<p>The namesake of dark matter is because it does not emit electromagnetic radiation. Humans have built detectors on all ranges on the electromagnetic spectrum and a single particle will likely not emit wavelengths that are very large. </p>

<p>However, dark matter may produce light in collisions with other dark matter particles or normal matter. That is the premise of large scintillator detectors. </p>

CC BY-SA 3.0
2017-11-16T11:02:20.847Z
Yes but what if we haven't discovered almost 85% of the EM spectrum yet. That we have only scratched the surface of the spectrum. Like 5%, the part of the universe we can see and detect?
Pre-alpha
CC BY-SA 3.0
2017-11-16T18:32:01.467Z
@TransPlanetInjection you can't exactly discover "part of a spectrum." As soon as we figured out that light is EM waves with "colors" according to wavelength, we discovered the whole spectrum of light.
Asher
CC BY-SA 3.0
2017-11-19T22:15:46.553Z
@Asher Yes of course, please refer to the edit I made to the question
Pre-alpha
CC BY-SA 3.0
2017-11-16T06:54:36.703Z
2017-11-16T06:54:36.703Z
t.sand
<p>If it could produce EM radiation, that means it could interact via EM fields. That means there would be internal friction in the dark matter clouds, because friction ultimately boils down to electric forces.</p>

<p>But the dark matter distributions we're observing seem to indicate that there is no friction between dark matter particles, whatever they are.</p>

<p>Ergo, dark matter cannot produce EM radiation at any frequency or wavelength.</p>

CC BY-SA 3.0
2017-11-19T22:39:35.437Z
Do EM radiations and friction inherently come together. Isn't EM radiation one of the by-products of friction along with heat? Could you please elaborate or point me to some sources?
Pre-alpha
CC BY-SA 3.0
2017-11-20T19:13:14.470Z
The force of friction between two objects is essentially an electric interaction. No EM interactions, no friction.
Florin Andrei
CC BY-SA 3.0
2017-11-21T09:44:04.773Z
Interesting, so what kind of definitive proof do we have that completely rules out friction in DM?
Pre-alpha
CC BY-SA 3.0
2017-11-16T18:48:26.373Z
2017-11-16T18:48:26.373Z
Florin Andrei
<p>Could it be possible that dark matter is emitting EM radiations on a scale that is not known or perceivable by humans yet and undetectable by man-made instruments? </p>

<p>A type of radiation that our instruments were just not designed to pick up on? Being insensitive and not advanced enough? Thus we do not yet have all the pieces to solve the puzzle?</p>

<p><em>Edit:</em> We need to remember that there are infrared and gamma rays on either end of the spectrum and we are aware that dark matter is definitely not emitting visible light, or any of the other type of EM waves. Considering that gamma rays were discovered roughly only a hundred years ago, isn't it possible that the spectrum could be further extended on either side and that we're still not aware of it?</p>

CC BY-SA 3.0
2018-01-02T19:37:43.963Z
Your Edit makes no sense. "infrared" is by far not the lower end of the spectrum, and gamma rays not the other end. So, it shows you really haven't researched much about electromagnetic waves. There's no need to "extend" "the spectrum". Wavelength and frequency are two sides of the same medal, and also just a number; there's nothing to be "discovered" here.
Marcus Müller
<dark-matter>
Dark matter emitting EM radiations beyond our currently known spectrum?
Pre-alpha
# Dark matter emitting EM radiations beyond our currently known spectrum?

(Asked by: username_0 on 2017-11-16)

Could it be possible that dark matter is emitting EM radiations on a scale that is not known or perceivable by humans yet and undetectable by man-made instruments?

A type of radiation that our instruments were just not designed to pick up on? Being insensitive and not advanced enough? Thus we do not yet have all the pieces to solve the puzzle?

*Edit:* We need to remember that there are infrared and gamma rays on either end of the spectrum and we are aware that dark matter is definitely not emitting visible light, or any of the other type of EM waves. Considering that gamma rays were discovered roughly only a hundred years ago, isn't it possible that the spectrum could be further extended on either side and that we're still not aware of it?

**Tags:** dark-matter
> **Comments:**
> **username_1**: Your Edit makes no sense. "infrared" is by far not the lower end of the spectrum, and gamma rays not the other end. So, it shows you really haven't researched much about electromagnetic waves. There's no need to "extend" "the spectrum". Wavelength and frequency are two sides of the same medal, and also just a number; there's nothing to be "discovered" here.  

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## 2 answers

### Answer by username_2 on 2017-11-16. Score: 2

The namesake of dark matter is because it does not emit electromagnetic radiation. Humans have built detectors on all ranges on the electromagnetic spectrum and a single particle will likely not emit wavelengths that are very large.

However, dark matter may produce light in collisions with other dark matter particles or normal matter. That is the premise of large scintillator detectors.

> **Comments:**
> **username_0**: Yes but what if we haven't discovered almost 85% of the EM spectrum yet. That we have only scratched the surface of the spectrum. Like 5%, the part of the universe we can see and detect?  
> **username_3**: @TransPlanetInjection you can't exactly discover "part of a spectrum." As soon as we figured out that light is EM waves with "colors" according to wavelength, we discovered the whole spectrum of light.  
> **username_0**: @Asher Yes of course, please refer to the edit I made to the question  

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### Answer by username_4 on 2017-11-16. Score: 2

If it could produce EM radiation, that means it could interact via EM fields. That means there would be internal friction in the dark matter clouds, because friction ultimately boils down to electric forces.

But the dark matter distributions we're observing seem to indicate that there is no friction between dark matter particles, whatever they are.

Ergo, dark matter cannot produce EM radiation at any frequency or wavelength.

> **Comments:**
> **username_0**: Do EM radiations and friction inherently come together. Isn't EM radiation one of the by-products of friction along with heat? Could you please elaborate or point me to some sources?  
> **username_4**: The force of friction between two objects is essentially an electric interaction. No EM interactions, no friction.  
> **username_0**: Interesting, so what kind of definitive proof do we have that completely rules out friction in DM?  

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