Talk:Electromagnetic spectrum

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Image formatting[edit]

what the hell is wrong with the image formatting on this page?--68.121.86.23 01:40, 17 October 2006 (UTC) ALSO: frequencies should be arranged lowest to highest...

Wavelengths[edit]

Somebody put some wavelengths and/or frequencies in?ÇĢÇ+ɭ=92/3

The Wikipedia article on "X-rays" states (with several references) that the distinction between x-rays and gamma rays today is based on origin, not energy; high energy photons generated by nuclear or particle processes are gammas, while those resulting from electron transitions or acceleration are x-rays.173.9.146.174 (talk) 21:51, 24 March 2011 (UTC)

Electromagnetic radiation[edit]

This article covers very similar territory to Electromagnetic radiation. Shouldn't they be merged? -- The Anome

This article is very similiar in topic to that one ... JDR

No, I think there is two different types of information in the articles. Merging would not make sense. --ScienceMind (talk) 11:26, 27 July 2008 (UTC)

Needs image[edit]

What we really need here is a good (and colorful!) picture of the visible spectrum!!! Malbi 13:34, 2 Dec 2003 (UTC)

See Color. Patrick 01:58, 28 Jan 2004 (UTC)

Removed statements[edit]

Removed statement about low wavelength EM being impossible to measure directly. There is no lower limit on wavelength detection, and one should be able to detect arbitrarily low wavelength EM via compton scattering.

Roadrunner 21:34, 1 Apr 2004 (UTC)

Removed this from the UV section: "It was discovered to be useful for astronomy by a Mariner probe at Mercury, which detected UV that "had no right to be there". The dying probe was turned over to the UV team full time. The UV source turned out to be a star, but UV astronomy was born.". Even if it's true, it's badly written and no proof nor real data is given about it

Speed of light[edit]

Value of the speed of light corrected in km/s: from 300 (previous) to 300,000. Doctorcito 2 Aug 2005

High to low?[edit]

Wouldn't it make more sense to have the colors in the wavelength/frequency chart near the bottom go from violet to red? Most electromagnetic charts go from high energy to low energy. Same with the page. D'Agosta 15:14, August 9, 2005 (UTC)

Periodicity[edit]

"It is commonly said that EM waves beyond these limits are uncommon, although this is not actually true. The 22-year sunspot cycle, for instance, produces radiation with a period of 22 years, or a frequency of 1.4*10-9 Hz."

Is this true? If so can we have some sort of source? It seems to me that it might be confusing the periodicity of sun-spots with the frequencies of radiation that might be emitted as a consequence.

inconsistency with ELF image[edit]

The chart on this page (and the identical one in Electromagnetic radiation) is not consistent with page on ELF which gives the frequency range of ELF as 3-30 Hz, not 30-300 Hz (which is SLF). Also, instead of using VF for the range of 300-3kHz, it would be more consistent to use ULF. DaraParsavand 20:18, 12 March 2007 (UTC)

EM Spectrum "Timeline"[edit]

Has anyone made a "timeline" similar to this Vocal and instrumental pitch ranges chart? If not I think one should be started. Anyone want to help? Zhatt 19:51, August 9, 2005 (UTC)

Something that can end up looking like this. Zhatt 22:42, August 9, 2005 (UTC)

Semiprotected[edit]

I have semiprotected this page from editing from anon and new users due to reports of persistant vandalism from IPs registered to public schools in the State of Nebraska. Please request unprotection at Wikipedia:Requests for page protection when appropriate. -Loren 17:20, 15 February 2006 (UTC)

Some people define radio freqeuncy as the range from 3kHz to 1GHz, i.e., they don't include the microwave range. But here the microwave range is inluded in the radio frequency, I thought this needs some clarification....

frequency v?[edit]

What are we using v to represent frequency? Am I wrong to consider f a more apt choice of variable?

Zeta

Using the Greek letter nu (ν) to represent frequency is quite common in physics. Using f might be more appropriate for an introductory article like this one, I don't know. Pfalstad 01:58, 16 May 2006 (UTC)

Unit consistency[edit]

The units for labelling the spectrum chart at top right include some curious choices: da (presumable deca), d (deci) and h (hecta) are rarely used either in scientific fields nor common language. From experience as an engineer, these would be greeted with ridicule by anyone with a scientific background, incidentally neither of them are recommended as ISO multiples (nor is cm). For consistency, these would be better shown using the standard multiples (nm, um, mm, m, km, etc.) of m only, with a multiplier of 10 or 100 where necessary.

