With great power comes great responsibility, said the wise uncle of Peter Parker, a.k.a. Spiderman. The same might be true of Nobel laureates.

Every October, a new class of formerly obscure scientists is hurled into the limelight, their lives changing literally overnight with that phone call from Stockholm. Their daily routine changes from one of quiet hours in the lab to one encompassing many new demands on their time, from speaking engagements to invitations to sign the latest petition for peace and justice on the planet (see page 374).

In theory, this is a good thing. Most Nobel prizewinners are thoughtful people with insightful things to say about the world. And there is a rich history of prominent scientists playing crucial roles in major world decisions — Albert Einstein warning US President Franklin Roosevelt that the Germans might be thinking of building an atomic bomb, or the Federation of American Scientists drawing attention to the dangers of nuclear proliferation early in the atomic age.

But scientists need to take care not to overstep their expertise. It is reasonable to expect a Manhattan Project physicist to weigh in on the dangers of nuclear weapons, with which he or she is entirely familiar. It is less clear-cut to, say, support the candidacy of a politician.

In the United States, a group called Scientists and Engineers for America formed last year with the benevolent-sounding goals of good government, open debate, competent leadership and political participation. It sprang mainly, however, from years of frustration with the administration of President George W. Bush and its many instances of reportedly twisting science to its own ends. There is little doubt that US federal science has suffered under Bush, but it is unclear how this group will accomplish concrete goals to counter this.

Political advocacy can, in fact, be the trickiest road for a scientist–activist to navigate. Nobel-prizewinning economists, for instance, are routinely recruited to either side of US presidential campaigns, with their names trotted out like endorsements. In Scotland earlier this month, a group of 62 scientists (including Ian Wilmut, creator of Dolly the cloned sheep) wrote to The Herald newspaper, days before the country's elections, claiming that funding for science in Scotland would suffer in the event of “separation” from the United Kingdom. But the election wasn't about separation, it was about who was best equipped to run the Scottish parliament. The Scottish National Party won the election. In aligning themselves so clearly with the Labour Party's cack-handed attempts to scare its own former supporters back into the fold, the signatories at least ran the danger of seeming to be self-interested, grant-obsessed, and out of touch with people's desire for change.

Scientists who want to promote change in the world would be better off selecting their areas of activism carefully. Nobel laureates have a special responsibility, as they are regarded by the public with a level of awe. Many of them do use their names wisely to advance education or underappreciated areas of science. Last week, for instance, 40 of them helped launch a US$10-million fund to support scientific research in the Middle East. Such efforts are targeted, specific and worthy of the Nobel name.