Wikipedia:Reference desk/Archives/Science/2018 January 24

= January 24 =

Could neutrinos be used practically for cooling?
I was looking at the Dyson sphere thread above and musing on other ways heat might be radiated, when I recalled vaguely the Urca process for cooling neutron stars via the emission of neutrinos. The cosmic neutrino background is at 2K, but it is very sparse - at best 1 million per cubic centimeter - so that's no use I think. But the same paper suggests 0.2 eV is the upper limit of neutrino mass, so could you just make a bunch of neutrinos and antineutrinos from thin air, then use them to carry away heat energy in their momentum? If you knew how, I mean. Wnt (talk) 02:53, 24 January 2018 (UTC)
 * "If you knew how". There's the rub, innit?  If you knew how to do magic, you could just cast a spell...-- Jayron 32 03:58, 24 January 2018 (UTC)
 * Well, 99.99% of the nifty things we want to do, physicists say it's impossible, you're nuts for trying, if you made it work it's a scam. So saying we don't know how to do it is like saying it's going to be in the supermarket in a couple of decades.  I have no idea if  is useful for getting at how to do it or not. Wnt (talk) 08:44, 24 January 2018 (UTC)
 * The real trick is knowing which of the millions of possible lines of inquiry are likely to produce useful results. I can wish to do any of a number of fantastical things.  I don't have time to test an infinite number of fantastical things.  I need to pick ones that I expect to do something useful.  -- Jayron 32 14:53, 24 January 2018 (UTC)

Taking a first stab at this, the Boltzmann constant tells me that there is 0.013 eV in each of three degrees of freedom at room temperature for about 0.05 eV of cooling per neutrino pair created. Our articles on neutrino mass and neutrino helpfully omit all guesstimates of neutrino mass except that the three flavors should add up to less than 0.120 eV, so the most they should weigh is 0.04 eV. That means that you should be able to get at least 1.2 units of cooling for every 1 unit of energy spent neutrino-making ... if your magic wand is perfectly efficient. But looking for guesstimates online I find this illustration from indicating that with either possible configuration of neutrino masses there ought to be something with a mass^2 = 7.6E-5 eV^2 or 0.0087 eV per neutrino, a ratio of about 6 to 1. Which is ... cool. I mean, it seems like if you could make enough neutrinos and do enough cooling you could use this as a cold reservoir for a heat engine and have some kind of ridiculous dystopian "global cooling" problem from the rampant abuse of energy technology. ;) Wnt (talk) 14:32, 24 January 2018 (UTC)


 * The coupling of the matter in the system to the neutrinos must be strong enough. A lesson from history is the discussion in the early days of quantum mechanics about the photon mass. A wrong argument put forward was that the photon must be exactly massless, that it couldn't have even an astronomically small mass, because a massive photon would have a longitudinal polarization, so black bodies would also radiate photons with longitudinal polarization, therefore the Stefan–Boltzmann constant would have to be be 3/2 of the known value, and that's then obviously false. But this reasoning is flawed because the coupling of the longitudinal component to matter tends to zero in the limit of zero photon mass. So, matter becomes transparent to longitudinal photons in that limit. Count Iblis (talk) 15:06, 24 January 2018 (UTC)


 * I was thinking the invention of a small neutrino detector suggested better coupling was possible than commonly believed. This gives some comments about it but I don't pretend to understand, and I admit, it doesn't sound like a whole hell of a lot of coupling.  But I find it uncommonly easy to believe that there is a lot of secret neutrino physics, since you can (possibly) use them to track nuclear submarines and other nukes, and AFAIK if you could do enough pair production, you could perhaps aim your beam at those nukes and make them go off spontaneously, not to mention secret comm networks and the for practical purposes all but perpetual motion machines described above.  I am suspicious that the lack of a nuclear weapon(s) concealed in the collapsing WTC towers gives a hint that smuggling nukes into a country is harder than people think, which in turn makes me think that powerful, high-res detectors have been available for a very long time, so I wonder if physicisits might be many decades behind the spooks...  Wnt (talk) 01:01, 26 January 2018 (UTC)

