Wikipedia:Reference desk/Archives/Science/2015 October 13

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October 13

Epileptic seizures, memory loss, and theories of consciousness

I'm currently taking a Philosophy of Mind class with John Searle at UC Berkeley. In one of our readings the author makes a big issue out of the fact that certain kinds of epileptic seizures result in people still continuing to be able to function (e.g., someone has a mild seizure while driving and rather than crash continues to drive on "auto pilot"). The issue is that the author: Ned Block is trying to distinguish two kinds of consciousness and posits these examples to show someone can be attending to what they are doing (reacting to traffic, following a path to a destination) without being conscious in the sense of being aware of what they are doing. He infers that last bit because the epileptic patients report after the fact that even though they didn't crash their cars they have no memory of driving. Now here's my issue: my understanding is that seizures cause memory loss. I KNOW that is true for ECT, I used to work in a psych hospital and every patient that had ECT would experience memory loss of the event plus usually hours or even a day more more before. And from what I've gleaned from Wikiepedia and other sources the same is true for non-induced epileptic seizures. So if that is the case how can we trust that what the patients in these examples are saying doesn't reflect memory loss as opposed to them not being conscious at the time? I.e., maybe they were conscious but simply don't remember being so. The paper in question is "On a confusion about a function of consciousness" by Ned Block and his sources are books (which unfortunately I don't have or have time to get before the class) by Searle and Penfield. Interested in any opinions, thanks in advance. --MadScientistX11 (talk) 02:22, 13 October 2015 (UTC)

I'm tempted to simply reject Ned Block's work out of hand simply because he's a philosopher speculating about neuroscience. Actual neuroscientists still don't understand what consciousness is, let alone how to prove whether someone is actually experiencing it. Just think about all the various conditions that trigger anterograde amnesia in persons who, were you not trying to test their memory, seem perfectly awake and self-aware. Someguy1221 (talk) 02:30, 13 October 2015 (UTC)

LOL. I agree with you. It may seem strange I'm taking a class, auditing actually but still, from Searle given that I think that but I kind of wanted to see what someone who is very well respected thinks on these topics even though I disagree with him a lot and agree with your general critique of philosophers who try to make all these pronouncements about consciousness when we aren't anywhere close to having a theory that explains much more basic questions. Patricia Churchland wrote an excellent little article on why the Neural Correlate of Consciousness (NCC) idea and the idea that consciousness is the "hard problem" must die for the same reasons. But because I disagree with him a lot I don't think Searle likes me very much and before I speak up I like to have my arguments be very solid so I while I agree with your point of view I would still like to get some feedback by people who have deep knowledge on the specific question about epileptics who can do things like drive during a seizure. Am I correct in assuming that its a gaping hole in the argument to ignore the hypothesis that they just don't REMEMBER being conscious or is there some data I'm not aware of that supports that they actually are conscious not just that they don't remember being so? BTW, I'm not familiar with anterograd amnesia. Will google it and look for Wiki articles, if there is more you can say on that topic feel free. Thanks for the help. --MadScientistX11 (talk) 02:54, 13 October 2015 (UTC)

What you have to be careful about here is implicitly assuming that the word "consciousness" has a genuine real true meaning which we can figure out by investigating it. "Consciousness" is merely a word that different people use in ways that are at least subtly inconsistent. If you try to define it explicitly, and particularly if you try to define it operationally, you run into difficulties -- into things that probably violate your intuition. That's Block's central point. Don't focus on whether the people in question are actually conscious, focus on whether you can give an explicit non-circular definition of consciousness that gives an answer you feel is correct when it is applied to them. Looie496 (talk) 19:40, 13 October 2015 (UTC)

original link. Wnt (talk) 08:04, 13 October 2015 (UTC)

Let me run these thoughts by you. If someone is have a seizure, their long term skill (how to drive) may still be intact. Yet their short term memory doesn't pass into long term memory because of the localized electric storm in their brain, so they have no recollection afterwards. ECT is a little different. It is more global (regardless of were the electrodes are placed). ECT can and does fracture long term memories. At one time it was though that psychiatrists had ECT sussed. I.E., Put the electrodes in the right place and the patient could still talk and behave normally after treatment but when the patents tried to go back to work they found their physical skills had deserted them. So, I would say Yes, People with certain types of epileptic seizures are still conscious in every meaning of the word, but the temporal experience of that period does not always go into long term memory. Of course, some time they can find themselves between two realities. The brain storm has created a dam between different parts of the brain. Yet the brain is still capable of being aware. The individual is also aware -of being aware- during a fit but afterwards they have no recollection of some things when asked.--Aspro (talk) 21:48, 13 October 2015 (UTC)

