Wikipedia:Reference desk/Archives/Science/2017 July 13
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July 13
[edit]Do midwives have knowledge of abortifacients and induce abortions?
[edit]Who actually performs abortions? A surgeon, physician, midwife, or a pharmacist/apothecary? Is the physician traditionally for rich folks but the apothecary is for poor folks and the midwife is for women? 50.4.236.254 (talk) 01:16, 13 July 2017 (UTC)
Off topic. The gist is the OP should use the encyclopedia more, and a lot of people like Wiki-policy too much. |
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The following discussion has been closed. Please do not modify it. |
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Recommended reading: Midwife, Abortion. Blooteuth (talk) 15:51, 13 July 2017 (UTC)
- Midwives don't do abortions. Their role is to assist in standard childbirth. Abortionists do abortions. âBaseball Bugs What's up, Doc? carrotsâ 21:25, 14 July 2017 (UTC)
- I guess as a tautological statement, that's true, but "abortionist" is not a title or occupation used anywhere in the world, that I'm aware of, except in reference to unlicensed/"back alley" procedures, perhaps. In most of the world where the procedure is legal and regulated (and even in many nations where it is illegal) abortions are performed by a medical doctor (they could possibly be a surgeon or a general physician, but they are likely to be specialists in obstetrics).
- You are actually mistaken that midwives never perform abortions; in many developed countries they do. In fact, a Swedish midwife very recently went before the European Court of Human Rights, asserting unfair dismissal from her position as midwife after she was terminated for refusing to perform abortions, for religious beliefs. But part of this is a matter of variation in nomenclature and licensing schemes; midwives are not licensed to perform abortions in the U.S., for example. And given the focus of their work, I would speculate that most would not want to (though no small number of them will have provided assistance in a miscarriage at some point in their career). Pharmacists do not perform abortions (not legally anyway), though most would have the knowledge of how to trigger one with medication, though this would be very dangerous, especially outside a controlled environment and not under the guidance of someone trained in the procedure.
They like careful answers as well as careful questions, but this is still off topic here |
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The following discussion has been closed. Please do not modify it. |
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What to do if you asked two experts and they have conflicting opinions?
[edit]If you don't know much (or nothing at all) about some issue, but have to take a decision: what to do if you asked two (or more) experts and they have conflicting opinions? --Hofhof (talk) 17:56, 13 July 2017 (UTC)
- Then you, yourself, can either a) seek more information or b) remain agnostic on the decision, that is, take no stance yourself. In formal statistical logic, this is called the Principle of indifference, and holds that you should believe that each person has a 50% chance of being correct, i.e. you should think that neither is more right than the other until more evidence comes along from other sources. Or, you have no reason to do anything. It is rare that exactly two, and no more, equally respected people are sufficiently knowledgeable in that subject. That is, you always have more than two opinions usually (except, perhaps, the Schleswig-Holstein Question, but I think there you had at least 3 people who knew about it). From a philosophical point of view, what you're asking about is an abstract version of Buridan's ass perhaps. Since you're speaking in the abstract, I'm not sure what help we can give you except to direct you to vague philosophical concepts. If you gave us the specific conundrum you face, we could perhaps direct you to more information on it to break your indecision. --Jayron32 18:30, 13 July 2017 (UTC)
- We have a nice article on decision theory, SEP's article [2] is better. There's statistical methods, bayesian and frequentist inferential methods, etc etc. Here's [3] a freely accessible older but well-cited scholarly article on the topic of behavioral decision theory. One key distinction is to separate normative from descriptive branches of study. "deciding agents should do this" is a very different from "this is what deciding agents are observed to do." While this theory has some application in systems science and Management_science, it also has implications for AI design, control systems, expert systems, etc. If you can give us more context you might be a better answer but this is a huge field of inquiry, and there is no one correct answer, either from normative or descriptive points of view. It's all well and good to remain uncertain or seek more information, but in the real world, no decision is often worse than a bad decision, and things have to be decided with only partial information and consensus. SemanticMantis (talk) 18:38, 13 July 2017 (UTC)
- Thanks for the answers so far. I was asking from a general point of view, but I have an interest in complex practical issues like the security of my PC or personal investing. Hofhof (talk) 18:55, 13 July 2017 (UTC)
- I can't give a reference but I use the 3 P's. Possible, Plausible and Probable. If it fails any of these I'm dubious. 41.13.198.49 (talk) 20:00, 13 July 2017 (UTC)