What factors can we say are responsible for the lifespans of Homo (human) members increasing to 70 years, as seen in modern hunter-gatherers?
There’s a study on modern Homo (human) hunter-gatherers that states that most of them live to 70 years: http://www.anth.ucsb.edu/faculty/gurven/papers/GurvenKaplan2007pdr.pdf but I’m in doubt that members of the Homo genus have always lived this long. Members of the other genuses in the Hominidae family, which are Pan (chimpanzee), Gorilla (gorilla), and Pongo (orangutan), usually live 30-40 years. So the earliest Homo members must have originally lived 30-40 years as well (and probably looked like Pan members). But I’m curious what factors we can say are responsible for the lifespans of Homo members increasing to 70 years, as seen in modern hunter-gatherers. I’m not sure if cooking was a factor. MisterH2005 (talk) 04:47, 24 January 2018 (UTC)
 * Chimpanzees usually live around 36 years in the wild. This was the initial lifespan of humans. Since Australopithecus is part of the human lineage that branches off from the Chimpanzee-Human Last Common Ancestor, it should be reclassified as Homo. Yellow Sunstreaker (talk) 06:53, 30 January 2018 (UTC)
 * The following study posits (regarding Homo lifespan):
 * See: cooperative breeding —107.15.152.93 (talk) 06:20, 24 January 2018 (UTC)
 * See: cooperative breeding —107.15.152.93 (talk) 06:20, 24 January 2018 (UTC)

You are also ignoring the difference between (average) maximum life span, and (average) life expectancy. Life span is the normal length of a life not shortened by violence or the action of another (disease or enemy/predator) organism. That has long been around 70, and is increasing as we improve our medical technology. There is a trade-off involved here. 70 year-old grandparents make great child caregivers and stores of wisdom.

But certain other genes like ones for large breasts may increase fecundity and child survival, while killing the mother at 40 of breast cancer. Evolution tends to select for those genes which have the longest term benefit toward surviving children. In apes, wouded forty-year old males have little to offer, while medicine-men grandfathers among humans offer both wisdom and prestige.

The second issue is average life expectancy. A couple only needs 2.X (X being a small number to deal with non-breeding offspring) to replace it. A couple might have 11 children, and the wife die at forty in childbirth. But if she has a 20 year-old daughter who can help raise two other children to maturity, then although the father and two children might live to 70, the mother to 40, and 10 children to age 1, you have 260 years/13 people = 20 year average life expectancy, but a stable population. μηδείς (talk) 03:07, 25 January 2018 (UTC)


 * The question was addressed by Leslie Aiello in Evolution of Human Life History Patterns, eighth of nine lectures in the CARTA symposium Origins of Genus Homo held on Feb 5th 2016: see here. Each of the nine lectures lasts no more than 25 minutes (click on the little filmstrip symbol by each item to see it on YouTube), and I've linked the whole web page since the other eight lectures may be of some relevance and interest: I recommend watching all of them in order.
 * There are of course a number of other symposia on the CARTA website, some of which may also contain material of interest – search via the SYMPOSIA or RESOURCES drop-down menus. {The poster formerly known as 87.81.230.185} 94.0.128.132 (talk) 06:42, 25 January 2018 (UTC)


 * Reducing infant mortality is largely (and arguably only) major contribution in life expectancy at birth, followed by childhood deaths. This is evident in comparisons of third world and first world population graphs by age graphs.  Nations with high infant/child deaths have a 1/x type graph of population by age, first world have a shifted gaussian.  The telling statistic is actuarial table that estimate average lifetime at different ages.  A 60 y/o person has a median remaining years of say 20 years more.  An 80 y/o has a median of 5, at 100 it's about 1.  At 110 it's about 6 months.  The telling statistic is that maximum lifespan and actuarial tables beyond 60 years old have really not improved much.  Certainly not as much as the lifetime from birth which gets a massive bump from vaccines, antibiotics and childbirth survival rates. --DHeyward (talk) 11:53, 25 January 2018 (UTC)


