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Ilya
2008-Oct-13, 07:00 PM
As far as I know, Grote Reber (http://en.wikipedia.org/wiki/Grote_Reber) was the first person to collect radio signals from space in a systematic way, and his original findings were met with disbelief from professional astronomers. It was easy to calculate how much energy Sun emits in radio band (not a lot), and by extrapolation it was assumed that all radio emissions from distant stars should be vanishingly weak. When Reber announced the existence of several powerful radio sources (which we now know are associated with active galaxies and/or black holes), the initial reaction was that it is either a mistake or a hoax.

My question is -- how exactly did Reber prevail over his detractors? All I can find on the Web is that "at first" he was derided, and several years later accepted. What happened in between? Who was won over first, and who held out longest?

trinitree88
2008-Oct-13, 07:11 PM
As far as I know, Grote Reber (http://en.wikipedia.org/wiki/Grote_Reber) was the first person to collect radio signals from space in a systematic way, and his original findings were met with disbelief from professional astronomers. It was easy to calculate how much energy Sun emits in radio band (not a lot), and by extrapolation it was assumed that all radio emissions from distant stars should be vanishingly weak. When Reber announced the existence of several powerful radio sources (which we now know are associated with active galaxies and/or black holes), the initial reaction was that it is either a mistake or a hoax.

My question is -- how exactly did Reber prevail over his detractors? All I can find on the Web is that "at first" he was derided, and several years later accepted. What happened in between? Who was won over first, and who held out longest?


Ilya. :lol::lol::lol: pete

First, most of the prevailing scientists had to die of old age. Then it was easy for the next generation to see the light. Ciao. pete

Ilya
2008-Oct-13, 07:20 PM
Ilya. :lol::lol::lol: pete

First, most of the prevailing scientists had to die of old age. Then it was easy for the next generation to see the light. Ciao. pete
Ah, but apparently Greber's ideas became accepted within about five years. That's an awfully rapid die-off among astronomers! :lol:

ngc3314
2008-Oct-13, 07:45 PM
Reber was close enough to be able to interact with astronomers at the University of Chicago and Yerkes Observatory, and likewise close enough to remind them of his presence form time to time. (As I describe it in classes, he was the first person in history to annoy the neighbors with a large parabolic dish antenna in a suburban yard). As I understand the oral history, the astronomers were eventually impressed with his technique and care in measurement. The longer-term issue was that astronomers had no previous exposure to processes giving off relatively large amounts of energy in the radio bands (duh, radio astronomy not having been done systematically before that), so it was difficult to connect what they knew about - pretty much stellar dynamics, stellar atmospheres and a bit of nebular astrophysics - with anything Reber was detecting. Thus the first generation of radio astronomers was rich in folks trained in electrical engineering, since there was no established body of knowledge to get past in order to do leading-edge research. (this exemplifies a pattern in physicists doing astrophysics - they have often entered the field in waves as new techniques could be applied, in new areas where nobody else understood things either).

Reber's ideas caught on with some of the locals - Otto Struve, director of Yerkes Observatory in the 1930s and 1040s, went on to be the first director of the National Radio Astronomy Observatory.

jlhredshift
2008-Oct-14, 12:38 AM
I checked my library and so far the only reference that I have found that goes beyond what has already been said is from Discovering Astronomy by Jefferys and Robbins 1981;pgs 186 and 188.


One of the few people to become seriously interested was an amateur astronomer and professional radio technician named Grote Reber, who set up a small radio telescope-the first one designed for the purpose- in his backyard in Illinois. He began to make systematic observations and was the first to make a map of the radio sky.

World War II interrupted his work, ...
Figure 11-26 shows Reber's original contour map of the sky.

See attached scan of map 11-26

jlhredshift
2008-Oct-14, 12:59 AM
And here is one more reference in Astronomy and Astrophysics by Zeilek and Gregory 1998 pg 184.


However an American engineer, Grote Reber, read Jansky's work and decided to search for cosmic radio static in his spare time. By the 1940's, Reber had made detailed maps of the radio sky and had detected the Sun. He sensed that a new astronomy was in the making and so took an astrophysics course at the University of Chicago to learn more about astronomy and to discuss his discoveries with astronomers- only a few of whom were impressed.
Edit to add: neither textbook gives any references or footnotes, oral histories indeed. I wonder if the students papers in those courses could be so naked? (rhetorical)

Ilya
2008-Oct-14, 01:30 PM
Thanks!

Tim Thompson
2008-Oct-14, 11:57 PM
Book to read: The Early Years of Radio Astronomy: Reflections Fifty Years after Jansky's Discovery (http://www.amazon.com/Early-Years-Radio-Astronomy-Reflections/dp/0521616026/ref=sr_1_2?ie=UTF8&s=books&qid=1224026186&sr=1-2) by W.T. Sullivan (he & I worked together on a project back in the early 80's). Also see the history chapters in Radio Astronomy (http://www.amazon.com/Radio-Astronomy-John-D-Kraus/dp/0070353921/ref=sr_1_1?ie=UTF8&s=books&qid=1224026348&sr=1-1) by John Kraus (the classic in the field).

