens. But at some point you reach the limits of elasticity of the band and it snaps. The same thing happens with human systems.

If you ask which of the scenarios I think is most dangerous, though, I will give a different answer. In that form of the question, I regard a nuclear attack, terrorist-generated or otherwise, as the most threatening combination of likelihood and long-term damage to modern life today.

I think that in the immediate aftermath of a superhuman machine intelligence revealing itself, most people would feel very threatened but take solace in the thought that we can always pull the plug.

The world is awash in more debt than there is money enough in the world to liquidate it.