Wikipedia:Reference desk/Archives/Science/2015 November 2

= November 2 =

What kind of bee?
Megachile lapponica is referred to as a "non-metallic bee". This article mentions "metallic and non-metallic bees". I don't seem to be able to find a definition. Is it just coloring/appearance or something more technical? Clarityfiend (talk) 02:49, 2 November 2015 (UTC)


 * I've never looked into the etymology of this entomological term (how often to do get to combine those two?), such that I could say with confidence but typically it does seem to be applied specifically to species which have a phenotype which disposes their exoskeleton to an iridescence suggestive of metal: . As an interesting little aside, some species of bee do have a tiny amount of metal embedded in a sensory structure that allows the bee to detect and orient itself in relation to magnetic fields.  S n o w  let's rap 07:49, 2 November 2015 (UTC)


 * Iridescent.green.sweat.bee1.jpg Yes, it refers to the shiny/metallic/iridescent look. However, it could be that the bees that have that trait must all fall into a certain group, though it is almost certainly not a clade. I mean sure, technically they do fall in the group of "metallic bees", but does that mean anything biologically? Let's see: the Agapostemon have metallic members and are Halictidae, but the Euglossa are metallic Apidae. So the most it could mean in terms of systematics is that metallic bees are in superfamily Apoidea, but that superfamily is paraphylletic anyway. And while it's true that all metallic bees are in the suborder Apocrita, so are all non-metallic bees. So I don't think this can mean anything biologically in general other than they look metallic. However, when restricted to a certain case, it may be more meaningful. For example, here's a new taxonomy of the metallic members of Lasioglossum subgenus Dialictus, which seem to be all closely related.
 * Mostly, I think the metallic trait and terminology is just an easy trait to check off in the field - the metallic bees are very easy to notice, and there aren't terribly many of them, compared to non-metallic bees, so that's a good way to get ID started. SemanticMantis (talk) 13:21, 2 November 2015 (UTC)
 * I can't help directly with the OP but structural coloration might be a starting place. DrChrissy (talk) 13:43, 2 November 2015 (UTC)
 * Right, and there is some interesting biology there. I don't have time today to look for refs specifically about the metallic bees, but for e.g. blue bottle flys and tiger beetles, the iridescent structural color is thought to be involved in predator evasion, but also thermoregulation, and also, funnily enough, mimicry of metallic wasps . Sexual selection may come in to some of the bees, since some of them have iridescence as a sex marker (N.B. all the metallic bees I know of are less social than eusocial, so unlike honeybees, the males actually do a bit more than deliver sperm). Here's a nice freely-accessible review of functions of iridescence across all of the animal world. SemanticMantis (talk) 15:33, 2 November 2015 (UTC)
 * Thanks all. Way more than I needed, but interesting. Clarityfiend (talk) 22:52, 2 November 2015 (UTC)

Sweating horrendously on demand
I take part in a play, and there's an intense scene where I have to shake uncontrollably and sweat waterfall. I work on the shaking (still not look natural enough, but I hope I'll get it eventually) but sweating?? Is there any SAFE drug that will make me sweat? My director advised very spicy food, but I really don't want that. אילן שמעוני (talk) 10:21, 2 November 2015 (UTC)


 * I would have thought makeup would be more reliable and safer than actually making yourself sweat. This site recommends a 2:1 mixture of water and glycerine, and there are plenty of special-effects makeup companies that sell suitable products. Tevildo (talk) 11:05, 2 November 2015 (UTC)


 * Problem is I need to start sweating mid-scene. Otherwise it would be good. BTW, are you evolving to be Sauron or are you a cat? אילן שמעוני (talk) 11:47, 2 November 2015 (UTC)


 * Somewhat OT, but the question was asked. I am named after the illustrious Tevildo Vardo Meoita, but am not he. Whether I am a cat or not is a matter for MOS:IDENTITY. Tevildo (talk) 13:31, 2 November 2015 (UTC)


 * Chewing peppermint will have a diaphoretic (sweat-inducing) effect, but probably not enough to be noticeable unless someone's standing next to you. I believe you answered your own query in your initial question; anything with a diaphoretic effect rapid enough to sweat on cue, and strong enough to be visible at a distance, is going to be highly toxic. You're a lot better off using makeup. &#8209; iridescent 12:35, 2 November 2015 (UTC)