Remember this was all in the 1930's & 1940's. At that time astronomers worked almost exclusively with eyeball light. Nicholson & Pettit had done infrared observations with the 100-inch telecope on Mt. Wilson, but other than that, I am unaware of any other astronomy done at the time that was not visible light (i.e., Pettit & Nicholson, 1924 (http://adsabs.harvard.edu/abs/1924PASP...36..227P)). Karl Jansky (http://en.wikipedia.org/wiki/Karl_Guthe_Jansky) had discovered "star static" while studying noise (mostly lightning) for Bell Labs. He was an electrical engineer, as was Reber. Janksy had talked about his discoveries, but mostly to fellow engineers, and Reber was one of them. Jansky had to eventually quit and go back to noise measuring, while reber built a 30-foot meridian transit parabolic dish in his back yard, much to the consternation of Mrs. Reber I believe (he also noted that it was a great sound amplifier and he dived for cover once when an airplane went by while he was at prime focus).

Reber mapped the sky at 160 MHz (Reber, 1940 (http://adsabs.harvard.edu/abs/1940ApJ....91..621R) & Reber, 1944 (http://adsabs.harvard.edu/abs/1944ApJ...100..279R)) and submitted his papers to The Astrophysical Journal, which was then edited by Otto Struve. Astronomers had not paid much attention to Jansky because they could not think of any physical reason for the sky to host radio emission. Many also recommended against publishing Reber's sky maps, but Struve held that it was better to publish something that turned out to be wrong, rather than not publish something that turned out to be right. So his 1940 & 1944 papers were published by Struve. But by then WWII was on and they just didn't get much notice in a world busy at war.

But during the war Allied radar scientists discovered that what they had thought was German jamming was actually the Sun. And Jan Oort had identified neutral hydrogen emission; the story goes that he had an "underground" copy of Reber's paper (in German occupied Holland), but I can't verify that. in any case, after the war it was known that there were real physical reasons for looking at radio emission from space, and that's when radio astronomy took off.

I started in radio astronomy in 1981, but even then the field was dominated by electrical engineers. You could always tell when a paper was written by an engineer because it was crammed with details about the instrument and how the observations were made. You could read one of their papers and know exactly what they had done. But the astronomers would leave out all kinds of stuff and drive you nuts trying to figure out what they were doing.

Jerry
2008-Oct-15, 03:58 AM
I started in radio astronomy in 1981, but even then the field was dominated by electrical engineers. You could always tell when a paper was written by an engineer because it was crammed with details about the instrument and how the observations were made. You could read one of their papers and know exactly what they had done. But the astronomers would leave out all kinds of stuff and drive you nuts trying to figure out what they were doing.
That's great! Thanks for sharing.

trinitree88
2008-Oct-15, 11:51 AM
Book to read: The Early Years of Radio Astronomy: Reflections Fifty Years after Jansky's Discovery (http://www.amazon.com/Early-Years-Radio-Astronomy-Reflections/dp/0521616026/ref=sr_1_2?ie=UTF8&s=books&qid=1224026186&sr=1-2) by W.T. Sullivan (he & I worked together on a project back in the early 80's). Also see the history chapters in Radio Astronomy (http://www.amazon.com/Radio-Astronomy-John-D-Kraus/dp/0070353921/ref=sr_1_1?ie=UTF8&s=books&qid=1224026348&sr=1-1) by John Kraus (the classic in the field).

Remember this was all in the 1930's & 1940's. At that time astronomers worked almost exclusively with eyeball light. Nicholson & Pettit had done infrared observations with the 100-inch telecope on Mt. Wilson, but other than that, I am unaware of any other astronomy done at the time that was not visible light (i.e., Pettit & Nicholson, 1924 (http://adsabs.harvard.edu/abs/1924PASP...36..227P)). Karl Jansky (http://en.wikipedia.org/wiki/Karl_Guthe_Jansky) had discovered "star static" while studying noise (mostly lightning) for Bell Labs. He was an electrical engineer, as was Reber. Janksy had talked about his discoveries, but mostly to fellow engineers, and Reber was one of them. Jansky had to eventually quit and go back to noise measuring, while reber built a 30-foot meridian transit parabolic dish in his back yard, much to the consternation of Mrs. Reber I believe (he also noted that it was a great sound amplifier and he dived for cover once when an airplane went by while he was at prime focus).

Reber mapped the sky at 160 MHz (Reber, 1940 (http://adsabs.harvard.edu/abs/1940ApJ....91..621R) & Reber, 1944 (http://adsabs.harvard.edu/abs/1944ApJ...100..279R)) and submitted his papers to The Astrophysical Journal, which was then edited by Otto Struve. Astronomers had not paid much attention to Jansky because they could not think of any physical reason for the sky to host radio emission. Many also recommended against publishing Reber's sky maps, but Struve held that it was better to publish something that turned out to be wrong, rather than not publish something that turned out to be right. So his 1940 & 1944 papers were published by Struve. But by then WWII was on and they just didn't get much notice in a world busy at war.

But during the war Allied radar scientists discovered that what they had thought was German jamming was actually the Sun. And Jan Oort had identified neutral hydrogen emission; the story goes that he had an "underground" copy of Reber's paper (in German occupied Holland), but I can't verify that. in any case, after the war it was known that there were real physical reasons for looking at radio emission from space, and that's when radio astronomy took off.

I started in radio astronomy in 1981, but even then the field was dominated by electrical engineers. You could always tell when a paper was written by an engineer because it was crammed with details about the instrument and how the observations were made. You could read one of their papers and know exactly what they had done. But the astronomers would leave out all kinds of stuff and drive you nuts trying to figure out what they were doing.

Tim. Interesting read. Thanks. pete

ToSeek
2008-Oct-22, 03:27 PM
Moved from Astronomy to Q&A.