Wikipedia:Reference desk/Archives/Science/2013 July 19

= July 19 =

Distilled vulcanoids?
Vulcanoids are hypothetical undiscovered asteroids near the Sun between 100 m and 6 km in size. They are believed to lie in a zone with an inner radius imposed by the Poynting-Robertson effect so that they don't get any hotter than 1000K or so. If they get nearer, they slowly spiral into the Sun.

Question: how slowly?

As they get very close to the Sun, they should exceed the 3100 K boiling point of iron, at which point I would expect it to vaporize away, leaving concentrated siderophiles such as rhenium, iridium and tungsten that are key commodities of asteroid mining.

Question: can these asteroids actually become "distilled" to contain only these exotic elements in nearly pure form? Or would alloying produce azeotropes, etc. that would be resistant to distillation?

Now if you have a molten ball of highly valuable metal that is about to fall into the sun, no sense wasting it. I would assume that a missile, encased in high-temperature ceramic and decelerated from Earth orbit, could strike such a blob with extreme force, and if very carefully simulated and very carefully aimed, this could spray gobs of the exotic metal into an orbit so distant it might solidify and be retrievable by specially built mining craft.

Question: would that work?

Last but not least: even as expensive as elements like these are, would they really be worth enough to pay off the energy expended to slow the missile down (even if it uses a fancy slingshot maneuver) and to bring them back? Wnt (talk) 20:11, 19 July 2013 (UTC)
 * If you evaporate your rock, you will likely end up with something like Calcium–aluminium-rich inclusions which are believed to be the first to condense. The vapour pressure depends on the other elements present due to the formation of compounds. Where you have mixtures the vapour will include some of all the parts making it up,  There may not be much concentration of very rare substances. Graeme Bartlett (talk) 22:03, 21 July 2013 (UTC)

These objects are probably among the very few things in the known universe that literally "spiral out of control". --  Jack of Oz   [pleasantries]  23:49, 23 July 2013 (UTC)

video games
is there a difference in how people with adhd/autism gets influenced by video games, especially violent compared to people without autism/adhd? someone must have done a study about it. --80.161.143.239 (talk) 20:12, 19 July 2013 (UTC)


 * It's going to be hard to generalize because autism is a "spectum" condition that ranges from mild assperger syndrome all the way to people who are completely shut off from the world.  ADHA is frequently a "comorbid condition" of autism...but not all adhd sufferers are autistic or vice-versa.  I doubt that a clear study will have been done. SteveBaker (talk) 00:54, 20 July 2013 (UTC)


 * I found one scholarly study on the relationship between video games and autism spectrum disorder. One study found that, "problematic video game use was significantly correlated with inattention and oppositional behavior. Boys who played Role-Playing games had higher levels of both problematic game use and oppositional behavior. Finally, problematic game use and Role- Playing game genre were significant predictors of oppositional behavior, even when controlling for age and amount of time spent playing video games."
 * Mazurek, M. O., & Engelhardt, C. R. (2013). Video game use and problem behaviors in boys with autism spectrum disorders. Research in Autism Spectrum Disorders, 7(2), 316-324.


 * I also found four studies on the relationship between video games and ADHD. One study found that, "Puzzle games appear to have a therapeutic effect on ADHD by increasing children's attention span, providing stress relief, and improving memory strength and focus."
 * Video games therapeutic for children with ADHD. (2008). Journal of Psychosocial Nursing & Mental Health Services, 46(10), 10.


 * Another study found that, "Adolescents who play more than one hour of console or Internet video games may have more or more intense symptoms of ADHD or inattention than those who do not."
 * Chan, P. A., & Rabinowitz, T. (2006). A cross-sectional analysis of video games and attention deficit hyperactivity disorder symptoms in adolescents. Annals of General Psychiatry, 5


 * A third study found that, "ADHD children exhibited more problems associated with videogame playing. It seems that a subgroup of ADHD children could be vulnerable to developing dependence upon video games."
 * Bioulac, S., Arfi, L., & Bouvard, M. P. (2008). Attention deficit/hyperactivity disorder and video games: A comparative study of hyperactive and control children. European Psychiatry, 23(2), 134-141.


 * The last study I looked at examined the relationships between time management skills, ADHD, and video game use. The results are somewhat of a morass in my opinion, but it might be worth a further look.
 * Tolchinsky, A., & Jefferson, S. D. (2011). Problematic video game play in a college sample and its relationship to time management skills and attention-deficit/hyperactivity disorder symptomology. Cyberpsychology, Behavior, and Social Networking, 14(9), 489-496. Lord Arador (talk) 06:25, 20 July 2013 (UTC)