 * WP:OR... Some Chili peppers have that effect on me, especially habaneros. -- Jayron 32 13:17, 2 November 2015 (UTC)


 * If you need something that's visible at a distance, I'd recommend something mechanical. Sponges of water under the armpits give you an easy way to soak your shirt on demand, although you'll probably need to them to be fitted as soon as possible before the sweating scene, both for your comfort and to stop them dripping too early. If you have fairly long hair or wear a hat, you could try putting thin tubes (this sort of thing) over your scalp with little holes in them, and squeeze water out of them - for instance, from a bottle under your armpits which you squeeze (but unless you can get the blocking right, it might look a bit strange to the audience!) Smurrayinchester 14:16, 2 November 2015 (UTC)


 * Thanks all that contributed. I'll try the Chili (Ouch ): אילן שמעוני (talk) 16:09, 2 November 2015 (UTC)


 * That won't work, for several reasons:


 * 1) The sweating will start as soon as the chilis hit your tongue, not mid-scene.


 * 2) It won't be visible to the audience, except perhaps the front row.


 * 3) A burning mouth will be so distracting you won't be able to perform.


 * The mechanical system (a damp sponge tied under each armpit) will work far better. Make sure you wear a shirt that will darken noticeably when damp.  I also suggest another sponge under a hat or wig (tied down so it doesn't fall off when you shake).  You can pretend to scratch your head but really push down on the sponge then.  A more sophisticated system could have a water-release mechanism under your wig or hat, either on a timer or with a remote control operated by a stagehand. StuRat (talk) 16:19, 2 November 2015 (UTC)


 * If the play's author is among the living, you could ask them how they expected it to happen. ←Baseball Bugs What's up, Doc? carrots→ 16:01, 2 November 2015 (UTC)
 * I know of some friends who have used packs of fake blood under a wig to simulate a head wound - perhaps something similar with a pack of the fake sweat suggested above would work for brow sweat on cue? You'd need to burst the bag (a paperclip concealed in the cuff of a shirt can work for this), but a suitable motion could probably be incorporated.  The pain in your mouth from a chili strong enough to make you sweat might well interfere with gettin your lines out reliably. MChesterMC (talk) 16:17, 2 November 2015 (UTC)


 * My view is that in close up cinematography, sweat oil makeup may be advantageous but on stage it will not perceivable to an audience. Remember too, many great actors became so because they could disagree with the director when he was wrong (i.e. eating spicy foods). Remember, a director is just that, he is not a god and does a not know it all. Suggest to him at playing it your way. Meaning by that, this sounds like an amateur thing. A good playwright,  would I think, indicate in the script that the actor should mime wiping his brow etc.,  and announce “look how I sweat”. So, add your own way of emphasising that your character is sweating profusely.
 * As for the shaking: Avoid trying to tense up you muscles in order to shake. That produces a repetitive tremor (which is fine when displaying frustration but frustrated people don't normally sweat). Relax and perform multiple muscle twitches. After all, that is what uncontrollably  means. This has to be a whole body effect. Practice in front of a full length  mirror; since one's legs also turn to jelly and knees  knock together, ones actions and guidance of limbs are not longer smooth, one has trouble of controlling ones voice in timber, tone and volume, etc.  Think back to any time in your life were you ever felt like this and draw upon that too. Video your performance in front of the mirror whilst saying your lines. Place the camera well back because subtle movements will not come across to the audience. Actions have to be a little exaggerated compared to real life.
 * It has to be a whole body performance that makes your audience believe you (you're character) is really and truly sweating buckets and shaking uncontrollably.--Aspro (talk) 17:03, 2 November 2015 (UTC)


 * Thanks for the input. By now I produce quite convincing head and hands shaking- should suffice. The theater is VERY small, and I doubt more than 30 people or so will be in the audience... As for the director, I had enough brushes with him already as it is... but I WILL consider it after I try the chili.
 * As an anecdote, I have a friend who consumed raw eggs (which is bad, Salmonella and such) on stage for the sake of performance. He had to do it three time each show. He only drew the line when they had to perform three times the same day on Akko festival. I can't remember how the director handled that. I do believe an actor must aspire for the perfect in order to get at least decent performance. אילן שמעוני (talk) 20:02, 2 November 2015 (UTC)