 * 1. Diet - no chronic diseases such as stroke, congestive heart failure, diabetes, hypertension
 * 2. No deadly infectious diseases - most are caused by domesticating animals
 * 3. Isolation - limited contact with outsiders who spread deadly infectious diseases such as smallpox, gonorrhea and syphilis
 * 4. Active - no obesity
 * 5. Strong immune systems - exposed to environmental bacteria
 * 6. Plenty of food (no famine) because of high infant mortality limits population explosions
 * 7. No famine due to not relying on one variety of crop
 * 8. No modern pollutants - no smog, engine exhaust, modern dyes, radioactive clouds from atomic bombs and reactor meltdowns
 * 9. Sun exposure - synthesis of Vitamin D in the skin


 * The Kitavan islanders studied in 1989 are stone age tropical farmers who hunt fish, gather fruit and grow root staples. The gardens are infertile and only yield one crop before a new garden needs to be slash and burned. The men appear to be lazy as the diet only has 10% protein. The men fish and prepare the gardens for the women who also gather fruit.
 * The Hadza Bushmen of Tanzania are nomadic hunter gatherers that live in family groups of around 30 people
 * The Maasai of Kenya and Tanzania are stone age nomadic pastoralists who neither hunt nor gather. They eat milk, meat, blood and no vegetables. They are exposed to famine if their cattle die from an infectious disease. Sleigh (talk) 12:41, 25 January 2018 (UTC)


 * I think everyone is drifting away from the OP's actual query. MisterH2005 isn't asking about the life-span contrasts between (modern) hunter gatherers and other modern humans, but about the evolved contrasts between the genus Homo (for whom modern hunter-gatherers merely provide a conveniently studyable proxy) and earlier non-Homo Hominidae – or so I read it. Paleoanthropological research (including that which I linked above) suggests that this increased lifespan evolved along with other distinctly Homo traits as a synergistic package (if I may coin a term). {The poster formerly known as 87.81.230.195} 94.0.128.132 (talk) 08:46, 26 January 2018 (UTC)
 * Interesting. I guess meat eating wasn’t a factor, then. The earliest Homo members (such as Homo Habilis, etc.) probably lived 30-40 years. Homo Erectus probably did too but only in its earliest years of existence. MisterH2005 (talk) 04:16, 27 January 2018 (UTC)
 * I'm not sure where you draw those conclusions from. To my understanding, the data shows that a significant step up from australopithecine life spans was made by the earliest Homo species, and a further steady increase continued through successor species. This is presumed to be bound up with the adoption of new styles of food gathering (including cursorial hunting, see e.g. here) and preparation (chopping with stone tools, and cooking) as part of a suite of behaviours: preparation and eating of (more) meat was certainly a significant factor within this. {The poster formerly known as 87.81.230.195} 176.249.197.124 (talk) 07:46, 27 January 2018 (UTC)
 * What I understood from the data was that extended longevity and thus a slow life history not seen in the members of the other Hominidae genuses originated in the later years of Homo Erectus. Earlier Homo species had a life history of an australopithecine pattern. Also, from what you’re saying, cooking was indeed a factor then. That’s what’s different about the modern hunter-gatherers in the study I linked to above. They all cook. MisterH2005 (talk) 18:25, 27 January 2018 (UTC)

Oxyanion naming confusion
Where did IUPAC publish its decision (mentioned in the bohrium article) to name bohrium oxyanions bohriates to avoid confusing them with borates? There would of course be some precedent for this insertion of -i-, since lutetiate (e.g. here) seems to be more frequent than lutetate (I imagine because it is not at all clear how the latter ought to be pronounced), but I'd like to see the original source for bohriate.

