When, in 1850, the Chancellor of the Exchequer asked Michael Faraday about the practical value of his experiments with electricity, the great physicist famously answered: 'One day, Sir, you may tax it.' Faraday’s reply neatly encapsulates how even the most apparently far-fetched fundamental research can, in due time, have unforeseeable ramification in everyday life. Advanced societies cannot afford to stifle the most powerful drive of technological and social progress, namely scientific curiosity for its own sake. As a professional astrophysicist, I am well aware that my discipline addresses some of the most fundamental questions about the cosmos we live in: where did the Universe come from? What is it made of? What will its ultimate fate be? And - perhaps the most fundamental question of them all - why is the structure of reality the way it is?
In my experience, the public is very actively engaging with those questions. The workings of the Universe exert what could be described as a primordial fascination on many of us. And it’s not just the amateur astronomers who are engaging: I have given hundreds of lectures to adults and children, participated in science festivals in the UK and abroad, visited schools, worked with teachers, artists, designers and architects to reach out to a very diverse audience. I have been surprised to discover how people from all walks of life want to know the latest findings about dark matter, dark energy and the Big Bang. They want to explore the intellectual thrill of Einstein’s theory, and what it says about the cosmos. They want to stretch the limits of their imagination when trying to picture an expanding Universe. They want to be part of one of the greatest intellectual adventures that is helping define what it means to be human.
Observational, not experimental
But much engagement remains tied to the old model of top-down communication of science, where the role of the professional scientist is confined to lecturing, explaining, showing, answering questions, trying to achieve that wonderful ‘ah-ha!’ moment where an abstract notion such as the expansion of the Universe suddenly clicks into place. This is not because of lack of openness to a fully-fledged dialogue on the part of the scientists. Rather, it is a direct consequence of the intrinsic nature of astrophysics as an observational science. This distinction sets astrophysics aside from almost all the other sciences, which adopt an experimental approach, and it is a fundamental element when thinking about public engagement models for astrophysics.
The key characteristic of astrophysics and cosmology is that most of their objects of study lie beyond the boundaries of our solar system, hence completely outside the realm of practical experimental manipulation. They are separated from us by an almost unimaginable stretch of empty space. Even nearby stars in our galaxy are several light years away. To cross our own galaxy, the Milky Way, a light beam travelling at 300,000 km per second would take 10,000 years. It is sobering to think that the light hitting your retina from the closest galaxy in our local group, Andromeda (visible to the naked eye in a dark night as a fluffy smudge in the sky), left 2.5 million years ago, at the time when modern humans had not even started evolving on Earth.
All that means that astrophysicists must be content with gathering as much observational evidence as they can about the Universe, then try to put the puzzle back together, working backwards from observations to possible theoretical explanations for them. The work of an astrophysicist is akin to that of an archeologist, trying to reconstruct the workings of an entire civilization from a few scattered fragments of pottery. The difference is that, often, the astrophysicist is trying to infer the location of the cow that gave the milk that went into making the cake that was contained in that pot of which only a few fragments survive - all of that, from millions of light years away.
The observational nature of astrophysics means that major conceptual revolutions (such as the Copernican model of the solar system, or the discovery by Hubble of the expansion of the Universe, or the proof that the Big Bang happened) constitute cultural paradigm shifts of great symbolic and intellectual significance, but often without the everyday life applications of other types of science.
In contrast, biotechnology, or stem cell research, or nuclear physics and its use in power generation carry with them significant ethical, moral and practical questions as to their application and their impact on society. A two-way dialogue with the public is not only mandatory for such research, but also in a way easier to set up, thanks to the obvious common ground between scientists, public and stakeholders - the potential way such research might impact on everybody’s life. The absence of such immediate, practical consequences of astrophysics makes a truly dialogic encounter between scientists and the public more challenging.
The blessing of astrophysics – its being concerned with fundamental, pure questions that fascinate almost everybody – thus turns into something close to a curse when it comes to spearheading more inclusive forms of public engagement.
Towards a new encounter
How can then the public be included in a more active way in shaping fundamental research in astrophysics? As a whole, the field is shifting towards a model where large, expensive facilities are required to make new discoveries. The planning, construction and exploitation of both ground based and (even more so) space based observatories requires decades of work, hundreds of millions of pounds of investment, and the effort of thousands of scientists and engineers. The romantic idea of a lone astronomer working from their back garden is today very much the exception.
The community already has permanent commissions (for example, the Decadal Survey in the US, or various panels within the Science and Facilities Research Council in the UK) as well as ad hoc ones that survey the state of the field and produce recommendations with a view to prioritising future investment. It would be positive if members of the public could give input to this process, so that the views of the public at large could be considered more fully when deciding future research directions.
Web-based initiatives such as GalaxyZoo , and Cosmology@Home , which invite members of the public to contribute from home to ongoing research, are very positive and hugely successful. However, it is still the professional scientists who decide in which direction the efforts of the public should be directed.
Art is the secret
In my science communication activities, I found that talking about astrophysics in an artistic language can provide the common ground needed for a two-way dialogue with the public. Casting scientific ideas in an artistic form largely removes the knowledge step between the professional and the public. Feelings, emotions, sensory experiences brought about by art transcend the technical knowledge that often constitutes a barrier to a true dialogue.
This was the driving idea behind the Urban Sputnik project,  a collaboration involving colleagues at Imperial, a designer and an engineer. Our aim was to create a sensory experience, loosely based on abstract cosmological and astrophysical concepts, that could give the user a metaphorical connection with phenomena never otherwise experienced on a human scale. The sculptures of Urban Sputnik tried to convey an experience, rather than teach; they strived to interrogate, rather than provide answers; they spoke to the heart, rather than just to the mind. In this way, the public and the scientists are thrown together into a new territory, one in which the technical aspects of astrophysics are but one of the strands of the discourse.
At its best, this art and science approach can further a deeper communication between scientists and the general public, fostering a better understanding of the views of each, for the benefit of both astrophysics and society.