Wikipedia:Reference desk/Archives/Science/2013 November 16

= November 16 =

Fear of abortion
What would the name be, and would it be considered a mental disorder if it incited someone to act violently? --
 * The name would be "Fear of abortion". Not every concept needs other words to describe it.  Often, the words that already exist are sufficient.  -- Jayron  32  01:03, 16 November 2013 (UTC)
 * If what incited someone to act violently? And who's asking? μηδείς (talk) 01:15, 16 November 2013 (UTC)
 * It was CensoredScribe. And I suppose it could be "abortionphobia", if there were such a thing. I've never heard of anyone who "feared" abortion. Some favor abortion rights, some oppose, some are neutral. If he's talking about what characters like Eric Rudolph did, that's not abortionphobia - it's just plain terrorism. ←Baseball Bugs What's up, Doc? carrots→ 01:43, 16 November 2013 (UTC)
 * Fear of Genocide? We acted pretty violently to stop the Nazis.  --DHeyward (talk) 03:07, 16 November 2013 (UTC)
 * DH is right. Forced abortion?  Induced abortion?  Spontaneous abortion?  If the OP wants a reasonable answer he should clarify himself. μηδείς (talk) 03:12, 16 November 2013 (UTC)
 * "Incited someone to act violently" isn't the deciding factor. Something can be a mental disorder without any violence, and not all the things incite violence are considered mental disorders. There are many things called "fear of…" or "…phobia" are not mental disorders, as our article Phobia mentions. You need to clarify if you mean the clinical or the non-clinical meaning of the term.Sjö (talk) 09:55, 16 November 2013 (UTC)


 * Somebody wise said that more evil has been done in the world because of the love of a leader than because of the hatred of an enemy. An anti-abortionist acting violently over that issue is most likely showing an over-the-top love of his Christian god, whose earthly spokesperson told him that abortion was a bad thing that must be prevented (at all costs). HiLo48 (talk) 10:24, 16 November 2013 (UTC)
 * Or not. --DHeyward (talk) 10:38, 16 November 2013 (UTC)
 * That's a bit of a distorted way of looking at things, most people wouldn't call that genuine love. It'd be like saying that a jealous husband who beats his wife does it out of an over the top love for her. It's not that you can't contort the phrase to make that technically work, but without specifying a bunch of "I mean this by this" 's, it sounds like you're saying something very different than what you are, and which isn't actually accurate.Phoenixia1177 (talk) 11:07, 16 November 2013 (UTC)
 * I did say "over the top love". It was meant to describe something irrational. HiLo48 (talk) 11:27, 16 November 2013 (UTC)
 * True, I apologize. I've seen a lot of statements like the one you made (on both sides of the fence) used to distort issues, so I'ma bit bitchy about them. Sorry, I honestly didn't intend for that to come off as it did:-).Phoenixia1177 (talk) 11:32, 16 November 2013 (UTC)


 * That does not suggest "fear", it's more like "righteous indignation". The idea of "fearing" abortion only makes sense in terms of the embryo or fetus (who doesn't know what's happening anyway); and the mother contemplating an abortion but being fearful of the procedure. Neither of those scenarios suggests consequent murder-and-mayhem by the respective parties. ←Baseball Bugs What's up, Doc? carrots→ 16:25, 16 November 2013 (UTC)


 * The prejudiced legal tactic of 'homosexual panic', and subsequently the inept word 'homophobia', has engendered many abuses of the English language, in which ideological hatred and irrational fear are confounded. 'Islamophobia', for example.  To continue this sorry trend, one need only look up abortion in Greek (the older the Greek, the better) and attach -o-phobia.  Looking up on the web I came up with two of the big ones, then finally went to a decent source: http://www.lexilogos.com/english/greek_ancient_dictionary.htm .  This gets stuff like ἄμβλωμα / ἄμβλωσις, ἀπόφθαρμα , ἔμβρημα , ἐξάμβλωμα .  A drug to produce abortion is φθορεῖον , and procuring abortion is διαμβλώττω .  It would help of course to narrow down the 'phobia' desired - is it the fear of a pregnant woman that someone will hold her down or poison her, or is it (as I suspect) the fear by someone of having it legally practiced in a community?  (Or, more specifically, the fear of a husband having his child taken without his consent, contrary to the Code of Assura?)  In any case, one need merely transliterate the various roots, which I shall most inexpertly, missing many nuances, do as amblōma / amblōsis , amophtharma, embrema, examblōma; phthoreion, diamblōttō.  Searching I didn't find amblosophobia, amblomophobia, amophtharmophobia, embremophobia, examblomophobia, phoreiophobia, or diamblottophiba (also tried -osso-).  I could very readily have missed some variation, but my guess is that you have an open field here to pick whichever one you like the best, and in ten years people may be using it to sound 'educated', and in 20 to avoid appearing politically incorrect. Wnt (talk) 17:42, 16 November 2013 (UTC)
 * Spot on, Wnt. We've had this same "what do you call the insanity of (insert socially conservative position here)" before, recently in regard to homophobia and islamophobia. Perhaps someone can suggest a term for leftist political trolling at the wikipedia ref desks. μηδείς (talk) 20:00, 16 November 2013 (UTC)
 * Leftist? Now, there's a seemingly simple but appallingly misused word! HiLo48 (talk) 20:50, 16 November 2013 (UTC)
 * Says the raving Leftist. μηδείς (talk) 21:28, 16 November 2013 (UTC)
 * Define raving. HiLo48 (talk) 21:44, 16 November 2013 (UTC)
 * Simple, lol. By definition all Leftists are raving.  The political trolling per se is the problem though.  We just so rarely get things like this it can be monotonous. μηδείς (talk) 03:36, 17 November 2013 (UTC)