I agree somewhat. But it is also somewhat culturally determined. In Netherlands (where I live) wheather reports mention pressures in mbar, while in Dutch-speaking Belgium, as well as in Sweden, they use hPa. The unit dm is sometimes used in common language over here. In my field of science (spectroscopy), the cm is used very often for things like intensity (W/cm2) and inverse wavelength (cm-1). Han-Kwang 10:27, 8 June 2006 (UTC)
Granted, there may be cultural/common-use differences, but I wouldn't like to rely on them as a pointer for use in a technical/scientific document (we still use inches, feet and miles in england for measuring people/clothes/road distances, but no draughtsman would even dream of dimensioning a drawing with them). Also, I am very surprised that a professional branch of science is using a non-ISO measurement unit - in my experience, not a single industry (electronic, construction, mechanical, architectural) has used them. --Inzy 00:23, 25 June 2006 (UTC)

Misleading Comparaison[edit]

The comparision between what i assume is the Alternating current system used for power grids (50htz here) and the low end of the EM spectrum. I made a minor edit that emphasises that electricity is not part of the em sepctrum but i think it still needs revision.---bladeScythe 10:45 19 August 2006 (EST)

I checked for any actual connection between electricity and ELF but couldnt find any. A comparison of frequencies between electricity and light is an irrelevant one, so I replaced the refrence to electricity with "radio" since radio waves are the lowest commonly used frequency.Mloren 12:52, 19 August 2006 (UTC)

== UNABLE TO READ

Sorry, but I can't read this page because this article is unable to read !! 83.23.248.244 19:34, 22 January 2007 (UTC)

Sorry of my English, I'm living in Poland and I'm learning English

Range of electromagnetic spectrum[edit]

I always thought that the electromagnetic spectrum ranges from 0 to 1 to 10^24 to 1/0 (undefined) Hz.--Mathsexpressions 00:03, 17 March 2007 (UTC)

There is nothing about the lowest measured wavelength/highest frequency of gamma radiation. —Preceding unsigned comment added by 86.138.30.152 (talk) 03:27, 16 March 2008 (UTC)

Limits of the EM spectrum[edit]

I saw this quote "It is commonly said that EM waves beyond these limits are uncommon, although this is not actually true." Limits being "from thousands of kilometres down to fractions of the size of an atom." Can someone give a source for this or explain it please? 70.124.85.228 12:19, 14 August 2007 (UTC)

You mean a source for "commonly said that"? I'm not sure what is there that needs explaining. Han-Kwang (T) 13:22, 14 August 2007 (UTC)

Beyond the measurable spectrum?[edit]

      • !!!***

OMG "Until the middle of the 20th century it was believed by most physicists that this spectrum was infinite and continuous." is WRONG. Ummm... it is STILL BELIEVED TO BE INFINITE.

To assume the EM spectrum is limited to what "most sources" reference is a fundamental miss and this wiki sentence is as preposterous as denying Moore's Law - every frequency we check exists and there is no evidence to say it will end. The mathematics of Maxwell's equation are limited to a finite spectrum? Really? Are infinitely small derivative lengths also finite? THE EM SPECTRUM IS BOTH CONTINUOUS AND INFINITE, BY ASSUMPTION, TO THE BEST OF OUR KNOWLEDGE. This wiki sentence is philosophical semantics. It's like saying, "Until the middle of the 20th century it was believed by most physicists that God and all other deities ('this spectrum') was infinite and continuous. [But today, we know they are finite creations that do not exist beyond empirically measured boundaries]."

1) Any frequency: 1. and 1.000000...001 exist (assume this, because if you care about this stuff beyond philosophical babble than you'll have some empirical knowledge about it - i.e. can measure the effects of the thing). 2) Beyond gamma rays, THERE ARE EM WAVES >> 10^15 Hz and << radio waves (or whatever), you can name them if that makes you feel better, but not sure they have a name unless they are used for something "empirically"

Sidenote: I feel very confident about these simple points, although haven't considered how QED or physics particle theory plays in...

