Wikipedia:Reference desk/Archives/Science/2014 October 9

= October 9 =

do fish ever sink?
does a fish stay floating forever after death? — Preceding unsigned comment added by 173.87.170.135 (talk) 04:33, 9 October 2014 (UTC)


 * No, they float due to a build up of gasses resulting from decomposition, once the gasses escape faster than gas be regenerated, they will sink. Plasmic Physics (talk) 04:38, 9 October 2014 (UTC)


 * As an aquarium keeper, I can tell you that in my experience, most dead fish sink and are consumed within a day or two by other fish in the tank. Having said that, you do occasionally get a floater. Zzubnik (talk) 10:18, 9 October 2014 (UTC)


 * Many fish have an internal organ called the swim bladder which they use to achieve neutral buoyancy. I'm not sure if that affects their buoyancy post mortem, but hopefully somebody here will know. Alansplodge (talk) 12:00, 9 October 2014 (UTC)


 * Doing some more research shows that most fish sink on death, then as they decompose they float to the surface because of gaseous build-up, as PP said above. Once they have been nibbled by other fish, they can sink again, as the gas containing flesh is stripped away. This explains why I only ever see them as sinkers. Zzubnik (talk) 12:35, 9 October 2014 (UTC)


 * A fish carcass will sink eventually. Even if part of it gets eaten, the rest will eventually sink. For a reference, see marine snow. SemanticMantis (talk) 15:00, 9 October 2014 (UTC)


 * There's a specific term, see Whitefish (fisheries term) μηδείς (talk) 15:37, 9 October 2014 (UTC)
 * See also Lutefisk. ←Baseball Bugs What's up, Doc? carrots→ 16:01, 9 October 2014 (UTC)
 * Sorry, you've lost me on those last two answers. "Whitefish" is any edible fish with white flesh that isn't oily fish. Lutefisk is Norwegian dried fish. I don't think anybody would eat a dead fish that they found floating on the water, would they? Alansplodge (talk) 21:37, 9 October 2014 (UTC)
 * Well, sea creatures that don't mind rotting fish would certainly eat floaters. I think the point Medeis was making is that some species of whitefish, the bottom feeders, don't have that natural buoyancy. ←Baseball Bugs What's up, Doc? carrots→ 21:44, 9 October 2014 (UTC)
 * Yes, in general, Bugs is entitled to speak on my behalf on totally obvious matters of common sense. The fact that there's a term for fish of negative buoyancy is at least tangentially related to the subject, and the OP may or may not be interested, but the purpose of the refdesk is to make any comments that might help future users who use the archive search function.  That being said, I have started an urgent new thread to discuss this dire matter and its relevance to shutting the whole project down at the talk page.  Further comments should be posted there. μηδείς (talk) 03:10, 10 October 2014 (UTC)
 * Thanks for the clarification. I didn't mean to be rude, but it really wasn't clear (BTW, cod do have swim bladders ). Alansplodge (talk) 11:15, 10 October 2014 (UTC)
 * Just to make it obvious, Alan was not rude here. No harm, no foul. μηδείς (talk) 21:15, 10 October 2014 (UTC)
 * Would a completely skeletonized fish sink in the Dead Sea? InedibleHulk (talk) 11:26, 10 October 2014 (UTC)
 * Nominal density of the Dead Sea water is 1.24 kg/l according to the article, but I can't easily find any density estimates for fish bone. You could take a sample weight and volume yourself to compute the answer. If you're going to go that far, you can also recreate Dead Sea water at ~30% salt and just see if your fish bones float :) SemanticMantis (talk) 18:14, 10 October 2014 (UTC)
 * Unfortunately, I neither eat fish nor keep them as pets. Maybe I'll try it with my next dead chicken. InedibleHulk (talk) 20:46, 10 October 2014 (UTC)
 * I can't really recommend keeping a dead chicken as a pet. ←Baseball Bugs What's up, Doc? carrots→ 20:59, 10 October 2014 (UTC)


