Martin Rees

“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.”

“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.”

“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 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.”

“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.”

“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.”

“Just as there are many Jews who keep the Friday ritual in their home despite describing themselves as atheists, I am a 'tribal Christian,' happy to attend church services.”

“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.”

“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.”

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

“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.”

“The next humans to walk on the moon may be Chinese. Only China seems to have the resources, the dirigiste government, and the willingness to undertake a risky Apollo-style programme. If Americans or Europeans venture to the moon and beyond, this will have to be in a very different style and with different motives.”

“Most practising scientists focus on 'bite-sized' problems that are timely and tractable. The occupational risk is then to lose sight of the big picture.”

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

“Stars that become supernovae start off at least eight times heavier than our sun. They're so short-lived that, even if they have planets, there is unlikely to be time for life to get started. The surface is 40,000C and, as a result, the colouring will be extremely blue.”

“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.'”

“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.”

“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.”

“Darwin and his successors taught us how our biosphere evolved, and thereby transformed our conception of humanity's place in nature. In the twenty-first century, space scientists are setting Darwin in a grander cosmic context - probing the origins of Earth, stars, atoms and the universe itself.”

“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.”