 * The thing is, though, that while attaching "-phobia" to "homo" and "Islam-o" carries a measure of political bias, there are people who are actually afraid of homosexuals and/or Muslims. When have you ever heard of someone being "afraid" of abortion? ←Baseball Bugs What's up, Doc? carrots→ 23:17, 16 November 2013 (UTC)


 * It is hard to believe that there is not a feature horror film, based on some corresponding story of a few pages from H.P. Lovecraft, entitled The Abortionist. "My senses swirled about me as I giddily stumbled into that final chamber, and my unbelieving eyes absorbed the truth of Gosnell's dark rituals.  My gaze darted from the minute and carefully preserved faces of the dead to the pulsing entrails of the living, but infinitely more disturbing was the thing -- how dare I speak of it? -- the proud result of all Gosnell's experiments, which looked up from its orgiastic feeding of primordial life-force to behold me with eyes, such eyes, perfect youth and vigor, infinite age and malice! Wnt (talk) 00:54, 17 November 2013 (UTC)
 * I don't follow. Who is it, in that quote, who's "fearing" abortion? ←Baseball Bugs What's up, Doc? carrots→ 00:57, 17 November 2013 (UTC)
 * A patient at Arkham Asylum, I should suppose. If people are afraid of cemeteries, of houses where people died, why not abortion clinics? :) Wnt (talk) 01:03, 17 November 2013 (UTC)
 * The OP asked about fear of abortion, not fear of clinics. It would be nice if he would come back here and explain just what he was trying to ask. ←Baseball Bugs What's up, Doc? carrots→ 01:15, 17 November 2013 (UTC)
 * That would be a first. Trolling is even less fun than humor when you have to explain it. μηδείς (talk) 03:40, 17 November 2013 (UTC)
 * And Islamophobics are afraid of turbans -- more often than not, the guy they pick out of a crowd to beat up is a Sikh... Wnt (talk) 01:41, 17 November 2013 (UTC)
 * Kind of the way acrophobics beat up cliffs and skyscrapers? The term you want is ignorant bigot, Wnt.μηδείς (talk) 03:40, 17 November 2013 (UTC)
 * Well, as I suggested above, I don't see these 'phobias' as true phobias. While people can be afraid of any number of things based on prejudice, that fear is based on the prejudice and rational deduction from that premise rather than the other way around. Wnt (talk) 04:26, 17 November 2013 (UTC)
 * Whether "true phobia" or not, I would still like to see Censored Scribe define exactly what he means by "fear of abortion". ←Baseball Bugs What's up, Doc? carrots→ 14:09, 17 November 2013 (UTC)
 * The OP has posted a number of times to other pages since the post here. I have asked him to explain what "fear of abortion" is supposed to mean. If we don't get an answer by his next post, I recommend the entire thread be boxed or deleted as trolling. ←Baseball Bugs What's up, Doc? carrots→ 14:13, 17 November 2013 (UTC)


