The limits of science: Martin Rees
Einstein averred that “the most incomprehensible thing about the universe is that it is comprehensible”. He was right to be astonished. It seems surprising that our minds, which evolved to cope with life on the African savannah and haven’t changed much in 10,000 years, can make sense of phenomena far from our everyday intuitions: the microworld of atoms and the vastness of the cosmos. But our comprehension could one day “hit the buffers”. A monkey is unaware that atoms exist. Likewise, our brainpower may not stretch to the deepest aspects of reality. The bedrock nature of space and time, and the structure of our entire universe, may remain “open frontiers” beyond human grasp. Indeed, our everyday world presents intellectual challenges just as daunting as those of the cosmos and the quantum, and that is where 99 per cent of scientists focus their efforts. Even the smallest insect, with its intricate structure, is far more complex than either an atom or a star.
Everything, however complicated – breaking waves, migrating birds, or tropical forests – is made up of atoms and obeys the equations of quantum physics. That, at least, is what most scientists believe, and there is no reason to doubt it. Yet there are inherent limits to science’s predictive power. Some things, like the orbits of the planets, can be calculated far into the future. But that’s atypical. In most contexts, there is a limit. Even the most fine-grained computation can only forecast British weather a few days ahead. There are limits to what can ever be learned about the future, however powerful computers become. And even if we could build a computer with hugely superhuman processing power, which could offer an accurate simulation, that doesn’t mean that we will have the insight to understand it. Some of the “aha” insights that scientists strive for may have to await the emergence of post-human intellects.