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October 19

Science and translating ideas into English

In science, the best journals are in English. Sure, there are other-language journals, but if a scientist wants better recognition, then an English-language journal is best, and thus, English-language skills are required. Given that other-language papers exist, are there groups that translate foreign ideas into English and vice versa? Or are English-speaking scientists trapped inside their own language circles, not really knowing what other people have discovered in other countries? (Machine translation is still not adequate yet, partly because it fails to understand context and take into account of hidden knowledge.) 50.4.236.254 (talk) 02:08, 19 October 2017 (UTC)[reply]

Scientific writing should translate more cleanly than general writing. There shouldn't be much use of ambiguous terms, slang, or aphorisms. So, while "Put your nose to the grindstone" may well translate as "Grind your nose on a wheel", that doesn't mean that "Add 5.8 mg of ethyl alcohol" won't machine translate properly. Therefore, the machine translation should be enough to get started, but if they are going to spend a lot of time with a foreign-language source, then a human translation would be a good idea. StuRat (talk) 02:12, 19 October 2017 (UTC)[reply]

In the fifties my mum did a chemistry degree at a uni in London, and was required to write her final year paper in German, since most of the chemistry papers were in German. So I guess my answer would be, why would anyone publish a paper in any other language than English, if their aim was to disseminate knowledge globally? or even get cited? Greglocock (talk) 03:16, 19 October 2017 (UTC)[reply]

Not every work of science is aimed at the entire global audience. Nimur (talk) 03:45, 19 October 2017 (UTC)[reply]

There is an immense and lucrative commercial market for technical translation services. Anecdotally: at one point in my career, I was able to earn more money translating other people's research documents into and out of the English language than I could possibly have hoped to earn by selling my own research on the commercial market. In my experience, such specialized services were expensive, so the resulting papers were not redistributed as free content. This might be a contributing factor to explain why our OP doesn't see such material.

For perspective: a good book, in the English language, on the scientific and engineering discipline of geophysical prospecting costs between $20 and $500. Here's one of the classics, available via Amazon for about $20.

But, if your audience consists of Spanish-speaking geoscientists: no amount of United States dollars can buy the Spanish language version of the book you might want [1]. You will have to commission a technical translator, at cost. Consider that there is an enormous community of fluent Spanish-English translators - but unless you're throwing copyright to the wind, your translated copy will be more expensive than the work in its original language. Somebody has to pay the translator.

If your translation was a single document, and not a whole book, here's a whopper - totally true retail price to translate an academic publication between Japanese and English - one technical paper - begins at a discount member price of over one thousand U.S. dollars with a few weeks turn-around time. This is what I would call amazingly cheap by industry standards. And if you need the paper now - today - not in two weeks - sales agents are standing by to price it for you!

Did you ever wonder how the Lexus ES assembly line workers at the factory read the proverbial "blueprints" explaining how to actually build the vehicles? Hint: the design engineers in Aichi Praefecture do not expect the plant workers in Kentucky to develop proficiency in the Japanese language. Somebody, somewhere on this planet, at some layer of abstraction in the engineering and development process, must translate the technical documents.

There exist other parts of the world where the community of fluent bilingual technical experts is considerably smaller, but there's always a (small) community of people who need to know what scientists are saying in those languages. Here's some free career advice for the young'uns in our reading audience: get a good, solid degree in a hard STEM field like chemistry or physics or chemical engineering, and develop expert-level proficiency in Korean, or Dari, or Pashtun. I hear that there's an immediate need for Levantine Arabic speakers.