 * Mental illness is not required for being a phobic - being stupid is often sufficient. ←Baseball Bugs What's up, Doc? carrots→ 03:15, 17 November 2013 (UTC)

spaceship water shielding
I just watched the film Europa Report, which I had heard was remarkably scientifically accurate (for being a science fiction movie). During one scene, a crew member ejects what they call "water shielding". It's never shown what it is, but it apparently was very heavy. Is this a real thing, or a sci-fi invention? --209.203.125.162 (talk) 01:51, 16 November 2013 (UTC)
 * Neutron can be very dangerous.
 * You need water. There must be a water storage on a spaceship. A water molecule is one oxygen plus two hydrogen atoms (one neutron + one electron). Hydrogen is really good at stopping neutron. A water shield is a water tank made to shield astronauts from dangerous cosmic radiation. I think it's also a good idea to use food (contains water), fuel (especially liquid hydrogen) and anything that can be used to protect astronauts to create a wall between a spaceman and the space. -- Toytoy (talk) 02:33, 16 November 2013 (UTC)
 * Ummmm, what? That hydrogen thing.  Uhhh, no.  Just no.  --03:10, 16 November 2013 (UTC)
 * These all mention water shields:, , , and . The idea is as above, using water to shield the crew from radiation.Phoenixia1177 (talk) 07:36, 16 November 2013 (UTC)


 * Our article on Radiation protection mentions the use of water as shielding a couple of times. Someguy1221 (talk) 08:05, 16 November 2013 (UTC)
 * If they could go to Europa then robots could easily have got ice from comets for shielding, and anyway I'd hope they'd use robots on Europa before sending people!. Until then though I'm a bit sorry they just destroy satellites at the end of their life rather than moving them all together into a single mass in a higher orbit to use as shielding or as raw materials for future missions. Dmcq (talk) 10:58, 16 November 2013 (UTC)
 * On a space trip, water can be used for shielding a human crew from radiation during solar flares. Water as such is not a magic substance that is particularly good for a shield; any substantial mass of matter will do. In scenarios such as going to Mars water and food are often mentioned as radiation shields because you'll have those things for drinking and eating anyway. You could bring along a big block of lead but that doesn't have the dual use that a tank of water has. I'm not sure why you'd eject the water though because after you use it for radiation shielding it's still good for drinking, bathing, growing plants, flushing your toilet, etc. 88.112.41.6 (talk) 20:57, 16 November 2013 (UTC)
 * Europa Report says: "The crew agrees to leave in order to bring their discovery back to Earth, but the engines malfunction. As the ship hurtles back to Europa's surface, Xu unbuckles from his seat to remove water shielding to reduce the impact speed." So the plan was presumably to keep the water for the home trip. PrimeHunter (talk) 11:35, 17 November 2013 (UTC)
 * If neutrons are what you're shielding against, then wouldn't something like beryllium, boron or cadmium make a better shield than water? 24.23.196.85 (talk) 02:22, 17 November 2013 (UTC)

In a nuclear war, you need water to shield you from neutron.

Now I think you may need to shield yourself from gamma ray in deep space. -- Toytoy (talk) 10:36, 17 November 2013 (UTC)
 * I had a look once at a radioactive pile in a deep pool of water. It had a pretty blue glow all around it. I'd probably be dead now if the water wasn't there. Dmcq (talk) 11:32, 17 November 2013 (UTC)
 * In the case of radioactive waste storage, the water is there not just to absorb the radiation -- even more importantly, it's there to absorb the heat generated by the radiation, which would otherwise melt or ignite the radioactive waste and disperse radioactive smoke all over the place (as happened at Chernobyl, although in that disaster, the initial dispersion was due to an explosion). And yes, gamma rays are a serious danger in space. 24.23.196.85 (talk) 01:57, 18 November 2013 (UTC)

Heavy water is probably a better candidate for radiation shielding. — Preceding unsigned comment added by 168.178.74.25 (talk) 22:34, 18 November 2013 (UTC)


 * No, ordinary water is better for neutron shielding -- it absorbs neutrons better (which is why they have to slightly enrich the uranium for light-water PWR and BWR type reactors, but not for the heavy-water CANDU type). As for shielding against gamma rays, both kinds of water are equally ineffective -- gamma-ray shielding requires lead, concrete or heavy armor plate (or a combination of the three). 24.23.196.85 (talk) 07:39, 19 November 2013 (UTC)
 * It's just you need a much smaller thickness of lead, it depends more on the total mass and lead is much denser than water. A deep pool is quite effective against gamma rays. Dmcq (talk) 12:55, 19 November 2013 (UTC)
 * If you're concerned at all about weight (as would be the case in any aerospace application), then lead or armor plate would be the best choice. 24.23.196.85 (talk) 21:44, 19 November 2013 (UTC)

