Lord Rees explores 'limits of science' in Romanes Lecture

Lord Rees of Ludlow giving the Romanes lecture. Photo: John Cairns

Lord Rees explored the limits of our current understanding of science, whether there are intrinsic limits to our scientific understanding, and the factors limiting how science is applied, at Oxford University’s Romanes Lecture on Wednesday 2 November 2011.

Video of the full lecture is now available to watch here.

Lord Rees of Ludlow, who was the President of the Royal Society from 2005 to 2010, is the Astronomer Royal and Master of Trinity College and Professor of Cosmology and Astrophysics at the University of Cambridge. He used the hour-long lecture entitled ‘The Limits of Science’ to tackle a range of topics showing the importance of science to society and the way we think.

Speaking to a full house at the Sheldonian, Lord Rees said he would ‘scan some horizons in my own field of astronomy,’ and then ‘ask if there are intrinsic limits to our scientific grasp – phenomena within the remit of science that nonetheless transcend human understanding,’ before tackling ‘more practical concerns: the threats and opportunities science presents, and the limitations on how it’s applied that are set by politics, prudence or ethics.’

Discussing the possibility of alien life Lord Rees said: 'We may learn this century whether biological evolution is unique to the ‘pale blue dot’ in the cosmos that is our home, or whether Darwin's writ runs through a wider universe that teems with life – even with intelligence. But even in the latter case, such intelligence could be qualitatively different from our own – assemblages of superintelligent ‘social insects’, or computers.'

Talking about how astronomers view life differently he said that people think humans are ‘the culmination of the evolutionary tree’ without imagining that post-human evolution could stretch billions of years into the future: any creatures witnessing the Sun’s demise won’t be human – they’ll be as different from us as we are from a bug.

‘Maybe we should be open-minded about the obverse possibility – that we hit the buffers because our brains don’t have enough conceptual grasp,’ Lord Rees said. ‘Einstein averred that “The most incomprehensible thing about the universe is that it is comprehensible”. He was right to be astonished. Our minds, evolved to cope with the life of our remote ancestors on the African savannah. It’s amazing these minds can comprehend so much of the counterintuitive microworld of atoms, and phenomena billions of lightyears away.’

In his speech he highlighted the global population reportedly rising to 7 billion this week and the need to provide basics such as clean water and primary education to the world’s poorest people.

‘Modern engineering and agriculture could provide food and energy for 9 billion by mid-century and avert irreversible degradation. And other advances, especially in healthcare and information technology, offer grounds for being techno-optimists,’ he said. ‘But we can’t be so optimistic about nations achieving the cooperation that’s needed if these benefits are to be shared by the developing world.’

He also discussed the role of scientists saying that as ‘scientific citizens’ they have a special obligation to engage with important issues – whether through blogging and journalism or campaigning and political activity.

Concluding the lecture by looking at the challenges facing humanity, Lord Rees said: ‘To survive this century, we’ll need the idealistic and effective efforts of natural scientists, environmentalists, social scientists and humanists. They must be guided by the best evidence, but inspired by values from beyond the limits of science.’

The Romanes Lecture is an historic public lecture at Oxford University. The first was given in 1892 by William Gladstone. Subsequent speakers have included Theodore Roosevelt, Winston Churchill, Sir Isaiah Berlin, Iris Murdoch, Edward Heath, AJP Taylor, Tony Blair and Sir Paul Nurse.