Nimur (talk) 03:57, 19 October 2017 (UTC)[reply]

Usually to get a graduate degree in science (don't know about humanities but likely similar) you have to demonstrate some reading capability in a couple of other languages. I'm not fluent in anything but English but if I look at a science or math paper in a European language I can usually figure out what it says. And while machine translation can't produce a publishable finished product, the stuff that comes out is usually good enough for a patient reader to understand what it means. 173.228.123.121 (talk) 05:22, 19 October 2017 (UTC)[reply]

Just a note to say that language proficiency requirements like you describe are an American thing. Here in the UK they do not exist, and on the continent, the only requirement is for good English proficiency usually. Fgf10 (talk) 07:45, 19 October 2017 (UTC)[reply]

Ditto for New Zealand. In Malaysia your English level tends to be much more important although I believe you will generally be required to have some level of Malay (for Malaysia students you generally need a good enough level for admission as established by local secondary school results, for foreign students without these results you probably have to pass a basic course e.g. [2]). Nil Einne (talk) 13:01, 19 October 2017 (UTC)[reply]

Non-English language requirements used to be a thing in science, but the American university science programs that I know well all discontinued them 15+ years ago. Dragons flight (talk) 06:42, 20 October 2017 (UTC)[reply]

Yes seems you're right. I earlier searched and thought I came across some. But I found this weird since I'd never heard of it despite having known people who'd looked into PhDs in the US. Looking more closely now, I realised I didn't look properly at my results. Some say "all students" etc but they are actually from the Department of English or Art History or something. Others are from the graduate school of arts and science or whatever and give you details of how to fulfill it, but they actually say some departments or programmes require it. And I never found any science programmes that do. I think the closest I came across was Science History or something. I'm sure there are a tiny number who still do, but it seems very rare. This [3] suggest it was still quite common for maths in 2005, but even then was not common for the hard sciences. Nil Einne (talk) 07:55, 20 October 2017 (UTC)[reply]

In my experience working in research, the fraction of research that is in languages other than English is so small, and usually of such quality, that it is simply completely ignored. (In my field of neusicence at least). </OR> Note that when articles get indexed on PubMed, non-English articles almost always get a English title at the very least, so you know what they are about. Fgf10 (talk) 07:45, 19 October 2017 (UTC)[reply]

In general basic research in natural sciences is 80-90% in English. And there's no translation of valuable peer-reviewed work into English needed. Serious foreign scientists would publish and hold conferences in English, and very probably use the services of a proofreader, but not of a translator. And the ratio of English to non-English articles is increasing.

Even if the ratio were not so overwhelmingly English, there are abstract services that grant you access (often for free) to a summary of the article.

Things start to get multilingual when you need country-specific information, technical docs (as mentioned by @Nimur above), contracts and so on.B8-tome (talk) 13:12, 19 October 2017 (UTC)[reply]

Does the human body store salt?

I have a question about how vitamins and minerals are stored in the human body. (No, I am not asking what or how many vitamins to take -- this question is about the biology of the human body).

As we all know, if you take large doses of Vitamin C you end up with expensive urine, but if you take large doses of Vitamin D you can get Hypervitaminosis D, because unlike Vitamin C, your body stores excess Vitamin D. But what about salt? If you eat a large amount of salt (a hiker eating a lot of salted Jerky, for example) does you body store it somewhere? Or would you just have extra-salty urine? (Let's assume that you have as much fresh water as you want to drink). If so, where is it stored? --Guy Macon (talk) 03:47, 19 October 2017 (UTC)[reply]

Salt poisoning. Sagittarian Milky Way (talk) 04:05, 19 October 2017 (UTC)[reply]

That's a really helpful page. Thanks! It looks like that page talks about too much salt for the amount of water you are getting. I am wondering about the case where you get too much salt, but you have plenty of fresh water and a raging thirst that comes from eating too much salt. Will the body flush out the salt? (Within reason; I am talking about eating heavily salted meat (along with plenty of fresh water), not just eating a bag of granulated salt.) --Guy Macon (talk) 06:59, 19 October 2017 (UTC)[reply]

Yes, but the process isn't instant, so the person may suffer from sodium sensitive hypertension or other problems until their sodium level returns to normal, and this can cause permanent damage. StuRat (talk) 15:40, 19 October 2017 (UTC)[reply]

