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Born in 1924, Antony Hewish is a pioneer of radio astronomy known for his study of intergalactic weather patterns and his development of giant telescopes. He was awarded the Nobel Prize for Physics in 1974, together with Martin Ryle, for his discovery of pulsars. [Listener: Dave Green].
TRANSCRIPT: We decided to keep our tongues quiet until we knew what was going on. But there I was in Churchill College marking away, and at night wondering what the heck was going on. And I mentioned this quietly one day to a very distinguished man called Sir Edward Bullard, he was a fellow of Churchill College, and the advantage of Cambridge is that you have lunch with important people sitting next to you every now and again, and I mentioned it quietly to him, and said, 'Look, I'm getting this very odd signal at Lord's Bridge, what do you think it is?' He was a man of very wide experience and he said, 'Well, if it's narrow band have you thought about intelligent signals from outer space? Perhaps you're the first person to pick up aliens'. And, well, the thought had crossed my mind, but I dismissed it as being totally ludicrous. But there I was, sitting marking examination papers and couldn't do anything.
Well, a week later, I was able to get back to the lab and the first thing I did was to set up accurate timing. I got time, seconds, time pips on the record and compared those with the pulses we were getting and found out that this thing was keeping time to better than a millionth of a second per day. I mean, it was absolutely repeatable; that was the first thing that happened and that was a shock. I mean, it was better than our clocks and, whatever it was, it was very odd. I mean, that was the first result.
The second was following up, actually, what Teddy Bullard had said, if it's narrow band… we were measuring the bandwidth, we were doing that anyway, but it turned out that this was a narrow band signal and that strengthened the possibility that we were picking up alien signals and, furthermore, the signal was dispersed, that's to say we measured the bandwidth of it and… from the shape of the bandwidth you know that the signal has traversed a certain distance of space because pulses travelling through space travel at slightly different speeds and this produces a characteristic… if you pick up over a finite bandwidth, you pick up what we call a dispersed signal, the pulse arrives slightly earlier at slightly shorter wavelengths and you can detect this in your equipment. And we measured that and, from what we then knew about the density of electrons in the… in the interstellar space - I did a quick calculation which showed that this thing was about 40–50 parsecs away, which is about… what… that's about 100–150 light years or something like that. So here was a signal sending… coming from 150 light years, which is amongst the nearby stars, producing regular pulses. Well, it makes you think, doesn't it? It just looks so artificial. And I discussed this with Martin Ryle and we said, well, is it or is it not intelligence? Naturally, we kept our mouths tightly shut because any hint that we'd picked up intelligence from outer space and the lab would have been absolutely full of reporters and media.
So we kept our mouths tightly quiet and decided what we would do, and we decided that we ought to handle this through the Royal Society, which was the top scientific brass at the time and, if they first of all believed what we'd done, and then they… we'd require their advice to sort of handle this, because it isn't astronomy anymore, it's almost politics, isn't it, if you pick up alien signals? But I decided also that the signals were accurate enough that I could detect motion of the source that was sending them using the Doppler effect. If you're picking up life on another planet, that planet is in orbit about some star, and if it's sending regular signals to you, they'll… they'll be Doppler shifted according to the orbit. And I… I would have been able to measure the orbital speed. And so when I got back to the lab and started continuing these timing measurements I decided to look for orbital effects, and that took me 3 weeks. And it's not easy to do because the Earth itself is moving through space and you have a huge effect to subtract first, which is the orbital motion of the Earth. But after 3 weeks I'd subtracted that off and decided there wasn't any orbital effect left. I mean, to begin with, it was a little bit worrying because there was a huge Doppler shift immediately detectable from the day-to-day measurements, but that was all due to the motion of the Earth. And when that was subtracted away there was nothing… nothing left; and that took me about 3 weeks to do. [...]
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