It turns out that the left temporal lobe, if there's a lesion there, will create hyper-religiosity. People become super-religious. They see demons and spirits everywhere. We think Joan of Arc may have had it.

One in 200 stars has habitable Earth-like planets surrounding it - in the galaxy, half a billion stars have Earth-like planets going around them - that's huge, half a billion. So when we look at the night sky, it makes sense that someone is looking back at us.

It's pointless to have a nice clean desk, because it means you're not doing anything.

What we usually consider as impossible are simply engineering problems... there's no law of physics preventing them.

In string theory, all particles are vibrations on a tiny rubber band; physics is the harmonies on the string; chemistry is the melodies we play on vibrating strings; the universe is a symphony of strings, and the 'Mind of God' is cosmic music resonating in 11-dimensional hyperspace.

The human brain has 100 billion neurons, each neuron connected to 10 thousand other neurons. Sitting on your shoulders is the most complicated object in the known universe.

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.

If you are teaching Muslim sixth formers in a school, and you tell them they can't have their God and Darwin, there is a risk they will choose their God and be lost to science.

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.

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.

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.

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).

Most theorists suspect that space has an intricate structure - that it is 'grainy' - but that this structure is on a much finer scale than any known subatomic particle. The structure could be of an exotic kind: extra dimensions, over and above the three that we are used to (up and down, backward and forward, left and right).

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 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.

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

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.

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.

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.

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.

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.

Indeed, evolutionists don't agree on how divergently our own biosphere could have developed if such contingencies as ice ages and meteorite impacts had happened differently.

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.