Thanks to Aspro, Wnt, and Someguy1221 for the excellent comments. The class was yesterday but I saw the last comment just before hand so all were useful. FYI, the consensus of the class was in agreement with Aspro which is also what I think is the most likely hypothesis. I don't know about you guys but I tend to waver in my general feelings about these kinds of discussions. On the one hand I prefer topics in computer science or math where we can get definite answers. On the other hand I think that these kinds of discussions can get at some very interesting issues, even if we can seldom get an absolute right or wrong answer the discussion itself can be meaningful. Anyway, thanks again guys, Wikipedia is awesome for providing help like this. --MadScientistX11 (talk) 15:24, 14 October 2015 (UTC)

DNA question? What people are in the Negroid/Black races?

I was reading a book that said there are only 3 base human races in the world. Those races are Caucasian, Mongoloid and Negroid. How can I find out who belongs to the Negroid/Black category? I'm looking for names (like Jamaican) so I can research each distinct type. — Preceding unsigned comment added by 173.245.202.56 (talk) 06:22, 13 October 2015 (UTC)

This is a thoroughly discredited idea that was in vogue among Europeans (and European-influenced cultures like the U.S.) from the mid 18th to early 20th centuries. I suggest you find some books on anthropology that are a little more up-to-date. Our articles on human race may serve as a starting point. --71.119.131.184 (talk) 06:41, 13 October 2015 (UTC)

If you're interested in the history and something about the different ways the human race has been divided, Scientific racism is the article. Your example can be found in one of the references, a 1950 document from UNESCO, but it doesn't have any criteria for classification. Sjö (talk) 15:19, 13 October 2015 (UTC)

I'm not a biologist but I just want to add one more agreement to the more knowledgeable people commenting above. Left wing people will often say that "race is a completely social construct" and while that is going just a bit too far it is essentially correct. In terms of biology race is just some very minor phenotypes like skin pigment. Races do not correlate to sub-species or any other meaningful biological concept. Not to mention, I think it was George Carlin who originally said it, the best way to combat racism is to have sex with lots of people (the way George said it was a bit more vulgar and a lot more funny) because eventually all those differences get melded together which is happening. --MadScientistX11 (talk) 15:28, 13 October 2015 (UTC)

• Of course the comments above are the usually PC bollocks. If you are scared of the word race, you can use "populations" or "ancestry" or circumlocutions like "Mediterranean men are more prone to Kaposi's Sarcoma, or West-African populations tend to carry a gene that confers resistance to malaria while causing sickle-cell anemia, or Northern Europeans tend to be blonder than other populations, as well as being lactose tolerant.

"Race" is scary because people have done bad things in the name of supposed racial science or ideology. To be afraid of the term itself makes about as much sense as saying there are no such thing as eyeglasses because the Khmer Rouge executed people wearing them, under the assumption they were educated and possible counterrevolutionaries. For recent scientific articles on race and DNA see African genes from Eurasian farmers and post=Columbus genetics of the Americas You can say things like this:

The study found the confirmed, well-established genetic ancestry of the Americans, but also new things like: Carribeans had a larger African genetic contribution than other Americans; the ancestors of the Yoruba people from West Africa (especially Nigeria) had the largest genetic ancestry from Africa to all current American peoples; Sicilians and South Italians had the largest impact in Puerto Rico and Colombia; the Basques, from Northern Spain contributed genetically to South American populations, they must have been among the Spanish conquistadores, or a subsequent wave of migrants. Also, some of the African-Americans from Southern USA had French ancestry, in accordance with the historical French colonialism from Southern US.Just as long as you leave the word race out of it.

μηδείς (talk) 16:08, 13 October 2015 (UTC)

The problem, though, is not that we're disputing the validity of population genetics. No one above even comes close to disputing that. The relationship between population genetics as a science, and the traditional Anglo-American division of all of humanity into strict black-yellow-white categories based on superficial physical characteristics is basically total bullshit however. It is not "PC bollocks" to state that. No one has done what you are accusing them of doing. They reflecting clear, un-political, unambiguous, and universally agreed scientific agreement that the 19th century tripartate division of humanity into three racial colors is total bullshit. --Jayron32 17:51, 13 October 2015 (UTC)

The problem is when we go from "the way in which races have historically been divided is deeply flawed" to "there is no such thing as race". You can call them "gene pools" or whatever else you like, but the fact remains that there are significant genetic differences between populations, which are important for medical reasons, tracking ancestry, etc. Now, I don't know the answer to the OP's Q, but it would look something like "Membership in the sub-Saharan gene pool historically identified as 'the black race' may be determined by the presence of the following genetic markers and absence of these genetic markers ... If you also include those historically from Melanesia, Australia, and the Indian subcontinent, then the following genetic markers apply ... " StuRat (talk) 17:58, 13 October 2015 (UTC)