Also, this is unlikely to come up (since Ra forms a strongly basic oxide), but is there a way to distinguish between radium and radon oxyanions instead of having both be radates? Double sharp (talk) 09:57, 24 January 2018 (UTC)
 * I can find nothing that uses the word "Bohriates" outside of Wikipedia and mirrors. I would tag the statement and/or remove it pending the production of an actual source.  -- Jayron 32 11:49, 24 January 2018 (UTC)
 * ON the second issue (this is pure speculation), radonates would work, as some elements take the whole name + ate to form oxyanion names (c.f. zincate, nickelate), though I haven't looked for IUPAC rules on that one. -- Jayron 32 11:54, 24 January 2018 (UTC)
 * On bohriates, that was what I was going to do, but Martyn Poliakoff does mention it on The Periodic Table of Videos: "There's still a question with this name – boron and bohrium – because what happens when you start having the salts of these? Because borate and bohrate: sounds just the same! Nobody hears the h when you say it. So it's been decided that the salts of bohrium will be called bohriates rather than bohrate so that people won't be confused." I've cited him on the article. The question though is where he got that information from: I hope this isn't yet another case of citogenesis. Double sharp (talk) 15:21, 24 January 2018 (UTC)
 * I love Poliakoff and Brady Haran's videos in general, but that sort of pop-science stuff isn't the greatest as a scholarly source, I think we need to search for something a bit more definitive. I'd tag that source as "dubious" given that the purpose and nature of the video (as sciency entertainment) isn't quite what we would expect as a source for a statement like this.  -- Jayron 32 15:25, 24 January 2018 (UTC)
 * Also, just for the record, PubChem only has records of 12 Bohrium containing compounds: and none of them have oxyanions of bohrium.  Maybe it has never come up... -- Jayron 32 15:28, 24 January 2018 (UTC)
 * It certainly hasn't come up in experimental chemistry, but it does make it difficult to actually write the articles. I mean, I mention predictions (cited) in Bohrium, and is mentioned as the most likely way BhVII would be stabilised (analogous to Mn, Tc, and Re); it is frustrating to have to dance around it by never mentioning the name because we're not sure what it ought to be. And similarly for Rn: in Radon I mentioned the predicted RnVIII compound Ba2RnO6, and named it rather straightforwardly as barium perradate. Except that now I've realised that that's actually ambiguous. If I can't find a good answer for each of these cases here I will take away those names and write around them, but I continue to hope that IUPAC has come up with an official answer. ^_^ Double sharp (talk) 15:38, 24 January 2018 (UTC)
 * According to the IUPAC Red Book: bohrate, argonate, kryptonate, xenonate, radonate. Burzuchius (talk) 15:59, 24 January 2018 (UTC)
 * Well, there you go. -- Jayron 32 16:03, 24 January 2018 (UTC)
 * Thank you! It's against common usage for perxenates, but for the rest (since oxyanions of Ar, Kr, Rn, and Bh are undiscovered AFAIK) I will edit the Rn and Bh articles accordingly. Double sharp (talk) 01:58, 25 January 2018 (UTC)

