Encounter 23 · 23 of 42 · August–November 1967
The pulse that was not interference
In 1967 a graduate student found a radio pulse so regular it was first nicknamed LGM, little green men. It was a star.
Mullard Radio Astronomy Observatory, Cambridge
The scruff is small. The prize is later furniture.
A stranger does not arrive knowing what the wire in the field was for. It was not built to find pulsars. Pulsars did not yet have a name. Six people took two years to put up about a hundred and twenty miles of cable. Bell built the prototype. The question on the proposal was quasars.
Her work, once it was up, was to look. Hewish pointed out that the scruff occupied about a quarter inch: one part in ten million of the paper. He thought she might have wired the telescope wrong. They switched to a faster recorder. For a month it wrote nothing. On 28 November 1967 the pulses came, about one and a third seconds apart.
Expected
Interference, a fault in the wiring, or a terrestrial beacon. The working nickname, LGM, little green men, was a joke they could still afford while they checked.
Observed
The pulse kept its place among the stars. A second telescope on the site saw it once they had the timing right. A second source appeared later. A unique alien transmitter became a class of object. They retired the joke.
She found it by looking.
Bell later said that if they had had a computer they would never have programmed it to look for something so unexpected. How do you pick up the things you don’t know exist? That sentence is afterward. The 1967 fact is the quarter inch.
1967
The chart
Scruff. A faster recorder. 28 November. A star that had not been asked for.
1974
The prize
The Nobel Prize in Physics to Antony Hewish and Martin RyleHewish for pulsars, Ryle for aperture synthesis. Bell was not named. She has since spoken about the omission without letting bitterness become the whole story, and without pretending it was nothing. Later honors she has used to fund others. That is afterward.
She is not the only woman this Guide is willing to credit. The omission is part of the later record. It is not the 1967 night.
How do you pick up the things you don’t know exist?
Private. No one else will see it.
Source
- primary01 · Hewish, Bell, Pilkington, Scott, and Collins, Nature, 1968First paper. Rapidly pulsating radio source. Bell second author.Record
- interview02 · Bell Burnell, Cambridge “Journeys of discovery”Later recollection: array as agricultural frame; quarter inch; Hewish on the wiring; 28 November 1967; LGM; second telescope; the unexpected.Record
Cambridge · 1967 · a chart that was not noise