 * In TV commercials where somebody needs to be shown eating or drinking, they usually just spit it out at the end of the take to avoid getting sick from overeating on all those takes (see Vitameatavegamin for a fictional example of what can happen when this was not done). In TV shows and movies, where it's not as critical to show people actually eating, they typically just mimic the motions, like bringing a spoon up to the mouth but not actually swallowing anything (camera cuts before they would).  So, these might apply to theater, too.  They could spit food or drink out when out of view.  Or they could do some slight of hand to appear to be eating while really only palming the food. StuRat (talk) 23:08, 2 November 2015 (UTC)


 * I had the exact same task a few years ago and a fellow actor told me of his trick of inserting a jalapeno where the sun dont shine. Only trubble was that it brought tears to my eyes as well.109.144.180.19 (talk) 23:23, 4 November 2015 (UTC)


 * Imagine Donald Trump as the next president. If that doesn't get you sweating up a storm, nothing will. Clarityfiend (talk) 23:25, 4 November 2015 (UTC)


 * Oh. Thanks a lot Clarityfiend ! That thought not only brings me out in a sweat but likely  bring  me nightmares tonight.--Aspro (talk) 00:15, 5 November 2015 (UTC)


 * How can you be scared of somebody with a halo hovering above their head ? ... oh, wait, that's not a halo, that's his "hair". StuRat (talk) 00:26, 5 November 2015 (UTC)

Can one believe that the Moon&rsquo;s ocean disappeared inside the Moon?
Arthur C. Clarke writes in the introduction to The Sentinel that the Moon’s ocean disappeared inside it as the Moon froze. I thought it was obviously absurd but it turns out that some scientists, including Edward Frankland, considered it plausible. I find the argument that internal cavities originated from thermal shrinking obviously absurd, considering that such a cavity would immediately collapse under the enormous pressure inside the Moon. Is this theory still viable? Was it viable in 1951? Otherwise, why would the author come up with such an outlandish claim? --Yecril (talk) 12:06, 2 November 2015 (UTC)


 * Maybe not our moon, but Saturn's moon Enceladus has a documented underground ocean: . So it isn't a plainly ludicrous idea; whether or not our moon has such an underground ocean aside, the notion that it could is borne out by the fact that other similar bodies in the solar system DO have them.  -- Jayron 32 13:15, 2 November 2015 (UTC)


 * I think the notion of the Moon cooling down and water disappearing into cracks inside it is pretty ridiculous. The cracks would inevitably get warmed now and then and outgas a telltale water vapor.  Other moons with subsurface oceans are covered with ice, not bone-dry dust.  However, there's another way for water to disappear into the Moon, which is how much (most) of it disappeared on Earth - by chemical incorporation into the rocks, most notably ringwoodite.  The People's Republic of China is showing some interest in finding ringwoodite deposits on the Moon that are exposed by cratering.  Wnt (talk) 15:00, 2 November 2015 (UTC)


 * I don't believe liquid oceans could ever have existed on the Moon, since it lacks the gravity necessary to keep enough of an atmosphere to support an ocean. With little atmosphere, the water would just evaporate into space. StuRat (talk) 15:08, 2 November 2015 (UTC)


 * If I remember correctly from seeing a local exhibit of moon rocks in the 70's, wasn't the lack of hydrated minerals taken as an indication that the moon is essentially "dry"? μηδείς (talk) 17:25, 2 November 2015 (UTC)

Cytisine
What parts of Laburnum contain Cytisine and how is it extracted and processed into the medicinal form? 114.38.128.163 (talk) 13:01, 2 November 2015 (UTC)
 * According to this it is found throughout the tree and this tells you how it can be extracted from the seeds. However, it's not clear to me whether or not cytisine is extracted from laburnum commercially to be used as a medicine.  Richerman    (talk) 15:38, 2 November 2015 (UTC)
 * Ah, according to this it is: "a company in Bulgaria named Sopharma made a stop-smoking drug called Tabex. The pills contained cytisine, a natural compound found in the tree’s seeds. The drug was farmed from massive laburnum orchards in Bulgaria". Richerman    (talk) 15:53, 2 November 2015 (UTC)

Word for "other member of the same species"
Is there a handy word for "other members of the same species", that would fit into the sentence fragment "Unlike the Lemur catta on Madagascar, their "X" in zoos across the world..."? I feel like something of the form "homospecies" or even just "specimen" would sound right, but I'm honestly not sure if there's even a short way to to describe this concept.12.109.68.198 (talk) 17:03, 2 November 2015 (UTC)