Why does a washing machine take hours to do the laundry?
Why can't it be done in, say, 15 minutes? Count Iblis (talk) 15:07, 24 January 2018 (UTC)
 * My washing machine has cycles that last from 14-6 minutes for the wash, with a rinse and spin dry lasting about 10 minutes. My washing machine has no cycle that lasts as long as an hour, even if you do a maximum wash time allowed with a double rinse cycle.  I have a fairly standard washing machine which is common in most western households (washing machine designs are fairly universal except for higher end, new fangled front loaders, or high efficincy machines.  The standard washing machine design hasn't changed in about 50 years, with some minor cosmetic updates).  Your premise is wrong.-- Jayron 32 15:12, 24 January 2018 (UTC)
 * Washing machines are nothing like universal, even in "the West". There are national variations between US vertical axis top loaders, Western European front loaders, Northern European horizontal axis top loaders and in Greece and Turkey there are still plenty of non-automatic twin tubs in use.  Also their uses of water temperature, detergent and even (in some backward countries) universal bleaching vary a lot.
 * My own washer (modern LG, but nothing radical) will do a load in between 2 hours and 20 minutes, depending on whether that's a super-medical-clean boil wash for white linen or a "clean shirt now!" panic. Andy Dingley (talk) 15:40, 24 January 2018 (UTC)
 * Fair enough. Of all the washing machines that I, or any of my family, have owned and used (and I've probably used a dozen or so in my life) they are basically all identical.  Point taken.  I have stricken the false statements I made.  The premise that "a washing machine takes hours" is, however, demonstratedly false: My washing machine takes between 15-25 minutes depending on the cycle.  If Count Iblis wants to know why HIS washing machine takes hours, he would need one of us to come over his house and look at it.  But many washing machines get the job done in 15 minutes.  -- Jayron <b style="color:#090">32</b> 15:58, 24 January 2018 (UTC)
 * But you're in the US. Last time I did laundry there, it was typical to take the laundry from the machine pretty wet, and then move it manually to either a spin drier or a tumble drier. Here in the UK I line dry stuff, other people tumble dry, and many (who aren't watching the energy consumption!) use combination machines which tumble dry automatically, within the same drum.
 * Also (which I should have noted) my machine weighs the load and adjusts run times accordingly. Andy Dingley (talk) 18:20, 24 January 2018 (UTC)
 * Our article suggests that top-loading machines (more common in the US) are faster, though less effective and efficient, than front-loading machines, common in the UK and Europe. See Washing_machine. DuncanHill (talk) 20:00, 24 January 2018 (UTC)
 * Yeah as I noted below even for a top loader 15 minutes sounds like the time it would take for the wash or spin cycle in NZ or I think Australia. Even if you're able to wash and rinse the clothes with a full cycle in 15 minutes, I can't imagine you can magically get them as dry one with a 15 minute spin cycle in a top loader you may find in NZ or Australia which makes me think the clothes are probably a fair amount wetter. So they're either going to take longer to dry on the line, or your tumble dryer is going to be doing more work. Or you're spin drying them in a separate machine. Nil Einne (talk)
 * He never mentioned a clothes dryer. He only mentioned a washing machine.  If he meant both washing and drying his clothes, he would have said so.  That takes another 50-60 minutes to dry the clothes.  I'm not sure a practical way to speed that up.  I mean, one could just raise the temperature, but I want my clothes dried, not scorched.  -- Jayron <b style="color:#090">32</b> 13:42, 25 January 2018 (UTC)
 * Jayron, I think you are getting confused between a spin dryer and a tumble dryer. Nil Einne was commenting on the degree of dryness after spin drying. DuncanHill (talk) 13:45, 25 January 2018 (UTC)
 * Regardless, we're dicking about minutes here. The OP said it takes hours, as in at least 2, for him to wash his clothes.  I can't even run my washing machine for as long as one hour, if I even wanted to.  I'd have to run two cycles.  A full cycle, including wash, rinse, and spin takes about 30 minutes, which leaves the clothes slightly damp.  But hours seems outrageously long.  -- Jayron <b style="color:#090">32</b> 15:40, 25 January 2018 (UTC)
 * Two points - 1) Did you bother to read the comparison between top and front loading machines linked above? and 2) "hours" is colloquial English for "ages", "a long time", "longer than thought reasonable or necessary". And, as pointed out elsewhere in the thread, some programmes do take more than two hours. DuncanHill (talk) 15:57, 25 January 2018 (UTC)
 * Two points: You are right, and I am wrong. Everything you said is correct, and everything I said is wrong.  I apologize for being so misleading.  I will try to do better in the future.  -- Jayron <b style="color:#090">32</b> 16:06, 25 January 2018 (UTC)
 * I'm glad we got that cleared up! DuncanHill (talk) 21:10, 25 January 2018 (UTC)
 * BTW in case there still doubt, my main point was that I don't want to get into debate whether American machines get clothes as clean as NZ and Australians ones and whether they do it by eg using a much hotter wash or detergents which are nastier. But here where top loaders are still common, I'm fairly sure 10-15 minutes or more will be normal for the spin dry cycle of a top loader and it's hard to imagine the shorter US cycle will get clothes as dry. This implies as Andy said that clothes likely come out wetter. Whether this is a bad thing is again not a debate for the RD but it does seem to suggest a longer dry time whether line or tumble. The tumble dryer will likekly use more energy than the spinning. Alternatively you may use a separate machine for spinning only. P.S. There may also be differences in average size of loads, materials, etc which will affect spin time drying efficiency. Also I do agree multi hours isn't the norm for standard top loader cycles in NZ although they do tend to be longer than those quoted here for US washing machines. The Choice ref suggests maybe close to an hour. As I said below this seems more likely at least in part to do with front loaders which in many countries are not new fangled. Nil Einne (talk) 14:32, 26 January 2018 (UTC)
 * Also although I'm fairly sure this has nothing to do with the question, it's worth noting combination washing and tumble dryer machines are a thing as others have noted. These are still rare in NZ but my impression is they're getting more common in Malaysia where the climate and tradition of line drying even in apartments means stand alone tumble dryers are AFAIK very rare. These mean you just load clothes once and don't have to worry that much about when they finish unless you need them urgently. As I'm sure one of the linked wikipedia articles notes, if you include parts of Asia there is also the difference between the design if top loaders, impeller design for top loaders common there vs agitator common here and my impression is in the US too. I'm not saying this affects times. Nil Einne (talk) 15:13, 26 January 2018 (UTC)
 * Machines obviously vary considerably. Here in the UK, my cheap front-loader takes nearly two hours, and that's without a pre-wash, and only a spin dry.  It does have a quick wash option, but I seldom use it.   <i style="color: blue;">D</i><i style="color: #0cf;">b</i><i style="color: #4fc;">f</i><i style="color: #6f6;">i</i><i style="color: #4e4;">r</i><i style="color: #4a4">s</i>  16:02, 25 January 2018 (UTC)
 * Per earlier comments, you need to be more specific on what you're measuring. For example, I have a fairly modern front-load washer. When I set it for a "normal wash", the timer suggests things will be done in 1:15 (or thereabouts, depending on weight), but I typically select "short wash" (we just don't get that dirty), which cuts the time in half and still includes final spin and tumble. Now if you're talking about the industrial jobs you see in laundromats, my experience - though dated - is that they sacrifice speed for durability and may take longer than equivalent-sized personal machines. That's just a (dated) personal observation, though. Matt Deres (talk) 17:20, 24 January 2018 (UTC)
 * The manual for my Zanussi automatic front-loading washing machine lists programme times from approx. 50 minutes for woollens, to approx. 147 minutes for the heavily soiled whites programme. In my experience these times are fairly typical of automatic machines in the UK. The manual notes that "actual times will vary depending on incoming water temperature and pressure". These times include spin, but not tumble (I have a separate machine for that). DuncanHill (talk) 19:52, 24 January 2018 (UTC)