 * This is completely unreferenced and based on my own experience, so maybe out of place. I have Aspergers and Tourette's (both diagnosed). The only impact I notice games having on me is that 1.) I get fixated on it and kind of zone out, kind of like staring at a lava lamp for too long; 2.) My random tics tend to go away after I play for a bit. Ultimately, they tend to be stress relieving, but I lose track of time when I'm playing. I've never had a game have a marked psychological impact on me to the extent of acting different as a result; as in: I don't feel especially violent, or aggressive, as a result of playing violent games, usually just the opposite. Personally, I don't feel that games impact me any differently than the rest of the populace (based on watching other people play) except that playing for 15 hours straight without a break and not realizing may be a result of getting fixated (but I do this with anything I find enjoyable; I watch tv for 15 hours straight, read books this long, whatever else I'm involved in). (As stated, this is purely my experience, if it is unhelpful or pointless, hat it or delete it if you want, I just figured it may be relevant.)Phoenixia1177 (talk) 07:24, 20 July 2013 (UTC)


 * Interesting. And do you avoid playing video games which involve other people, preferring to play single-player games ?  (Of course, I take it your case isn't very severe, if you choose to communicate with others here.) StuRat (talk) 19:40, 22 July 2013 (UTC)

Aphasia?
Is there a name for the phenomenon where, in a heated argument or under stress, one cannot speak because of overwhelming emotion? --TammyMoet (talk) 20:46, 19 July 2013 (UTC)
 * Aphonia is the medical term for inability to speak, so it could be called something like "transient iratogenic aphonia" if one wished to sound pretentious about it. (Or if one wished to decieve people into incorrectly informing one that it should be "iatrogenic"). Tevildo (talk) 21:34, 19 July 2013 (UTC)
 * Speechlessness. DreadRed (talk) 23:18, 19 July 2013 (UTC)
 * If someone says "I'm speechless", is that technically a self-contradiction? ←Baseball Bugs What's up, Doc? carrots→ 23:37, 19 July 2013 (UTC)
 * Well, if they are claiming to be unable to speak...then yes. But if they merely happen to have lost their notes for an up-coming commencement address then maybe not! SteveBaker (talk) 00:50, 20 July 2013 (UTC)
 * The term "rendered apoplectic" has been used for this, although looking up the work apoplexy it has a highly technical and far more serious meaning. μηδείς (talk) 01:06, 20 July 2013 (UTC)
 * I'm not so sure "apoplectic" is used all that often anymore. The preferred term seems to be "going ballistic". Which makes about as much sense. In the old radio show Fibber McGee and Molly, McGee (Jim Jordan) had a knack for flustering Mayor LaTrivia (Gale Gordon) to the point where the mayor couldn't construct a complete sentence. That schtick would be a pretty good example of the concept. ←Baseball Bugs What's up, Doc? carrots→ 10:11, 20 July 2013 (UTC)
 * No, I only know apoplectic from old movies/TV. μηδείς (talk) 17:38, 20 July 2013 (UTC)
 * Obligate Hugh Laurie: -- 71.35.127.252 (talk) 17:19, 20 July 2013 (UTC)
 * Quite a good clip! μηδείς (talk) 21:29, 20 July 2013 (UTC)


 * Tevildo, may I please borrow "transient iratogenic aphonia"? It sounds so much better than "I'm speechless with rage".  --   Jack of Oz   [pleasantries]  23:46, 23 July 2013 (UTC)

Things getting stuck inside bivalves?
Before I saw this video, I'd have suspected that the concept of a clam/oyster/etc. clamping shut on an extremity and trapping it to be an urban legend, or something from cartoons, because I didn't think that the shells actually shut that tight, all things considered.

Has there ever been a confirmed case of this happening to a human? --Kurt Shaped Box (talk) 23:37, 19 July 2013 (UTC)


 * See this from Natural History if you believe the account. This is a question where google ("diver killed clam") would have been a good first choice. μηδείς (talk) 00:59, 20 July 2013 (UTC)


 * Have you ever tried to open an oyster or mussel by hand with no tools? They can shut very tightly. Dunno about bigger shells and humans though. HiLo48 (talk) 04:38, 20 July 2013 (UTC)


 * A Tridacna giant clam can easily crush a limb if one got caught in it -- there have been a few cases of that actually happening. 24.23.196.85 (talk) 19:00, 20 July 2013 (UTC)


 * We have an article, Pearl of Lao Tzu which is the pearl described in the 1939 Natural History story linked by Medeis above. The author, Wilburn Dowell Cobb apparently re-invented the story in 1969, claiming that the pearl had been artificially grown in ancient China and lost at sea off the Philippines in a storm. In the original 1939 story, a native diver had drowned trying to retrieve the 6.4 kg pearl from a giant clam, which then closed on his arm. Cobb claimed that the valves can "clamp shut with the suddenness and strength of a bear trap". Our "Trdacna" article says; "The popular opinion that they pose danger to divers who get trapped or injured between the closing sharp-edged shell is not very real, as the closing reaction is quite slow". Alansplodge (talk) 14:33, 21 July 2013 (UTC)


 * "Authenticated incidents in which a giant clam has actually trapped and drowned a diver, however, are notably lacking." From: Ellen Prager (2011), Sex, Drugs, and Sea Slime: The Oceans' Oddest Creatures and Why They Matter, The University of Chicago Press (pp. 64-65). Alansplodge (talk) 18:21, 21 July 2013 (UTC)


 * Otherwise you'd expect predatory bivalves to be a lot more common. μηδείς (talk) 02:09, 22 July 2013 (UTC)