In future, visitors to the headquarters of the Royal Society in London are to be greeted by a stone bust of Lucie Green, one of the UK's best-known astrophysicists and astronomers.

While she has already made a public name for herself on television as Sir Patrick Moore's natural heir, that she has been chosen to welcome those who step over the door of this prestigious scientific institution is almost as big a step for womankind as was Neil Armstrong's for the human race. Nor will she be the only one thus honoured.

As part of a radical new move, Green will be kept company by other brilliant women, among them Mary Somerville, the Scottish astronomer and mathematician, and Dorothy Hodgkin, the Nobel Prize-winning chemist. In addition, portraits of leading women scientists are to be commissioned to hang on the Society's walls, so that eventually an old and cruel imbalance will, in a small way, have been redressed. That the decision is supported by the likes of Dame Athene Donald, Professor of Experimental Physics at the University of Cambridge, suggests that the achievements of women in science have been - as in many walks of life - scandalously overlooked. Fewer than 7% of the Society's 1600 members are female, which rather speaks for itself.

You might wonder what difference displaying a few women's faces can make. Incalculable, I'd say. As giant billboards on every high street make clear, images change the way we think, and the things we aspire to. Girls in particular are bombarded with pictures selling them notions of how they should look and behave. When it comes to the world of the mind, however, suddenly the signposts disappear. It's as if, with the exception of becoming a doctor, it is deemed unattractive for girls to be ambitious, or brainy, or to think more about their intellect than their looks. No wonder so few go on to study engineering, science or technology, when the achievements of chemists or physicists or mathematicians in centuries past is rarely, if ever, talked about. With the exception of Marie Curie, who of the female role models in this field are ever discussed for younger women to be inspired by?

Nor is this a benign form of neglect. Women and their experiments and equations have been routinely belittled, sidelined or airbrushed from the record. It probably goes on still. But there are plenty of disgraceful stories in other arenas too. Take the art scene where, until the second world war, women were deemed useful only as a model, mistress or muse. Discussing a forthcoming exhibition at the Scottish National Gallery of Modern Art this winter intended to resurrect a mislaid generation of women, one expert said: "just because artists were bohemian didn't mean they weren't misogynists". As a result, good and possibly great works were utterly ignored. Meanwhile in America, Project Vox has been set up to resurrect the reputation of four influential but unknown female philosophers, among them Anne Conway and Margaret Cavendish, whose role in shaping modern thought was crucial, though you would never think that to read the textbooks, where they are absent except as a footnote.

And therein lies the problem. We like to think there has never been a more self-promoting era than ours. In reality, however, every age has had its own methods of advancing people's reputations, by which some have flourished, and others have either fallen between the cracks, or been actively pushed into them. The history of women's contribution to many academic and artistic realms, and our ignorance of them, is not due entirely to the fact that it was unseemly - and unthinkable - for women to trumpet their achievements. It's more sinister than that. They were actively kept in the shadows. Thanks to prejudice, not to mention fear, work had to be done under a husband or colleague's name, or a male pseudonym. In science, well into the 20th century, women often had to do their jobs as volunteers, because universities would neither educate nor employ them. The Royal Society itself only allowed women to join in 1945.

It could keep you awake at night, wondering about the geniuses who have been lost: their discoveries dismissed, suppressed or destroyed, their voices and ideas unheard. When it comes to great minds from the past, out of sight is indeed out of mind. That an ancient bastion of male interests such as the Royal Society finally understands this should encourage all institutions that are built partially on the endeavours of women to follow suit. From now on, every woman who enters the Society's HQ will recognise that they can play a role here, should they wish to. It's not rocket science - although for some it will be - but it's a powerful idea.