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#1
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Hi:
What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? Thanks, Radium |
#2
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![]() "Radium" wrote in message ps.com... Hi: What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? Thanks, Radium Radium As the article suggests, higher frequencies are considered as being in the infra red wavelengths of light, so 3,438 GHz can be considered to be at the upper limits of radio frequency astronomy. Visible light, ultra violet light, x-rays and gamma rays are all electromagnetic waves at higher frequencies and are also used for astronomy observations and experiments. Satellites are generally used to observe in the ultra violet, x-ray and gamma ray spectrums as these wave lengths are largely absorbed by the earth's atmosphere. Remember, there are no strict cut off frequencies where one type of electromagnetic wave becomes another type. Radio merges into infra red which merges into visible light, ultra violet, x-rays and so on. Any limits are purely arbitary ones applied by humans in order to categorise the way in which electromagnetic waves of a certain frequency can be expected to behave. Look at a colour palette. It is easy to pick out the primary colours. Everyone who isn't colour blind can pick out red, blue, green, yellow etc. But where do you draw the line to decide where red becomes green, blue or yellow? The colours slowly merge from one to another just as the characteristics of radio waves change as frequency increases. Mike G0ULI |
#3
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On Aug 30, 3:08 pm, "Mike Kaliski" wrote:
"Radium" wrote in message ps.com... Hi: What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? Thanks, Radium Radium As the article suggests, higher frequencies are considered as being in the infra red wavelengths of light, so 3,438 GHz can be considered to be at the upper limits of radio frequency astronomy. Visible light, ultra violet light, x-rays and gamma rays are all electromagnetic waves at higher frequencies and are also used for astronomy observations and experiments. Satellites are generally used to observe in the ultra violet, x-ray and gamma ray spectrums as these wave lengths are largely absorbed by the earth's atmosphere. Remember, there are no strict cut off frequencies where one type of electromagnetic wave becomes another type. Radio merges into infra red which merges into visible light, ultra violet, x-rays and so on. Any limits are purely arbitary ones applied by humans in order to categorise the way in which electromagnetic waves of a certain frequency can be expected to behave. Look at a colour palette. It is easy to pick out the primary colours. Everyone who isn't colour blind can pick out red, blue, green, yellow etc. But where do you draw the line to decide where red becomes green, blue or yellow? The colours slowly merge from one to another just as the characteristics of radio waves change as frequency increases. Mike G0ULI Sorry, I meant to ask whether 3,438 GHz is the highest radio frequency used to receive audio signals from outer space. I should have made my question more specific. Radio-astronomers study sounds from the sun as well as visual data. I wonder if a space station with a 3,438 GHz AM receiver could pick up any extremely-distant audio signals between 20 to 20,000 Hz [from magnetars, gamma-ray-bursts, supernovae and other high-energy but cosmic objects] after demodulating the 3,438 GHz AM carrier wave. |
#4
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Radium wrote:
Sorry, I meant to ask whether 3,438 GHz is the highest radio frequency used to receive audio signals from outer space. I thought perhaps the O.P. was from Europe or the U.K. and that the comma in the above numeric was a substitution for a decimal point, but alas the posting IP is from So. Cal. .... Regards, Michael |
#5
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On Sep 1, 8:44 am, msg wrote:
Radium wrote: Sorry, I meant to ask whether 3,438 GHz is the highest radio frequency used to receive audio signals from outer space. I thought perhaps the O.P. was from Europe or the U.K. and that the comma in the above numeric was a substitution for a decimal point, but alas the posting IP is from So. Cal. .... Regards, Michael Hello Off-Topic "Radium-Lite" Cross-Posters, Since "Radium" Posted this Question to several Newsgroups and the Topic is a Non-Shortwave Radio Question that is being Cross-Posted to the Rec.Radio.Shortwave Newsgroup : Let me 'morph' this Question so that it is something related to Shortwave Radio. "What is the Highest Radio Frequency used for Shortwave {High Frequency) Radio ? i want to know -cause- i have been 'radiumized' ~ RHF |
#6
