🧵 /sqt/ - stupid questions thread (aka /qtddtot/)
Anonymous at Tue, 2 Jul 2024 18:54:08 UTC No. 16264698
Previous >>16235350
>what is /sqt/ for?
Questions regarding maths and science. Also homework.
>where do I go for advice?
>>>/sci/scg/ or >>>/adv/
>where do I go for other questions and requests?
>>>/wsr/ >>>/g/sqt >>>/diy/sqt etc.
>how do I post math symbols (Latex)?
rentry.org/sci-latex-v1
>a plain google search didn't return anything, is there anything else I should try before asking the question here?
scholar.google.com
>where can I search for proofs?
proofwiki.org
>where can I look up if the question has already been asked here?
warosu.org/sci
eientei.xyz/sci
>how do I optimize an image losslessly?
trimage.org
pnggauntlet.com
>how do I find the source of an image?
images.google.com
tineye.com
saucenao.com
iqdb.org
>where can I get:
>books?
libgen.rs
annas-archive.org
stitz-zeager.com
openstax.org
activecalculus.org
>articles?
sci-hub.st
>book recs?
sites.google.com/site/scienceandmat
4chan-science.fandom.com/wiki//sci/
math.ucr.edu/home/baez/physics/Admi
>online courses and lectures?
khanacademy.org
>charts?
imgur.com/a/pHfMGwE
imgur.com/a/ZZDVNk1
>tables, properties and material selection?
www.engineeringtoolbox.com
www.matweb.com
www.chemspider.com
Tips for asking questions here:
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>ask anonymously
>recheck the Latex before posting
>ignore shitpost replies
>avoid getting into arguments
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>do not mention how [other place] didn't answer your question so you're reposting it here
>if you need to ask for clarification fifteen times in a row, try to make the sequence easy to read through
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>I'm not google translating your spanish
>don't ask to ask
>don't ask for a hint if you want a solution
>xyproblem.info
Anonymous at Tue, 2 Jul 2024 19:05:50 UTC No. 16264721
>>16263871
effective focal length of apochromats is a cubic function of wavelength
Anonymous at Tue, 2 Jul 2024 20:56:25 UTC No. 16264926
>>16264721
The thing about apo lenses is that they sound good when you're only thinking about chromatic aberration, but all the hype over them never mentions that adding an extra element to the lens is necessarily going to increase other errors in the lens system. Comparing any apochromat to an acromat, you're adding in 2 extra surfaces which means higher total errors in lens shape and also increased dispersion. Apos are just a sales gimmick, they're expensive because not too many people fall for the gimmick so theres little economy of scale in manufacturing them.
Anonymous at Wed, 3 Jul 2024 17:04:12 UTC No. 16266203
saved
Anonymous at Thu, 4 Jul 2024 03:32:44 UTC No. 16267121
>>16264926
if you want to photograph someone and you're extremely concerned about chromatic aberration and absolutely need to have all wavelengths focus at exactly the same focal length then a reflecting system is what you should be using. if diffraction rustles your jimmies then there are numerous solutions for unobstructed reflecting systems, schiefspieglers being the most common one for some reason.
Anonymous at Fri, 5 Jul 2024 03:44:52 UTC No. 16268418
bump
Anonymous at Fri, 5 Jul 2024 04:02:11 UTC No. 16268432
two threads? great.
Anonymous at Fri, 5 Jul 2024 19:41:43 UTC No. 16269381
>>16268432
This one was posted first, the other one is spam created by a shitposter that was angered by seeing a black female homosexual immigrant scientist
Anonymous at Sat, 6 Jul 2024 06:39:18 UTC No. 16270043
>>16267121
High focal ratio acromats aren't all that bad on chromatic aberration and the don't have the coma of schiefspieglers. Folded light paths fix all the tube flexure issues.