 * The Dead Sea has no native vertebrate life, and while it's density is 1.24, Calcium's relative density is 1.55, and Calcite's is 2.71, so bones would tend to sink. μηδείς (talk) 21:11, 10 October 2014 (UTC)
 * Lousy science! But if I keep raising dead chickens, I'll probably figure out how to refloat fish, too. InedibleHulk (talk) 22:40, 10 October 2014 (UTC)
 * Think about it. If fish skeletons floated on the Dead Sea you'd see a special about it on NatGeo.  In the meantime, See this absolutely horrific website. μηδείς (talk) 00:05, 11 October 2014 (UTC)
 * Well. There go all those years of trying to forget Jim Henson's lovable Skeksis Emperor. InedibleHulk (talk) 04:15, 11 October 2014 (UTC)
 * Then you'll want to avoid seeing the Farscape episode, Out of Their Minds. μηδείς (talk) 15:25, 11 October 2014 (UTC)
 * Halosians, eh? I think I'm probably old enough to escape any new childhood trauma. Hadn't even heard of this show. Thanks (maybe). InedibleHulk (talk) 23:45, 11 October 2014 (UTC)

Some fish sink. The proof is that we have fossils of fish spanning 400 Million years.... Captainbeefart (talk) 14:22, 13 October 2014 (UTC)

Hückel theory
Is there a synonym for the 'hopping' β parameter, as used within the Hückel models? Within graphitic systems, is it a constant, or does it depend on the molecular structure? Meaning does it vary between benzene and naphthalene? Plasmic Physics (talk) 04:44, 9 October 2014 (UTC)
 * Two days without a response, so I'm just going to come out and say it, does this have anything to do with the minimal possible distance in which to do the Kessel run? μηδείς (talk) 15:18, 11 October 2014 (UTC)


 * I'm not a huge Star Wars fan, so if this is a joke, the punch line is lost on me. Plasmic Physics (talk) 01:12, 12 October 2014 (UTC)


 * Well, yes I looked it (Hueckel theory) up, and it actually is a real thing, but the exotic German name sounds like perfect sci-fi verbiage, something about reversing the polarity of the chronoton flux. Sorry I can't be of better help on this other than maybe to draw attention. The Kessel run is some ad-libbed nerdiage that has survived a meme going on 40 years. μηδείς (talk) 01:42, 12 October 2014 (UTC)


 * Except for the Halo franchise, I detest most science fiction, because most such material is built on twaddle, or fictional science rather than scientific fiction. The suspect authors and script writers have no idea what they are talking about, being carried away by their imagination. They use specialist concepts or language to confound the reader or audience into believing the plausibility of the scenes. Because of my extensive knowledge of scientific theories, hypothesis and ideas, I cannot knowingly disregard the perpetual codswallop issuing forth for the sake of appreciating these works. What on this good green earth is a 'chronoton', some sort of non-existent time affecting or affected particle, with no doubt, magical properties? Plasmic Physics (talk) 12:55, 12 October 2014 (UTC)
 * Is the Halo Franchise by Greg Bear? Heinlein's mature (but not late) and Niven's early work usually avoided utter nonsense, although both usually assume some sort of teleportation or FTL travel.  Except for AI, The Moon is a Harsh Mistress is entirely hard science, and Niven actually predicted Flash mobs in one of his short stories from the late 60's or early 70's.  In any case, I agree with the preference for hard science fiction over science fantasy  Star Wars is a simply a pirate romance where the hero rescues the girl, destroys the Spanish Armada, and kills Torquemada in the span of 90 minutes. No science involved. μηδείς (talk) 16:22, 12 October 2014 (UTC)


 * Granted, Halo does contain a fair amount of poppycock, but I'm engrossed with it nonetheless, since certain elements within it resonates with something close to my heart. The books are contributed to by a few different authors, however, they are still constrained by the owners of the franchise. It is actually a sort of amalgamation of several of Larry's works, including Ringworld. So that is what my bane is called (science fantasy). Plasmic Physics (talk) 22:38, 12 October 2014 (UTC)