- You bring the two experts together, and get them to talk it through. Then you will have three opinions. Wymspen (talk) 20:05, 13 July 2017 (UTC)
- In science expert opinion counts for nothing. The whole point of the scientific revolution a few centuries ago was to reject any arguments from authority (X says Y, and X is a well respected expert so Y must be true). We stopped doing that since about the 17th century and in the few centuries that have passed, the entire World got transformed into the modern technological world. But we have evolved over hundreds of thousands of years to respect authority, so the scientific method is not the way we intuitively think. Count Iblis (talk) 20:25, 13 July 2017 (UTC)
- That is quite wrong. The motto of the Royal Society is indeed Nullius in verba, but that is a statement of principle, not of practical operation. Expert opinion is not sacrosanct, and ancient authorities are even less so, but of course expert opinion has significant weight. Why else hire expensive professors to do the teaching when the word of a bum of the street has the same weight? Things don't go into the scientific canon because Professor X says so. But he is probably a good candidate to tell you what is currently widely accepted, and possibly even why. --Stephan Schulz (talk) 22:00, 13 July 2017 (UTC)
- Also notice that my question was about using knowledge that already exists. It was not about obtaining scientific knowledge from nil.Hofhof (talk) 02:58, 14 July 2017 (UTC)
- Well I can give one bit of advice. Do not listen to the experts, and do not look at the experts, just read what they say and then make the decision. Dmcq (talk) 22:15, 13 July 2017 (UTC)
- The Delphi method is a formal way to do this. -Arch dude (talk) 00:16, 14 July 2017 (UTC)
- It also depends on the nature of the question. In your example of PC security there are some well established principles that experts agree on (e.g., don't use a dictionary word as a password) while other ideas have less agreement (e.g., whether requiring frequent password changes is a help or hindrance to security). Shock Brigade Harvester Boris (talk) 03:31, 14 July 2017 (UTC)
- you may use the old (Odysseus') method of dealing with "Between Scylla and Charybdis" issue: opt to pass by Scylla and lose only a few sailors, rather than risk the loss of entire ship in the whirlpool; same as minimax. This is the basis of insurance: rather incur a certain moderate loss, than a chance to lose everything. If no insurance can be given and even "moderate" loss is too heavy, just go boldly to charybdis and hope for the best. Gem fr (talk) 06:24, 14 July 2017 (UTC)
- Consult more experts, until you see a consensus emerge.
- In some cases, you should then decide for yourself, based on the evidence. For example, if you are on a jury and the case depends on a finger-print ID, and the defense has an expert claim that he's 100% certain that's not a match with the accused, while the prosecution puts forth an expert that says he's 100% sure it is a match, I'd suggest you look at it and decide for yourself. StuRat (talk) 19:06, 14 July 2017 (UTC)
- Err, no. You are not an expert in the subject of fingerprints (unless you actually are). If two expert witnesses polarizingly disagree, as a juror you ignore their evidence entirely and the benefit of the doubt goes to the accused. Akld guy (talk) 22:30, 14 July 2017 (UTC)
- That would mean the defense only needs to pay off a so-called expert to lie, and their man goes free. Fingerprints have the advantage, unlike DNA, that whether two prints match is something a juror can hope to decide on their own. More generally, one side will always trot out "experts" who are paid to lie for their side, so it's important NOT to just say "well, there's an argument on both sides, so let's do nothing", as in the case of cigarettes causing cancer, and now man-made global climate change. StuRat (talk) 22:40, 14 July 2017 (UTC)
- Why did you single out the defence? Isn't the prosecution just as likely to call a witness who is prepared to lie? That's what jurors are for; to determine who to believe. See List of miscarriage of justice cases. Akld guy (talk) 20:58, 16 July 2017 (UTC)
- I agree that they are just as likely to lie, this is why I wouldn't rely on either expert in cases where the jury can decide things for itself. That's why they are there, after all. This, BTW, is one reason I find DNA tests troubling, that if the "expert" witnesses lie, there's no way for the jury to tell, unlike if they say two fingerprints match when it's obvious to the jury that they don't. At the very least, there should be rather extreme penalties for experts lying under oath, but prosecutions for this are few and far between. StuRat (talk) 02:17, 17 July 2017 (UTC)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d8/EgyptphoneKeypad.jpg/220px-EgyptphoneKeypad.jpg)
- I was serving on a jury at Crown Court and the prosecution lawyer mentioned that the accused had lined up as no. 6 in an identity parade but the witness had pointed to no. 7 on the cards in front of him. After the lunch break I passed a note to the judge pointing out that in Arabic (the witness was a Muslim) the number "six" is written "7". We were immediately sent home for the day, and the following morning were told the case was still not ready to proceed. Finally the court reconvened and we heard from an expert witness who had been called to introduce the new evidence. So it's not necessarily best to keep quiet. 92.19.185.111 (talk) 14:21, 15 July 2017 (UTC)
Temperature at which water vapour forms