Except what we call a race really doesn't correlate to what we call gene pools and populations and the like. So it doesn't work that way. Two radically different population groups may both have been called "negroid" race, and not share much genetic similarity at all; that debunks the idea that "negroid" is a valid classification from a genetic point of view. The point is that trying to maintain adherence to antiquated and incorrect notions of what kinds of groupings should matter leads us to radically wrong conclusions, and that is why it is bullshit. When someone says "they're both black, so they should have similar genetics" or "they're black and white, so they should be more genetically different than two black people would", BOTH of those statements are experimentally false, and for that reason, the social concept of race is biologically not very helpful in making reliable predictions of a genetic nature. Of course, race itself is a valid social construct, and vital to understanding various sociological, anthropological, cultural, and historical realities of the human condition. It's just a very poor correlation for biological stuff. --Jayron32 18:16, 13 October 2015 (UTC)

If it was such a poor correlation, then it wouldn't be used for assessing medical risk factors. Take the Mayo Clinic, which states, regarding sickle-cell anemia: "In the United States, it most commonly affects blacks." [1]. Sure, a detailed genetic profile is best, but you can't do that on everyone, so doctors paying attention to race is a good start. StuRat (talk) 18:30, 13 October 2015 (UTC)

That's because in the United States, black people come from a very small subset of worldwide black people. Black people in the U.S. are mostly here because their ancestors were brought over during the transatlantic slave trade, and those people brought over come from some very specific population groups. When someone means "the black race", however, as a general concept, they don't mean "only those people who were brought to the U.S. from these few closely related population groups". They mean "all the dark skinned people". That's what negroid basically means, which is why it isn't valid. The reason that the Mayo Clinic report you cite starts "In the United States..." is that the sickle cell gene is found mostly among the very narrow set of black people that came to the U.S. during the Transatlantic Slave Trade. So, the statement "Black people have the genetics to get sickle cell anemia" is demonstrably false. Most black people do not have the genetic trait, and are most "black" population groups are not closely genetically related to those population groups that do have that gene. Only those population groups from a very small subset of West Africa carries the gene. Most black Americans are descended from those specific population groups, but not from a monolithic "negroid people"; there is not a single black African population group that shares genetic commonalities. This is what happens when we focus on a simplified perspective without understanding the greater history involved. You read "commonly affects blacks" and ignored the entire history of which population groups came to the United States. The United States does NOT have an arbitrary mixture of all of "black people". It has a small subset of those people, from specific groups. --Jayron32 18:41, 13 October 2015 (UTC)

The mutations for sickle cell anemia in particular are known to pop up rather quickly in all populations extensively exposed to malaria. In particular, historically it also was frequent in mediterranean populations and in (east-)Indian populations, neither of which would usually be classified as "negroid". ---Stephan Schulz (talk) 19:04, 13 October 2015 (UTC)

At the very least, we've established that there is enough correlation between race and genetics in the US to use race as part of the medical diagnostic procedure.

One could also argue that the sexes can't be defined and everyone lies on a continuum, rather than there being strictly males and females, but medical science will still consider sex as significant in the diagnostic process. StuRat (talk) 19:24, 13 October 2015 (UTC)

Well, you see, that's the problem. When you say "This tiny example where the darker skinned people have some genetic commonality which is not shared by the lighter skinned people in that part of the world..." That's a very different thing than saying "the black-white-yellow division of humanity into three races is a valid biological thing." (what the OP is asking about) It isn't. To say "Because black Americans get sickle cell anemia, and white Americans don't, race is genetic" is a laughably inaccurate overreach to draw some greater statement about the biology of race. "Because X happens to me where I live, X is a universal way the world works" is not the way to demonstrate the validity of a statement. You can't extrapolate the truth of black American biology to worldwide, universal biological concepts. Reducing humanity to three "races" is bullshit for that reason, even if black American get sickle cell anemia and white Americans do not. --Jayron32 20:06, 13 October 2015 (UTC)

It's not just sickle-cell anemia, there's a wide range of diseases for which race is a significant risk factor. StuRat (talk) 21:19, 13 October 2015 (UTC)

Whoosh....sorry, but you argue the wrong quantorquantifier. --Stephan Schulz (talk) 22:11, 13 October 2015 (UTC)

