“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.”

“All space projects push the frontiers of technology and are drivers of innovation.”

“Campaigning against religion can be socially counter-productive. If teachers take the uncompromising line that God and Darwinism are irreconcilable, many young people raised in a faith-based culture will stick with their religion and be lost to science.”

“Collective human actions are transforming, even ravaging, the biosphere - perhaps irreversibly - through global warming and loss of biodiversity.”

“Crucial to science education is hands-on involvement: showing, not just telling; real experiments and field trips and not just 'virtual reality.'”

“Devastation could arise insidiously, rather than suddenly, through unsustainable pressure on energy supplies, food, water and other natural resources. Indeed, these pressures are the prime 'threats without enemies' that confront us.”

“During the 20th century, we came to understand that the essence of all substances - their colour, texture, hardness and so forth - is set by their structure, on scales far smaller even than a microscope can see. Everything on Earth is made of atoms, which are, especially in living things, combined together in intricate molecular assemblages.”

“Ever since Darwin, we've been familiar with the stupendous timespans of the evolutionary past. But most people still somehow think we humans are necessarily the culmination of the evolutionary tree. No astronomer could believe this.”

“Everything, however complicated - breaking waves, migrating birds, and tropical forests - is made of atoms and obeys the equations of quantum physics. But even if those equations could be solved, they wouldn't offer the enlightenment that scientists seek. Each science has its own autonomous concepts and laws.”

“From a personal perspective, I am disappointed that we have yet to really achieve a full understanding of the origins of life on Earth. What was the spark that, billions of years ago, kickstarted the process of evolution that has brought us life as we know it today? I hope that we will get some answers to that in my lifetime.”

“From the growth of the Internet through to the mapping of the human genome and our understanding of the human brain, the more we understand, the more there seems to be for us to explore.”

“Given the scale of issues like global warming and epidemic disease, we shouldn't underestimate the importance of a can-do attitude to science rather than a can't-afford-it attitude.”

“I have no religious belief myself, but I don't think we should fight about it. In particular, I think that we should not rubbish moderate religious leaders like the Archbishop of Canterbury because I think we all agree that extreme fundamentalism is a threat, and we need all the allies we can muster against it.”

“I hope that by 2050 the entire solar system will have been explored and mapped by flotillas of tiny robotic craft.”

“I would support peaceful co-existence between religion and science because they concern different domains. Anyone who takes theology seriously knows that it's not a matter of using it to explain things that scientists are mystified by.”

“If we do find ET, we will at least have something in common with them. They may live on planet Zog and have seven tentacles, but they will be made of the same kinds of atoms as us. If they have eyes, they will gaze out on the same cosmos as we do. They will, like us, trace their origins back to a 'Big Bang' 13.8 billion years ago.”

“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.”

“If you represent the Earth's lifetime by a single year, say from January when it was made to December, the 21st-century would be a quarter of a second in June - a tiny fraction of the year. But even in this concertinaed cosmic perspective, our century is very, very special: the first when humans can change themselves and their home planet.”

“If you take 10,000 people at random, 9,999 have something in common: their interests in business lie on or near the Earth's surface. The odd one out is an astronomer, and I am one of that strange breed.”

“I'm a technological optimist in that I do believe that technology will provide solutions that will allow the world in 2050 to support 9 billion people at an acceptable standard of living. But I'm a political pessimist in that I am concerned about whether the science will be appropriately applied.”

“I'm not myself religious but have no wish to insult or denigrate those who are.”

“In future, children won't perceive the stars as mere twinkling points of light: they'll learn that each is a 'Sun', orbited by planets fully as interesting as those in our Solar system.”

“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.”

“In the case of climate change, the threat is long-term and diffuse and requires broad international action for the benefit of people decades in the future. And in politics, the urgent always trumps the important, and that is what makes it a very difficult and challenging issue.”

“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.”

“Indeed, the night sky is the part of our environment that's been common to all cultures throughout human history. All have gazed up at the 'vault of heaven' and interpreted it in their own way.”

“Ironically, it is only when disaster strikes that the shuttle makes the headlines. Its routine flights attracted less media interest than unmanned probes to the planets or the images from the Hubble Telescope. The fate of Columbia (like that of Challenger in 1986) reminded us that space is still a hazardous environment.”