Your kidneys excrete excess sodium and chloride. Electrolyte levels have to be kept within a fairly narrow range for you to not die, and doing this is one of the kidneys' main jobs. Inversely, if you don't consume enough sodium (or any other electrolyte), the kidneys pull it back in from the filtrate. See also hypernatremia and hyponatremia. Your body's sodium is mostly located outside cells, in the blood and other extracellular fluid. Sodium is actively pumped out of cells, and potassium in, by the sodium-potassium pump. The body can't really "store" electrolytes, but, as mentioned, it tries to limit excretion of them if intake is insufficient. However, some loss of electrolytes in the urine is unavoidable. In terminal dehydration, the ultimate underlying cause of death is usually cardiac arrest, when electrolyte levels get out-of-whack enough that the heart can no longer beat. --47.138.160.139 (talk) 06:32, 19 October 2017 (UTC)[reply]

Salt dissociates into sodium and chloride ions in water (and in your body, which is mostly water). These ions are stored in your blood, in your cells, and in other fluid compartments. If you take in lots of water and salt, that increases your blood volume and thus your blood pressure, which in extreme cases could lead to a stroke. That's largely theoretical, though--you would have to drink gallons of water which would feel very uncomfortable. Before then, your body will work very hard to remove that water and salt through your urine. C0617470r (talk) 07:50, 19 October 2017 (UTC)[reply]

The human body stores a lot of salt, but in no special place. Born from an ancient dilute-salty sea, it contains [4] 98-106 mEq/L of chloride and 135-147 mEq/L of sodium. Those are monovalent ions, so there is 1 mEq/mmol, and we can multiply by 35.453 and 22.989 g/mol respectively - serum contains 3.47-3.76 grams of chlorine and 3.10-3.38 grams of sodium per liter. Now I have to be less precise after this because intracellular fluid and other things (like fat) in the cells are different, generally with less sodium; see body water and fluid compartments. But if you just consider five liters of blood, that alone contains more than 15 grams of sodium, while some commentators try to encourage people to push salt sodium intake below 1200 mg a day. So we already have a decent reserve built up in our blood against the risk that someone will try to nutrition us. Composition of the human body says that the total amount of sodium in the body is 100 grams for an "average" 70 kg person. (This is still much less than if you took 70 kg * 1 L/kg * 3.2 g/L = 224 g) The prevalence of sodium in the body explains why it would be very strange to make a storage protein for it - unless biology came up with a *really* clever mechanism (which it could), you'd need to make well over 100 grams of protein to store 100 grams of salt! The weight and expense of that much protein would be hard to "justify" in selective terms when all your food contains some sodium and when it often can be found at some level in available water or soil components. Wnt (talk) 13:31, 19 October 2017 (UTC)[reply]

Fatty-acid metabolism disorder

Resolved

In people with Fatty-acid metabolism disorder what happens to the fatty acids which their bodies are unable to oxidize? Do they get excreted or stored as adipose tissue? The article doesn't say. I assume they can't just get stored as adipose tissue indefinitely and never used or excreted because then people with this disorder would presumably gain weight continuously and never be able to lose it. — Preceding unsigned comment added by 103.4.167.238 (talk) 10:33, 19 October 2017 (UTC)[reply]

It says so in the third paragraph near the top. --Jayron 32 13:45, 19 October 2017 (UTC)[reply]

Thanks but that still doesn't really answer the question. The third paragraph says they get sent to the liver and then on to other internal organs, where they can't be used. Then what? They can't just stay there, unused, otherwise people with this disorder would have ginormous internal organs. Maybe I'm just being very stupid but I'm still struggling to understand. Something else has to happen to all these unused fatty acids, they have to go somewhere. They can't be used, so where do they go after that? 103.4.167.238 (talk) 16:10, 19 October 2017 (UTC)[reply]

The second part of the last sentance in that same paragraph says it. It starts with a comma. --Jayron 32 18:48, 19 October 2017 (UTC)[reply]

Either I'm a complete idiot or your web browser is displaying something different to mine because I'm still not seeing where the fatty acids go after they've reached the liver and internal organs where they can't be used. The third paragraph displays in my web browser as;

If left undiagnosed many complications can arise. When in need of glucose the body of a person with a fatty-acid metabolism disorder will still send fats to the liver. The fats are broken down to fatty acids. The fatty acids are then transported to the target cells but are unable to be broken down, resulting in a build-up of fatty acids in the liver and other internal organs.