I was wondering, what is beyond gamma rays or ELFs? The first sentence here says

The electromagnetic (EM) spectrum is the range of all possible electromagnetic radiation.

and I'm thinking that, for science's sake, we should reword it to say "all measurable electromagnetic radiation". According to the De Broglie hypothesis, all matter has a wavelength, it's just when you get to sub-atomic particles do the wavelengths have a measurable effect, such as X-rays or color or heat or what-have-you. How does this sound to the wikipedia crowd? Rhetth 02:51, 25 August 2007 (UTC)

Most sources are not very careful in the matter, but the usual definition of radio waves is electromagnetic radiation of wavelength longer than 1 mm, with no longest wavelength, thus there cannot be anything "beyond" radio waves. Similarly, there is no lower limit on the wavelengths of gamma rays.
One can of course point out that only theory holds that the spectrum can extend infinitely, while experimental evidence is confined within finite bounds. To take the lowest and highest frequencies for which direct physical evidence exists to be the "ends" of the spectrum would give a lower limit of < 30 Hz (see for instance http://www.cv.nrao.edu/course/astr534/Pulsars.html ) and, perhaps somewhat
arguably, even < 1 Hz (See the "P-Pdot diagram" on that website, with the longest periods being several seconds, thus if you accept that the loss of rotational energy can be ascribed to radiation of EM waves at that frequency this would qualify). The highest frequency would correspond to the highest energy gamma quantum yet observed from space (nu = E / h, so for E = 12 TeV this is roughly 2.9 * 1027 Hz.)
Taking the limits to be 2.9 * 1027 Hz and 0.133 Hz (corresponding to a period of 7.5 seconds on the P-Pdot diagram), the observed EM spectrum spans over 28 powers of 10, and over 94 powers of 2 or 'octaves'!

-User: Nightvid

layout[edit]

there's way too many pictures and not enough text!!!! but good job on this thing! =] Lady Nimue of the Lake 10:55, 4 September 2007 (UTC)

  • Yes, I agree, I may be able to help with this article, I'll put it in my 'to-do'.-- Penubag  04:19, 6 September 2007 (UTC)

hehe —Preceding unsigned comment added by 194.154.22.53 (talk) 10:35, 7 September 2007 (UTC)

messed up completely[edit]

Some one messed up completly on this —Preceding unsigned comment added by 70.188.191.92 (talk) 23:46, 4 October 2007 (UTC)

Don't know if you think it's too much, but if reciproc centimeters was added to the other units I think it would be perfect. Even though it properly need a little text to be explained. It is very used in spectroscopy and would be nice to have next to the other units. Sorry for the bad spelling, that's why I don't do any direct editing :) —Preceding unsigned comment added by Nanopete (talkcontribs) 14:32, 8 October 2007 (UTC)

Appropriate Forum?[edit]

I'm wondering, is this the proper page to discuss questions about EM radiation, or should we limit it to just discussing the contstruction of the article? Where would be a good place for a novice like me to ask questions about physics issue3s in general? —Preceding unsigned comment added by 63.255.108.25 (talk) 01:20, 29 November 2007 (UTC)

I don't think this is the area for general discussion, it should be about the article. You should join us at physicsforums.com for physics debates! --ScienceMind (talk) 11:31, 27 July 2008 (UTC)

Or on-wiki there is the Science Reference Desk. - Eldereft (cont.) 11:47, 27 July 2008 (UTC)

Image correction[edit]

The first image: http://upload.wikimedia.org/wikipedia/commons/a/a9/Light_spectrum.png needs to be corrected. A frequency of 300Hz does not correspond to a wavelength of 1km. It should be changed to 1Mm. —Preceding unsigned comment added by Cmusco618 (talkcontribs) 20:56, 29 November 2007 (UTC)


Also wavelengths of 10dam and 100 hm should read 10m and 100m, but I could not change them.

notthe600 Notthe600 (talk) 10:55, 9 December 2007 (UTC)

Also, the wavelengths that supposedly are stopped by the Earth's atmosphere are nonsense, of course UV light gets through our atmosphere - hence sun burn. And Radiowaves do as well, otherwise the Apollo missions would have failed. —Preceding unsigned comment added by 81.79.216.188 (talk) 20:10, 16 January 2009 (UTC)

Planck Length[edit]

I have changed part of the introduction to read "...the short wavelength limit is likely to be in the vicinity of the Planck length...". This corrects a common misconception about the Planck length, namely that it is a directly meaningful physical quantity which defines a precise limit where one type of physics ends and a new type begins. In reality, its construction is fairly arbitrary (for example, there is no physical justification for using h-bar instead of h), and thus it only provides an order of magnitude estimate for the length scales of quantum gravity. Hyperdeath (talk) 12:46, 30 December 2007 (UTC)

Layout changes[edit]

I made some changes to the formatting and layout of images, as well as to the math, but I didn't realize i wasn't logged in. I appologize.

