Fifty years ago this month Jocelyn Bell was going through the chart recorder output from a new radio telescope she and a few others had built at Cambridge . She had worked herself up to about a hundred feet of it a day looking for anything interesting in the squiggly line of ink. Very boring work. Lots of noise and bits of the expected.
But there was this "bit of scruff" when the telescope was pointed in a particular direction. The scruff was repeating every 1.3 seconds. Very regularly.1
You always doubt your equipment. Regular noise is usually something man-made or an artifact from the apparatus. And there were those new fangled satellites beeping away,. Carefully you try to eliminate the possibilities. She and her advisor eliminated most possibilities, but they weren't that certain. Then she found another bit of scruff. That regular pulsing .. now at a different rate, but still very accurate. Better than the clocks they had in the lab. She had found something - something out there.
There was a flurry of activity when they announced. Astronomers around the world dropped what they were doing. Theoretical physicists and astrophysicists conjectured. A few of the conjectures advanced to hypotheses. And in this swirl of activity she found and third ... and then a forth. And in theoryland of the hypotheses made sense. It was called a pulsar.
She had found the crack in the door to some of the deepest Nature yet encountered.
In 2017 something like two thousand have been found. Shortly after the discovery it was suggested a star could collapse so dramatically that it's core was nothing but neutrons. Imagine a mass greater than the Sun compressed down to something about a dozen kilometers in diameter. Like a skater pulling in her arms it spins much faster than the star it started out as. The first went around every 1.3 seconds, but some spin more than a thousand times a second. Their magnetic fields are trillions of times stronger than the Earth's and, combined with the rotation a beacon-like signal forms. It sweeps through the sky like the light from a lighthouse as it rotates.
She and her advisor opened up an entirely new and unexpected branch of astrophysics that has led to a much deeper understanding of both astronomy and physics. Pulsars and their close relatives are hot areas of research. And they can even be useful. A GPS system is just a group of accurate clocks with transmitters orbiting the Earth. Pulsars are as accurate as atomic clocks. You could use them to build a galactic positioning system that would work anywhere in the Milky Way and not than just on Earth. And you can make use of their regular beat to build another kind of gravity wave detector. One that is complementary to the current interferometry technique.
Some of the techniques developed since then have trickled down into important technology we use and many hundreds of astronomers and astrophysicists have spent some time in the private sector making their contributions to the economy. Pure science is a very inexpensive mechanism for creating future value. The "problem" is you can't predict where it might lead.
Hewish went on to receive a Nobel Prize in Physics for the discovery. It is widely felt in the astronomy community that Jocelyn Bell should have shared in the discovery as her contributions were enormous. But: 1967 and female. She spoke of it ten years after the discovery:
"demarcation disputes between supervisor and student are always difficult, probably impossible to resolve. Secondly, it is the supervisor who has the final responsibility for the success or failure of the project. We hear of cases where a supervisor blames his student for a failure, but we know that it is largely the fault of the supervisor. It seems only fair to me that he should benefit from the successes, too. Thirdly, I believe it would demean Nobel Prizes if they were awarded to research students, except in very exceptional cases, and I do not believe this is one of them. Finally, I am not myself upset about it – after all, I am in good company, am I not!"
She's being far too generous. This was one of those exceptional cases. At least she's received other significant honors she's had throughout her career.
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And something sad.
I rarely use the term genius to describe anyone alive. Maryam Mirzakhani was an exception. A fearless mathematician, she was the only women to receive the Field Medal: math's highest recognition. She died on Saturday at age forty. She was just warming up. Here's a well-written piece about her that appeared in Quanta a few years ago.
Excuse my political comment, but Mirzakhani was female, brilliant and from an Islamic county. I doubt someone with these "liabilities" would be welcome here now ...
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1 She recognized that pulsars are astronomical sources where others had failed because she noticed that the pulses in her data (Figure 6.1) didn’t look like other forms of interference and they reappeared exactly once per sidereal day, indicating an origin outside the Solar System. She and Hewish, “decided initially not to computerize the output because until we were familiar with the behavior of our telescope and receivers we thought it better to inspect the data visually, and because a human can recognize signals of different character whereas it is difficult to program a computer to do so.” Other people were using software to filter out noise and were throwing out the interesting signal in the process..
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