The last sentence in that paragraph after the comma displays to me as;

, resulting in a build-up of fatty acids in the liver and other internal organs.

There is no further explanation of what happens after they have reached the liver and internal organs that I can see. Can you copy and past it here for me if you are seeing something more there? The fatty acids surely cannot just indefinitely build up in the liver and other internal organs because fatty acids are constantly being ingested with every meal every day even if a person follows an ultra low fat diet. 103.4.167.238 (talk) 19:06, 19 October 2017 (UTC)[reply]

They build up there. Which means they accumulate. Which means they stay there and just be there. --Jayron 32 11:19, 20 October 2017 (UTC)[reply]

Many of the bodily wastes are in the end finally in fact simply exudated. --Askedonty (talk) 14:05, 19 October 2017 (UTC)[reply]

103.4.167.238, Fatty-acid metabolism disorder#Carnitine/transport explains: the fatty acids are transported by carnitine, and defects in this process are associated with several disorders. The associated scientific paper linked to, DISORDERS OF CARNITINE TRANSPORT AND THE CARNITINE CYCLE will give you some precisions: Deficiency of the OCTN2 carnitine transporter causes primary carnitine deficiency, characterized by increased losses of carnitine in the urine and decreased carnitine accumulation in tissues. The paper focuses on deficiencies related to carnitine. Note that Fatty_acid_metabolism#Dietary sources of fatty acids, their digestion, absorption, transport in the blood and storage marks the limits of currently available information in the near of that area: "All cells in the body need to manufacture and maintain their cell walls and the membranes of their organelles. Whether they rely for this entirely on free fatty acids absorbed from the blood, or are able to synthesize their own fatty acids from the blood glucose, is not known". --Askedonty (talk) 19:35, 19 October 2017 (UTC)[reply]

Thank you for explaining. 103.4.167.238 (talk) 21:11, 19 October 2017 (UTC)[reply]

Carnitine palmitoyltransferase I deficiency, one of the listed Fatty-acid metabolism disorders features as one of the causes associated with Hepatomegaly indeed. I'm putting in a request for advice at Wikipedia_talk:WikiProject_Molecular_and_Cell_Biology on wether some definitions might need widening, or others some narrowing in the series of articles concerned perhaps. Thanks to you, for helping us improve the encyclopedia.-- Askedonty (talk) 10:33, 20 October 2017 (UTC)[reply]

According to [5], "Reducing CPT-1 activity, and thereby fatty acid oxidation, with glibenclamide should lead to a shunting of acyl-CoA esters to lipid esterification products. That this indeed occurs in the sulfonylurea-exposed islets is amply illustrated in Fig. 4...." A product they look at is diacylglycerol. I haven't worked out all the biochemistry and I don't know what other routes the lipids are cleared by, but it's sort of interesting to see that a class of antidiabetic drugs works by mimicking this disease in the beta cells (they note that genetic CPT1 deficiency causes hypoglycemia also) Wnt (talk) 14:24, 20 October 2017 (UTC)[reply]

Unidentified bird

What is this bird? I found the image without any context as to where it was taken, so unfortunately I can't supply a location. 169.228.153.251 (talk) 15:29, 19 October 2017 (UTC)[reply]