Tiny.ian (talk) 21:49, 4 January 2008 (UTC)

EM spectrum chart error[edit]

The chart at the top of the page, Image:EM_Spectrum3-new.jpg, must be incorrect, because some of the sun's UV rays do penetrate the Earth's atmosphere. If they did not, people would not be able to get tanned or sunburned naturally. --Kyoko 21:00, 16 January 2008 (UTC)

I've inquired a scientist for his opinion (pending...), I'm not an expert at this but the image is made by NASA so it has credibility -- penubag  23:14, 25 January 2008 (UTC)
Image:Ozone altitude UV graph.jpg-- penubag  00:51, 26 January 2008 (UTC)

UPDATE: I have updated the mainpage diagram that should address your concern. -- penubag  23:55, 28 January 2008 (UTC)

The image is still incorrect. These are the correct values

UVA 800 nm - 564 nm UVB 563 nm - 426 nm UVC 435 nm - 203 nm hehehehe

from the "ultraviolet radiation" page. If that picture makes any kind of sense, then UVs should be at least in the grey zones. I think it is too approximate and pictorial, and uninformingly so. Someone should do a better one. --Triptaruga

It's not exact, but does it need to be? I' happy with it the way it is as it's educational to the layperson either way.--ScienceMind (talk) 11:33, 27 July 2008 (UTC)
Plot of Earth's atmospheric transmittance (or opacity) to various wavelengths of electromagnetic radiation.

The chart lower on the page, Image:Atmospheric electromagnetic transmittance or opacity.jpg, seems to claim that the atmosphere is opaque to radio waves longer than about 30 m (10 MHz). If that were true, then medium wave AM broadcasting (520 kHz–1,610 kHz) wouldn't work. Is that a simple error in the chart, or is there something I'm missing here? --68.0.124.33 (talk) 17:05, 19 July 2008 (UTC)

The upper atmosphere is opaque to AM frequencies which allows them to be reflected off the atmosphere and back to earth's surface. This is one reason why AM radio can be received where other radio cannot.163.1.208.166 (talk) 16:15, 10 June 2009 (UTC) UNOTLD ORIGINALITYItalic text

Radio Frequencies[edit]

WRONG

Light Frequencies[edit]

The second picture of Electromagnetic Spectrum is also wrong: 10^15 Hz is not visible light (it corresponds to a wavelength of 300nm). —Preceding unsigned comment added by 85.232.195.217 (talk) 08:00, 17 April 2010 (UTC)

Corrected the image file. Materialscientist (talk) 08:40, 17 April 2010 (UTC)

Try to find a more simple definition for kids!!![edit]

That's a good page but i wanted a simple definition such as- the entire range of electromagnetic waves is called the electromagnetic spectrum. :) —Preceding unsigned comment added by 66.81.29.191 (talk) 01:10, 2 October 2008 (UTC)

You should check out the Simple English Wikipedia for easier definitions. The only bad thing is that we're scarce on articles in Simple English; we don't have an Electromagnetic Spectrum article. -- penubag  (talk) 03:30, 2 October 2008 (UTC)

Radio Frequency/MRI[edit]

I removed MRI from the list of applications of radio waves. MRI uses a magnetic field oscillating at radio frequency, but does not use radio waves - it uses the near field, which does not propagate. The section is titled 'Radio frequencies' but describes RF waves - in MRI the distinction is important. GyroMagician (talk) 20:45, 25 December 2008 (UTC)

Used as source[edit]

{{source}} there are sources for??

High energy gamma rays Creation of particle-antiparticle pairs. At very high energies a single photon can create a shower of high energy particles and antiparticles upon interaction with matter.