 * To bring this back to a scientific angle, I suspect the ultimate answer has something to do with chemical kinetics and reaction rate constants. Insofar as we can simplify a complicated process, a washing machine can be described as a chemical reactor, in which we emplace fiber, dirt, detergent, and water, and use an agitator to encourage mixing and to accelerate mixing, and to physically dislodge particles.  The goal is to chemically or physically separate dirt from fiber, by any means necessary.
 * To what extent can we quantitatively model the rate of chemical and physical action until a material is free of debris, dirt, and chemical contaminant? To what extent does a petri-dish model scale up to provide useful descriptions for a real-world washing-machine?
 * I know, for example, that autoclaves (professional cleaning machines that are used to sterilize medical and scientific materials) have carefully prescribed durations, pressures, settings, and so on: here's an example blog series on autoclave basics, including data such as exposure duration. Bear in mind that in those contexts, the goal is to kill microbacteria, not simply to dislodge dirt and contaminant - but the idea is that we can directly measure how many minutes are required to get something clean, and then we build a machine to automate that cycle-time using a mechanical process.
 * Nimur (talk) 19:24, 24 January 2018 (UTC)
 * On the subject of "how many minutes are required to get something clean", how is this affected by the type of soap or detergent selected? 86.169.56.163 (talk) 19:59, 24 January 2018 (UTC)
 * A lot more of it changes because of engineering, not the chemistry of the cleaning products.
 * For one thing, cleaning products have a short time to market. I can buy (tasty, tasty) Tide pods today, but my machine will still have a soap drawer designed around loose soap powder and I'm pouring liquids in there from a generation inbetween. I'm unlikely to change machine just because the consumables suggest so. It took a very long time before the majority of European machines in service could wash at the lower temperatures which newer detergents had permitted from the '90s.
 * Mechanical changes have changed the washing cycles. Water consumption in particular has dropped, encouraged by Europe's pretty fine-grained energy rating system. We've also seen a shift to single connection cold-fill machines (electric heat of less water, inside the machine) than the old approach of hot fill, as a gas-heated supply was considered to be cheaper (this is turn has even affected European domestic solar power designs - not much point in the difficult problem of solar heating truly hot water for laundry, if the detergent doesn't need it and the machine won't even use it). We now see a lot more use of low-volume continual pumping water systems which recirculate as sprays. More efficient rinsing also reduces the time and water volume needed to do it inefficiently (one area where horizontal axis really beats vertical axis). Andy Dingley (talk) 20:02, 24 January 2018 (UTC)