I'm fairly certain it's a dollarbird. Most have orange beaks, but some subspecies and color varients have brown beaks like the one shown, I think it's a juvinile of some sort, which have the brown (rather than orange) beaks. Compare to some pictures at http://identify.what bird.com/obj/1234/overview/Dollarbird.aspx (take out the space between what and bird. It's blacklisted for some odd reason), especially the lower right one in the grid. That website, is a decent resource for finding unknown birds. --Jayron 32 15:57, 19 October 2017 (UTC)[reply]

That looks like a match to me, thank you! I suspected the bird was a juvenile because of its uneven-looking plumage. 76.80.178.3 (talk) 00:55, 20 October 2017 (UTC)[reply]

The beak looks wrong for that identification - the very wide mouth with a small hook on the upper beak makes me think you have one of the Caprimulgiformes (nightjars, frogmouths, etc) but I don't know which one, and there are too many to search through without knowing a bit about where it was found. Wymspen (talk) 15:33, 20 October 2017 (UTC)[reply]

I have to go with a possible Roller, like the Dollarbird. The legs look more like a near-passerine than a caprimulgiform, although I see the resemblance to the latter group in the mouth. The latter usually have shorter legs and bodies that look less like perching birds. This looks like a songbird-relative with a mouth convergent on the nightjar family. Also, juvenile birds usually have wider gapes to cadge food. μηδείς (talk) 22:27, 20 October 2017 (UTC)[reply]

Immune System

I have questions regarding the immune system (ex. main structures and cells), Thanks! — Preceding unsigned comment added by 24.88.84.255 (talk) 20:49, 19 October 2017 (UTC)[reply]

There is a lot of information in our article Immune system and in the linked references. Do you have questions that are not answered there? Dbfirs 21:19, 19 October 2017 (UTC)[reply]

October 20

What is a "nucleated brain"?

I'm auditing a class on Evolution of the Human Brain. Most of the people in the class have a much deeper knowledge of biology than I do so there are some questions I feel aren't appropriate to ask (or I'm egotistical and just don't want to look dumb). A while ago some people here helped me out with a question I had about neurotransmitters. Here is another one. Every once in a while when the professor is talking about non-human animals, and also (I think) about non mammals he says they have "nucleated brains". In a recent lecture talking about the history of early neurobiology and the work of Marie Jean-Pierre Flourens on birds he said (reconstructed from notes but I think this is accurate):

"the more telencephalon was damaged the more the animal was impaired... he said that the size of the ablation correlated with the extent of the problem but the localization within the telencephalon didn't effect specific functions... it [the bird brain] is not organized in maps the way the mammal brain is, remember that the bird brain is NUCLEATED, damage to the bird brain is not going to be as localized as in mammals"

I get the point that mammal brains are more likely to show damage to specific functions due to where a lesion occurs (e.g. vision in one area hearing in another) but I don't understand what the professor means when he says that bird brains (and I think he says this of all brains that don't have cerebral cortex, i.e., most non mammals) is nucleated. I looked up nucleated and found the definition for individual cells but I don't think that is what he means here. --MadScientistX11 (talk) 17:45, 20 October 2017 (UTC)[reply]

Nucleus (neuroanatomy)? --Jayron 32 17:48, 20 October 2017 (UTC)[reply]

I think the basic distinction here is between brain areas where the neurons are organized into two-dimensional sheets and areas where they are organized as three-dimensional "nuclei". Actually all types of animals have both types of brain areas -- in mammals, for example, the cerebral cortex is layered but the basal ganglia have a nuclear organization. However, there are some areas of the bird brain that have a nuclear organization but appear to correspond with areas of the mammal brain that are layered. The most important example is the dorsal ventricular ridge, which is nuclear in structure but is thought, by at least some anatomists, to correspond to at least part of the mammal cerebral cortex. Looie496 (talk) 19:07, 21 October 2017 (UTC)[reply]

(Wow, how can that be a red link? Gotta fix that! Looie496 (talk) 19:09, 21 October 2017 (UTC))[reply]

Death toll due to anti-vaccin movement

I am looking for reliable sources for this number. I have located this, however, it does not cite any source.