187.4.208.77 (talk) 14:27, 19 March 2009 (UTC)

This is the most common means of detection of very high energy gamma rays, a bit of discussion can be found at, for instance, [1]. 69.140.12.180 (talk) 22:07, 26 May 2009 (UTC)Nightvid

Before I got to this section of the talk I rated this article as a WOW!
(really good job!) Ti-30X (talk) 13:35, 31 May 2009 (UTC)

Error in "The electromagnetic spectrum" image[edit]

380nm = 7.89*10^14Hz / 750nm = 3.99*10^14Hz / 299.8 = 1*10^15Hz / Frequency 1*10-15Hz is not in visible spectrum ! / Wavelength and frequency measures are errornously shifted. Softvision (talk) 17:27, 23 July 2009 (UTC)

Corrected the image file. Materialscientist (talk) 08:40, 17 April 2010 (UTC)

Inclusion of Cosmic Waves in the discussion[edit]

I believe that further away from RAdio waves we have cosmic waves. is this true ?? should this also not be added to the article. Ap aravind (talk) 09:12, 16 October 2009 (UTC)

Red light is made of radio waves?[edit]

This image at the top of the page needs work.

  • The colors red and magenta don't extend all the way across the entire spectrum. Magenta's not even a spectral color.
  • "Penetrates Earth's atmosphere" is not a binary thing. The brightness could be varied along with the actual absorbance spectrum. Ultraviolet doesn't pass through the Earth's atmosphere?
  • Things at negative 170 degrees C are red hot?
  • Why isn't the spectrum spaced evenly with the logarithmic powers? The distance between 10^12 and 10^16 is larger than the distance between 10^8 and 10^12
  • File_talk:EM_Spectrum_Properties_edit.svg —Preceding unsigned comment added by 71.167.67.65 (talk) 00:05, 14 August 2010 (UTC)

I second these complaints. This image is very misleading in that it makes radio waves look red. Everything not in the visible portion of the spectrum should be black on the chart because that it what humans see when looking at light sources of non-visible wavelength. Also, the colors are not lined up properly with their frequency values. 74.104.22.121 (talk) 14:51, 29 December 2012 (UTC)

Edit request from Ennisdb, 15 February 2011[edit]

{{edit semi-protected}} In the second figure, the legend incorrectly states "VF/ULF" and it should state "LF/ULF." There is no "VF" spectrum. Ennisdb (talk) 05:08, 15 February 2011 (UTC)

VF is mentioned in the figure, and thus we can't just change the caption. It might mean voice frequency. Materialscientist (talk) 05:25, 15 February 2011 (UTC)

History?[edit]

I think this article could use a history section. Does anyone object? Eomund (talk) 04:25, 14 February 2012 (UTC)

Of course not. Everything in WP could use a history section. SBHarris 17:59, 14 February 2012 (UTC)
Well there a start. It could probably use some cleanup and some references. I'll probably take another look at it in a couple of days. Eomund (talk) 04:09, 15 February 2012 (UTC)

Optical Radiation[edit]

Infrared, the visible region we perceive as light, and Ultraviolet are now generally brought together under the title Optical Radiation.
It would be good to place this text somewhere in this page. — Preceding unsigned comment added by Arie Klerk (talkcontribs) 18:40, 14 February 2012 (UTC)

This seems to be a sort of regulatory classification, and I don't even know how it would be implemented without some kind of RBE or quality factor to compare the damaging effects to the eyes of 100 nm UV to that of (say) 10,000 nm IR. Perhaps some line about "EM radiation capable of damaging the retina is referred to in occupational safety literature as "optical radiation." SBHarris 21:35, 15 February 2012 (UTC)

Grammer error[edit]

In the history section, third sentence, 'studied' should read 'study'. 6th sentence should read temperature 'of' different colors. 14 th should be 'an' apparatus. 2nd last sentence, he first thought 'that they were' particles... — Preceding unsigned comment added by Snzaisuru (talkcontribs)

Fixed as suggested, thanks. Materialscientist (talk) 12:45, 23 February 2012 (UTC)

properties are where ???????? — Preceding unsigned comment added by 121.54.35.178 (talk) 00:57, 28 February 2012 (UTC)

Is this what you are looking for? Eomund (talk) 03:50, 28 February 2012 (UTC)

Error[edit]

In visible light section-- "most" of EM radiation output from Sun/stars is NOT visible, though peak intensity can be. See Planck's Law. Not sure why editing is disabled on this page; someone else can fix it if they like.

