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.

Charles Darwin [is my personal favorite Fellow of the Royal Society]. I suppose as a physical scientist I ought to have chosen Newton. He would have won hands down in an IQ test, but if you ask who was the most attractive personality then Darwin is the one you'd wish to meet. Newton was solitary and reclusive, even vain and vindictive in his later years when he was president of the society.

Cosmology does, I think, affect the way that we perceive humanity's role in nature. One thing we've learnt from astronomy is that the future lying ahead is more prolonged than the past. Even our sun is less than halfway through its life.

I think all countries need to aim to cut the CO2 emissions per person, taking account of externalities like imports and exports.

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

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.

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.