The Limits of Science

Lord Rees of Ludlow delivers the 2011 Romanes Lecture. Telescopes
reveal the remote universe; accelerators probe the subatomic world.
Thanks to such instruments, astronomers have established, in
outline, how our cosmos has evolved from a still-mysterious
beginning more than 13 billion years. Billions more years - and
perhaps even an infinite time - lie ahead of it. But 99 percent of
scientists focus neither on the very small nor the very large, but
on the even greater complexities of our everyday world. Materials
science, biology and the environmental sciences proceed apace,
revealing remarkable insights, and opening up an ever-widening
range of applications - both opportunities and threats. We live on
an ever more interconnected and crowded planet, where each person
is empowered by transformative technology but is making increasing
demands on the world's resources. There is a widening gulf between
what science enables us to do, and what it's prudent or ethical
actually to do. The Earth has existed for 45 million centuries but
this is the first when one species, ours, can determine the
long-range planetary future. The stakes are high; optimum policies
require a longer-term and less parochial perspective than normally
prevails in political debate, the deployment of the best scientific
advice, and engagement of a wider public. In science itself, the
most dramatic conceptual advances are the least predictable. But,
in scanning these intellectual horizons, we must be mindful that
there may be fundamental limits to our understanding - concepts
about key aspects of reality that human brains (even
computer-aided) can't grasp. Lord (Martin) Rees was the President
of the Royal Society from December 2005 to December 2010. He is
Master of Trinity College and Professor of Cosmology and
Astrophysics at the University of Cambridge. He is also Visiting
Professor at Leicester University and Imperial College London. He
was appointed Astronomer Royal in 1995, and was nominated to the
House of Lords in 2005 as a cross-bench peer. He was appointed a
member of the Order of Merit in 2007.