An ideal account would be based on death toll in the industrialized countries only from preventable disease, because that's where vaccines availability is high so any death due to preventable-by-vaccine disease is sure to be through lack thereof. אילן שמעוני (talk) 18:53, 20 October 2017 (UTC)[reply]

Have you looked at the FAQ section of the page you pointed at? It is got at by a link at the top. It seems to use the sorts of sources you talk about. Dmcq (talk) 19:21, 20 October 2017 (UTC)[reply]

Thank you! I have missed that. אילן שמעוני (talk) 21:54, 20 October 2017 (UTC)[reply]

There are age limits to giving vaccines, possible failure to develop or sustain antibodies and also cases of immune-system deficiency and allergies which may prevent vaccine usage even where the is high vaccine availability which are reasons that herd immunity is important. We cannot be certain a death from a vaccine-preventable disease is due to anti-vax intentions. Rmhermen (talk) 17:07, 21 October 2017 (UTC)[reply]

While true, the best way to estimate the damage is comparing the number of deaths from preventable disease (through vaccines) before and after the anti-vaccine movement. The figures I located so far suggest 2 magnitudes increase, which make the CDC numbers reliable with only few percents margin. Thanks for the input. אילן שמעוני (talk) 18:27, 22 October 2017 (UTC)[reply]

Zero because the anti-vaccine movement doesn't physically prevent anyone from getting vaccinated. They do make propaganda, but they don't have control over the media. So, if people end up not getting the vaccines they need, it is because they didn't get the right education in school. It's not because stupid people are saying stupid things, because that's a factor that's always in play. Count Iblis (talk) 04:05, 22 October 2017 (UTC)[reply]

Misinformation is going to have an effect, no matter how well educated people are to begin with. Unfortunately, the way people judge things to be true is mostly based on how often they hear it, so if those sending out the misinformation manage to get more air time than those with the sensible but boring message, they will convince people. And if the crazy message happens to come from somebody famous, like a former TV actor or reality TV star, then they are even more likely to believe it. If it comes from somebody they never heard of, like a competent scientist, then they ignore it. StuRat (talk) 04:51, 22 October 2017 (UTC)[reply]

Could you leave out the guns don't kill forum type argument and stick a bit closer to the question like Rmhermen did thanks. Dmcq (talk) 10:16, 22 October 2017 (UTC)[reply]

The source is the Centers For Disease Control (see this and following tables [6]) as its source. They also mention that not all death can be computed as caused by anti-vaxx movement. There are other reasons for not getting vaccinated (like being an illegal alien from a third world country). Hofhof (talk) 23:21, 22 October 2017 (UTC)[reply]

October 21

Ternary ideal mixture obtained from non-ideal binaries

Is it possible to get a(n) (almost) ternary ideal solution/mixture from two non-ideal binary mixture with different sign of deviation from ideality: one binary with negative deviation and the other with positive deviation so that the opposite sign cancel each other, thus producing a practically ideal ternary solution? What properties of mixtures data is available for this possibility? (Thanks!)--82.137.11.130 (talk) 21:50, 21 October 2017 (UTC)[reply]

Generally, you would have to consider the deviation from ideality of all 3 binary pairs, so that ΔH_AB + ΔH_BC + ΔH_AC = 0, though there are probably nearly ideal binary solutions where one of the enthalpies of mixing can be ignored. I'm not sure that what you propose is possible, but here are some references that might get you started (with a lot of work) from a mathematical angle: this [7] from here [8] talks about the thermodynamics of non-ideal solutions and what some of the non-ideal terms mean. This [9] briefly extends the concepts to ternary solutions. This [10] (mostly behind a pay wall) discusses mathematical modeling of non-ideal ternary solutions. Between them, you might be able to get a good idea of what causes non-ideality and how to counteract it.

