I'm among the 93% of scientists who, in a recent survey by the UK's Campaign for Science and Engineering (CaSE), agreed that EU membership benefits UK science and engineering research.
It's not surprising that the scientific and technological community is overwhelmingly positive on this issue. Some of Europe's greatest technical successes - in particle physics and in aerospace, for instance - have required multinational collaboration. Such achievements show that Europe can fully match the US if its expertise is coordinated optimally. Bodies like CERN and the European Space Agency, for instance, are underpinned by international treaties: they aren't directly linked to the EU. However the EU has been an important 'facilitator' of collaboration across the whole range of 'wissenschaft'.
The EU fellowships and network programmes have been an effective stimulus and catalyst. The Erasmus programme has allowed 200,000 UK students to gain experience on the mainland. Our Universities currently host over 120.000 students from the rest of the EU.The European Research Council (ERC) supports outstanding individuals at all levels of seniority, on the basis of stringent peer review (and the UK receives more than its pro-rata share of the benefits).
The improvement in quality, reach and impact - and the freedom of movement - facilitated by EU membership allows "Grand Challenge" problems to be tackled more effectively than any one country could achieve alone. Without multilateral collaboration, European nations are generally too small to foster as many peaks of specialized excellence as there are in the US, either in research or in high-tech industry. And in an ever more interconnected world, we need more trans-national harmonissation. At the level of individual consumers, this includes (for example) uniform roaming charges for mobile phones. At the industrial level Sir Andrew Witty, head of GSK, has emphasised that the existence of common regulations for drug approval across the community is a 'big deal'.
The challenges of dealing with environmental issues, and building a network for optimum low-carbon energy generation, will require new infrastructure on a continental scale. In the long run we need a new grid to link northern Europe with the sunny south, and to provide east-west links that can smooth peak demand by connecting different time-zones.
Academia, high-tech industry and the professions in this country benefit hugely from talent attracted from across the EU. In my own Cambridge college the strongest academic cohort are students from mainland Europe, many from the 'enlarged EU' - from Hungary, Poland, the Czech Republic and other nations with a strong academic tradition. Polls reveal the younger generation, overall, to be more positive than their elders about the EU. They see themselves as 'Europeans' with a shared culture, and recognise that our continent can best achieves growing prosperity - and tackle global challenges - through the exploitation of science and technology. Europe can be a progressive political force in a turbulent and multipolar world. Indeed, although the science-linked arguments are themselves compelling, they're trumped for many of us by these broader ones.
But despite the strong support for the EU, especially among the young, the universities, the technical community, and a majority of our business and professional leaders, opinion among the public at large seems closely balanced between "inners" and "outers". All too many think of 'Europe' as the landmass across the England Channel: they should of course refer to 'mainland Europe' - we on this island are Europeans too. We can't yet rule out a frightening scenario where the UK votes to exit the EU; Scotland might then (with justification) seek independence -breaking up the union with England and Wales that has prevailed for more than 300 years, and seek to rejoin the EU as a separate nation. England would then try to negotiate new 'customised' links with the EU. But we'd be kidding ourselves if we thought these would be as benign as the EU's long-standing agreements with (for instance) Norway. You get a far better deal in a civil partnership than after an acrimonious divorce.
David Cameron has convincingly articulated the 'in' case. But by committing us to holding a referendum at this time, he's risking an outcome that irreversibly weakens Europe, and breaks up the United Kingdom too - what a devastating legacy that would be!
Martin Rees, based at Cambridge University, is the UK's Astronomer Royal and a member of the House of Lords