“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.”

“It is astonishing that human brains, which evolved to cope with the everyday world, have been able to grasp the counterintuitive mysteries of the cosmos and the quantum.”

“It is foolish to claim, as some do, that emigration into space offers a long-term escape from Earth's problems. Nowhere in our solar system offers an environment even as clement as the Antarctic or the top of Everest.”

“It might seem paradoxical that the biggest scientific instruments of all are needed in order to probe the very smallest things in nature. The micro-world is inherently 'fuzzy' - the sharper the detail we wish to study, the higher the energy that is required and the bigger the accelerator that is needed.”

“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.”

“It's often better to read first-rate science fiction than second-rate science - it's far more stimulating, and perhaps no more likely to be wrong.”

“Manned spaceflight has lost its glamour - understandably so, because it hardly seems inspiring, 40 years after Apollo, for astronauts merely to circle the Earth in the space shuttle and the International Space Station.”

“Manufacturing doesn't just mean building cars and metal-bashing; it includes making pharmaceuticals and hi-tech electronics. A crucial part of the process is the research and development that allows better and greener products to come to market. Britain has traditionally had a strong science and engineering base.”

“Maybe the search for life shouldn't restrict attention to planets like Earth. Science fiction writers have other ideas: balloon-like creatures floating in the dense atmospheres of planets such as Jupiter, swarms of intelligent insects, nano-scale robots and more.”

“Not even the most secular among us can fail to be uplifted by Christianity's architectural legacy - the great cathedrals. These immense and glorious buildings were erected in an era of constricted horizons, both in time and in space.”

“Over most of history, threats have come from nature - disease, earthquakes, floods, and so forth. But the worst now come from us. We've entered a geological era called the anthropocene. This started, perhaps, with the invention of thermonuclear weapons.”

“Perhaps future space probes will be plastered in commercial logos, just as Formula One cars are now. Perhaps Robot Wars in space will be a lucrative spectator sport. If humans venture back to the moon, and even beyond, they may carry commercial insignia rather than national flags.”

“Post-human intelligence will develop hypercomputers with the processing power to simulate living things - even entire worlds. Perhaps advanced beings could use hypercomputers to surpass the best 'special effects' in movies or computer games so vastly that they could simulate a world, fully, as complex as the one we perceive ourselves to be in.”

“Science is a part of culture. Indeed, it is the only truly global culture because protons and proteins are the same all over the world, and it's the one culture we can all share.”

“Science is the one culture that's truly global - protons, proteins and Pythagoras's Theorem are the same from China to Peru. It should transcend all barriers of nationality. It should straddle all faiths, too.”

“Science isn't just for scientists - it's not just a training for careers.”

“Science shouldn't be just for scientists, and there are encouraging signs that it is becoming more pervasive in culture and the media.”

“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.”

“Scientists surely have a special responsibility. It is their ideas that form the basis of new technology. They should not be indifferent to the fruits of their ideas. They should forgo experiments that are risky or unethical.”

“Some claim that computers will, by 2050, achieve human capabilities. Of course, in some respects they already have.”

“Some global hazards are insidious. They stem from pressure on energy supplies, food, water and other natural resources. And they will be aggravated as the population rises to a projected nine billion by mid-century, and by the effects of climate change. An 'ecological shock' could irreversibly degrade our environment.”

“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.”

“Space and time may have a structure as intricate as the fauna of a rich ecosystem, but on a scale far larger than the horizon of our observations.”

“The atmospheric CO2 concentration is rising - mainly due to the burning of fossil fuels. It's agreed that this build-up will, in itself, induce a long-term warming trend, superimposed on all the other complicated effects that make climate fluctuate.”

“The bedrock nature of space and time and the unification of cosmos and quantum are surely among science's great 'open frontiers.' These are parts of the intellectual map where we're still groping for the truth - where, in the fashion of ancient cartographers, we must still inscribe 'here be dragons.'”

“The Blair government perhaps ranks as the best the U.K. has had for 50 years. It cannot match the scale of Attlee's reforms, but has a fine record of constitutional reform and economic competence. In my own areas - science and innovation - there have been well-judged and effective changes.”