So, if no one knows the answer, do they know where I can find it perhaps? Plasmic Physics (talk) 22:38, 12 October 2014 (UTC)

Infrared goggles and bullets
Let's say you have a pair of infrared goggles, are non-tracer bullets visible using those goggles? ScienceApe (talk) 15:40, 9 October 2014 (UTC):


 * Are you referring to 'thermal' IR night-sights or near-IR-passive. Near-Passive-IR sights are very slow. A round is unlikely to leave a visible trace in your view finder. A round fired from a rifle on the on the other hand is hot thermally. These 'may' leave a visible trace depending on the class of one's thermal IR device. Best advice I can give is, if you hear a report of a gun keep your head down and don't look. Err.. unless you have a bigger gun and then you can join in the fun!--Aspro (talk) 16:20, 9 October 2014 (UTC)


 * The problem in seeing bullets is their speed, not spectrum. Most guns will get hotter, of course. μηδείς (talk) 17:14, 9 October 2014 (UTC)


 * ? Spectrum sensitivity of the sensor is everything. Can you do this in thermal? ? ! ! --Aspro (talk) 22:02, 9 October 2014 (UTC)


 * I think "no" must be the answer; otherwise, somebody wouldn't have gone to a lot of trouble to invent and patent "...a tracer composition for small caliber projectiles bullets that, when ignited, emit a controlled amount of near infrared light to allow a flight path of the projectile to be tracked without causing a “bloom” in Generation III night vision systems" (the "bloom" referred to seems to be that caused by a conventional tracer round).  Alansplodge (talk) 18:42, 9 October 2014 (UTC)


 * No, you can't. You can't see a bullet in daylight with the naked eye - the IR sensor is nowhere near as good as the naked eye.   The problem is that while the bullet may be hot, it's very, very small - so it doesn't fill a complete pixel and is averaged into the background...and it's present at that pixel for less than the sampling interval of the device, so, again, it's contribution to the intensity at that pixel is small when averaged over the entire sampling period. SteveBaker (talk) 19:40, 9 October 2014 (UTC)


 * Pixels? The human eye is better than that. Read Schlieren photography. I if I say F**** duck, then you duck or risk going home in a body-bag.--Aspro (talk) 22:02, 9 October 2014 (UTC)


 * Is it possible for an IR sensor or what not to detect the bullet, position and track the bullet but visually represent it larger than it is so it is visible. Perhaps some type of futuristic augmented reality projected on to a militarized head mounted display? ScienceApe (talk) 04:51, 10 October 2014 (UTC)


 * I don't see any fundamental reason why that couldn't work. The CPU would need to look for fast moving small thermal traces, then display them on the screen.  Doing it in real time so it shows up as the bullet is moving might not be possible, but I would think displaying the bullet trace a second after it flew by would be darned useful to locating and killing the enemy.  You might want to leave the trace on until cleared by the user, or you could have a mode where they fade away over a few seconds to keep the screen from getting overly cluttered during a firefight.


 * IR could also be used to detect muzzle flashes, but without the bullet traces you wouldn't know if they are shooting at you or just firing at random to celebrate a wedding or something. StuRat (talk) 15:55, 11 October 2014 (UTC)


 * Interesting question. It wouldn't be possible to distinguish the signal straightforwardly but analysing the output from a night sight using a computer might show a track of excess signal along a path, would one see the bullet if it was shown stationary for a second at a distance of a hundred meterss? Dmcq (talk) 16:52, 11 October 2014 (UTC)


 * One donsent have to look futeristicaly. If one needs to know where a round comes from, then use the right tools for the job, rather than hope that different technology will catch up.--Aspro (talk) 17:31, 11 October 2014 (UTC)


 * The radar would work in some situations, but in others it would give away your position. The object is to know where the enemy is and not have them know where you are.  (Of course, if the enemy was smart they wouldn't fire until they know where you are, but they aren't always smart.). StuRat (talk) 17:55, 11 October 2014 (UTC)

question about three studies
Question moved from Miscellaneous Desk.

