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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
I hope that by 2050 the entire solar system will have been explored and mapped by flotillas of tiny robotic craft.
We are 'nuclear waste' from the fuel that makes stars shine; indeed, each of us contains atoms whose provenance can be traced back to thousands of different stars spread through our Milky Way.
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.
Space doesn't offer an escape from Earth's problems. And even with nuclear fuel, the transit time to nearby stars exceeds a human lifetime. Interstellar travel is therefore, in my view, an enterprise for post-humans, evolved from our species not via natural selection, but by design.
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.
Science shouldn't be just for scientists, and there are encouraging signs that it is becoming more pervasive in culture and the media.
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.
I've got no religious beliefs at all.
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.
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.