You are saying that regular water is better than the heavy water, then how about the Norwegian hydroelectric plant in WWII that produced heavy water for the Nazis? Why did people risk their lives to destroy it and deprive them of this vital material for a nuclear bomb? — Preceding unsigned comment added by 168.178.74.104 (talk) 16:57, 19 November 2013 (UTC)
 * No, no, no, you got it all bassackwards -- the Nazis used heavy water as the MODERATOR for their reactor, not as SHIELDING! The role of the neutron moderator is not to shield the operator from neutrons -- it's specifically to slow the neutrons down INSIDE the reactor so they have time to react with the uranium (or plutonium) instead of flying out like they would do at the speeds at which they normally fly!  And since the moderator's purpose is to help the neutrons react with the uranium, the best moderator is one that would slow the neutrons down effectively WITHOUT absorbing them -- which is what heavy water does, which is why it's better than ordinary water AS A MODERATOR!  Whereas if you want SHIELDING, you want to ABSORB neutrons or REFLECT them rather than just slow them down -- which is why ordinary water would be better FOR SHIELDING than heavy water. 24.23.196.85 (talk) 21:44, 19 November 2013 (UTC)

Lecithin
The article says it lowers cholesterol. Is the source good? Thanks. 67.243.4.94 (talk) 02:08, 16 November 2013 (UTC)


 * If you're concerned about yourself or someone else with high cholestoral, you should follow your doctor's orders on the matter. ←Baseball Bugs What's up, Doc? carrots→ 02:22, 16 November 2013 (UTC)


 * Since lecithin is a nutritional supplement, not a medicine, advice on when to take it is not medical advice. StuRat (talk) 02:40, 16 November 2013 (UTC)


 * Is that some sort of legal situation in the USA? It seems to match the bit of text in the article that says "Lecithin is marketed as a dietary supplement. As such, no claims may be made as to its usefulness in treating or preventing a disease or condition." HiLo48 (talk) 02:49, 16 November 2013 (UTC)


 * Yes, as "nutritional supplements" are exempt from regulation by the FDA. StuRat (talk) 03:42, 16 November 2013 (UTC)


 * I don't think that's exactly correct. It's a "food" instead of a "drug" and so must comply with food labeling and marketing including special rules for Dietary supplements that's enforced by the FDA (F=Food). Claims about what the food can do is regulated as well but obviously a food group is different than a medication.  It cannot claim that it fights disease as that would run afoul of the labeling rules but "cholesterol" is not a disease, rather it's correlated to one.  Lowering cholesterol through lecithin, for example, has no known health benefit and another section links lecithin to an increase in TMAO which is also not a disease but linked to one.  --DHeyward (talk) 07:24, 16 November 2013 (UTC)


 * The OP asks "Is the source good?" I'm particularly keen on the source that says "...the expansion of the soybean crushing and soy oil refining industries in Europe after 1908 led to a problem disposing the increasing amounts of fermenting, foul-smelling sludge. German companies then decided to vacuum dry the sludge, patent the process and sell it as "soybean lecithin." Scientists hired to find some use for the substance cooked up more than a thousand new uses by 1939" I think one must always be cautious about an allegedly good-for-you product derived from someone else's waste product. HiLo48 (talk) 02:47, 16 November 2013 (UTC)


 * This sounds similar to the situation with peanuts, which weren't of much value until George Washington Carver experimented with different uses for them, coming up with peanut butter, peanut oil, and a few other products. StuRat (talk) 03:46, 16 November 2013 (UTC)
 * Depends on your definition of value - something that goes so well with a beer is of value to me! Equisetum (talk &#124; contributions) 23:03, 18 November 2013 (UTC)


 * If the OP's question is whether claims in out articles are well sourced he should either specify the sources he doubts or ask the question at the article's talk page. μηδείς (talk) 03:16, 16 November 2013 (UTC)

Hot water improving cleaning ability
It seems that the warmer the water, the better cleaning ability it has -- especially when used in conjunction with soaps and detergents. How/why does water temperature affect cleaning ability? --209.203.125.162 (talk) 19:29, 16 November 2013 (UTC)


 * Both the mechanical agitation caused by increasing the heat of the water molecules and any increased rate of reaction of any chemical reactions would improve cleaning and bleaching speeds. μηδείς (talk) 19:48, 16 November 2013 (UTC)


 * Solubility of oils, fats etc in water generally increases with temperature. AndyTheGrump (talk) 20:00, 16 November 2013 (UTC)


 * Agreed, and edible fats, in particular, tend to be solid at cold water temperatures and liquid at hot water temperatures. Think of the liquid bacon grease poured off from the frying pan, which then solidifies as it cools.  Detergents tend to be far more effective in dissolving liquid fats than solid fats (technically emulsifying the fats in water).  StuRat (talk) 20:59, 16 November 2013 (UTC)


 * How many items of clothing a year do you launder due to their accumulated bacon grease? μηδείς (talk) 21:27, 16 November 2013 (UTC)