@Stephan Schulz: Speaking of the wrong quantor, how did a histamine H2-receptor antagonist get mixed into this? Wnt (talk) 22:22, 13 October 2015 (UTC)

I hate false friends! --Stephan Schulz (talk) 22:28, 13 October 2015 (UTC)

The problem with speaking of a "black" race is that there are three main branches of humanity, all represented in Africa. Though you might speak of partial Neanderthal and Denisovan ancestry in some non-African groups outside that, I'm not convinced it's the basis for a meaningful 3-way racial split. Wnt (talk) 21:32, 13 October 2015 (UTC)

Sturat, there are black people in Africa who are more similar to you genetically (I'm assuming you are white) than they are to some OTHER black Africans. Vespine (talk) 04:20, 14 October 2015 (UTC)

• The assumption is unnecessary, of course. —Tamfang (talk) 05:29, 14 October 2015 (UTC)

• That would depend on which genes you are comparing. If you compare the genes normally associated with race, like melanin production in the skin, then that's obviously (but trivially) not true. StuRat (talk) 16:14, 14 October 2015 (UTC)

• Possibly not even that. As Human_skin_color#Genetics_of_skin_color_variation notes " genetic studies have discovered a number of genes that affect human skin color in specific populations, and have shown that this happens independently of other physical features such as eye and hair color. Different populations have different allele frequencies of these genes, and it is the combination of these allele variations that bring about the complex, continuous variation in skin coloration we can observe today in modern humans." In simpler terms, the specific mix of genes that produces dark skin one one population may not be the specific mix of genes that produces it in another; the could very well be two different population groups living in close proximity in Africa whose skin color genetics is actually quite different, despite having similar skin tones. --Jayron32 16:22, 14 October 2015 (UTC)

Sturat, you are either being completely disingenuous or just thick. There are 20,000-25,000 genes, clearly I didn't mean if you just make a comparison between a cherry picked handful. If you read the article it might actually open your mind a little. Vespine (talk) 22:12, 14 October 2015 (UTC)

Race doesn't mean "the summation of all a person's genes", it refers to some specific phenotype variations, one of which is skin color. To just do a gross comparison of all genes and thus conclude that there is no such thing as race is the opposite of cherry picking, it's casting too wide of a net to reach a meaningful conclusion. Using your logic and going back to my example about sexes, you could compare the vast majority of genes that don't vary between males and females and thus conclude that sexes don't exist either. StuRat (talk) 01:52, 15 October 2015 (UTC)

Actually, i think you are STILL failing to see the point. Using your gender example, there are several things that males have in common with males and females have in common with females. By that measure you would have more in common with African males, than African males would have with African females. You might ALSO have more in common with the most masculine female than the most effeminate male, 'however THAT would be the exception. It is NOT the exception that there would be a pollution of Africans that would be more closely related to YOU and your kin, than ANOTHER large population of Africans. THAT'S the point I think you are failing to grasp. there is MORE genetic variance in Black Africans then the rest of ALL the other "races" combined, don't you see the implication this has to the "race" hypothesis? Vespine (talk) 03:52, 15 October 2015 (UTC)

("a pollution of Africans" ? Let's hope that's not a Freudian slip)

I plead accidental racism by spellcheck. Vespine (talk) 22:00, 15 October 2015 (UTC)

If I were to do the same comparison as you, I would look at some genes completely unrelated to sex, like eye color, note that I, as a male, have the same eye color as many women do, and conclude that therefore sexes do not exist as a genetic concept, since I may very well have more genes in common with European women than Chinese men. StuRat (talk) 13:30, 15 October 2015 (UTC)

Let me spell it out for you. You are genetically more closely related to Europeans, Asians and Native Americans, than some Africans are related to some other Africans. Vespine (talk) 04:23, 15 October 2015 (UTC)

Again you make the same mistake of comparing all genes, rather than just those related to race. StuRat (talk) 18:24, 15 October 2015 (UTC)

I'm not comparing anything Sturat, actually you can leave the word "genetically" out of the above statement, does that make it clearer? You ARE more closely related to Asians, Europeans and Native Americans, than some Africans are related to other Africans. That's an objective fact, it has been determined using genetics, NOT by cherry picking what you think are "race related genes", and it completely shoots the "race" hypothesis out the window. Vespine (talk) 21:33, 15 October 2015 (UTC)

That statement simply isn't relevant, if it's somehow meant to prove that races have no genetic basis. You've yet to respond to my argument that if race has no genetic basis, then neither do the sexes (since the same comparison of all genes, rather than just the genes in question, yields the same result, in both cases). StuRat (talk) 03:48, 16 October 2015 (UTC)