 * What in the world? Are you still having your womenfolk bang your shirts on rocks, Count Iblis?  I usually just let the launderer do my laundry, since it comes back folded, mended, and unharmed at the same price I would pay in quarters; and I tip.  The standard setting on my parents' and my sister's machine is 12 minutes, plus a drain/rinse/spin cycle, for a total of about 15-20 minutes depending on how long it takes to fill (a small wash is 1/5th the volume, and goes much quicker than the largest load.
 * There is a presoak cycle that adds either 10 or 30 minutes of soaking (with just enough agitation to distribute the detergent) which is followed by the normal run. But I almost never use that option.  Even back in the 80's, commercial washers only took about 30 minutes, and they were monsters.  The dryers often took two hours, so the trick was to do the jeans and towels separate from the lighter items.  But an average hour-minimum cycle for a standard washer? μηδείς (talk) 02:52, 25 January 2018 (UTC)
 * As already noted, one big issue is probably the difference between the type of washing machine used. An hour or longer for a standard wash on a domestic front loader isn't exactly uncommon, and these washing machines are more common than top loaders in a number of countries and are definitely not "new fangled". As high efficiency top loaders often share some similarities in operation principle with front loaders, they are generally similar. This US source [//www.consumerreports.org/front-load-washers/5-things-to-know-about-front-load-washers/] notes the time difference so I don't think even the US has front loaders with such short cycle times. That said, 15-20 minutes for a normal full cycle even for a top loader seems fairly short to me, the responses here make me think this is a US thing. 15-20 minutes sounds more like the time for the wash or spin cycle. See e.g. this info from an Australian source with average times [//www.choice.com.au/home-and-living/laundry-and-cleaning/washing-machines/articles/cycle-times] Nil Einne (talk)