I saw three studies on hormonal iuds in teenagers.
 * One study said the failure rate after one year is 1.8 percent.
 * Another one didn't report any pregancies among 179 teenagers.
 * And finally, the third one reported the failure rate as 5.1 per 1000.

Which study would you say is the most accurate about the first year failure rate?Whereismylunch (talk) 04:33, 9 October 2014 (UTC)


 * All of them. ←Baseball Bugs What's up, Doc? carrots→ 04:49, 9 October 2014 (UTC)What I mean is, which study would you trust the most if you want to know the first year failure rate of hormonal iud among teenagersWhereismylunch (talk) 07:22, 9 October 2014 (UTC)
 * The three studies study very different things - the first looks for complications among teenage users (as indicated by insurance claims), the second looks at one particular device in one particular country, and the third has a very much non-representative population. I don't think any of these studies have been designed to answer the question you ask. --Stephan Schulz (talk) 11:27, 9 October 2014 (UTC)


 * Clearly, they all need some work. If the failure rate is indeed in the 1.8% range, then following just 179 teens is nowhere near enough - you'd only expect, on the average, to get 3.2 failures - and that number could easily vanish by chance (eg if you picked a group with lower-than-typical rates of having intercourse).  A rate of 5.1 per 1000 is just saying that there is an 0.51% failure rate - it tells you nothing about the size of the group they used.  To analyze these results carefully, you need to know how big each study was, how did they define 'failure'?  What were the error bars that they gave?  Did they use a control group?


 * This is why Wikipedias WP:MEDRS rules generally require a meta-study...a study where they looked at all of the other studies and compared them.


 * These kinds of studies are notoriously hard to do. In particular, people lie about their sex lives.  Teens who get pregnant may decide to quietly have an abortion and not tell anyone.  They might be using back-up measures like condoms (eg if they want to avoid STD's - which the hormone iud won't help with).


 * You need to understand all of those details - and unless you're an active researcher in the field, that's going to be very hard to do.  That's why meta-studies are so important in medical science.


 * SteveBaker (talk) 13:42, 9 October 2014 (UTC)

445 teenagers in the third study used a hormonal iud. Also, the third study did keep track of live birth, pregancy, and induced abortionWhereismylunch (talk) 16:12, 9 October 2014 (UTC)


 * We had a lively discussion about IUD studies a couple of weeks back - was that you as well? Any of these questions should probably be asked at the Science desk, not the Miscellaneous desk. You may get a better response over there. Regarding these three studies, Steve Baker is correct - you need to understand the details before you can assess their value. You are asking about the effectiveness of IUDs in preventing pregnancy, but what were the studies looking for?


 * Study 1 Complications and Continuation of Intrauterine Device Use Among Commercially Insured Teenagers:"This study examined whether 15–19-year-old IUD users were more likely to experience complications, failure, or early discontinuation than adult users aged 20–24 years and 25–44 years and whether there were differences in these outcomes between users of levonorgestrel-releasing intrauterine systems and copper IUDs."


 * Study 2 A nationwide cohort study of the use of the levonorgestrel intrauterine device in New Zealand adolescents: "A nationwide cohort study of 179 adolescents in New Zealand using the LNG-IUD, by means of a follow-up questionnaire to their practitioner, was conducted to determine the indications for insertion of the LNG-IUD and to establish patterns of use, including duration of use and reasons for removal."


 * Study 3 Provision of No-Cost, Long-Acting Contraception and Teenage Pregnancy: "We assessed pregnancy, birth, and abortion rates in a cohort of teens among whom these three barriers to highly effective reversible contraception were removed, and we compared these rates with rates observed nationally among all teens in the United States."


 * So we have one study comparing complications based on age groups, one assessing the use of IUDs in adolescents, and one investigating the effectiveness of free contraception in reducing pregnancy. None of these were trying to directly measure the effectiveness of hormonal IUDs in preventing pregnancy.


