“If we ever established contact with intelligent life on another world, there would be barriers to communication. First, they would be many light years away, so signals would take many years to reach them: there would be no scope for quick repartee. There might be an IQ gap.”

“Scientists habitually moan that the public doesn't understand them. But they complain too much: public ignorance isn't peculiar to science. It's sad if some citizens can't tell a proton from a protein. But it's equally sad if they're ignorant of their nation's history, can't speak a second language, or can't find Venezuela or Syria on a map.”

“It would be sad if the expertise built up during the 40 years of the U.S. and Russian manned programmes were allowed to dissipate. But abandoning the shuttle, and committing to new launch vehicles and propulsion systems, is actually a prerequisite for a vibrant manned programme.”

“And we should keep our minds open, or at least ajar, to concepts on the fringe of science fiction. Flaky American futurologists aren't always wrong. They remind us that a superintelligent machine is the last instrument that humans may ever design - the machine will itself take over in making further steps.”

“In our interconnected world, novel technology could empower just one fanatic, or some weirdo with a mindset of those who now design computer viruses, to trigger some kind of disaster. Indeed, catastrophe could arise simply from technical misadventure - error rather than terror.”

“It is mistaken to claim that global problems will be solved more quickly if only researchers would abandon their quest to understand the universe and knuckle down to work on an agenda of public or political concerns. These are not 'either/or' options - indeed, there is a positive symbiosis between them.”

“Space doesn't offer an escape from Earth's problems. And even with nuclear fuel, the transit time to nearby stars exceeds a human lifetime. Interstellar travel is therefore, in my view, an enterprise for post-humans, evolved from our species not via natural selection, but by design.”

“The first voyagers to the stars will be creatures whose life cycle is matched to the voyage: the aeons involved in traversing the galaxy are not daunting to immortal beings. By the end of the third millennium, travel to other stars could be technically feasible. But would there be sufficient motive?”

“Issues relating to global health and sustainability must stay high on the agenda if we are to cope with an ageing and ever-increasing population, with growing pressure on resources, and with rising global temperatures. The risks and dangers need to be assessed and then confronted.”

“Advances in technology - hugely beneficial though they are - render us vulnerable in new ways. For instance, our interconnected world depends on elaborate networks: electric power grids, air traffic control, international finance, just-in-time delivery, and so forth.”

“To ensure continuing prosperity in the global economy, nothing is more important than the development and application of knowledge and skills.”