Sorry there's too many threads in this discussion now. If you read the articles you will see that it's NOTHING like what you present. Genetically there are a few very well defined genetic markers which distinguish males from females. As pretty much EVERY article I linked says at some point, molecular genetic studies are proving with more and more certainty that no such markers exist which determine the races. It just sounds like you don't want to accept it. Vespine (talk) 04:55, 16 October 2015 (UTC)

"Genetically there are a few very well defined genetic markers which distinguish males from females." This is EXACTLY what I am saying. There is obviously a genetic basis for the difference between the sexes, despite there being very few genetic markers which actually distinguish the sexes. Similarly, there is a genetic basis for the difference between the races, despite there being very few genetic markers which actually distinguish the races. StuRat (talk) 21:31, 16 October 2015 (UTC)

Because you're not actually making arguments. You've presented, as yet, zero references to back up anything you say. Your just throwing shit on the wall to see what sticks. That's not how this desk works. You don't get to have any statement you make acceptable merely by the fact that you assert it. Provide some useful reading for people to use or GTFO. --Jayron32 03:52, 16 October 2015 (UTC)

It's completely unacceptable for an editor, much less an Admin, to use obscenity like that towards another editor. StuRat (talk) 04:01, 16 October 2015 (UTC)

So you're saying you don't have to provide references to support claims you make because someone said the word "shit" in your presence. Yup, that's logical... --Jayron32 12:01, 16 October 2015 (UTC)

No, I'm saying you need to treat people with respect, even when you disagree with them. Or are you modeling your behavior after Donald Trump ? I will ignore you but continue to respond to those who are capable of a civil discussion. StuRat (talk) 21:24, 16 October 2015 (UTC)

Ok I should have done this many posts ago, since this is the ref desk, please provide some references to support your claims that there is such a thing as genetic "races". Here are some that oppose that hypothesis,

there is no such thing as race

Genetically Speaking, Race Doesn't Exist In Humans

As we harvest ever more human genomes one fact remains unshakeable: race does not exist

RACE - The Power of an Illusion. Ten Things Everyone Should Know About Race

The Main Reason Races Don’t Exist

Bill Nye: Race is a Human Construct

Why Your Race Isn't Genetic. DNA doesn't determine race. Society does.

Vespine (talk) 21:49, 15 October 2015 (UTC)

Here you run into a PC wall. Based on the history of science and eugenics, no scientist wants to be seen supporting the concept of race, at least if he expects to continue to have his projects funded. (BTW, I would say "Race is a human construct based on underlying genetic differences" just as I would say "Gender is a human construct based on underlying genetic differences between the sexes". Note that the language is better at distinguishing the two in the case of gender and sex, while we lack separate words for the human construct and genetic basis when talking about race.) StuRat (talk) 03:48, 16 October 2015 (UTC)

Did you read any of the articles? What I am doing is the OPPOSITE of running into a "PC wall", it's you who is running into a bias wall: "The folk concept of race in America is so ingrained as being biologically based and scientific that it is difficult to make people see otherwise," Find a single reputable article that argues the opposite? Vespine (talk) 04:50, 16 October 2015 (UTC)

Sure, reality has a PC bias here I guess. Perhaps race means something different to you than it does to, well, everyone else. There are indeed genetic polymorphisms that are more commonly found in people of one race than others. And taking many of these polymorphisms into account, you can actually generate algorithms that predict a person's self-described race from his genome with 99% accuracy (there are many publications on such things, and some are referenced in Wikipedia). I suppose you could look at something like that and say, "aha! race is genetic!" I suppose this is true in the same sense that blue eyes are genetic, or blond hair, etc. But the reason geneticists look at this data and say, "aha! race is not genetic!", is that they are disproving a different concept. Remember, the entire historical concept of race is that your skin color or bone structure indicated your ancestry. Explicit in the concept of race was that all members of a race were more similar to one another than they were to other races. When you actually build a phylogenetic tree of people, you find that this is entirely untrue. Each "race" contains multiple disjointed and overlapping ancestries, not to mention the vast amounts of interbreeding between these ancestries (virtually every African American, for instance, is at least one eight white European). So your appearance is genetic, but your race is not, unless you want to crudely define race as "what you look like". Someguy1221 (talk) 04:01, 16 October 2015 (UTC)

Maybe compare it to coat colors and breed in dogs. "Black" is not a breed of dog, and no breeder would let you get away with saying otherwise. Even though every black dog has similar pigmentation, and that pigmentation is genetically determined, not all black dogs are particularly close to one another in terms of ancestry. Even something more specific, like "chocolate Labrador" would not be a breed. Those all look basically the same, but chocolate labs are rather dispersed throughout the lab phylogeny, unlike the overall lab group within the dog phylogeny. Someguy1221 (talk) 04:08, 16 October 2015 (UTC)

