Just after we linked to the Physics and Cake blog's post about whether there might be a "ceiling" in the level of theoretical physics that humans can understand, Reith Lecturer Martin Rees wrote an essay for the London Times, explaining the first of his Reith Lectures. And Rees does believe that there may be intrinsic limits to human understanding of the cosmos:

Ever since Darwin, we've been familiar with the stupendous timespans of the evolutionary past - the billions of years of evolution that led to our emergence. We are more than just another primate species. We are special: self-awareness and language were a qualitative leap, allowing cultural evolution and the cumulative diversified expertise that led to science and technology.

But we should be open to the prospect that some aspects of reality - a unified theory of physics, or a full understanding of consciousness - might elude us simply because they're beyond human brains, just as Einstein's ideas would baffle a chimpanzee.

Even so, that need not mean that the fundamental questions were for ever unanswerable. That's because we humans need not be the culmination of the evolutionary tree: indeed it seems implausible that we are, because astronomy makes us aware that immense time-horizons extend into the future as well as into the past. Our Sun formed 4.5 billion years ago, but it's got six billion more before the fuel runs out. And the expanding Universe will continue, perhaps for ever, becoming ever colder, ever emptier.

So let's hope our distant ancestors are smarter than us, I guess. I also love the quote from Woody Allen that Rees cites: "Eternity is very long, especially towards the end." [London Times via Humanist Life]