Earth and Space

Beating the professionals

Stories from Physics for 11-14 14-16 IOP RESOURCES

Grote Reber ranks among the many amateurs who have made significant discoveries in astronomy. He was a professional radio engineer and a radio ham who built the world’s first dish-shaped telescope. Reber had wanted to work with the astronomer Karl Jansky, but when he applied to work with him at the Bell Laboratories during the Great Depression, there were no available posts. Undeterred, Reber built a radio telescope in his back yard with a 9 m metal dish. To save for the parts for his telescope, he chose not to buy a car but travelled on public transport.

Reber initially tried to detect emissions at the 3,300 MHz frequency because he believed that the radiation from the Milky Way would be from thermal sources. However, after finding no signal, he tried at 1000 MHz, again with no luck, before finally detecting a signal at 160 MHz. He carried out a careful mapping of the ‘cosmic static’ to develop the first radio map of the sky, avoiding interference from car ignition static by working at night, keeping his day job and only sleeping for a few hours after dinner.

When his contour map of static was submitted to an astrophysical journal, the editor was sceptical of the amateur’s findings and sent two researchers to examine Reber’s telescope. Once the results were determined to be credible, his map was published in 1944 and still coheres well with contemporary data.

References

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