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EM waves with astronomical wavelength


quiet

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Hi. I have put in the internet search engine the following:

longest wavelength electromagnetic waves in space

The following appeared in the list of the findings:

https://hypertextbook.com/facts/2001/RachelShapiro.shtml

Electromagnetic waves as long as the distances between astronomical objects. Do those waves fulfill any known function?
 

Edited by quiet
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"fulfill any known function" is kind of awkward wording. An object will radiate according to the laws of physics. There need not be any purpose or function for that.

One way of generating EM waves is  by accelerating a charge, and the EM radiation is related to the nature of the acceleration; e.g. for a cyclic acceleration of a charge moving in a magnetic field, the fundamental frequency will be the frequency of the charge's orbital frequency. So a charge in a weak field may be undergoing a relatively gentle acceleration with a very long period of oscillation. 

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5 hours ago, swansont said:

"fulfill any known function" is kind of awkward wording.

Hello swansont. I asked for some function because I remembered the case of such an isotropic microwave noise, detected by Penzias and Wilson, wich was there without explanation until the cosmologists recognized the function of that radiation. If cosmology, or any branch of physics, has recognized that these electromagnetic waves of astronomical length fulfill a specific function, I would like to receive the news.
 

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7 minutes ago, quiet said:

Hello swansont. I asked for some function because I remembered the case of such an isotropic microwave noise, detected by Penzias and Wilson, wich was there without explanation until the cosmologists recognized the function of that radiation. If cosmology, or any branch of physics, has recognized that these electromagnetic waves of astronomical length fulfill a specific function, I would like to receive the news.
 

That's the cosmic microwave background, which has no function, as such. We know the source of it. Is that what you mean?

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19 minutes ago, quiet said:

Hello swansont. I asked for some function because I remembered the case of such an isotropic microwave noise, detected by Penzias and Wilson, wich was there without explanation until the cosmologists recognized the function of that radiation. If cosmology, or any branch of physics, has recognized that these electromagnetic waves of astronomical length fulfill a specific function, I would like to receive the news.
 

When you say “function” do you mean something like “significance” or “meaning”?

(Also, the reason/explanation of the microwave background was understood before it was spotted by Penzias and Wilson - that is why it was so important)

Edited by Strange
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Perhaps one day in the dim and distant future there will be a very very very large baseline array microHertz telescope, with astronomers lobbying for a nanoHertz telescope.

BTW I think astronomers could learn from chess, where they stopped at 'hypermodern' in the 1920s rather than continuing with ultrahypermodern, superhypermodern etc.

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13 hours ago, Carrock said:

Perhaps one day in the dim and distant future there will be a very very very large baseline array microHertz telescope, with astronomers lobbying for a nanoHertz telescope.

Problem is that to detect with reasonable efficiency your telescope aperture needs to approach the size of the wavelength (e.g. quarter-wave). Ability to detect drops off as you get away from this.

13 hours ago, Carrock said:

BTW I think astronomers could learn from chess, where they stopped at 'hypermodern' in the 1920s rather than continuing with ultrahypermodern, superhypermodern etc.

Wut?

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Thanks to all the people who have made themselves present. Each written note contributes to the reflection and that helps me.

Let's leave the word function, because we have other less confusing. And let's leave the microwave background to think about electromagnetic waves of astronomical length, which really have been detected. If it is also a residue of previous stages of cosmic evolution, we would have a scenario for our thinking. And a very different scenario if it is part of something astronomical objects do normally all the time.

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1 hour ago, swansont said:
15 hours ago, Carrock said:

Perhaps one day in the dim and distant future there will be a very very very large baseline array microHertz telescope, with astronomers lobbying for a nanoHertz telescope.

Problem is that to detect with reasonable efficiency your telescope aperture needs to approach the size of the wavelength (e.g. quarter-wave). Ability to detect drops off as you get away from this.

I was hinting at that with 'very very very large.'

1 hour ago, swansont said:
15 hours ago, Carrock said:

BTW I think astronomers could learn from chess, where they stopped at 'hypermodern' in the 1920s rather than continuing with ultrahypermodern, superhypermodern etc.

Wut?

I had thought the names were more imaginative... It seems astronomers actually limit themselves to only two words per telescope of 'very, large, long, giant' etc.

 

Very Large Array (VLA)

Very Long Baseline Array (VLBA)

Atacama Large Millimeter Array (ALMA)

Large Millimeter Telescope (LMT)

Cosmology Large Angular Scale Surveyor (CLASS)

Large Latin American Millimeter Array (LLAMA)

Giant Metrewave Radio Telescope (GMRT)

etc

and in fairness

Very Small Array (VSA).

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