Wikipedia:Reference desk/Archives/Science/2015 February 1

= February 1 =

Q-Spoil
Came across this Q-Spoil article in the orphanage, it has no sources and I can't find any reference to the term via Google, anyone know if such a thing exists? — Preceding unsigned comment added by Vrac (talk • contribs)
 * I can't find anything. WP:PROD may be appropriate to use here: Tagging it for prod would give anyone who cares time to fix it up, but if no one is caring about it, then it can be deleted.  -- Jayron 32 02:05, 1 February 2015 (UTC)
 * Cheers, prod it is. Vrac (talk) 02:30, 1 February 2015 (UTC)
 * It's definately a thing, though I cannot judge its notability:  . I suspect, from the third link, that it may be a particular application of the Kerr effect. --Tagishsimon (talk) 02:43, 1 February 2015 (UTC)


 * The PR encyclopedia of laser techniques doesn't mention "q-spoil", and Google searches turn up zero relevant hits. There is a thing called the "Q-factor" of a laser, and a technique for producing short pulses called Q-switching (both of which we have articles about).  So I'm kinda suspicious that this is way, way too obscure for an article.  With no references whatever, no other articles linking to it, and after languishing for 8 years with essentially zero improvement having been done on it - this article shouldn't be here.  If it's a real thing then a line can be written about it in some other article.  SteveBaker (talk) 03:57, 1 February 2015 (UTC)


 * I've redirected the article to Q-switching, for which it is a synonym, at least in the context of laser switching. A search in GBooks and GScholar shows a number of sources verifying its existence. --Mark viking (talk) 05:04, 2 February 2015 (UTC)

evolution of bacteria and washing
Apart from evolution of bacteria to resist our antibiotics, has there been any detected evolution to resist being washed off by water or by soap and water from human skin? Or maybe evolution to appear "less dirty", give less of a "sticky sensation" on skin? Is this kind of evolution expected to happen by scientists? Thanks. Rich (talk) 04:21, 1 February 2015 (UTC)


 * Washing them off should put less evolutionary pressure on them to adapt, since presumably they survive either way. So there's no effect that those that manage to stick to the hands are more likely to survive and pass on those genes. StuRat (talk) 06:11, 1 February 2015 (UTC)
 * Agree with that, but see Antibacterial Soaps Concern Experts which says; "recent research suggests these products [anti-bacterial soaps] may encourage the growth of “superbugs” resistant to antimicrobial agents". Alansplodge (talk) 16:58, 1 February 2015 (UTC)
 * I'm guessing the development of superbugs can occur with antibacterial soaps due to the antibacterial properties killing some of the bacteria. I'm assuming he meant washed off as in came off the hands and went somewhere else, in that case the bacteria are still alive. 70.210.72.107 (talk) 02:47, 3 February 2015 (UTC)

Incandescent light bulb history
Just watched the PBS show on Thomas Edison, and I have a question. The incandescent light bulb was eventually perfected by using a thin tungsten filament and evacuating the bulb of air. Before that, light bulbs would burn out in a few minutes. But, it seems to me, that another approach would have been to just use a thicker filament. After all, electrical resistance space heaters manage to produce a red glow with exposed wire coils. They do use a fan, but is that required to keep them from burning out quickly ? I'd think a bit less electricity and no fan would keep it red hot, but no hotter, so the wires would last. Now, admittedly red light isn't ideal, and all the excess heat would be annoying in summer, but perhaps quite welcome in winter. When compared with the poor choices available before Edison took on the light bulb, it seems to me that my approach would have been a welcome alternative to gas lights, for indoor lighting. StuRat (talk) 06:08, 1 February 2015 (UTC)


 * Actually the tungsten filament represented the second generation of light bulb, allowing higher temperatures and therefore whiter light. As you will see at the Edison article you linked, Edison's bulbs that lasted for over 1,000 hours had carbon-based filaments. --65.94.50.4 (talk) 10:06, 1 February 2015 (UTC)