[edit]I put a pot of cold water on the cooktop and turn it on. The water starts to heat up. Well before the water boils, steam (or water vapour) starts to rise from the water. At exactly what temperature does this occur, and what is the significance of this temperature? -- Jack of Oz [pleasantries] 21:54, 13 July 2017 (UTC)
- It's not a single temperature. At any temperature, the molecules of water have an average kinetic energy, but the energy distribution follows a particular formula (for ideal gases it's the MaxwellâBoltzmann distribution, but I'm not enough of a physicist to know which one applies to liquids). In this distribution, some molecules will have enough energy to overcome surface tension and leave the liquid phase. The higher the temperature, the more molecules will be able to do so, but there will be some at any temperature. --Stephan Schulz (talk) 22:08, 13 July 2017 (UTC)
- I see. So, there are molecules spontaneously separating out of any container of water (or any liquid?) sitting at room temperature, but we can't see them because there's not enough of them; it's only when their volume increases under the effect of heat that we can see them. I get that. -- Jack of Oz [pleasantries] 04:09, 14 July 2017 (UTC)
- Almost. You can't see the molecules because water vapor is a colorless gas. You can only see water when it is a liquid or solid. The water vapor mixes with colder air above pot and condenses to form tiny liquid droplets that you can see. Shock Brigade Harvester Boris (talk) 04:30, 14 July 2017 (UTC)
- One possible answer to Jack's original question would be that you can see the visible fog when you get the vapor pressure high enough that the humidity above the pot rises enough that the dew point
drops belowrises above the ambient temperature. However the relationship between vapor pressure and humidity may be complicated. --Trovatore (talk) 05:34, 14 July 2017 (UTC)
- One possible answer to Jack's original question would be that you can see the visible fog when you get the vapor pressure high enough that the humidity above the pot rises enough that the dew point
- Almost. You can't see the molecules because water vapor is a colorless gas. You can only see water when it is a liquid or solid. The water vapor mixes with colder air above pot and condenses to form tiny liquid droplets that you can see. Shock Brigade Harvester Boris (talk) 04:30, 14 July 2017 (UTC)
- I see. So, there are molecules spontaneously separating out of any container of water (or any liquid?) sitting at room temperature, but we can't see them because there's not enough of them; it's only when their volume increases under the effect of heat that we can see them. I get that. -- Jack of Oz [pleasantries] 04:09, 14 July 2017 (UTC)
- See vapor pressure. As the temperature rises, the vapor pressure does as well, until it reaches the ambient pressure, which is when the water boils (that's slightly simplified; see nucleate boiling).
- As a side note, the visible white "steam" or "water vapor" is neither â it's actually (tiny drops of) liquid water, condensed from the water vapor as it hits cooler air. Water vapor itself is invisible, though you might be able to detect it from the change in refractive index. --Trovatore (talk) 00:50, 14 July 2017 (UTC)
- It also happens below the freezing point, as water vapor will sublimate well below the freezing point from solid ice. If you've ever left an ice cube tray in a freezer for a long time, you've already done the experiment to prove this if you've ever noticed the cubes to have shrunk. Here is a table of vapor pressures of ice at temperatures down to -100C. You'll note they are small, but decidedly non-zero. The answer to your question is likely absolute zero, or near enough as to not matter.--Jayron32 03:31, 14 July 2017 (UTC)
- Grr, peeve alert â "sublimate". The perfectly proper and euphonious verb form is "sublime". I don't know when people started saying "sublimate" like it was a repressed memory or something, but I do wish they would stop. --Trovatore (talk) 20:59, 14 July 2017 (UTC)
- It started in 1559 (or earlier) according to the OED, long before Freudian theory. Dbfirs 21:25, 14 July 2017 (UTC)
- The OED is a sublime work. -- Jack of Oz [pleasantries] 23:26, 14 July 2017 (UTC)
- It started in 1559 (or earlier) according to the OED, long before Freudian theory. Dbfirs 21:25, 14 July 2017 (UTC)
- Grr, peeve alert â "sublimate". The perfectly proper and euphonious verb form is "sublime". I don't know when people started saying "sublimate" like it was a repressed memory or something, but I do wish they would stop. --Trovatore (talk) 20:59, 14 July 2017 (UTC)
- It also happens below the freezing point, as water vapor will sublimate well below the freezing point from solid ice. If you've ever left an ice cube tray in a freezer for a long time, you've already done the experiment to prove this if you've ever noticed the cubes to have shrunk. Here is a table of vapor pressures of ice at temperatures down to -100C. You'll note they are small, but decidedly non-zero. The answer to your question is likely absolute zero, or near enough as to not matter.--Jayron32 03:31, 14 July 2017 (UTC)
- You can tell that some of the water in the pot becomes vapor even at room temp (provided the relative humidity in the air is less than 100%), because the water will all eventually evaporate. And, technically, some of it still evaporates even at 100% humidity, but just as much water condenses in the pot from the air, so the equilibrium is maintained. StuRat (talk) 21:21, 14 July 2017 (UTC)
Is the wrapper by Klondike ice cream made of real aluminum?