 * The word is "conspecific", but I think it would be better to rewrite your sentence so that it doesn't need such a word. Looie496 (talk) 17:20, 2 November 2015 (UTC)


 * It depends on the context and audience. It's a simple con- construction, and any e.g. college student should expected to understand terms like "conspecific", "congeneric", "confamilial", etc. In the OP's sentence "counterparts" would fill in X without restructuring the sentence. If this is for WP, then the appropriate concept can easily be wikilinked, like we do with any other cromulent term that may or may not be known to readers. SemanticMantis (talk) 17:34, 2 November 2015 (UTC)


 * Using a word most people won't know, like conspecific, and then providing a link, is not a good idea, as long as there is an easy way to avoid using the confusing word in the first place. In the above example, I would just use "their species" or "that species" or "that same species".  That's quite clear without readers having to research the words to understand it. StuRat (talk) 18:17, 2 November 2015 (UTC)


 * I write a lot in animal articles and I used to use the term "conspecific" regularly, However, after receiving many complaints that most people would not understand the term, I have changed my editing.  Now I would write "  ...members of the same species (conspecifics)..." and use "conspecifics" thereafter.  To the OP (and others), please avoid using the word "specimen" when referring to animals - most writers would avoid that term these days. DrChrissy (talk) 19:24, 2 November 2015 (UTC)


 * Okay, thanks!12.109.68.198 (talk) 19:38, 2 November 2015 (UTC)


 * You should ignore those critics. There's all kinds of words in articles that people don't already know -- just like in the rest of the written world. But -- this is important -- that's how we learn new words! Especially when we are reading the worlds largest hyperlinked collection of knowledge, the answers are only a click away. Seriously, we shouldn't use a five-dollar word when a penny one will do, but we're also completely allowed to used the correct word for a concept, without being overly worried that some readers may not know it. If that were our guiding principle, we couldn't even have an article on sheaf cohomology, or Induced pluripotent stem cells, etc., etc. SemanticMantis (talk) 23:16, 2 November 2015 (UTC)


 * They didn't come here to increase their vocab. And the problem is that if they go to the linked article to understand that term, and it in turn requires following other links to understand, and so on, they may never finish and leave in frustration.  Authors of dictionaries try to follow the principle of defining words using simpler words, whenever possible, to avoid this very problem. StuRat (talk) 23:25, 2 November 2015 (UTC)


 * This is an issue that has come up time and again via MoS, Village Pump, the talk pages of policy articles, and various other community spaces.  The (extremely rough) consensus I have taken away from those discussions (and the few polices that treat the matter directly) is an approach somewhere between your and SM's positions.  That is to say, we should be using general terminology and typically choosing an approach that will be able to effectively inform as a broad a selection of readers as possible, but,  that being said, there is no shortage of articles and topics which cannot be approached in the slightest without heavy reference to technical and scientific jargon.  Some content and some concepts are just too rarefied to be explained in layman's terms, because they are so divorced from every day experience.  If I had to stop in the middle of every sentence on an article in the topic of neuroscience and explain every physiological concept to the level of understanding of the average layman and then do the same for every clinical term that came up in those definitions, it would create a constant feedback loop that would lead to articles of this nature being hundreds of times longer than they would otherwise need to be, incredibly dense, and poorly organized and off-point to a degree that they would be unusable for their intended purpose.  This is clearly one of the main functions (if not the main function) of internal linking in the first place.


 * This quote from WP:What Wikipedia is not, is instructive here: "Introductory language in the lead (and also maybe the initial sections) of the article should be written in plain terms and concepts that can be understood by any literate reader of Wikipedia without any knowledge in the given field before [emphasis added] advancing to more detailed explanations of the topic."


 * Personally I see no problem with Dr. Chrissy's approach of defining a concept (for which parentheticals are particularly useful) and then leaning on the term thereafter, where appropriate. In fact, I know that's enshrined in some policy, though I am drawing a blank on just where.  S n o w  let's rap 23:27, 3 November 2015 (UTC)


 * Note that the same "feedback loop" still exists when the explanations of each term are in external articles. So, at some point you get topics that simply can not be made readable by a general audience.  If you want to understand them you will need to go get a PhD in the field first.  Thankfully, that only applies to a small number of articles and, with the rest, we have the choice of making them readable to a general audience or totally opaque. StuRat (talk) 23:50, 3 November 2015 (UTC)