 * I was brought up in gaslight, supplemented by paraffin lamps, before electricity reached the area where I was born, and I can assure you that it was far superior to the dull red glow from an electric filament in air. It is easier to read by firelight than by (exposed filament) electric heater light. Nichrome wasn't patented until 1905, but perhaps similar materials were available earlier for heaters.    D b f i r s   07:20, 1 February 2015 (UTC)


 * Didn't gas lights and paraffin lamps badly pollute the air ? Then there's the risk of explosion and/or fire.  (There's also some risk of fire from exposed electrical resistance wires, but less than gas lights, I should think.) StuRat (talk) 18:13, 1 February 2015 (UTC)
 * I assume that they're much safer in the hands of people who grow up using them than they would be in mine, just as an electric lamp would be considerably hazardous to someone who knew nothing about them. Wnt (talk) 23:21, 1 February 2015 (UTC)


 * The article incandescent light bulb in the Joseph Swan "On 18 December 1878, a lamp using a slender carbon rod was shown at a meeting of the Newcastle Chemical Society, and Swan gave a working demonstration at their meeting on 17 January 1879......These lamps used a carbon rod from an arc lamp rather than a slender filament. Thus they had low resistance and required very large conductors to supply the necessary current, so they were not commercially practical,". So it seems the reason Swan and Edison settled on the filament was the larger rod draw too much current. Also I didn't here this in the PBS show but I was flicking (this quote is from the Joseph Swan page "Though Swan had beaten him to this goal, Edison obtained patents in America for a fairly direct copy of the Swan light," Dja1979 (talk) 21:13, 1 February 2015 (UTC)


 * He must have been going for white light. Red should require far less current. StuRat (talk) 22:09, 1 February 2015 (UTC)


 * Red light still requires a large current unless the wire is very thin, then it burns out. High currents were probably more dangerous than gas and paraffin, where there was (limited) technology to reduce the fire risk.  I don't recall pollution being a problem (our air was much purer because of the lack of internal combustion engines), but it's true that a badly trimmed paraffin lamp could produce a lot of smoke if left unattended.    D b f i r s   23:22, 1 February 2015 (UTC)


 * Not sure they cared too much about risk over cost at the time, as people went for Tesla's A/C over Edision's D/C, cost was the main driver. As for air pollution, there may not of been the internal combusion engine but there were coal fired plants in the cities, these casued smog (from the smog article ".... a familiar and serious problem in London from the 19th century to the mid 20th century"). I wouldn't like to say which is worse. Also these light are being used in the house which is a confined space so any amount of soot produced will go on the wall paper and there is only a limit amount of oxygen so CO could be produced. Dja1979 (talk) 23:54, 1 February 2015 (UTC)


 * Yes, you are correct about the soot, though this was a very small amount in a well-trimmed lamp. Carbon monoxide might have been a problem if rooms had been sealed as they sometimes are in modern houses, but open fires provide a good circulation of fresh air.   D b f i r s   07:14, 2 February 2015 (UTC)


 * An incandescent lamp with a thick low resistance filament would have needed much higher current than the 1880 vintage Edison lamp. The 1880 vintage Edison lamp was suitable for operation from a generating plant a mile or so away, without having an impractically high cost for the copper conductors to get the current from the generator to the lamps in the district. It had a carbon filament of very small cross section, sealed in a glass bulb with a very high vacuum. The incandescent lamps which are being phased out and replaced by halogens, compact fluorescents and LEDs had tungsten filaments and operated in a glass globe with low pressure inert gases. A work-around allowing thick carbon conductors in the late 19th century would have been to use alternating current with a step-down transformer near the lamp. The copper conductors would have had to be larger in cross section to supply the same watts, resulting in higher cooper costs to wire a building, unless multiple transformers were used, which could result in high transformer costs. Engineering economics was a critical part of the success or failure of lighting technologies.  Edison paid close heed to the copper costs as well as the fuel costs, installation costs, etc. i devising a workable and practical system. Today one sees halogen bulbs which run on 12 volts in common use. The user has a stepdown transformer in the same room as the lamps are used.