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![]() "Radium" wrote in message ups.com... On Aug 30, 3:08 pm, "Mike Kaliski" wrote: "Radium" wrote in message ps.com... Hi: What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? Thanks, Radium Radium As the article suggests, higher frequencies are considered as being in the infra red wavelengths of light, so 3,438 GHz can be considered to be at the upper limits of radio frequency astronomy. Visible light, ultra violet light, x-rays and gamma rays are all electromagnetic waves at higher frequencies and are also used for astronomy observations and experiments. Satellites are generally used to observe in the ultra violet, x-ray and gamma ray spectrums as these wave lengths are largely absorbed by the earth's atmosphere. Remember, there are no strict cut off frequencies where one type of electromagnetic wave becomes another type. Radio merges into infra red which merges into visible light, ultra violet, x-rays and so on. Any limits are purely arbitary ones applied by humans in order to categorise the way in which electromagnetic waves of a certain frequency can be expected to behave. Look at a colour palette. It is easy to pick out the primary colours. Everyone who isn't colour blind can pick out red, blue, green, yellow etc. But where do you draw the line to decide where red becomes green, blue or yellow? The colours slowly merge from one to another just as the characteristics of radio waves change as frequency increases. Mike G0ULI Sorry, I meant to ask whether 3,438 GHz is the highest radio frequency used to receive audio signals from outer space. I should have made my question more specific. Radio-astronomers study sounds from the sun as well as visual data. I wonder if a space station with a 3,438 GHz AM receiver could pick up any extremely-distant audio signals between 20 to 20,000 Hz [from magnetars, gamma-ray-bursts, supernovae and other high-energy but cosmic objects] after demodulating the 3,438 GHz AM carrier wave. Radium You are referring to "the music of the spheres". The random noises generated by very distant quasars, galaxies, supernovae and other objects. Yes it probably could and you would hear all sorts of weird pops, whistles and background noise. Just like at pretty much any other frequencies you care to monitor. Mike G0ULI |
#7
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What is the highest radio frequency used for astronomy? Is it 3,438
GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? That's very much a matter of convention. It all depends what you choose to call "radio frequency" and what you choose to call something else. As the article you cite points out, the measurements at 3438 GHz (3.438 THz) blur the lines between microwave measurements (which many would call "radio") and far-infrared measurements (which may would not call "radio frequency"). One source I see gives a frequency of 3.0 THz as the boundary between "microwave" and "infrared". That boundary point is, I believe, entirely one of human convention - there's no magical change in the behavior of the signals as you cross from one side of this frequency to the other. If you choose to treat the conventional boundary point of 3.0 THz as being significant for the purpose of your question, then one would have to say that the 3,438 GHz measurements you refer to are *not* "radio frequency" measurements, but rather "far-infrared" measurements. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#8
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![]() "Dave Platt" wrote in message ... What is the highest radio frequency used for astronomy? Is it 3,438 GHz? According to the link below, it is 3,438 GHz: http://books.nap.edu/openbook.php?re...=11719&page=11 Is 3,438 GHz the highest radio frequency used for astronomy? That's very much a matter of convention. It all depends what you choose to call "radio frequency" and what you choose to call something else. As the article you cite points out, the measurements at 3438 GHz (3.438 THz) blur the lines between microwave measurements (which many would call "radio") and far-infrared measurements (which may would not call "radio frequency"). One source I see gives a frequency of 3.0 THz as the boundary between "microwave" and "infrared". That boundary point is, I believe, entirely one of human convention - there's no magical change in the behavior of the signals as you cross from one side of this frequency to the other. If you choose to treat the conventional boundary point of 3.0 THz as being significant for the purpose of your question, then one would have to say that the 3,438 GHz measurements you refer to are *not* "radio frequency" measurements, but rather "far-infrared" measurements. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? Tam |
#10
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On Thu, 30 Aug 2007 17:02:02 -0700, Don Bowey wrote:
"Tam/WB2TT" wrote: ... I am curious here. At some point you have to switch from metallic conductors and antennas to lenses and other optics. Any idea what the highest frequency RF amplifier works at? It's all subject to state-of-the-art. 50 years ago 300 MHz. was complex to work with and 10 GHz. was considered way out there. Today 300 MHz is about as simple as DC and 10 GHz. is fairly straightforward to work with. I imagine that in another 50 years or less, Integrated hybrid circuits for 3 THz. will be on the shelf items for experimenters to play with. Whenever they discover neutronium, they can make ångstrom-sized klystrons. ;-) Cheers! Rich |
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