Is there any possibility of giving international air travel, which we all need and use and hate, a touch of glamour, or even of reliable, soulless efficiency? I suspect future historians will puzzle over our failure. But by then, of course, we shall be in the age of mass space travel, with its fresh and unimaginable crop of horrors.

Indeed it is the protean ability of Western civilization to be self-critical and self-correcting - not only in producing wealth but over the whole range of human activities - that constitutes its most decisive superiority over any of its rivals.

In the past, the U.S. has shown its capacity to reinvent its gifts for leadership. During the 1970s, in the aftermath of the Nixon abdication and the Ford and Carter presidencies, the whole nation peered into the abyss, was horrified by what it saw and elected Ronald Reagan as president, which began a national resurgence.

The planet Earth, though not threatened with destruction by man-made global warming, is by no means indestructible. There are many unpredictable events within our solar system, and still more outside it, that could make Earth uninhabitable by humans.

The peculiarities of my childhood, of constantly moving through so many different cultures, of always being the outsider, may have made me extraordinarily self-sufficient, but it had also bred a certain detachment, a sense that the world was a place to explore rather than truly inhabit. This manifested as a kind of shyness, even timidity.

I'd love to say that I'm this brave person doing this big adventure and that it's easy. The truth is, the night before I left, I called my mom, crying and nervous, thinking, 'What am I getting into? Can I really ride my bike across the country?'

Rocket scientists agree that we have about reached the limit of our ability to travel in space using chemical rockets. To achieve anything near the speed of light we will need a new energy source and a new propellant. Nuclear fission is not an option.

I Am Number Four' is an action-packed adventure entwined with a romantic story. I play the role of John Smith. John wants to be a normal kid, but he is from a different planet and he has been given this destiny of becoming a warrior.