Solution thermodynamics applies to the solid state as well as the liquid, and is a fundamental study in the field of metallurgy, and more generally materials science (see for example the examples from geology above). Textbooks on metallurgy will have entire chapters devoted to it.

Regarding your second question, there are tables of enthalpies of mixing and heats of solution. Perry's Handbook for Chemical Engineers, 7th Edition, table 2-224 pp.2-201 to 2-203 lists some heats of solution of inorganic compounds.

There may be a much simpler answer to your question, say an example of where this has been accomplished, or at least tried, but so far I haven't found it.--Wikimedes (talk) 22:19, 22 October 2017 (UTC)[reply]

October 22

How does a battery powered pendulum work?

How does a battery operated clock with a pendulum keep the pendulum swinging? I'd like to make something that will keep swinging but keep the mechanism small so it mustn't have any of that nonsense pertaining to time keeping. 185.81.136.19 (talk) 09:16, 22 October 2017 (UTC)[reply]

An Escapement is the way a pendulum is kept swinging to compensate for slowing due to friction. DMacks (talk) 09:28, 22 October 2017 (UTC)[reply]

That's the mechanical method, but are not electromagnetic pulses more common in battery clocks? (Reference needed.) Dbfirs 09:50, 22 October 2017 (UTC)[reply]

There are (at least) two ways:

The simplest and cheapest way for a clock is to have a battery powered clock mechanism, with a pulse motor driven by a quartz clock circuit. This ticks once per second (or twice that). A pendulum is attached and is 'pumped' by the motor, via the clock mechanism. The Q of the pendulum system is very low, so the system is able to run at a frequency far lower than the natural frequency of the pendulum, as the purely decorative pendulum is often far too short. The pendulum plays no part in the timekeeping.

An older version of this was used in cheap spring-wound cuckoo clocks, which used a balance wheel escapement to control timing, but also had a decorative pendulum. Those often needed to have the pendulum manually adjusted to be approximately in synch, otherwise they could run very unevenly.

A different approach is a pendulum that does the timekeeping (as a pendulum) and is driven by a magnetic arrangement. These are very common today, not as clocks but as solar-powered "dancing flowers" (We ought to have an article on these, they have some neat mechanisms). In these, there are two coils in the base, and a magnet on the pendulum. As the magnet swings past the coil, the "sense" coil detects it (a small current is induced in the coil). This triggers the circuit, which is a simple amplifier and which then puts a pulse through the larger "drive" coil, which accelerates the magnet in the pendulum and kicks it. The feedback and timing is controlled entirely by the mechanical pendulum. Andy Dingley (talk) 11:21, 22 October 2017 (UTC)[reply]

Thanks for that excellent explanation, Andy. My battery-powered clock has a quartz oscillator for timekeeping, and a completely independent magnetic pulse circuit to drive the "pretend" pendulum. The clock works with the pendulum stopped. Dbfirs 12:12, 22 October 2017 (UTC)[reply]

I did see a clock a while back which was like a big grandfather clock and had a complicated looking pendulum to compensate for the temperature. It operated off a car battery I think and had wires from it so it could drive secondary clocks elsewhere in time with it. I found [11] which describes something very like it. It hhad a display but I'm not altogether certain it was connected to the pendulum, it might have been a slave clock. Dmcq (talk) 15:11, 22 October 2017 (UTC)[reply]

Was it a Master clock? There are lots still working near to where I live. Dbfirs 16:59, 22 October 2017 (UTC)[reply]

Yes that does describe it well. I had multiple rods in the pendulum rather than the simple looking ones in the article but I guess there must have been quite a number of types. Dmcq (talk) 17:48, 22 October 2017 (UTC)[reply]

A master clock is almost the opposite of what we were discussing here. It's an old idea for a mechanical pendulum clock, controlled by the pendulum's mechanical timekeeping, which then operates switch contacts and in turn drives a number of other clocks. The pendulum clock also electrically powers itself, but this is (like the dancing flowers) just a power amplifier, not a timing regulator. The slave clocks are electrically powered and very simple.

