The group then began to run into a slightly uncertain future, I think. Because Martin Ryle was… was backing off from providing leadership in radio astronomy but he was still formally head of the radio astronomers in Cambridge. And he had a very serious operation in 1976 and was essentially an invalid after that, and not going to Lord’s Bridge and not really being a hands-on person to run things, and because I was the second chair in… in radio astronomy in… in Cambridge, I kind of took over the group, but I wasn’t formally appointed head of radio astronomy. Martin was head of radio astronomy until he retired in 1982, and that period when he was not interested in the subject very much, but still head of radio astronomy in Cambridge, was, I think… was not a helpful time for the development of… of research in this… in Cambridge. Because, having built the 5-km telescope which was a world beater… but the Australians… the Americans were then busy developing the very large antenna which was essentially the same principle as Martin Ryle’s 5 km, but with an array of dishes and using full aperture synthesis, was an instrument of much greater power and, as an international facility, was going to actually produce results which put the 5-km telescope – eclipsed our priority in… in that area. And Martin Ryle wasn’t thinking too much about what other things we could develop here, at Cambridge. And that was the time I kind of took over the reins, but wasn’t quite clear where the group should be going because I had my own research to look after and that’s what I’d been doing, but, at the same time, Lord’s Bridge as an observatory needed someone to look after it and organise things. And I… kind of unofficially took… took that over, there was no formal appointment of me as head of radio astronomy, but I virtually became head of radio astronomy after… after Martin Ryle was seriously ill and certainly after he retired in 1982.

Now, by then it was clear that the group had to be doing other things and we were moving then into… into international. This was our first move into… into international facilities and Richard Hills, who became head of radio astronomy not so long ago, became involved with millimetre wavelength astronomy. In the 1970s it had been discovered that there was a lot to do at the very shortest wavelengths in radio astronomy, which needed completely new instrumentation, millimetre wavelength was quite different from standard radio telescopes, you needed… you needed different technology and you needed different dishes, small dishes with extremely accurate surfaces, and such things were going to be extremely expensive. And I was actually chairing a committee for the DSIR [Department of Scientific and Industrial Research], or SRC [Science Research Council], as it was then called, to investigate millimetre wavelength astronomy in this country. And we eventually concluded that building the best millimetre dish in the world, which couldn’t be sited in the UK because it wasn’t a suitable climate, for millimetre wavelength astronomy it’s much like optical astronomy, you need to be up a high mountain in a… in a thin atmosphere with a… with a clear sky above you because the atmosphere makes the difference. In the millimetre waves you… you don’t want atmospheric absorption with water vapour and suchlike. You need clear skies. And I became involved with the… I wasn’t hands-on because that wasn’t my field, but I… I was chairman of this committee which… which decided that what the UK should be doing was building a millimetre wavelength telescope. And at that time young Richard Hills, as we called him, had just finished his PhD and was a graduate student and he was thinking about a millimetre wave telescope. And we began to think very seriously about that and to… what you would need to build. Richard Hills took up research in collaboration with the Rutherford Lab on the engineering project and simultaneously we began to think where to locate such an instrument. In the end we settled initially for the Canary Islands but, ultimately, when we began to seek international partners to help with the funding – and I wasn’t involved with that – I… I then began to hand over the reins to… to other people – but millimetre wave astronomy began to develop. And I think this group missed some opportunities because I wasn’t in an official position to make decisions, powerful decisions about things, and we could have been world leaders in millimetre wavelength radio astronomy. And that probably should have been the way the group went. And if I’d been a proper head of the group, given official freedom to do things, that’s the way we might have gone.

But that… that was the time, I think, when we missed some opportunities because the university, which had just let radio astronomy develop because radio… Martin Ryle was such a powerful figure, didn’t realise that he’d faded, and Cavendish Professors who were also not running the Department of Physics, who are the authority that really runs the group… the radio astronomy group formally within the university – we are part of the department and they’re responsible for funding and… and making appointments – didn’t… didn’t foster these developments, these international developments, and the group didn’t grow as it should have done in that period. And that was the time I was taking over as head of the group and it wasn’t terribly easy, I have to say, for me. But eventually, we sort of found our place, Richard Hills, in collaboration with the Rutherford Appleton Lab, did design the best telescope. We got international partners, initially the Dutch and then the Canadians, and… and the millimetre wavelength telescope, which became the James Clark Maxwell Telescope, JCMT, was mounted in Hawaii, which is the best site in the world. And that really came about as a result of pressure from our international partners who said, ‘Well, an instrument of this quality deserves the very best site in the world and that has to be Hawaii at… at the moment’. And that’s… I mean the JCMT has been a great success but I think Cambridge could have had a more dominant role in that than… than it did if… if Martin Ryle himself had not faded, but not… not retired, as it were, sooner. I mean I think, really, he should have taken early retirement, but I think he obviously didn’t for financial reasons, and that was a bit of group history which could have been better. The pinnacle was establishing the 5-km telescope, but Martin Ryle never carried on from there and clearly the group has… has now developed into international partnership on… on a large scale.