 * But the choice you are presenting is whether that loop is handled within the article (in which case it bloats, disrupts its structure and generally undermines utility) or using internal links for exactly the purpose they are meant to serve, thus keeping our content organized and allowing our readers to pursue the threads they need or want to pursue at their leisure without making each article an omnibus on ever field of inquiry the topic touches upon. We have clear and overwhelming community consensus on which of this approaches is better, at it's pretty easy to see why.  I also disagree that a certain amount of technical jargon requires an advanced degree to process; the entire point of Wikipedia is it now puts a wealth of information at the fingertips of its users to fill in the necessary blanks; all that limits this process is the reader's time and level of interest and the quality of the relevant articles.  But that quality is not improved by avoiding necessary clinical terms like the plague, even where that terminology presents a more refined and functional understanding of the topic at hand.


 * I think to some extent that your proposed standard puts the cart before the horse. When there exists two options to describe the same concept that are equally elucidative, and one utilizes more common usage terminology, by all means, use that option.  But if the choice is between a less accurate and less instructive option that any random person can read and one which requires some further understanding of the predicate terminology, that's the better choice for an encyclopedia.  We aren't writing for children here (at least, not as the standard for an "average person") and our readers are free to choose how far they want to follow a given thread.  Not giving them that option is manifestly against the very stated goals of this project.  That doesn't mean I want every article on Newtonian physics to start out with equations, mind you.  Obviously there is a learning curve, and that's what the lead and other contextualizing sections are for, and there's room for a lot of improvement on some articles written by academics working in their own fields before they fully understand the Wikipedia approach.  But more often than not, in an article on a scientific or technical topic, I'd just as soon the more precise description be given rather than one that levels the playing field relative to those who have no time to read even a single other article defining a predicate term.  S n o w  let's rap 00:19, 4 November 2015 (UTC)


 * Re: "bloats, disrupts its structure and generally undermines utility". I absolutely agree.  However, this is still the case when all the material the average reader will need to read to understand an article is at links.  Indeed, it's even worse, since navigation is now complicated by links within links within links, and external links aren't always focused on explaining the linked term (for example, the article at the conspecific link first explains "intraspecific" and "interspecific", with "conspecific" only defined after about 20 unnecessary sentences and bullets.).


 * Now don't get me wrong, when there is no other option than to use a complex term the average reader won't understand, then links and a simple explanation are in order (there's also a "mouse-over" definition, which can be a better option than a full link). But, links can be abused.  For an analogy, look at police use of tasers.  The idea was to give them a nonlethal alternative to shooting suspects.  And, when used in that way, they are good.  But, police also then started using them on anyone being uncooperative.  That's an inappropriate use.  Same with links, if people decide they can now use the most complex words they can possibly find, so long as they provide links for each. StuRat (talk) 23:26, 4 November 2015 (UTC)


 * Hey and, this isn't simple english WP. Shall I start replacing "amygdala" with "little almond-shaped bits of a brain"? Or maybe change "motherboard" to "biggest wafer with squiggly metal lines and boxes glued to it in a computer"? I could make suitable re-wordings to avoid both of those, as well as many other terribly complicated words... I'm mostly joking of course, but it does seem like you two have confused English WP with its Simple English cousin. :) SemanticMantis (talk) 23:11, 2 November 2015 (UTC) ETA- oh wait, I thought this seemed familiar: it was less than a year ago  that the three of us went down this same specific road before!


 * Those examples are words that have no simple, common equivalent expression in regular English. So, use those words with a link.  What we want to avoid is using needlessly complex words, either with or without links.  So, say "lied" instead of "prevaricated", for example, or "same species" instead of "conspecific". StuRat (talk) 23:20, 2 November 2015 (UTC)


 * I agree with Dr, Chrissy, that's the way I do it - use the correct term, linked if possible, and also explain what it means. Richerman    (talk) 23:43, 2 November 2015 (UTC)


 * That certainly is better than forcing them to follow a link in an attempt to decipher what you said. StuRat (talk) 06:52, 3 November 2015 (UTC)


 * Did you say cousin? "Their cousins in zoo's around the world..." that's what David Attenborough would say. Ssscienccce  (talk) 12:11, 3 November 2015 (UTC)


 * My instinct was to go with "relatives", though that is inexact (as is "cousins", of course). "Unlike the Lemur catta in their natural habitat on Madagascar, the members of the species in zoos across the world..."? --Stephan Schulz (talk) 12:33, 3 November 2015 (UTC)


