Conversation started Mar 17, 2020 at 4:28.
Guru Vishnu
Guru Vishnu
Mar 17, 2020 04:28
"When white radiation is passed though..." - In this context, does the "white radiation" refer to the visible white light (combination of wavelengths in the visible region) or X-rays?
Semiclassical
Semiclassical
you haven't told us the context, so....no idea
Guru Vishnu
Guru Vishnu
Ok. It's from the following question:
> When white radiation is passed though a sample of hydrogen gas at room temperature, absorption lines are observed in Lyman series only.
It seems to make sense only if "white radiation" is from X-rays else we need to have Balmer instead of Lyman.
Semiclassical
Semiclassical
okay. i see white radiation defined here: pd.chem.ucl.ac.uk/pdnn/inst1/xrays.htm
"The result is the production of a continuous spectrum of X-rays known as white radiation."
Guru Vishnu
Guru Vishnu
Thanks for the resource and clarification :) Could you tell why we chose to call it "white" when it's ambiguous to refer to the visible spectrum?
Semiclassical
Semiclassical
presumably the term is inspired by analogy with "white light"
but it's for a range of x-ray wavelengths of EM radiation rather than visible light
that said, i don't know the origin of the phrase
Guru Vishnu
Guru Vishnu
Mar 17, 2020 04:32
Hmm... It sounds reasonable. No problem. Thanks for your help!
Semiclassical
Semiclassical
(i also have no idea if the phrase originated in English.)
Guru Vishnu
Guru Vishnu
Might be similar to why a black box in an aeroplane is called "black" even thought it's orange in colour.
Semiclassical
Semiclassical
oh, this is interesting. the phrase "white radiation" shows up in a footnote to one of Planck's papers on blackbody radiation: chemteam.info/Chem-History/Planck-1901/Planck-1901.html
footnote 12: "Perhaps one should speak more appropriately of a "white" radiation, to generalize what one already understands by total white light."
(in particular, he seemingly cites that as a replacement for the phrase "black-body radiation")
If that's where the phrase originates, then the analogy with white light was intended right from the start @GuruVishnu
Guru Vishnu
Guru Vishnu
Fine. Then, it seems we'd refer to the entire electromagnetic spectrum as "white radiation" and not specifically X-rays. Did I understand that statement properly?
Semiclassical
Semiclassical
yeah. that said, it wouldn't shock me if the usage of the phrase evolved as it was absorbed by the community
and thus ended up having a rather more restricted meaning, at least within its community of users
Secret
Secret
Mar 17, 2020 04:41
> One may debate whether it makes sense to speak of free will even in the second case since
a deterministic theory implies that the outcome of any action or decision was in principle fixed
at the beginning of the universe. But even adding a random element (as in quantum mechanics)
does not allow human beings to choose one of several future options, because in this case the
only ambiguities about the future evolution (in the measurement process) are entirely unaffected
by anything to do with human thought. Clearly, the laws of nature are a constraint that can
This reminds me of a past dream where I dreamt of something called "superdeterministic randomness"
Basically:
Guru Vishnu
Guru Vishnu
Thanks. For the statement from my textbook, I think X-rays is the correct choice. Do you know any golden standard for definitions in physics like "The IUPAC Gold Book" for chemistry?
Semiclassical
Semiclassical
not really, no. but this is a more specific question than 'physics'---it's more like spectroscopy?
 
Conversation ended Mar 17, 2020 at 4:43.