 * For example, let's look at study 3. The effectiveness of IUDs would impact the results of this study, but the researchers weren't trying to measure that effectiveness. So the results might be confounded by other factors, e.g. a participant who received an IUD might have responded to the information she received in the study to also reduce her frequency of sexual intercourse, thus further reducing her chances of pregnancy. Or she might have added condoms to her contraceptive routine to address STD concerns. If the study didn't control for things like that, then any interpretation of the results to assess the effectiveness of IUDs would be flawed.


 * So the answer to your question is either "none of them," or "all of them." If you want to tease out information on the effectiveness of hormonal IUDs from these studies, you would need to assess all three and try to interpret the results in a metastudy, as Steve Baker points out. - EronTalk 17:14, 9 October 2014 (UTC)

But eron, even if you did a study directly measuring contraceptive effectiveness, couldn't it also be confounded by the factors you mentioned? — Preceding unsigned comment added by Whereismylunch (talk • contribs) 20:04, 9 October 2014 (UTC)


 * Yes it could, but I would control for them as best I could. For example, in addition to tracking which participants had IUDs and their pregnancy outcomes, I would also ask about other behaviours e.g. frequency and types of sexual contact, concurrent use of other contraceptive methods, etc. etc. These could then be factored into my analysis and results. - EronTalk 21:28, 9 October 2014 (UTC)


 * So basically the failure rate could be either higher or lower than reported in the three studies, but you can't really tell by looking at them alone due to other possible factors. in the first study,they didn't keep track of the expulsion rate, unlike the latter two studies, so that would probably be the least accurate study.The first one also didn't pay attention to luteal phase placement.199.119.235.181 (talk) 22:45, 9 October 2014 (UTC)
 * I can't speak for Eron but basically I would say your first statement at least is correct. Actually I would mention that I was thinking this even before Eron's responses and in fact from some of your earlier questions that you seem to fixated on getting a single value. It isn't uncommon nor surprising that you can often at best come up with a range, even with far better studies (for the stated goal) than the 3 mentioned available. By "you", I'm including a researcher in the field conducting a metastudy. Accepting and understanding that is an important part of understanding a lot of research. BTW, I don't know if you're aware but the American Academy of Pediatrics issued updated guidelines on contraception not long after you started asking questions here to recommend long-acting reversible contraception (including hormonal IUDs). You can see their guidelines here . I noticed that they said "The emerging adolescent-specific data on IUDs are promising" and "The limited data in adolescents". And while they mentioned a possibly higher rate of expulsion, unlike with some other methods they didn't mention the adolescent failure rate being different. All taken together, this suggests to me they are not confident enough in available data to comment on the failure rate in adolescents (but are confident enough it is sufficiently lower than non LARCs to suggest it along with other LARCs). The guidelines are IMO good reading if you're interested in this. I saw at least one good example of the complexities we've talked about above and previously. They mentioned (I'm pretty sure this isn't adolescent specific) that the contraceptive coverage rate of IUDs is similar when inserted in the immediate post partum compared to delayed insertion despite a higher expulsion rate. Many women despite desiring it at time of delivery, won't return for later insertion. (I had a quick look at one of the studies and it seems expulsions were replaced when detected, which also requires the woman to followup.) Of course all of this could also easily be different for adolescents. Nil Einne (talk) 13:34, 11 October 2014 (UTC)

I think that it would be better if I contacted the people who wrote the study myself199.119.235.181 (talk) 01:16, 10 October 2014 (UTC)
 * If you can't find a secondary source that talks about it, going directly to the primary source may be your best option. ←Baseball Bugs What's up, Doc? carrots→ 01:17, 10 October 2014 (UTC)

Phasor diagram
I'm trying to plot these phasors on 2 separate phasor diagrams.

x=2cos(pi/4), dx/dt=60cos(pi/4), d2x/dt^2=-1800cos(pi/4)

I'm assuming this should start going down 45 degrees and then plotting lines at 45 degree angles for velocity and acceleration.

The 2nd set of phasors are:

X=6cos(2-(pi/4)), dx/dt=-60cos((3pi/4)-2), d2x/dt^2=-1800cos(2-(pi/4))

I'm assuming this phasor should start by going up 45 degrees from the horizontal starting point as it is negative pi/4 and then the subsequent phasors would be at 45 degree angles.