Welcome to Wikipedia. Pick a username and sign in and you'll be able to edit articles like this one after 4 days and a few good edits. Meanwhile, add ~~~~ = 4 tildes to your posts so they will be autosigned.

Yes, you are right, only about 40% of the EM output of our Sun 1400 watt/meter a the top of the atmosphere) is in the visible band. SBHarris 15:29, 29 April 2012 (UTC)

Edit request on 9 May 2012[edit]

Add the missing closing parenthesis in 4th (final) paragraph of the "Ultraviolet light" section.

Text presently reads: ... are absorbed by nitrogen and (at longer wavelengths by simple diatomic ...

Text should probably read: ... are absorbed by nitrogen and (at longer wavelengths) by simple diatomic ...

203.206.166.87 (talk) 04:35, 9 May 2012 (UTC)

Tweaked using commas - there were too many brackets in that paragraph already. Thanks. Materialscientist (talk) 05:45, 9 May 2012 (UTC)

"The", first word[edit]

Why is the "The" (first word of the article) not on same line as the sentence? I fiddled with it, no luck. Is this a temporary gliche?--Wyn.junior (talk) 21:29, 11 April 2014 (UTC)

Can we add sound waves perceptible to humans on this chart?[edit]

--Wyn.junior (talk) 21:01, 4 May 2014 (UTC)

I hope you don't mind me moving that chart and diagram into the main article. --DavidCary (talk) 16:00, 3 June 2015 (UTC)

Question[edit]

If everything in the EM travels at the speed of light, then why does sound travel at the speed of sound?--Wyn.junior (talk) 02:12, 6 May 2014 (UTC)

If all birds have two wings, then why do dragonflies have four wings? --DavidCary (talk) 16:01, 3 June 2015 (UTC)

Sound is not electromagnetic radiation. It is in fact, pressure variation waves in a medium. As will all things, it is quantized, but this reality is not an issue in nearly all circumstances. The exception is largely in the field of material science in which phonon (NOT photon) vibrations travel through materials such as crystals. Examination of those phonons (losses, interference, energy distributions, ...) is sometimes used for analysis. Electromagnetic radiation, on the other hand is the interaction (as described by Maxwell) between electric and magnetic fields and 'packaged' as photons. NO underlying material is required and photons can travel through space. No ether (qv) is required either. 69.118.209.149 (talk) 14:22, 27 December 2016 (UTC)

SI[edit]

What could a chemist do with electronvolts?... Energy levels should rather be mentioned in J, J/mol, or at least both J and eV.— Preceding unsigned comment added by 5.204.15.9 (talkcontribs) 20:03, 28 June 2014 UTC

Semi-protected edit request on 6 February 2015[edit]

elkectromagnetic is cool

187.188.100.199 (talk) 19:19, 6 February 2015 (UTC)

Red question icon with gradient background.svg Not done: it's not clear what changes you want to be made. Please mention the specific changes in a "change X to Y" format. Anupmehra -Let's talk! 21:58, 6 February 2015 (UTC)

Empty column in table[edit]

please delete the empty column in table, i cant do it because when i delete it, table crush!--Viliam Furík (talk) 11:10, 30 March 2015 (UTC)

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Front table is wrong from 100 micron to 100 nm[edit]

The classications of near UV, visible, near IR, mid IR unfortunately do not fall on neat metric-powers-of-ten in wavelength and so the table, for all its elegance, is wrong. Correct classifications that would be consistent with the rest of wikipedia and the rest of the world:

  • 100nm to 380nm: FUV-NUV - Far ultraviolet to near ultraviolet. Note that "near UV" (NUV) itself is only a tiny span, ~ 300-400 nm!
  • 380nm to 780nm: VIS - Visible
  • 780nm to [3-5] micron: NIR - Near infrared
  • [3-5] micron to [25-50] micron: MIR - Mid infrared
  • [25-50] micron to 1 mm: FIR - Far infrared

For the NIR-MIR boundary and MIR-FIR boundary, there is a bit of disagreement (see infrared article) but you might as well peg it on the ISO 20473 scheme, which assigns 3 micron and 50 micron, respectively.