[edit]I tried to google it. But I couldn't find any results of the material of the wrapper. Is the wrapper made of real aluminum foil? Can it be used instead of buying aluminum foil? 50.4.236.254 (talk) 23:12, 13 July 2017 (UTC)
- Supposing it were (and I'm not at all convinced of it), would it be worth the bother of having to wash the thing before using as if it were aluminum foil? And it's pretty small, so its application would be limited. One thing you could try (very carefully) is to put a match to it and see if it burns. I suspect it's as much paper as anything else. âBaseball Bugs What's up, Doc? carrotsâ 23:32, 13 July 2017 (UTC)
- Sterile inoculating loops are used to culture plates. They can be made of plastic, which is disposable, or can be made of metal, which must be sterilized over an open flame before use. If one holds the metal loop long enough in the flame, then the loop will glow red. So, does that mean metals will glow red while paper combust? What if the wrapper is part aluminum and part paper? 50.4.236.254 (talk) 00:06, 14 July 2017 (UTC)
- Note that aluminum burns; in fact, all aluminum foil is covered in aluminum oxide (Al2O3, the basis of the mineral corundum, from which gems are made). It makes it able to scratch things you probably don't want it to. Atomized aluminum is fun stuff; you can mix it with perchlorate or chlorate or the like (solid sources of oxygen, basically) for flash powder (fireworks...). Of course, I would not tell you to do so, since celebrating the 4th of July in the old fashion would make you a terrorist... Anyway, point is you can more or less dispose of aluminum foil in a fire (leaving behind some residue), making this a bad test really. Wnt (talk) 01:36, 14 July 2017 (UTC)
- Good point. What I had in mind was some kind of test using the wrapper instead of foil. Like, for example, baking a (very small) potato in it. âBaseball Bugs What's up, Doc? carrotsâ 08:24, 14 July 2017 (UTC)
- Note that aluminum burns; in fact, all aluminum foil is covered in aluminum oxide (Al2O3, the basis of the mineral corundum, from which gems are made). It makes it able to scratch things you probably don't want it to. Atomized aluminum is fun stuff; you can mix it with perchlorate or chlorate or the like (solid sources of oxygen, basically) for flash powder (fireworks...). Of course, I would not tell you to do so, since celebrating the 4th of July in the old fashion would make you a terrorist... Anyway, point is you can more or less dispose of aluminum foil in a fire (leaving behind some residue), making this a bad test really. Wnt (talk) 01:36, 14 July 2017 (UTC)
- Sterile inoculating loops are used to culture plates. They can be made of plastic, which is disposable, or can be made of metal, which must be sterilized over an open flame before use. If one holds the metal loop long enough in the flame, then the loop will glow red. So, does that mean metals will glow red while paper combust? What if the wrapper is part aluminum and part paper? 50.4.236.254 (talk) 00:06, 14 July 2017 (UTC)
- Klondike does not publish what the wrapper is made of (except for the news about changing from metallic to plastic wrappers). However, there are tariffs on many items, including metallic wrappers. So, Klondike had to explain exactly what their wrappers were made of. If you check this, you will see a brief description of exactly how much aluminum is in the Klondike wrapper. 209.149.113.5 (talk) 12:41, 14 July 2017 (UTC)
- Very impressive answer! But to be clear, was your approach simply to go to customsmobile.com and search for rulings that contained Klondike wrapper - is that a general enough approach to find most brand products? - or is there a higher-level search mechanism that led you to this site? Wnt (talk) 21:19, 14 July 2017 (UTC)
- I knew that there was tariff issues on candy with metallic wrappers. So, I googled Klondike wrapper tariff. I hoped to see if there was a tariff and if it fell under aluminum. The first two hits were about switching to plastic wrappers to avoid tariffs. The third explained how much aluminum was used in detail. 71.85.51.150 (talk) 01:09, 15 July 2017 (UTC)
- Very impressive answer! But to be clear, was your approach simply to go to customsmobile.com and search for rulings that contained Klondike wrapper - is that a general enough approach to find most brand products? - or is there a higher-level search mechanism that led you to this site? Wnt (talk) 21:19, 14 July 2017 (UTC)