“The challenge of global warming should stimulate a whole raft of manifestly benign innovations - for conserving energy and generating it by 'clean' means (biofuels, innovative renewables, carbon sequestration, and nuclear fusion).”

“The 'clean energy' challenge deserves a commitment akin to the Manhattan project or the Apollo moon landing.”

“The extreme sophistication of modern technology - wonderful though its benefits are - is, ironically, an impediment to engaging young people with basics: with learning how things work.”

“The first arrival of earthly life on another celestial body ranks as an epochal event not only for our generation, but in the history of our planet. Neil Armstrong was at the cusp of the Apollo programme. This was a collective technological effort of epic scale, but his is the one name sure to be remembered centuries hence.”

“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?”

“The images of Earth's delicate biosphere, contrasting with the sterile moonscape where the astronauts left their footsteps, have become iconic for environmentalists: these may indeed be the Apollo programme's most enduring legacy.”

“The most important advances, the qualitative leaps, are the least predictable. Not even the best scientists predicted the impact of nuclear physics, and everyday consumer items such as the iPhone would have seemed magic back in the 1950s.”

“The practical case for manned spacef light gets ever-weaker with each advance in robots and miniaturisation - indeed, as a scientist or practical man, I see little purpose in sending people into space at all. But as a human being, I'm an enthusiast for manned missions.”

“The scientific community should work as hard as possible to address major issues that affect our everyday lives such as climate change, infectious diseases and counterterrorism; in particular, 'clean energy' research deserves far higher priority. And science and technology are the prime routes to tackling these issues.”

“The scientific issues that engage people most are the truly fundamental ones: is the universe infinite? Is life just a sideshow in the cosmos? What happened before the Big Bang? Everyone is flummoxed by such questions, so there is, in a sense, no gulf between experts and the rest.”

“The stupendous time spans of the evolutionary past are now part of common culture (though maybe not in the United States Bible Belt, nor in parts of the Islamic world). Most people are at ease with the idea that our present biosphere is the outcome of four billion years of Darwinian evolution.”

“The Swedish engineer who invented the zip fastener made a greater intellectual leap than many scientists do in a lifetime.”

“There are at least as many galaxies in our observable universe as there are stars in our galaxy.”

“There are lots of ideas which extend the Copernican principle one step further. We went from the solar system to the galaxy to zillions of galaxies and now to realising even that isn't all there is.”

“There are strong reasons for believing that space goes on beyond the limits of our observational horizon. There are strong reasons because if you look in opposite directions, conditions are the same to within one part in 100,000. So if we are part of some finite structure then, if the gradient is so shallow, it is likely to go on much further.”

“There is an ever-widening gap between what science allows and what we should actually do. There are many doors science can open that should be kept closed, on prudential or ethical grounds.”

“There's now, for the first time, a huge gulf between the artefacts of our everyday life and what even a single expert, let alone the average child, can comprehend. The gadgets that now pervade young people's lives, iPhones and suchlike, are baffling 'black boxes' - pure magic to most people.”

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

“To most people in the U.K., indeed throughout Western Europe, space exploration is primarily perceived as 'what NASA does'. This perception is - in many respects - a valid one. Superpower rivalry during the Cold War ramped up U.S. and Soviet space efforts to a scale that Western Europe had no motive to match.”

“We can trace things back to the earlier stages of the Big Bang, but we still don't know what banged and why it banged. That's a challenge for 21st-century science.”

“We do not fully understand the consequences of rising populations and increasing energy consumption on the interwoven fabric of atmosphere, water, land and life.”

“We know too little about how life began on Earth to lay confident odds. It may have involved a fluke so rare that it happened only once in the entire galaxy. On the other hand, it may have been almost inevitable, given the right environment.”

“We need to broaden our sympathies both in space and time - and perceive ourselves as part of a long heritage, and stewards for an immense future.”

“When scientists are asked what they are working on, their response is seldom 'Finding the origin of the universe' or 'Seeking to cure cancer.' Usually, they will claim to be tackling a very specific problem - a small piece of the jigsaw that builds up the big picture.”

“Whether it is to reduce our carbon-dioxide emissions or to prepare for when the coal and oil run out, we have to continue to seek out new energy sources.”