 * Thanks. Still, it seems that there were some individual home installations for rich people where cost wouldn't have been an issue.  StuRat (talk) 16:33, 4 February 2015 (UTC)


 * Re: "higher cooper costs", those darn barrel makers are bleeding us dry ! StuRat (talk) 16:33, 4 February 2015 (UTC)

Zyklon B
Dear Madam/Sir,

In English version of Wikipedia is a misinformation about current production of Zyklon B like insecticides. Uragan D 2 is produced by Draslovka Kolín who is "traditional" producer of Zyklon B (approx. 60t produced in 1943). In the subject it is stated Adezin as a producer, but the company is a disinfection, disinfestation and rodent control firm therefore only a user of the product. I made a change in the subject yesterday but it has been refused by censor. Solution is up to you.

Best regards

Karel Šikl — Preceding unsigned comment added by 2A02:2788:84:5DA:B4E4:DEE4:6EDA:2DAC (talk) 16:12, 1 February 2015


 * The edit in question to the article Zyklon B was reverted by User:DumbBOT (oops; actually by User:MrX as cited below) per WP:ELNO. A better place to discuss this is at that article's discussion page, Talk:Zyklon B.  Note that this reversion was done due to the use of the external link, possibly what you had intended as a reference, so it was an issue of formatting, and not necessarily content. -- ToE 17:13, 1 February 2015 (UTC)
 * We have no censors, another user removed it. You added the information on 13:43, 30 January 2015. It was reverted 30 minutes later by MrX. His change comment seems to be wrong, but he seems not to be happy with the link to http://www.draslovka.cz. This link doesn't mention Zyklon B, perhaps you meant another one? For your future reference, the correct place to ask about this is on the talk page. - LongHairedFop (talk) 17:16, 1 February 2015 (UTC)
 * Several things were wrong with the edit. First, it was insertion of an inline external link (see WP:ELPOINTS #2). Second, a manufacturer's website is not a reliable source for a claim of this magnitude. I agree that any further discussion should occur on the article talk page. There are 138 editors watching the article, largely because of vandalism and undesirable edits by holocaust-denialism-POV-pushers.- MrX 17:44, 1 February 2015 (UTC)

Is this real?
This. One kilowatthour and two pounds of polypropylene (PP), polyethylene (PE) or polystyrene (PS) plastic into one quart of oil, so they claim. Is it real? 75.75.42.89 (talk) 17:07, 1 February 2015 (UTC)


 * It appears to be real, there's some information in English on the company's website: http://www.blest.co.jp/seihin-english.html, but most of the website is in Japanese. Numerous sources report on this machine, e.g. here, and someone asked a question similar to yours on this website. The process is called Thermal_depolymerization, in which the long polymer chains in the plastic products are converted through heating into smaller and simpler molecules that also make up crude oil. Do note however that the device cannot convert all types of plastic and I personally would be concerned that it may produce toxic gasses if you put the wrong kind of materials in it (note: I don't claim any kind of expertise here, that's just something I would be worried about). - Lindert (talk) 17:49, 1 February 2015 (UTC)


 * Well, it certainly COULD be real. One quart of oil represents about 10 kilowatt hours of energy content.  Most plastics can be burned to produce about the same amount of energy as oil (pound for pound) and a quart of oil weighs around 2lbs - so it's not implausible that using a kilowatt hour of electricity could rearrange the chemistry of the plastics to resemble that of oil without altering the energy content.


 * Of course you might ask why you'd want to do that. This Penn-State project converts plastics into pellets that can be burned in a coal-fired boiler to produce comparable amounts of energy to oil. The only issue with burning the plastic directly is that it has to be done at high temperatures in order to avoid producing toxic by-products...but the Penn State machine is cheap and uses very little energy of it's own - so it's probably cheaper and more efficient than the machine you linked to.