Am I correct with my assumptions? I'm also not sure how to account for the fact that there is a 2 inside the cosine I.e. (2-(pi/4)). Thanks. — Preceding unsigned comment added by Clover345 (talk • contribs) 19:31, 9 October 2014 (UTC)


 * Welcome to . Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. - EronTalk 22:10, 9 October 2014 (UTC)
 * Firstly, it's not a homework question. It's a self study question. Secondly, I have attempted to solve the problem and have said exactly where I am stuck and asked for help. I didn't even post the entire question, only the part I'm stuck with. Clover345 (talk) 09:40, 10 October 2014 (UTC)
 * Yadda yadda. That pretentious template (it's a boilerplate warning) ought to be taken out back and beaten with a lead pipe.  Meanwhile, on the Refdesk, posters are (or should be) encouraged to talk through problems they hit when they have trouble with their homework.  In this case, alas, I'm hampered by not having a great depth of experience with phasors.  We have an article phasor, a Wikiversity section phasor, and a wikibook Circuit_Theory/Phasors.  The last of these describes an issue where some programs use a cosine convention and others use a sine convention, but pardon me if I'm not 100% sure this is what you've run into.  As for the 2 inside the cosine, it's still an angle, and every angle has a cosine... Wnt (talk) 22:38, 9 October 2014 (UTC)
 * Yadda yadda. That pretentious template (it's a boilerplate warning) ought to be taken out back and beaten with a lead pipe.  Meanwhile, on the Refdesk, posters are (or should be) encouraged to talk through problems they hit when they have trouble with their homework.  In this case, alas, I'm hampered by not having a great depth of experience with phasors.  We have an article phasor, a Wikiversity section phasor, and a wikibook Circuit_Theory/Phasors.  The last of these describes an issue where some programs use a cosine convention and others use a sine convention, but pardon me if I'm not 100% sure this is what you've run into.  As for the 2 inside the cosine, it's still an angle, and every angle has a cosine... Wnt (talk) 22:38, 9 October 2014 (UTC)


 * The template ought to be used only when the question is obviously copied directly from the assignment. —Tamfang (talk) 04:10, 10 October 2014 (UTC)

Your terminology is very odd. your differentiating seems very odd. the differential of cos is -sin. if you had written something like x(0)=2cos(pi/4), dx/dt=60cos(pi/4*t) then it would make more senseGreglocock (talk) 23:02, 10 October 2014 (UTC)

Bathyspheres and submersibles
Are there any cases on people in bathyspheres or submersibles being lost to the ocean floor?

Similarity, how many astronauts have been lost to outta-space?

22:51, 9 October 2014 (UTC) — Preceding unsigned comment added by 60.12.119.120 (talk)


 * There have been a number of people who have died in submarine accidents. The H. L. Hunley (submarine) sank in the American Civil War and wasn't raised until the year 2000. Wikipedia doesn't seem to have a complete list, but we have List of sunken nuclear submarines.
 * Nobody has been actually lost in space. All manned spacecraft have come back down one way or the other. But there have been a few space accidents. Check out List of spaceflight-related accidents and incidents.
 * APL (talk) 23:20, 9 October 2014 (UTC)
 * Kursk was the most notorious case in my memory, I was going to say "recent memory" but I can't believe it was back in 2000!!, pre 9/11 even! I would have guessed 5-6 years ago... Vespine (talk) 04:53, 10 October 2014 (UTC)


 * Note that the OP is referring to bathyspheres and submersibles. Here's one fatal incident: Johnson Sea Link accident.  71.20.250.51 (talk) 18:09, 10 October 2014 (UTC)