I'd love to see some of those sources you mentioned (I'm not questioning you at all, I just want to read them). StuRat (talk) 04:07, 16 October 2015 (UTC)

Here is one. Someguy1221 (talk) 04:15, 16 October 2015 (UTC)

Excellent ! "Genetic cluster analysis of the microsatellite markers produced four major clusters, which showed near-perfect correspondence with the four self-reported race/ethnicity categories. Of 3,636 subjects of varying race/ethnicity, only 5 (0.14%) showed genetic cluster membership different from their self-identified race/ethnicity." Looks like they found some of those genes associated with race and ethnicity. StuRat (talk) 21:36, 16 October 2015 (UTC)

Actually, pigmentation changes tend to rely on a few standard tricks over and over again, even in different species. On the other hand, I was just reading a Science review that mentioned that there was an "unknown" cause of skin color lightening in southern Africa, independent of the European lightening, looked like Angola on their little map. I meant to look that up, forgot... Wnt (talk) 01:20, 15 October 2015 (UTC)

Regarding everyone becoming gray, if people honestly fall in love with someone different I think that relationship is fine. But if men are Googling mixed children and then choosing a race of woman to impregnate based on what he wants his kids to look like there's a problem. Now to answer my own question. "Africans" is a no-brainer and these pages give us a partial answer

https://en.wikipedia.org/wiki/Traditional_African_religion#Traditions_by_region

https://en.wikipedia.org/wiki/Ethnic_groups_of_Africa

but they don't include Negroid/Black people outside of Africa like the Jamaicans and Afro-Brazilians. Luckily, I found a great Black People Around The World page on Pinterest and this list of countries on a black models website Bahamas | Barbados | Curacao | Dominican Republic | Guadalupe | Haiti | Jamaica | Martinique | Panama | Saint Vincent and the Grenadines | Trinidad | Turks and Caicos. I'll add the U.S. Virgin Islands and probably find the rest on Pinterest.

what is the machenism to form the C2

Shahjad ansari (talk) 17:15, 13 October 2015 (UTC)

You had the title and signature swapped. I fixed it. Now, is your Q the mechanism by which C₂ is formed ? StuRat (talk) 17:59, 13 October 2015 (UTC)

What meaning do you have as there are several at C2. If you mean the simple molecule, our article is at Diatomic carbon. But it does not talk about formation. Are you interested in flames, graphite vapourisation, or condensation in carbon stars? Graeme Bartlett (talk) 21:34, 13 October 2015 (UTC)

Physiological limitations of demonic possession in theory

Just for the sake of theory or a horror story (and since great strength is regarded as one of the telltales of the demonic possession), would it be correct to assume that during possession the demon's strength can't be always converted to its host's physical strength due to physiological limitations of the host? For instance, if a demon or multiple demons possess, say, a 16-year old girl, she still wouldn't be able to overcome one or two adult men due to her limited muscular mass and relatively fragile bones (so that if the demon applies excessive force her bones would fracture or the joints would dislodge)?--93.174.25.12 (talk) 19:38, 13 October 2015 (UTC)

There is no such thing as demonic possession, so whoever is writing the story can endow the character with whatever traits they want to. ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:53, 14 October 2015 (UTC)

There are many reported cases of people performing seemingly "superhuman" things in time of massive emergency. We have an article: Hysterical strength which describes many of them - but points out that doctors are skeptical.

But, assuming such acts of extreme performance under equally extreme provocation are indeed within the limits of the human body, I see no reason why you shouldn't claim something of the sort for the sake of a story. Clearly there would have to be limits - bones and muscles are only so strong - and presumably the victim of possession wouldn't be capable of doing this kind of thing routinely. SteveBaker (talk) 19:45, 13 October 2015 (UTC)

Note that a normal, healthy 16 year old girl does not have fragile bones. Bones are quite flexible at that age. StuRat (talk) 21:10, 13 October 2015 (UTC)