 * That said, the best use of waste plastics is to produce more plastics - that avoids the steep energy costs of creating plastics from stock materials. The difficulty with doing that is in separating out the plastics from other waste and sorting it by chemical content...but that problem still exists for the plastics-to-oil approach.


 * SteveBaker (talk) 17:59, 1 February 2015 (UTC)


 * Why is i even needed to form pellets to burn plastics ? It seems to me in a high temperature incinerator, they would burn just fine regardless of their form.  In fact, in some forms, like plastic shopping bags, they have a very high surface area to volume ratio already, so should burn quite well.  StuRat (talk) 18:08, 1 February 2015 (UTC)


 * I have no idea - beyond that they did that. Perhaps it makes the material easier to feed into a furnace of that type...I don't know.  But the point is that if all you care about is extracting energy, then burning the plastics directly is more energy efficient than converting it to oil first - and so long as humanity still needs more plastics, recycling the stuff is yet more efficient because you save far more energy by avoiding the manufacture of a pound of plastic than you get by burning a pound of the stuff.  But there is no reason that I could come up with why this Japanese machine shouldn't do what it claims.  I just ask why you'd want to do that. SteveBaker (talk) 04:37, 2 February 2015 (UTC)
 * Burning pellets, instead of burning the raw material the pellet is made of, has many advantages. You can burn it more thoroughly and generate more heat, but less ash. They are uniform in density, size and moisture, which makes the burning process predictable. A mixture of plastic bottles with plastic bags will burn differently each time. This also enables us to use them in automated ovens, as we can adjust the feed rate. Sometimes a binding material is also added in the process of manufacturing, which allows us to "tweak"" some property of the pellet.ListCheck (talk) 16:20, 2 February 2015 (UTC)

Why does the space lift need a cable of 22,236+ miles?
The ISS is much nearer the Earth than that (268 miles to be exact). Couldn't we just connect a cable to it and save thousands of miles in cable? --Senteni (talk) 18:17, 1 February 2015 (UTC)


 * Hint: see geostationary orbit. The rest is left as an exercise for the reader. Short Brigade Harvester Boris (talk) 18:20, 1 February 2015 (UTC)


 * Well, the ISS orbits at a speed of 27,600 km/h (17,100 mph), so you'd just need to keep the bottom of the space elevator moving at that speed to match the top. Easy, right ? StuRat (talk) 18:38, 1 February 2015 (UTC)


 * At the ISS orbit, the Earth's escape velocity hasn't been reduced substantially, at a geo-stationary orbit, it is about ⅖ of the surface value. LongHairedFop (talk) 20:22, 1 February 2015 (UTC)


 * David E. H. Jones, in his 1964 article which defined the concept, suggested that, for this application, the tether could be fixed at the north or south pole. Tevildo (talk) 20:46, 1 February 2015 (UTC)


 * I don't understand. The point is to connect to something in orbit about the Earth, and nothing stationary above the north or south pole (or anywhere else above the Earth) would stay up for long.  To stay in orbit, it must be moving.  The advantage of a geostationary orbit is that, at that height, an object's orbital speed matches the speed of the rotation of the Earth, at least at the equator. StuRat (talk) 20:56, 1 February 2015 (UTC)


 * The cable could be fixed anywhere, and the upper end would settle toward the equator's plane regardless. If it's fixed at a high latitude, you'd start your climb at a low angle; I doubt that could be enough of an advantage to overcome the cost difference of a longer (and thus heavier) cable. —Tamfang (talk) 21:13, 1 February 2015 (UTC)
 * Is there a latitude above which the cable lies on the ground? —Tamfang (talk) 09:59, 2 February 2015 (UTC)