 * Leaving to one side the eternal populist-v-expert war, I would just note that (unless I misunderstand it), the word "conspecific" doesn't actually work in the example sentence. *Unlike the Lemur catta on Madagascar, their conspecific in zoos across the world....  Not grammatical. --Trovatore (talk) 07:26, 3 November 2015 (UTC)


 * Hmm, maybe I have to amend that. conspecific lists a noun meaning, and I see above that Dr Chrissy uses it in the plural.  To my ear, though, it has an inelegant sound used as a noun. --Trovatore (talk) 07:44, 3 November 2015 (UTC)


 * To mine too. That's mainly why I suggested rewording the sentence -- it can be used as a noun but looks like an adjective. Looie496 (talk) 13:55, 3 November 2015 (UTC)


 * The noun use is as a Nominalized_adjective, and it usually has a plural form - "Grackles roost with conspecifics, while doves will roost with congeners." It is true that in many examples, the word can be avoided relatively easily. But other times we want to say something like "When corn flowers receive pollen from different species, they preferentially accept conspecific pollen, and heterospecific pollen will only fertilize if there is no conspecific pollen present. While congeneric cross-fertilization is relatively common, crosses outside the genus are unlikely." -- and explaining those (fictional) concepts with "members of the species/genus" workarounds will be result in a long and tedious mess. I do think it's interesting that you phrase this as "populist vs. expert". I hadn't heard that before, and thought it might be a common term for this type of debate. When I googled it, the first relevant hit was our own article on Anti-intellectualism, make of that what you will :)SemanticMantis (talk) 15:38, 3 November 2015 (UTC)


 * My rewrite:


 * "Corn flowers prefer pollen from their own species, but, if they have none, they will accept pollen from a different species. While cross-fertilization within the same genus is relatively common, crosses outside the genus are unlikely."


 * Is that incorrect or in any way awkward or confusing ? (My version is shorter, at 62 syllables versus your 84.)  I am reminded of the father in A River Runs Through It, who made his sons rewrite everything to make it more concise.  I would also aim for more accessible at the same time. StuRat (talk) 00:01, 4 November 2015 (UTC)

Glowing vapor/fume
What substances can produce vapor or fume that glows in the dark (with green, blue or other color, not simply colored fume)?--93.174.25.12 (talk) 19:57, 2 November 2015 (UTC)
 * One possibility is Will-o'-the-wisp. ←Baseball Bugs What's up, Doc? carrots→ 20:10, 2 November 2015 (UTC)
 * Wabbit farts when ignited.?31.55.64.143 (talk) 20:30, 2 November 2015 (UTC)
 * More like decomposing trolls. ←Baseball Bugs What's up, Doc? carrots→ 05:47, 3 November 2015 (UTC)




 * The colour of a flame can detect some metal ions. In pyrotechnics, the pyrotechnic colorants are used to produce brightly colored fireworks. Examples are:

 Arsenic - blue Boron - bright green Calcium and Cadmium - brick red Copper - Green Potassium - Lilac Sodium - Yellow Lead and Tin - Blue/white Rubidium - Red/violet Strontium - Crimson to Scarlet 
 * Bestfaith (talk) 21:00, 2 November 2015 (UTC)


 * Neon lighting or, more generally gas-discharge lamps. Also see Northern Lights.  If you wanted to simulate the effect, perhaps colored lights or lasers aimed at water vapor produced by a fog machine might be a practical method. StuRat (talk) 21:10, 2 November 2015 (UTC)
 * With separate illumination the following toxic gasses qualify.

 F2 - pale yellow Cl2 - green Br2 - red/brown I2 - violet

NO2 - ugly brown - copper metal in conc. HNO3 NOCl - orange/brown - NaNO2 in conc. HCl ClO2 - intense deep yellow - NaClO3 in conc. HCl (explosive)

CF3NO -  blue NC-N=O -  blue CH3COCOCH3 -  yellow/green vapor 
 * Bestfaith (talk) 23:45, 2 November 2015 (UTC)
 * Not many options I think... Powdered white phosphorus at low temperature might do it, it reacts with the oxygen in the air (would burst into flames in warm air). A mixture of ozone and nitric oxide could be another option. See chemiluminescence. Ssscienccce  (talk) 14:09, 3 November 2015 (UTC)