 * That comment makes me guess that you incorrectly refer to liquid dishwashing detergents as "dish soap" and only think detergents are used for laundry. StuRat (talk) 22:09, 16 November 2013 (UTC)
 * Well, no, but I was only thinking about cleaning cloth, not dishes. μηδείς (talk) 03:31, 17 November 2013 (UTC)
 * Do you not reckon that you need to wash clothing because of the accumulated sebum arising from skin secretions then? --TammyMoet (talk) 09:38, 17 November 2013 (UTC)
 * Not primarily, although I can't speak for others. In any case, sebum is not bacon grease, or at least it doesn't taste like it. μηδείς (talk) 18:44, 17 November 2013 (UTC)
 * A Bib (garment) or an Apron might be made of cloth and might to a degree be impregnated with bacon grease. Such items might require washing though understandably they might not be considered "garments". Bus stop (talk) 18:53, 17 November 2013 (UTC)
 * So, Stu, you wear a bib regularly? :) 00:43, 18 November 2013 (UTC)

Can I equate "m" from the following two equations?
We get "E/ c^2 = F/ a" after eliminating m from the following two equations.

F = ma &  E = mc^2

Which mean F, E, a and c are independent of mass. So is this true if "E/ c^2 = F/ a" is valid equation?162.157.235.1 (talk) 21:45, 16 November 2013 (UTC)EEC


 * I'd say normally no, since the m in F = ma is just the mass, while the m in E = mc2 is the mass converted to energy. I suppose there could be some special cases, though, like if a known force applied to an anti-matter particle achieved a measured acceleration, then this was used to determine the particle's mass, which was then converted to energy by ramming it into normal matter (although this would then double the mass converted to energy, so the formula would need to reflect this).  StuRat (talk) 21:48, 16 November 2013 (UTC)
 * Sure it's valid. Not very interesting, though, since it just says that the ratio of force to acceleration is the object's energy (perhaps rest energy, but the equations are slightly ambiguous; see relativistic mass) divided by the speed of light squared.  That's of course just two different statements of mass, so of course they're equal.  --Tardis (talk) 00:06, 17 November 2013 (UTC)
 * See Relativistic mechanics for the mathematics. To over-simplify a little, F = ma only applies if the mass is constant (which it may not be even in a classical system), and, in a relativistic system, the mass (the "m" in E = mc2) will vary with the velocity, so "m" in the two equations isn't the same. Tevildo (talk) 23:20, 16 November 2013 (UTC)
 * No, the "m" in both cases varies, and is the same. As the mass increases at relativistic speeds, the acceleration reduces (as seen by an observer left behind).  So the OP's suggested equation is correct, but one must just keep in mind that E is the relativistic energy (rest-mass energy plus kinetic energy).  —Quondum 05:02, 17 November 2013 (UTC)


 * Yes they are correct, but you are misinterpreting what they mean. E=m (c^2 is a constant) is an identity.  They are interchangeable.  The total energy (and mass) of an object is the sum of it's rest mass and kinetic energy.  Even "massless" particles like photons exhibit gravitational forces equivalent to the E=m identity (energy/mass of a photon is proportional to frequency).  As you approach relativistic speeds, the energy division between mass and velocity is observer dependent but the overall energy and gravitational force is not because that does not matter whether it's observed as mass or kinetic energy and the identity will always hold true.  The interesting thing is that this applies to everything so a baseball that is thrown has a slightly larger mass when you impart kinetic energy to it.  It's tiny but you can use E=mc^2 to find it.  --DHeyward (talk) 07:25, 17 November 2013 (UTC)
 * Careful &mdash; I believe that you end up off by a factor of 2 if you try to use a photon's relativistic mass and Newtonian gravity, even in the weak-field approximation. --Tardis (talk) 00:10, 18 November 2013 (UTC)
 * Yes, one has to be a little careful when one starts speaking of the gravitational effects on and by a system: these are not determined solely by the mass of the system. The gravitational influence of a system is determined by the stress–energy tensor, so the pressure contributes. In the case of photons, this additional effect is on the same scale as the effect of the mass.  But the gravitational effect does not form part of this question.  —Quondum 00:34, 18 November 2013 (UTC)


 * First let me point out that even if it made sense to eliminate m from the two equations, that doesn't mean that E, F, and a "independent of mass". The original equations are still valid showing how those things relate to mass. Second point: F=ma isn't a relativistically correct equation. It is a non-relativistic approximation.

Third point: Within that approximation, m stands for rest mass and the E taken from E=mc^2 will be the rest energy. The equation is than correct but is also boring because it adds nothing to the theory and doesn't help solve any problems.