 * There are some fancier ways to do things than the standard space elevator. Specifically there is an idea to have a rotating space tether or Skyhook (structure) that reaches down to the edge of the atmosphere, grabs hold of something (SpaceShipN?) that can barely make it up to space, and flings it out in a high Earth orbit.  I suppose in theory if things rendezvous with it that can change its course and boost its orbit to counteract the friction, it could even reach in to the atmosphere, with an orbit carefully calculated to bring its lower end almost stationary relative to the surface (it would make a great cliffhanger in a story, no?)  But no, a standard space elevator isn't gonna work at the North Pole :) Wnt (talk) 23:19, 1 February 2015 (UTC)


 * The geostationary orbit requires no additional lateral velocity or energy for orbit. By contrast, lower orbiting satellites often orbit in 90 minutes.  There's no reason why the space elevator couldn't be used to launch low altitude satellites but they will need fuel to propel them at the proper velocity.  Geosynchronous orbit is not always the desired orbit especially for GPS, Spy satellites and other satellites where distance is a negative.  Also note that this is equatorial.  A polar space elevator doesn't matter what height it is. --DHeyward (talk) 02:10, 2 February 2015 (UTC)


 * If the space elevator can lift a satellite to geostationary orbit, achieving low-earth orbit is easy. Just fire retrograde in geostationary orbit to reduce the satellite's orbital velocity by 1.5 km/s, which brings the periapsis into the atmosphere.  Aerobrake over several orbits to circularize the orbit.  1.5 km/s is far, far lower than the 9.5 km/s of delta-V required to get into orbit from Earth's surface.  --Bowlhover (talk) 09:19, 2 February 2015 (UTC)
 * There is necessarily a height at which, if you let go of the elevator, you'll fall into grazing orbit – less eccentric and thus easier to circularize – without such firing. —Tamfang (talk) 10:04, 2 February 2015 (UTC)


 * You're absolutely right. In that case, it's possible to reach low Earth orbit with no fuel (except the minimal fuel needed to raise the orbit after aerobraking).  --Bowlhover (talk) 02:26, 3 February 2015 (UTC)


 * Think about it a minute. The skyhook can be in a low orbit and moving very fast relative to the ground, but if it is also spinning, then the low end potentially could be stationary relative to the ground when it is at its lowest point (then of course moving much faster relative to the ground when it is above the skyhook's center of mass) Wnt (talk) 20:04, 2 February 2015 (UTC)
 * That's true but it would still be an equatorial rotation to be slowest relative to earth and it would be a very short window. A low altitude polar orbit wouldn't be any slower relative to earth for polar launches and the if you tried to compensate E/W earth velocity with rotating you still have N/S velocity. The payload would still need a sub-orbital boost and if you did that it wouldn't need to be slow relative to earth, just the payload.  There's still the problem of how to keep the skyhook in orbit and what orbit to put it at and how heavy it would have to be and how high so the sonic booms don't break things.  But before we hook things or ladder things, I suspect the EM Railgun will be first, possibly on a suborbital platform (nuclear reactor on large aircraft to generate the energy for launch).  --DHeyward (talk) 21:43, 2 February 2015 (UTC)


 * What is the least amount of material that would be required for such a device? ←Baseball Bugs What's up, Doc? carrots→ 08:39, 2 February 2015 (UTC)


 * I think the responses above are obscuring the answer, which is that if you hooked a cable from the ground to the ISS, the ISS wouldn't be able to move fast enough to stay in orbit, so the cable would pull it down to the ground. The same thing would happen at any altitude below geosynchronous orbit.  Once the cable reaches higher than that, its upper part pulls the remainder upward.  If you put enough mass there, the upward pull can balance the downward pull of the part that lies below geosynchronous altitude. Looie496 (talk) 18:48, 2 February 2015 (UTC)


 * It would go into orbit around the tether point, but stop suddenly after about a quarter of that orbit. —Tamfang (talk) 08:38, 5 February 2015 (UTC)

Neurology: Dearth of research on treating Periodic Limb Movement Disorder (PLMD) with Baclofen
http://www.ncbi.nlm.nih.gov/pubmed/6721446

The above study from 1984 at Stanford found that oral administration of baclofen somewhat improved sleep in patients with PLM-associated arousals. The results seem fairly positive, with the finding essentially that although baclofen increased the number of PLMs, it decreased their amplitude, and decreased the length of the arousals associated with PLMs.

