Talk:Electromagnetic radiation
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Gamma rays
How it is possible that some gamma rays have longer wave length than some x-rays? They would be called x-rays then, wouldn't they? Or is there some definition of gamma rays which does not refer to wavelength? --AxelBoldt
My understanding is that at least originally, gamma-ray was the name given to the photons generated from nuclear decay. X-rays on the other hand were generated by electronic transitions involving highly energetic inner electrons. Therefore the distinction between gamma-ray and x-ray is related to the radiation source rather than the radiation wavelength. Generally, nuclear transitions are much more energetic than electronic transitions, so most gamm-rays are more energetic than x-rays. However, there are a few low-energy nuclear transitions (eg. the 14.4 keV nuclear transition of Fe-57) that produce gamma-rays that are less energetic than some of the higher energy x-rays.
--Matt Stoker
The 'conflict' with some gamma rays having longer wave length than some X-rays arises becauses we use the terms (gamma ray and X-ray) for both i) certain parts of the electromagnetic radiation spectrum and ii) electromagnetic radiation from certain processes. --Css
Cause of electromagnetic spectrums
The recently added section titled "What causes electromagnetic spectrums" would probably be more appropriate on a page about Spectroscopy. In my opinion the electromagnetic radiation page should be constrained more to a discussion of the properties of the radiation itself, perhaps with references to spectroscopy and other uses of the radiation. Also, the new section needs some work, since emission and absorption of quanta are not only associated with electronic transitions, but are also associated with rotational, vibrational, and nuclear transitions. Also the section titled "Temperature" has some problems, since the continuous spectrum is not due to doppler broadening of atomic emissions, but is more likely due to vibrational emissions. --Matt Stoker
I have moved my section to spectroscopy - I agree this seems more relevant. I was also dubious of the doppler effect being the cause of continuous spectrum but it was the only cause I could find. Thanks for advice. -- sodium
Similar to Electromagnetic spectrum
This article is very similiar in topic to Electromagnetic spectrum -- The Anome
- should these be mereged? JDR
- I think there's a place for both, as this one could address radiation in general - not just the frequency ranges of radiation. It would need a lot of work though. --Laura Scudder 22:13, 31 Mar 2005 (UTC)
- This article is referenced about 360 times, so there is a clear demand for a catchall article on electromagnetic radiation, but I find the current version unsatisfactory. With this in mind I created a To do list that's mostly about article structure to get it going. Laura Scudder 00:12, 1 Apr 2005 (UTC)
X-rays vs gamma rays
By definition the difference between X-rays and gamma rays is that X-rays are produced by electrons releasing energy in the form of photons when they change energy levels while gamma rays are released by the nucleus as part of the process of radioactive decay. X-rays can have ridiculously high eV, even overlapping the wavelengths of more normal gamma rays but are still characterized as X-rays if they originate from electrons. -- Alex.tan 07:11, 16 Sep 2003 (UTC)
Moving charge
Thought I'd address the accelerating versus moving charge. Not all moving charge creates radiation. For instance, an infinite wire carrying constant current is an arrangement with moving charges. However, there is only a constant magnetic field - no electric field - so no power is radiated. Therefore, moving charges do not always create radiation. Accelerating charges do always create radiation. I think the author was explicitly thinking of Bremsstrahlung and synchrotron radiation. -- Laura Scudder 22:13, 31 Mar 2005 (UTC)