I grew up watching Carl Sagan presenting Cosmos on TV. I don't know how he became a broadcaster, but even if I did, it might not help me or anyone else wanting to follow in his footsteps. His career path was probably unique, just as my own adventure in science broadcasting has been the upshot of a happy series of chance events.
A couple of letters of mine to scientific journals (one a contribution to a jocular debate on the temperatures of hell and heaven, the other a warning of the perils of creationism) as well as some successes in competitive ballroom dancing, fencing, chess, and even my membership to Mensa attracted the attention of a widely read Galician newspaper (Galicia is an autonomous region of northwest Spain), which ran a story on me.
This story led to an appearance on a regional programme of the Spanish public television service, TVE-2. After the show I was invited to join the programme on a permanent basis, presenting a short section on things scientific. And I accepted. That was in September 1999.
Since the host programme was informal in style, so was my weekly science slot, which took the form of a 10 to 15 minute chat with the programme's compère. The topics had to be striking and attractive. They ranged from patterns of sexual selection among humans to the probabilities of winning in certain games. Being a physicist, I naturally introduced a number of physics-based topics, but always in relation to their implications for everyday life. For example, in a spot on "the physics of traffic" I did some simple calculations to drive home the lesson that reckless driving seldom gets you there faster (sorry for the play on words!), and to illustrate some sobering aspects of the physics of car crashes.
In spite of being a newcomer to the media, I had freedom to select the content of these slots, although I worked in collaboration with a professional TV scriptwriter. Our main watchword was to connect with topical events or issues. The day that the birth of the 6 billionth inhabitant of Earth was announced I spoke about demography; the day the clocks were put back was an opportunity to talk about the motion of the Earth in space. The level of my explanations was of course completely elementary: This was a general interest programme, not an Open University lecture, and we wanted to keep its 8% to 10% share of the audience (which was within the usual range for the channel).
When the host programme was taken off, its compère moved to Galician Public Radio, taking me and my science slot with him. I am currently still working at the same radio station, contributing an equally short but rather more formal weekly section to an evening programme, where in recent weeks I have been commenting, for example, on the achievements of this year's Nobel Prize winners.
Although special training might be expected for an activity involving such diverse skills as science broadcasting, I have had none, and nor have many other people I have met in the media. The essential requirement is not training, but the desire to communicate one's knowledge, some degree of innate talent for doing so (modesty apart), and a willingness to learn from experience and pay good heed to the advice of more experienced colleagues. Given all that, it's a question of jumping in at the deep end and doing one's best--just like so many other things in life.
At this point I should perhaps confess that broadcasting is basically a sideline for me--almost a hobby. My main job, lecturing and doing research at a university, must take precedence over the other. The situation might be different if broadcasting and similar communication activities were treated by academic authorities as merits in one's CV. In fact, one of the recommendations of the Workshop on Physics and Public Understanding held last year in Geneva as part of the "Physics on Stage" event for European Science and Technology Week was precisely this, that greater incentives, as well as recognition, should be provided for those who try to combat increasing scientific illiteracy in Europe by bridging the gap between scientists and the general public.
As things stand, I have never thought of working full time in science broadcasting, even if the opportunity arose. It is too unstable a world, and, in fact, I know very few scientists in Spain who have made a career in this area. Perhaps the most daunting obstacle to most science graduates who consider embarking on a career in the media is precisely the lack of a secure, established career path, and the small number of posts.
It is a different situation in the world of the press, where I see more possibilities for a professional career. Although newspapers have always had journalists who have picked up a little science rather than scientists who have turned to journalism, there are signs of a change for the better. The rapidly increasing role of science in society is gradually forcing the media to employ qualified scientists as intermediaries capable of placing the scientists' assertions in context. For example, I write occasionally for La Voz de Galicia, the leading newspaper in this region, in tandem with a professional journalist, a formula that deserves attention: The idealism of the scientist is moderated by the realism of the journalist, making the articles more intelligible to the layman, in a sort of "Quixote and Sancho Panza" coupling. Perhaps one of the most interesting recent developments in this area is the initiative taken by (among others) this newspaper: It funds a master's degree course  designed to make journalists out of people trained in other disciplines, including scientists. With schemes of this sort, it is to be hoped that scientific journalism of one kind or another will soon become an established career option in Spain, thus broadening the spectrum of career opportunities open to science graduates and, hopefully, improving the general public's appreciation of scientific issues.
* Jorge Mira Pérez is assistant professor of electromagnetism in the Departamento de Fisica Aplicada  of the University of Santiago de Compostela, Spain. His scientific research focuses on magnetism and magnetic materials, a field in which he has published about 60 papers in international journals.