See also Naomi Halas' converter site, which has all the conversions: http://halas.rice.edu/conversions

As for the left column, "ionizing radiation" should go to around the 300 nm level, i.e., not all UV radiation is ionizing. --Nanite (talk) 11:00, 18 November 2015 (UTC)

Semi-protected edit request on 13 June 2016[edit]

The word 'color/colour' is spelt inconsistently throughout this article. Please rectify this. As the spelling 'color' currently appears more often than 'colour' I strongly recommend the former spelling is preferred. Thank you.

ManSoAdmired (talk) 16:30, 13 June 2016 (UTC)

Red information icon with gradient background.svg Not done: The three occurrences of "colour" are all in quotes in the "Notes and references" section. Quotes have to be given verbatim with the original spelling. Favonian (talk) 16:41, 13 June 2016 (UTC)

That's sound man, but I checked the original source for note 7 and it is spelt 'color' there. So get it changed verbatim quicksharp. — Preceding unsigned comment added by ManSoAdmired (talkcontribs) 17:03, 13 June 2016 (UTC)

Your wish is our command. :P Favonian (talk) 17:07, 13 June 2016 (UTC)

I love you Favonian. Have you heard of Gary Ablett? — Preceding unsigned comment added by ManSoAdmired (talkcontribs) 17:32, 13 June 2016 (UTC)

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Semi-protected edit request on 13 November 2016[edit]

At the bottom of the page, there is a link for "Flash EM Spectrum Presentation / Tool" that has been marked as dead since July 2016. You can actually see that the same content is available here: http://attic.e-motiv.net/em-spectrum

The content is available at the same domain, they just changed the structure a little bit.

Craig Sandez (talk) 05:16, 13 November 2016 (UTC)

Done -- Dane2007 talk 06:32, 4 December 2016 (UTC)

Semi-protected edit request on 22 December 2016[edit]

Please change

| rowspan="2" style="text-align:right;"| 124  [[peV]]<!---col 7--->

to

| rowspan="2" style="text-align:right;"| 124  [[picoelectronvolt|peV]]<!---col 7--->

because the tooltip is missing

Thanks

Bageederd (talk) 06:18, 22 December 2016 (UTC)

 Done! DRAGON BOOSTER 06:55, 22 December 2016 (UTC).


Hmm ... it seems there are two competing forms of expression in that table. One which shows just the metric prefix and the other which uses the more appropriate unit to the column it is contained in (e.g. Pico- vs. picoelectronvolt). Would you mind updating that table column so the labeling of the units ends with "electronvolt". It really helps saps like me who have CRS syndrome.

Please & Ty

Bageederd (talk) 08:07, 22 December 2016 (UTC)

 Done! DRAGON BOOSTER 10:35, 22 December 2016 (UTC).

External links modified[edit]

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Redundant Image?[edit]

At the top of the article, there is a table listing information about the different classes of the EM spectrum. Right below it is what appears to be an image containing exactly the same information. Is there a good reason to have this redundant image? Myoglobin (talk) 20:13, 22 December 2016 (UTC)

Semi-protected edit request on 3 January 2017[edit]

Please change "1Hz" in "Frequency" column, last row of the first table (table with links) to "3Hz" because 1Hz is the wrong value and the correct value should be 3Hz as stated in the second table (picture) below. Jaredxwos (talk) 12:03, 3 January 2017 (UTC)

Done st170e 12:16, 3 January 2017 (UTC)

Sound[edit]

The audible range of the electromagnetic spectrum should be indicated, in the text and table. — Preceding unsigned comment added by 190.102.147.254 (talk) 14:02, 22 February 2017 (UTC)

Electromagnetic radiation iself is not audible at any frequency.DavRosen (talk) 14:49, 23 February 2017 (UTC)

specified name/ labels[edit]

how much could be these possible (correct)? :
X-ray: Xeno ray (xeno: strange)
UV: Ultra Vision (still can be seen by some)
infrared: Thermal Radiation, Radiotherm, RT
: after renaming electromagnetic spectrum as radiational spectrum: Radiospectrum
microwave: Magnetocyme (from magnetron, cyme: wave, greek)
: so radio telescope as Cymoscope etc.
radiowave: Electrocyme (from electric currents)
low frequency: Kryptocyme (K from kilometric wave, krypto: hidden)
and finally Macrocyme for the rest (and cosmocyme for deep space radiation; wavelenght of larger than one gigameter)
Tabascofernandez (talk) 08:50, 18 October 2017 (UTC)