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.

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

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

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

The physicist is like someone who's watching people playing chess and, after watching a few games, he may have worked out what the moves in the game are. But understanding the rules is just a trivial preliminary on the long route from being a novice to being a grand master. So even if we understand all the laws of physics, then exploring their consequences in the everyday world where complex structures can exist is a far more daunting task, and that's an inexhaustible one I'm sure.

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