My question then is why does there seem to be no follow-up research on the treatment of PLMD (i.e. arousals caused by PLMs) with baclofen? I understand that RLS (Restless Leg Syndrome) is accompanied by PLMS in about 80% of RLS cases, and since dopaminergics and anti-convulsants are generally more effective treatment for RLS than are muscle relaxants (like baclofen) the research on RLS and baclofen is not extensive. But in cases of PLM-associated arousals unaccompanied by sensations of restlessness (RLS), why is there no further research on the seemingly promising treatment of baclofen?

Note: let me please be quite clear that I am NOT asking for medical advice. I am interested in the research history of a particular drug.

Thanks!

146.50.147.161 (talk) 19:37, 1 February 2015 (UTC)


 * One of the awful realities of science is that a lot of irreproducible results are published. This is to be expected, because "statistical significance" generally means "one chance in 20 it could have happened by chance".  And people try a lot of things... sometimes failing to take into account the compound probability that one of the tests they make ought to work by chance alone.  Worse, when people fail to reproduce a result, they say so to other workers in the area informally but don't publish the negative result in the literature.  So when you see a result like this that isn't followed up, there is a likelihood but by no means a certainty that it failed to reproduce in someone else's hands.  Of course, because the negative result wasn't formally written up and peer reviewed, you never are totally sure it was done right either.


 * That said, some related negative results turn up in http://www.ncbi.nlm.nih.gov/pubmed/10947026 and http://www.ncbi.nlm.nih.gov/pubmed/1713829 . Honestly, I don't know a damned thing about myoclonus, and I haven't read the study at your original link, so how related those results are is at the moment a mystery to me, but it was worth mentioning.  So if you go back to PubMed and try searches of your own you can know more about this than I do in ten minutes.  But one thing I'd look at carefully in the original paper - the abstract makes a point of saying the 20 mg and 40 mg dosages worked best.  Usually someone would just say "dose-dependent" in a sentence like that ... did they put it that way because both higher and lower dosages did nothing?  That reduces the statistical significance and demands a more intricate/less probable explanation about the mechanism for the result to be real. Wnt (talk) 19:52, 1 February 2015 (UTC)


 * Maybe an important point here is that baclofen is a broadly acting central nervous system depressant, and has quite a number of undesirable side effects, particularly when taken orally at clinically significant doses. Looie496 (talk) 18:43, 2 February 2015 (UTC)


 * Well, from a research point of view that might not disqualify it from further study, because it could be used as a lead compound for further drug discovery. For example, consider the case of cannabinoids, where AFAIR someone discovered a sort of 'anti-marijuana', a Cannabinoid receptor type 1 inverse agonist that made people lose weight, but it was such a bummer they were more prone to suicide.  Ah, Rimonabant is the name.  Well the answer may be to come up with a drug that is like that, but won't cross into the brain; then a person gets the weight loss, but not the suicide.  (Perhaps -- I should note that I've never heard of any class of drugs with as much tendency to turn out to kill people in large numbers after they become popular as weight loss drugs)  Well anyway, with this drug you might find that you can block the brain effect that way, or maybe the receptor for the other effects is a close homologue but not identical to the one for the myoclonus effects, etc.  So this isn't a deal-breaker when all you're doing is basic research. Wnt (talk) 20:01, 2 February 2015 (UTC)

Swingset obsession sources?
Are there any scholarly or scientific sources that address a post-puberty/young adult's obsession with riding a swing on a swingset? The only (very unhelpful) thing I could find was http://www.theotaku.com/worlds/theswingset/tags/hetalia and other searches ended up addressing "mood swings" in obsessive-compulsives, which is not what I was looking for. Thanks. μηδείς (talk) 22:12, 1 February 2015 (UTC)


