Quote:
Originally Posted by tempestwizz
My understanding of the topic:
Visual astronomy will produce a much more resolved understanding of the etheric mostly due to the wavelength/aperture of the 'acquiring system'. Visual astronomy captures wavelengths in the visual range, ie some 600 nanometres down to 400-ish nanometres. Radio utilises much longer wavelengths. I believe Ha has a radiation at about 1620 MegaHertz - which has a corresponding wavelength of about 18.5 cm.
For say a 100mm visual device, it is some 200,000 wavelengths across at 500 nM. For a radio antenna to equate at 1620 MHz, it would need to be 37 kM in diameter! Clearly, this is impractical. The result with smaller aperture radio antennas results in a less defined result. The beam widths of typical antennas are in the order of 30 degrees. Hence hot, (or warm) areas of the sky can be detected, but not with much resolution.
Also radio astronomy is effectively like looking through a 1 pixel camera. We can get a 'brightness' value for the pixel, but unless we methodically scan an area of the sky to produce a brightness map it wont relate to any visual observations.
However, unlike visual observations, the atmospheric turbulence will have little affect on the instantaneous 'brightness' of the radio signal.Hence an AM demodulated signal would be a trrue reflection of galactic (not atmospheric) noise.
VBR
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Not quite true..
Athmospheric turbulence (especially in ionosphere) has the same if not bigger effect (and that strongly depends on wavelength), resulting in "twinkling" of the radio sources..
Also, interferometric methods (using two or more wider spaced antennas) can result in drastically increase resolution..
But in terms of "1 pixel camera" you are basically right...
And, some objects will be vert "bright" in radio bands, but invisible in visual.. that depends on mechanism that generates radiation.
Also some wavelengths pass through our atmosphere un-affected, some are blocked with water vapuou or other gasses, some are affected by Van Allen bands...
As I said, radio0astronomy is different, and complements visual (and other short-wave bands), resulting in more complete picture of the universe we are trying to put together.