Europe's Quest for the Universe
- Lodewijk Woltjer
“The progress of science depends on the technological development of its instrumentation,” claims Lodewijk Woltjer in the opening line of Europe's Quest for the Universe. From Galileo to Edwin Hubble and Riccardo Giacconi, this has been especially true for astronomy. But, as Europe's former research commissioner Philippe Busquin adds in his preface: “The star-studded sky acts as a source of wonderment and inspiration for our thoughts and dreams.” And that's lucky, in these days of obsessive, applications-oriented political pressures on science.
Both from the ground and from space, astronomy has been a success story for Europe, and one that needed to be told. Descriptions of bold endeavours can come from leaders in the field and be accurate yet not impersonal, or they can come from observers without a direct influence on the outcome. Woltjer was director-general of the European Southern Observatory (ESO) for eight years and has been a keen observer of astronomy in Europe and across the world. He writes, then, both as a leader and a commentator. This turns out to be a perfect recipe for the history of the varied and variable discipline of space science, in a continent that has more nations than big telescopes, and where the number of active space astronomy missions is close to the number of member states of the European Space Agency (ESA).
From the ruins of the Second World War, Europe, like Japan, has emerged to become a world-class power in the peaceful and cultural endeavour to understand our Universe. It all came together at the same time, in those magic years at the end of the 1950s when everything must have seemed possible: we had CERN, the European particle-physics laboratory; the European Space Research Organisation (ESRO); and, of course, the ESO. I wonder whether Europeans today would be capable of pulling off a similar coup in our extremely affluent society?
But a merely historical reading would be a limited and limiting one for Woltjer's book. I intend to make it required reading for my astronomy students (and strongly recommend the same for similar courses), mostly because it provides the right approach to the phenomenology of the Universe. Apart from the elusive gravitational waves, astronomers learn most about our Universe by gathering and analysing electromagnetic radiation from it. The art of astronomy is to extract the maximum information carried to us from the stars by travelling photons: arrival direction, arrival time, energy and state of polarization. And, of course, to gather as many photons as possible.
We've done this for centuries with bigger and bigger telescopes on the ground, but “we live at the bottom of an ocean of air”, as Galileo's favourite pupil, Evangelista Torricelli, remarked with astonishing insight. The bulk of the spectrum can only be studied properly from space. For the first time in the history of humankind, astronomy is possible out there, and we've had close encounters with planets and comets in the Solar System. Europe has sent probes to planets and comets (Huygens, Mars Express, Rosetta, Venus Express and so on) through ESA's science programme, and these are discussed in Woltjer's book.
Woltjer has also been a leading figure in space-astronomy planning for Europe, working with Roger Bonnet in crafting the first two long-range ESA science plans. It is a pleasure and an honour to report that this has continued in ESA's 2004 Cosmic Vision plan, based on the science proposed by a community that has trebled in size over the past 20 years.
Europe's Quest for the Universe tells the story of European astronomy with passion, immediacy and candour, and with as much mastery of science as it has personality.