 * What do you mean "address"? People can be obsessed with just about anything, is there anything further to learn about "swings" beyond the already very complex obsessive compulsive disorder? Vespine (talk) 23:59, 1 February 2015 (UTC)


 * Do you have any sources showing that there is such an "obsession", as opposed to park swings just being a place where teens can sit at night for relative privacy ? StuRat (talk) 00:05, 2 February 2015 (UTC)


 * By "address", I mean discuss in a technical manner. The word "swing" is not mentioned in the OCD article, and I am offering no opinion myself on the subject.  Stu, you seem to have missed the point that I am the one asking for refs.  If I had them I wouldn't bother to post.  I said nothing about a group of people sitting on a swing at a park for privacy. I am curious if anyone can find a medical or otherwise scholarly ref about a young adult who uses a swingset for what might seem abnormal circumstances.  If the refs mention autism, OCD, or masturbation, that's fine, but those are not my own words. μηδείς (talk) 00:36, 2 February 2015 (UTC)


 * You're being pretty confrontational. And you're the only one to have mentioned autism or masturbation in connection with this topic on here. But again: what makes you think this is a topic at all? I have no idea, from the little you've said here, what kind of sources you expect anyone to produce, or why you believe this to be a discrete subject with any literature whatever associated with it. AlexTiefling (talk) 03:39, 2 February 2015 (UTC)


 * I suppose I am, if one defines confrontational as asking a question, repeating that one is asking a question, and offering hypothetical circumstances which one explicitly says are not one's personal assertions. I suggest you simply refrain from commenting on anything I say in the future, since your comments are indeed personal, political, and hostile.  There's obviously nothing wrong with my question here, and we've got answers with references below, which I have actually found informative. Thanks. μηδείς (talk) 02:44, 3 February 2015 (UTC)


 * Can you think of any examples of obsession with swingsets? ←Baseball Bugs What's up, Doc? carrots→ 03:49, 2 February 2015 (UTC)


 * Swingsets per se? No. Swinging on a backyard swing? Yes. μηδείς (talk) 02:44, 3 February 2015 (UTC)


 * Just the one so far!Greglocock (talk) 04:42, 2 February 2015 (UTC)


 * Riding a swing is a periodic rocking motion that people may find soothing or comforting even into adulthood. Rocking has been shown in a study to help sleep. Rocking chairs and hammocks also provide such a motion and people love them. Rocking babies is a near universal way to calm them. Body rocking is sometimes associated with mental illness or autism There is also the article Self-reported body-rocking and other habits in college students. --Mark viking (talk) 05:27, 2 February 2015 (UTC)
 * So where's the line between normal rocking and "obsessive" rocking? ←Baseball Bugs What's up, Doc? carrots→ 08:36, 2 February 2015 (UTC)
 * Rock 4 Ever, dude! —Tamfang (talk) 10:07, 2 February 2015 (UTC)


 * The thing is that compulsions (in general) are a feature of human mental disorders. There is a massive body of research into compulsions in general.  I watched a TV show the other night about a woman who had literally fallen in love with a fairground ride...one that doesn't even work anymore.   Another became obsessed with what remains of the Berlin wall.   There seems to be little merit in researching a very narrow compulsion (eg with a swingset or a particular kind of motion).  These are all incredibly specific cases of compulsion in general...the precise subject of the compulsion is of little importance to the science of it all.   So for that reason, I doubt very much that you'll find research on this very narrow slice of that problem.   It's kinda like asking for research about people who are afraid of dogs...and then specifying that you want research about people who are specifically afraid of female grey poodles.   The details don't matter.


 * A highly specific compulsion exists...but it's just a compulsion.  Study compulsions in general - and there you find your answers.
 * SteveBaker (talk) 15:57, 2 February 2015 (UTC)


 * Thanks. I am not in a position to define the question medically. I used obsession as a lay term, to elicit more educated responses. μηδείς (talk) 02:44, 3 February 2015 (UTC)