Wikipedia:Reference desk/Archives/Science/2022 December 7

= December 7 =

Can you have an electromagnetic pulse without a planetary magnetic field?
(Electromagnetic pulse) Say on Venus, Mars or Titan. JoJo Eumerus mobile (main talk) 20:14, 7 December 2022 (UTC)
 * Yes. --OuroborosCobra (talk) 22:38, 7 December 2022 (UTC)
 * EMPs caused by lightning can occur on planets with an atmosphere, such as Venus. The EMP carried by a powerful coronal mass ejection can certainly impact all inner planets but will not cause a magnetic storm on those without magnetosphere. BTW, Titan's orbit skirts Saturn's magnetosphere, and a magnetic storm on Saturn might have a minor influence there. --Lambiam 03:57, 8 December 2022 (UTC)
 * Are there any papers or books discussing such a non-magnetic EMP? Jo-Jo Eumerus (talk) 10:53, 8 December 2022 (UTC)
 * EMP stands for electro magnetic pulse; they are as magnetic as it gets with pulses. Various types, distinguished by what causes them, are discussed in our article on this topic, which you linked to in the question. --Lambiam 12:04, 8 December 2022 (UTC)
 * Just to clarify, electromagnetism is one thing. If you have moving electrical charges, you're going to have a magnetic field.  If you have a magnetic field, there's a moving charge of some sort.  Insofar as lightning is an electric current, it will generate a magnetic field.  -- Jayron 32 13:08, 8 December 2022 (UTC)
 * Sorry, should have said "EMP on a body w/o an intrinsic magnetic field". Jo-Jo Eumerus (talk) 15:11, 8 December 2022 (UTC)
 * , you seem to be under a false impression of some sort, though I'm not entirely sure what. The existence of magnets, magnetism, and magnetic fields does not depend upon a planet having a magnetic field. If you take a permanent magnet from Earth and take it to Mars, it will still be a magnet and still have a magnetic field. If you take an electromagnet to Mars and turn it own (moving electrical charges through it), you will have a magnetic field. Second, an EMP is not a pulse of or through a planetary magnetic field. If you detonate a nuke on Mars, you will have an EMP. It's being generated by the nuke itself, and not an interaction with a planetary magnetic field. To put it another way, water is still wet on Mars, as it being wet is a property of water, and not the planet it is on. In either case, the existence (or absence) of "a body" with "an intrinsic magnetic field." --OuroborosCobra (talk) 14:59, 8 December 2022 (UTC)


 * As listed in the linked article, there are many kinds of electromagnetic pulses, differing in strength, spectrum, polarisation and cause. A nuclear electromagnetic pulse caused by a high-altitude nuclear detonation like the Starfish Prime test has a lot to do with the planetary magnetic field. It's horizontally polarised and very fast (nanoseconds). Your average nuclear detonation at ground level also causes an EMP, much weaker, and vertically polarised. That pulse doesn't depend on the magnetic field. A coronal mass ejection hitting the Earth's magnetosphere can cause a geomagnetic storm, a kind of EMP over a billion times slower than the nuclear kind (seconds to minutes) and with completely different effects. That pulse also depends on a planetary magnetic field. A lightning strike makes a pulse on an intermediate timescale (milliseconds) and doesn't depend on the planetary magnetic field. PiusImpavidus (talk) 17:14, 8 December 2022 (UTC)

Sugar solubility in sodium chloride solutions
What data are available re the solubility of sucrose in sodium chloride solutions of various salt content up to saturation in salt, compared to the solubility of sucrose in pure water? Is there salting-in or salting-out? 178.138.99.84 (talk) 23:53, 7 December 2022 (UTC)
 * "It's complicated as hell." See:
 * for a table of "solubility of sugar in aqueous salt solutions at 30°, 50°, and 70°". It in turn is cited to original data from page 313 of:
 * Wow, that was a fun fragment of a ref to decipher and trace! I think there may be a sub-title to that journal, as it has merged and split several times. DMacks (talk) 02:15, 8 December 2022 (UTC)
 * Wow, that was a fun fragment of a ref to decipher and trace! I think there may be a sub-title to that journal, as it has merged and split several times. DMacks (talk) 02:15, 8 December 2022 (UTC)
 * Wow, that was a fun fragment of a ref to decipher and trace! I think there may be a sub-title to that journal, as it has merged and split several times. DMacks (talk) 02:15, 8 December 2022 (UTC)


 * So, diving down a rabbit-hole, I could find only limited information about Schukow, so we won't get a new bio article from him. Apparently he was involved with the Association of Russian Sugar Manufacturers. I found proceedings of a 1906 meeting he attended where others were discussing ongoing development and validation of a fancy then-new test called Fehling's solution. That discussion also mentioned the name Violett in connection with that sort of reagent, but I'm at a dead-end finding any further info in that direction. Does anyone know if Violett is someone who involved with Fehling's (but whose name fell out of eponymous use) or if it is a different reagent that has itself long become obsolete? DMacks (talk) 05:08, 8 December 2022 (UTC)
 * The Ukrainian and Russian Wikipedias each have an article on Ivan Diomydovych Zhukov: uk:Жуков Іван Діомидович and ru:Жуков, Иван Диомидович. --Lambiam 11:53, 8 December 2022 (UTC)
 * Thanks! Anglicizing those names from older literature makes my brain hurt. DMacks (talk) 16:59, 8 December 2022 (UTC)
 * It is not a matter of age, but merely of a different method of Romanization for German as the target language. "Our" Georgy Konstantinovich Zhukov is Georgi Konstantinowitsch Schukow on the German Wikipedia. --Lambiam 21:16, 8 December 2022 (UTC)
 * Is it possible that the word Violett was the German term for the colour violet? --Lambiam 16:16, 10 December 2022 (UTC)
 * No, tracked down the source as Violette's solution. It is copper sulfate, rochelle salt and caustic soda in water, similar to Fehling's solution. Mike Turnbull (talk) 16:40, 10 December 2022 (UTC)