This is not a very good explanation, yet here goes: In the old days, people who where deemed to be possessed were suffering from a Gut–brain axis imbalance just as present day people suffer from, but now we call them metaly ill (for resaons which is unscientific because it is phsyologial – but it earns the drug companies billions). >http://www.google.co.uk/url?q=http://scholar.google.co.uk/scholar_url%3Furl%3Dhttp://www.researchgate.net/profile/John_Cryan/publication/49819526_The_microbiome-gut-brain_axis_from_bowel_to_behavior/links/09e4150cb743c5053d000000.pdf%26hl%3Den%26sa%3DX%26scisig%3DAAGBfm038eIWFDj4NMZoBStox33wCZPvkw%26nossl%3D1%26oi%3Dscholarr&sa=U&ved=0CBUQgAMoAWoVChMI6b6R_53AyAIViHA-Ch23KQLK&usg=AFQjCNE7i-NRrCIijOmiaxx8YSQ1cu9ZyA < A person suffering from this crises has cortisones (the stuff that professional athletes are not supposed to take) flooding through their blood stream and endorphinsthat make them oblivious to pain. Dealing with such a patient is a bit like dealing with someone who has OD'ed on PCP. They are super strong, authentic to the point of being able to leap over walls in a bound, and don't appear to feel pain. However, because they are 'speeding' ones own bones are likely to suffer first, due to their speed of action that comes before one's own reactions can protect oneself. So, in the repeating of these tales, the demonically possesed appear to have taken on super human attributes. Yet, they still flesh and bone. 20:44, October 13, 2015‎ Aspro (talk | contribs)

• I'm kinda wondering how Aspro managed to copy a URL with two redirects, rather than the target [2]. —Tamfang (talk) 05:32, 14 October 2015 (UTC)

I'm confused here. If the demon can't beat normal physical limitations, the question is reducible to "what could a crazy little girl on PCP do?" which I don't know the answer to but recognize is answerable. But if the demon can marionette muscles with demonic strength, then it can pull on them from the insertion end, or pull on the bone directly, and the muscle strength doesn't matter; it could pull on bones from multiple points so the bone's strength doesn't matter either, etc. It looks like you want the answer to the reduced question, but if that's so, let's reduce it to that answerable condition. Wnt (talk) 21:21, 13 October 2015 (UTC)

I agree - if the demon can exert supernatural force, then the strength of bone and muscle don't matter. The demon can apply force along any points, lines or planes, and functionally make the bone act like titanium and the muscles as strong as kevlar or whatever you want. Likewise, if a demon should decide, he could copy the golden gate bridge out of cooked ramen noodles and have the noodly version be equally strong. Such is the nature of supernatural force, if the author so desires. OP may be interested in perusing plot device, including deus ex machina. We have an article on shoulder angel but nothing corresponding to a cacodemon. We do have an article on demonic possession. SemanticMantis (talk) 22:00, 13 October 2015 (UTC)

(EC) Not to detract anything form the above answers, but since your question seems to assume demonic/spiritual possession is possible, it requires an answer derived from spiritual beliefs, not science. Worldwide, wherever demonic/spiritual possession is believed possible, it is considered a supernatural phenomenon (or, in the case of most Christian systems, preternatural). Just as an un-embodied spirit can affect the physical world by knocking things off shelves, causing illness/accidents/etc, using their "powers" or "energy", the girl's apparent physical strength in your example wouldn't be limited by her muscles or bones because it is really a result of the supernatural powers (or preternatural knowledge) of the demon/spirit and doesn't come from the girls body at all.--William Thweatt ^TalkContribs 22:11, 13 October 2015 (UTC)

Muscle spasms (specifically opisthotonos) in a person with tetanus. Painting by Sir Charles Bell, 1809.

According to our article on tetanus, the muscular contractions can cause bone fractures. μηδείς (talk) 01:09, 14 October 2015 (UTC)

Thanks, Wnt made a good point above in particular.--93.174.25.12 (talk) 16:37, 14 October 2015 (UTC)

I'm reading the OP's question a little differently from some of the other commenters above; I perceive that they are presenting a scenario in which the demon has supplanted the girl's control of her own body and is not subject to all of her sense of self (nocireception, sense of body integrity, concern for the body's well-being, ect.) but otherwise exerts no supernatural augmentation or control over the body in the sense of Newtonian force of any sort. That is to say, the demon is "pulling her strings" only in the sense that a hypothetical brain parasite might.

Proceeding from this assumption, only a broad answer can be made without knowing more about the degree of the demon's control. For example, does he have complete control of every cell in her adrenal gland? Does he have to use normal physiological mechanisms to control motor function? Does he have control of the body only to the extent that an average person has control of theirs? Or can he manipulate every aspect of the girl's neurochemistry and her endocrine system? If the latter, and he had no concern for the long-term condition of the body, then he could theoretically perform feats of strength well beyond the girl's normal capabilities, for a short period of time. There's a lot of potential energy in the human body, relative to that which is utilized in a given moment by a human individual programmed by genetics for self-preservation.

