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Speaker 1: This Day in History Class is a production of I

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Speaker 1: Heart Radio Greetings, I'm Eves and welcome to This Day

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Speaker 1: in History Class, a show that believes no day in

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Speaker 1: history is a slow day. Today is November. The day

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Speaker 1: was November. Nineteen sixty seven, Astell physicist Jocelyn Bill Burnell

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Speaker 1: became the first person to detect a radio pulsar. A

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Speaker 1: pulsar is a celestial source of pulse stating electromagnetic radiation

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Speaker 1: that is thought to be a rapidly rotating neutron star.

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Speaker 1: Pulsars amit pulses of radiation like radio waves, at short,

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Speaker 1: relatively constant intervals. In nineteen sixty seven, Jocelyn Bell was

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Speaker 1: pursuing her doctorate at the University of Cambridge, where her

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Speaker 1: advisor was radio astronomer Anthony Hewish. That year, Huish and

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Speaker 1: his graduate students completed a radio telescope that was designed

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Speaker 1: to observe the scintillation of stars, particularly quasars. A quasar

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Speaker 1: is a region at the center of a galaxy that

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Speaker 1: omits an exceptionally large amount of energy. The first quasars

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Speaker 1: were discovered by the early nineteen sixties. Bill helped build

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Speaker 1: the telescope at the Millard Radio Astronomy Observatory. Once the

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Speaker 1: telescope went into operation in July of nineteen sixty seven,

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Speaker 1: Bill began operating it and analyzing the data by hand.

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Speaker 1: One day, she noticed a strange signal at a wavelength

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Speaker 1: of three point seven meters. The signal continued to appear

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Speaker 1: over the next several months. On November, she captured a

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Speaker 1: recording of the signal that gave more detail. Bill called

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Speaker 1: the reading a quote bit of scruff in the data.

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Speaker 1: It showed that the signal corresponded to a burst of

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Speaker 1: radio energy that came in regular intervals of about one

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Speaker 1: point three seconds. The re was sinked with sidereal time

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Speaker 1: rather than Earth time, and it consistently came from the

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Speaker 1: same part of the sky. So she set about determining

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Speaker 1: the source of the signal. It couldn't be coming from

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Speaker 1: any natural sources like stars, galaxies, or solar wind, and

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Speaker 1: it did not come from any human or human made

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Speaker 1: sources like radar reflected off the Moon, other radio astronomers,

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Speaker 1: television signals orbiting satellites, or buildings near the telescope. After

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Speaker 1: ruling out all those sources, she and Huish called the

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Speaker 1: signal l g M one because they couldn't rule out

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Speaker 1: little green men a k a. Aliens, But soon Bill

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Speaker 1: found another signal, this one pulsing at one point to

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Speaker 1: second intervals. This signal was coming from a different part

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Speaker 1: of the sky. That meant that the signal was likely

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Speaker 1: not sent by extraterrestrial beings. Later that year, Bill noticed

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Speaker 1: a couple more of these unusual signals. In January nineteen

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Speaker 1: sixty eight, Bell Hwish in colleagues submitted paper describing their

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Speaker 1: discovery to the journal Nature, and the paper, Observation of

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Speaker 1: a Rapidly Pulsating Radio Source was published on February. The

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Speaker 1: paper noted that they had recorded unusual signals from pulsating

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Speaker 1: radio sources and positive that the radiation may be associated

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Speaker 1: with oscillations of white dwarf or neutron stars. But even

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Speaker 1: though they had announced the discovery, they still didn't know

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Speaker 1: the source of the signal. That didn't stop other scientists

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Speaker 1: from trying to discover more of these pulsating sources and

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Speaker 1: where they were coming from. By the end of nineteen

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Speaker 1: sixty eight, more had been discovered, and it had been

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Speaker 1: suggested that neutron stars were a source. Hewish first used

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Speaker 1: the word pulsar in an interview with the Daily Telegraph.

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Speaker 1: In nineteen sixty, Bell and Hwish changed the name of

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Speaker 1: the signal from l g M to CP or Cambridge Pulsar,

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Speaker 1: and the first radio pulsar they detected was dubbed CP.

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Speaker 1: Nineteen eighteen, he was received the nineteen seventy four Nobel

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Speaker 1: Prize in Physics for his role in the discovery of pulsars,

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Speaker 1: a controversial decision because Bill's contributions were not recognized. Since

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Speaker 1: their discovery, pulsars have been used to study extreme states

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Speaker 1: of matter and search for gravitational waves. I'm Eve Jeffcote,

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Speaker 1: and hopefully you know a little more about history today

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Speaker 1: than you did yesterday. Send your best history memes to

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Speaker 1: this day at i heeart media dot com. Thanks for

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Speaker 1: listening and we'll see you tomorrow. For more podcasts from

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