These were found in many telephone exchanges, where they would then drive clocks throughout the building and beyond. They often drove tower clocks (clocks in towers) because this made the clock in the exposed position much simpler and more reliable, keeping the sensitive parts closer to hand. For accuracy they usually had long pendulums but only rarely a gridiron pendulum for temperature compensation. It was more usual to have them themselves synchronised to a more accurate master clock (usually Greenwich), and those clocks would have an automatic synchronising mechanism (a "heart-shaped cam") as well. Andy Dingley (talk) 19:24, 22 October 2017 (UTC)[reply]

Another option is to just keep the pendulum mechanism entirely unpowered and unused for time-keeping. That is, it can use weights to run the pendulum, but not use the pendulum for anything. Thus, you could have the accuracy of a quartz clock with the "old-timey" feel of a pendulum. You could let the pendulum run down, when nobody is around to impress by it, rather than have it use up batteries. Then set the weights when company is coming over. StuRat (talk) 22:08, 22 October 2017 (UTC)[reply]

... only if the guests are making a very short visit! Dbfirs 00:01, 23 October 2017 (UTC)[reply]

A low friction pendulum should be able to continue for several hours, at least. See Longcase_clock#Description, which mentions an 8-day mechanism and a 30-hour mechanism. This one is supposedly on the small side, with corresponding reduction in run time, but shouldn't expend any pendulum energy moving the hands or chiming, which should make it last longer. StuRat (talk) 00:05, 23 October 2017 (UTC)[reply]

Suitable conduit for conveyance of steam from kettle

I would like to make a steamer for wood bending and I've read that a PVC pipe (like a drain pipe?) can be used as a vessel for this but I need a conduit to convey steam from my kettle on the gas stove to my PVC pipe. What would be a suitable but cheap material for such a conduit? How hot is it likely to get? I figure no more than 150 °C? --178.170.142.48 (talk) 22:50, 22 October 2017 (UTC)[reply]

To clarify, do you mean to convey the steam under pressure, or just at normal atmospheric pressure ? StuRat (talk) 23:01, 22 October 2017 (UTC)[reply]

Yes, the pressure would only be slightly higher than atmospheric. 23:27, 22 October 2017 (UTC)

If you design it like this one you don't need any conduit: [12] The steam box sits directly over the steam source. Rmhermen (talk) 23:17, 22 October 2017 (UTC)[reply]

Meaning directly over the kettle ? StuRat (talk) 23:22, 22 October 2017 (UTC)[reply]

I think that would just shift my problem somewhere else. I'd need to find a way to perch my wood container over the source of the steam in such a way as to capture it efficiently (and I don't wish to make a heater when I can just use my gas stove). --178.170.142.48 (talk) 23:27, 22 October 2017 (UTC)[reply]

This one uses a PVC pipe and a garden hose: [13] Rmhermen (talk) 23:21, 22 October 2017 (UTC)[reply]

Plain old PVC should work just fine, because that steam cannot be much hotter than boiling. However, if you want a conservative design, you can use CPVC instead for the conduit. CPVC is normally used instead of PVC for hot water under pressure. If you are truly paranoid, use a copper or stainless flex pipe of the type sold to connect a hot water heater to the house plumbing. -Arch dude (talk) 03:09, 23 October 2017 (UTC)[reply]
- If you find that the steam is losing too much heat and/or condensing in your pipe, hardware stores also sell closed-cell insulation that goes around hot water pipes. --Guy Macon (talk) 03:45, 23 October 2017 (UTC)[reply]

October 23

Do old farts dream of flying insects?

I want to know, outside of Germany, are the flying insects disappearing? Do old people remember there being more flying insects in their youth than there are today? 110.22.20.252 (talk) 03:54, 23 October 2017 (UTC)[reply]