So yes, I have no problem envisioning such a body (in which the demon has complete control of the mechanisms available to each cell) performing acts similar to reports of "hysterical strength" (though many of the reports of actual hysterical strength are, as Steve implies, questionable), though the biophysical limits to bone, muscle, and especially fascia would limit the duration of this frenzy considerably, as would organ failure, depending on how the metabolic/catabolic functions of specific tissues were altered. Of course, you then have to account for how the demon triggers those normal cellular functions, which I suppose in no less an ambiguous and nonsensical set of supernatural acts than the demon who controls the girl with purely mechanical force.

Alternatively, if the demon only has control of the girl's motor function and a disregard for her safety, then the body would only be capable of marginally larger feats of strength (though conceivably strong enough to take on the two adult attackers as in the scenario you posit -- afterall, there are very small people who with the right training and knowledge have proven capable of taking on multiple larger opponents). Snow ^{let's rap} 05:59, 16 October 2015 (UTC)

Titration question

A simple titration question. In a lab I performed for school, we were given 0.010 L of 0.25 M HCl solution and had to titrate the solution with a solution of NaOH of unknown molarity. Of course, since both are strong acids/bases, and we experimentally find the volume NaOH needed, then we can find the molarity of the NaOH solution since at equilibrium, the moles of HCl = the moles of NaOH. However, before performing the titration, we were told to add "approximately" 0.020 L of water to the HCl solution. My question is, if the solution of HCl now has a greater volume for the same amount of moles of HCl, wouldn't we expect the concentration of the HCl be less afterwards? Then the calculations we used would be wrong. Why, then, are we able to use the original concentration and volume of the HCl for the calculations? Thanks! 70.54.112.243 (talk) 22:24, 13 October 2015 (UTC)

The concentration of HCl would indeed be decreased, but the total amount of Cl- ion would be the same. Therefore, the amount of Na+ to titrate it would be the same.

However, you are right to feel suspicious, because any system shy of a perfectly strong acid and perfectly strong base with an indicator dye changing at precisely pH 7 is going to have its idiosyncrasies explored when you dilute it. To the extent that any HCl diatomic molecule exists in solution, there will be more of it formed when [H+] is high (before dilution) than when it is lower (after dilution). And if the indicator dye changes color at pH 5, then if you add a really huge amount of water, you could even make it turn without adding any NaOH! Still, for the actual laboratory exercise, going a drop too far or failing to mix perfectly as you are going along has more effect than such considerations. Wnt (talk) 01:26, 14 October 2015 (UTC)

Molecular HCl doesn't exist in water solutions, at least not at any concentration to throw of any such measurements. Also, even if this was done with a weak acid, like acetic acid, the stoichiometry would remain identical; because the dissociated acid is in equilibrium with the undissociated acid, it doesn't matter how much of each exists in the solution. Whatever you react away gets replaced anyways (Le Chatelier's principle), so adding water doesn't change the situation either. The ONLY thing that matters is the moles of reactants, and the moles of reactable acid (HCL) added initially is not altered by adding or subtracting water to the solution. There will be some minor variations in actuality (due to things like the autoionization of water, etc.) but these variations are literally too small to measure, on the order of differences of +/- 0.0000001, and I know of no measuring device which has tolerances to that range, so we can literally ignore them and they would not alter our expected results. --Jayron32 12:33, 14 October 2015 (UTC)

You're right that it's a hypothetical point in this case. What I mean is that if you look at a titration of acetic acid curve like this one, you see that catching it at the equivalence point requires you to have an indicator dye that changes at just the right pH (unless you're graphing pH readings directly, as they are). If you're using something that is a little off, the value you get will be off, but how much it is off will depend somewhat on the total volume. Wnt (talk) 13:03, 14 October 2015 (UTC)

Oh, there's a big difference between a titration curve and the stoichiometry of the reaction. Overall, the number of moles of the acid in question will not change, so it does not affect the stoichiometry, however the specific pH at a specific point along the reaction pathway as one adds one reactant to the other incrementally will be different depending on concentration and strength of the acid and base, as well as the actual pH (but not stoichiometry) of the end point. I guess the question remains what is the OP calculating. If one is just calculating "how much NaOH is needed to react with a given amount of HCl", then the water doesn't matter, and doesn't need to be taken into account in the calculations. If the question is "What is the pH of the mixture after X NaOH has been added to Y HCl", then that calculation DOES require one to include the TOTAL amount of water, since pH is a concentration measurement, and concentration is volume dependent. --Jayron32 13:11, 14 October 2015 (UTC)

Any small difference is going to be greatly overshadowed by human accuracy in reading the buret or determining the color endpoint. shoy (reactions) 13:06, 14 October 2015 (UTC)