Jocelyn Bell’s & Antony Hewish’s Discovery of Pulsars

Discovery Of Pulsurs noble prize

On November 28, 1967, Jocelyn Bell Burnell and Anthony Hewish have done discovery of Pulsars which was the first discovered pulsar- a fast rotating neutron star that emits a beam of electromagnetic radiation. The radiation of the pulsar can only be observed when the beam is pointing toward the earth, for example, we could only see a lighthouse when the light is pointing towards the observer.

Formation of pulsars

while the discovery of pulsars they found that low mass star spends much of their life cycles supporting themselves by burning through their supply of hydrogen. This process of fusion produces radiations which exerts an outward force counterbalancing the gravity of the star. Stars that are more massive than the sun move on to burn the heavier elements working their way down to the elements according to their atomic number until they reach iron, for elements heavier than iron energy is no longer produced during the fusion process thus any longer have a way to fight back against the gravitational pull. So the outer layers of the star collapse and it is called a supernova explosion.

Meanwhile, the core itself has become incredibly compact, so much so that electrons and protons have squeezed together to form a neutron. Eventually, the neutrons are so tightly packed that they exert a force that counteracts the gravity, leaving a dead star known as the neutron star. The neutron star is typically 10 to 20 km across, which means they pack roughly one and a half times the mass of our sun into a space of a big city. The light emitted by a neutron star is beamed into directions so that it shines out of opposite sides of the star instead of in all directions due to in part of the strong magnetic fields. If the beam of neutron star happens to be pointed in the right direction so that it sweeps over us here on earth-then we call it a pulsar.

Discovery of Pulsars

In the 1960s, in the discovery of pulsars, Jocelyn Bell Burnell and her advisor Anthony Hewish, along with a small team of other astronomers build a radio telescope at the Cambridge University in hope for finding the quasars- powerful radio source from a distant universe. The managed to find out 100 quasars by a paper readout of their spectroscopy. In 1967           Bell Burnell noticed a pulse of radio emission that repeated itself once every 1.5 sec.

Hewish classified the signal as artificial and famous labeled it “Little Green Men” luckily for us, Bell Burnell did not give up on the signal so easily. She went through mountains of paper data inch by inch. One day she found out something that didn’t fit in. She was determined it was real. And then she found a few more. They published their work in 1968 and Hewish, along with another collaborator Sir Martin Ryle.

Now we know of over 2000 pulsars, including a few hundred “Millisecond pulsars” that can make one full spin in only a few milliseconds.

Educational background of Jocelyn Bell Burnell and Anthony Hewish

Bell Burnell who has done Discovery of Pulsars was born on July 15, 1943, in Belfast, Northern Ireland. Her father was among the architects to design the Armagh planetarium and it was believed that during the visits she was encouraged by the staff to pursue astronomy as a profession. She attended the University of Glasgow to get a bachelor degree in 1965, then she moved on to the Churchill College at the University of Cambridge to continue her studies under Anthony Hewish.

Bell Burnell obtained a Ph.D. degree in 1969. At Cambridge, she began working together with Antony Hewish to construct the Radio telescope to study quasars, which had recently been discovered.

Anthony Hewish attended King’s College, Taunton. His undergraduate degree at Gonville and Caius College was interrupted by war services at the Royal Aircraft Establishment where he worked with Martin Ryle, returning to Cambridge in 1946 Hewish completed his degree and immediately joined Ryle’s research Team at the Cavendish Laboratory, obtained his Ph.D. in 1952.

The Noble Prize

In 1974, the Nobel Prize in Physics was awarded to two men Anthony Hewish and Sir Martin Ryle, for the discovery of pulsars the dead remnants of massive stars left behind after the massive supernova explosions that ended their lives, however the bulk of the work that led to the discovery from seven years earlier had actually been done by Jocelyn Bell Burnell,

It was normal in those days for senior lab scientists, who were almost men to take credit for everything that happened in the lab. These days we would call what they did to her morally inexcusable and perhaps criminal offense. She couldn’t risk taking a stand, against her more senior male colleagues, because she felt that making such a stand on principle would risk her future career, and she was a young ambitious woman. She said nothing, but when the time was right she said plenty after a few years. It was remarkable that the two men who accepted the Noble prize for a discovery they didn’t make were happy to do so. That too says a lot about the sense of entitlement at the senior levels of science back then.

It was just impossible to give a noble prize to a 24-year old woman, even if everyone knew she deserves it. Bell received a US$ 3 Million breakthrough prize after 50 years of the discovery

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