How long do smoke chemicals stay in ex-smoke rooms?
I was in a smoking room of a motel since yesterday. I opened the windows, left the air con on high (fan only) and left the door open sometimes despite the resulting exhibitionism (there's no ventilation shaft). Now it smells more generic burnt than cigarettey when I return from a 3 minute buying trip, which becomes almost undetectable after desensitizing again. I want to shut out the bothersome highway noise soon and stop the fan - it's 40 at night! But I want to see if it's smellable after a long trip outside first before nearly sealing the place. (my usual standard with smokers is that if I can smell it I leave right away and breath as little as possible, otherwise it doesn't affect my path or breath taking (okay, if I smelled it more than say 20 human reaction times (= like 4 unaborted breaths?) every day I would consider not living in such a dense+walkable place but I don't)) So, how long do I need to be away from the room before my nose regains maximum sensitivity to cigarettes? How much more cancer risk is there if I shut (off) everything now and stayed till Nov 1 than if I left now? In terms of seconds of strong secondhand smoke breathing and my previous day here. If I could do that and only double this motel stay's added health risk then I'm going to shut (off) everything now. How much cancer is a garden variety breath's worth of strong secondhand a day worth anyway? (On average) Like 0.000001 tumors? Or deaths or seconds of life lost or dollars you could sue for if there was some magic way to count everyone's exposure? 2604:6000:1413:801B:A0B6:B2F6:BFE7:6435 (talk) 23:42, 9 October 2014 (UTC)
 * How long it takes to re-sensitize to the smell of smoke is probably a matter of individual body chemistry. But as a non-smoker, I can tell you that the smell from a smoking room lasts forever, unless drastic changes are made to the room, i.e. discarding everything in it and starting over. ←Baseball Bugs What's up, Doc? carrots→ 23:48, 9 October 2014 (UTC)
 * I think you're right. I locked the windows and left for a longer time. It's stronger than after the shorter trip, and is flavored less like a creosote chimney than it did then. They should make a lawsuit for the nonsmokers against the smokers. Even if only a quarter percent get cancer from them, that's still several dollars per year per non-smoker, and my parents would be owed hundreds going back to the 1960s. 2604:6000:1413:801B:A0B6:B2F6:BFE7:6435 (talk) 02:30, 10 October 2014 (UTC)
 * I can relate because I am the son of two loving, but heavy smoking parents. I rebelled against my parents by not smoking and both of them died too early from diseases associated with smoking. I think that you should stay in dedicated "no smoking" motel rooms, and should not stay in any motel room that does not offer that option. If you choose to stay in a room designated as a "smoking room", then you thereby give up your right to complain about the odor or any other aftereffects of previous guests smoking in that room. Cullen328  Let's discuss it  05:30, 10 October 2014 (UTC)
 * Unless there's no other option available. ←Baseball Bugs What's up, Doc? carrots→ 11:33, 10 October 2014 (UTC)


 * As for the risks: here's an article from the Mayo clinic specifically about the risks of "third hand smoke" Using that search term will help you find more info. The short story: health risk of staying in a smoking room is detectable, but fairly minimal. You took a far larger risk driving to the motel ;) SemanticMantis (talk) 17:08, 10 October 2014 (UTC)
 * Small consolation for the assault on your nasal passages. ←Baseball Bugs What's up, Doc? carrots→ 20:12, 10 October 2014 (UTC)


 * I've been in the same situation. Note that non-smoking rooms aren't always smoke free.  They might have just changed the sign on the door and removed the ashtrays right before you arrived, or, even if it's always been designated a non-smocking room, that doesn't mean the occupants all complied.  Some smokers prefer to enter a nice-smelling smoke-free room, then light up a cigar.


 * As far as mitigation, here are my suggestions:


 * 1) Leave the windows open all the way when out of the room. Unfortunately, the housekeeping staff might close them.  You can try leaving a note, but if they ignore it you might need to come back after they have cleaned up to open the windows again.  When you return, close the windows and crank up the heat, or, if you can stand it, leave the windows open and use a sleeping bag to keep warm.


 * 2) Remove all fabric you can from the room. This includes bedding, towels, and drapes.  They might not like you removing the drapes, though.  I dumped everything in the hall. called the front desk to haul it away, and supplied my own bedding and towels.  You can't remove the carpet, of course, but at least it's not right in your face, like pillows and towels. StuRat (talk) 16:13, 11 October 2014 (UTC)