The Nobel Prize in Physics in 1974 created a lively controversy when it was awarded to the astrophysicist Anthony Hewish for the discovery of pulsars. The problem lies in the fact that pulsars were not discovered by Hewish, but by one of his doctoral students, Susan Jocelyn Bell.
A gigantic antenna
After putting a lot of effort into earning her degree in physics in 1965, Ms. Bell then pursued a doctorate in radio astronomy with Anthony Hewish. Her field of study was quasars, galaxies with black holes at their center.
She began by constructing a gigantic antenna, following Hewish’s plans. In two years she planted over 1,000 wooden posts to which she attached 2,048 antennas, connected by 14 km of cable and 2 tons of copper wire. In the end, the antenna covered an area of 20,000 square meters, or 2 hectares. It should be noted that Hewish did not condescend to help his student with any of this manual labor.
A strange signal
The antenna being fixed, only the objects crossing its field were observable. Observations began in July 1967. On the next August 6, Jocelyn noticed a strange signal that she called “scruff”. Informed of the signal, which did not repeat in the weeks that followed, Hewish responded to Bell that it was an eruptive variable star and that she had missed that.
Then in November, the source once again emitted a regular signal, one that repeated every 1.3 seconds. The regularity of the signal was surprising. Was it of human origin? Bell and Hewish explored all hypotheses to explain the signal, ranging from human interference to an emission by an artificial satellite.
Two other astronomers also observed the signal, and even estimated its distance to be 212 light-years away. Jocelyn Bell ironically named the signal LGM-1, for Little Green Men 1.
In December 1967, Jocelyn Bell discovered a second source of a repetitive signal. There was no longer any doubt: these signals were of stellar origin.
In early 1968, the journal Nature published an article relating the discovery of pulsars, with Anthony Hewish as first author and Jocelyn Bell as second.
Over the following months, astrophysicists understood that pulsars are neutron stars (the corpses of massive stars), endowed with a powerful magnetic field, that emit light and that rotate quickly like a top. When the beam is pointing in our direction, we detect a regularly repeating light signal.
The Nobel Prize in Physics
The Nobel Committee for Physics awarded the Prize in 1974 to Martin Ryle, for his work on observation techniques, and to Anthony Hewish, for the discovery of pulsars. It’s astonishing that the committee did not include Jocelyn Bell as a recipient of the Prize, knowing that three winners can be named each year.
Hewish later stated, in explanation of this circumstance, that Ms. Bell had done nothing except follow his instructions! But the fact remains that, thanks to her hard work, it was she who discovered the first two pulsars all by herself.
The oversight of the Nobel Committee notwithstanding, Jocelyn Bell’s name is forever inscribed in the history books.