>We can follow this line back to arguing that nothing is more disruptive than the Big Bang.

Well yes, but the Big Bang was not a discovery/invention made by man. Discovery of how to start a fire would probably be a good candidate for the most disruptive tech.

Part of the difficulty is that many discoveries and inventions reach the threshold of being necessary causes of the modern world. Once you pass that threshold, how do you rank them? The removal of any of them (eg fire, the wheel, mathematics, steel, steam ...) renders the current world impossible.

Are there degrees of impossibility? I'm not sure. We may be looking at a partially-ordered set here.