 * My answer was typed hours before it was posted, I didn't notice it didn't upload. That being said, my parent's machine is a top-loader and the was cycle is 12 minutes, with time added for a two filling and draining cycles, the time of which depends on the volume of water, and a two-minute rinse cycle.  When I use their machine it is usually for the largest load, since I will be doing bedclothes and whatever clothes I have with me for the weekend/holiday.  The full cycle runs about 20 minutes from start to finish.
 * My sister has a side loader. She and her husband are clean freaks (they all bathe twice a day at least, and three changes of clothing is normal) and they have an industrial strength machine that is in almost constant use, and it does have quite long cycles and will also heat the water already hot from the main.  But that was all by choice, not due to a set limitation of the machine, and it will happily do a normal load without all the extras meant to sterilize ebola and vaporize bedbugs in about 20 minutes.  With the outrageous money they spend on bathing, dishwashing, and laundry, they could go to Disney World every year. μηδείς (talk) 17:09, 25 January 2018 (UTC)


 * If I was the designer at a company that manufactures washing machines I would be looking at the size of the market; and what proportion of the likely customers are interested in a machine that can wash a load in 15 minutes, and whether they are willing to pay the premium cost associated with such a machine. I would be likely to conclude that potential customers are looking for a machine at a low cost; and doesn't damage the clothes. They are likely to see little or no advantage in a machine with a cycle time of 15 minutes compared with one that has a cycle time of 45 minutes or longer. The end result is that I wouldn't even bother recommending to the Board that the company adds a "15 minute" machine to its stable of products.  Dolphin  ( t ) 06:03, 25 January 2018 (UTC)
 * I should clarify when I said front loaders with such short cycle times, I mean a standard cycle time. I believe my front load does have some super quick cycle that is 15-20 minutes although I can't recall if it includes spin drying. Nil Einne (talk) 06:08, 25 January 2018 (UTC):
 * Yes, in the UK I've not seen a domestic top loading machine since the 1970s although I've used commercial ones on camp sites. The shortest cycle on our front loading washing machine is 30 minutes but that includes 10 mins for the spin cycle. The longest cycle is for cottons and is 3 hours 10 mins which includes a prewash, 90 degree wash and spin. I can't imagine what you would have to do to your cottons to require that long a wash - we normally only use the 30 min or 45 min cycles and an occasional seperate wash for 'delicates'. Back in the 50s and 60s my mother used to send the cotton bedding to the laundry every week but those type of laundries seem to have gone as automatic washing machines became popular. There are self service launderettes that also do a service wash but these seem to be disappearing too in most places. Ironing services are becoming more popular though my wife and I find that with modern fabrics and careful use of the tumble drier there is very little to iron anyway. It's strange how things are done so differently in different parts of the western world. However, I must take issue with the description above of an autoclave being a "professsional cleaning machine" - it isn't! An autoclave is basically a large pressure cooker used for sterilisation, and anything that goes in it that will be re-used has to be carefully washed before it goes in or the dirt will just get baked on. The length of the cycles it uses are worked out to ensure all the microorganisms are killed in the minimum amount of time - nothing to do with cleaning. Richerman  (talk) 10:56, 25 January 2018 (UTC)
 * Unless you're planning on hanging your laundry, there really isn't much benefit to having a private washing machine complete its task in significantly less time than it takes the dryer to do its task. As the laundry-doer (and general lazy ass), I would still only make the trek downstairs once I'd figured the dryer was finished and the time savings on the washing would be worth little to me. YMMV, of course, but I think many people do all their laundry on a specific laundry day and would have broadly similar habits. Matt Deres (talk) 17:14, 25 January 2018 (UTC)
 * In the UK most people have the washing machine in the kitchen (or, if they have a large house, in an adjoining utility room), so there is no trekking down and up stairs involved. It's always struck me as rather odd the way Americans seem to put the washing machine in the most inconvenient location they can find. DuncanHill (talk) 21:08, 25 January 2018 (UTC)
 * Kirstie Allsopp might disagree Andy Dingley (talk) 22:12, 25 January 2018 (UTC)
 * Well, granted (though we Canadians also like to stick the laundry downstairs), but it's really the timing that's important. If it takes 15 minutes to wash clothes and 45 minutes to dry them, you're going to have problems running the laundry in series. The first load will only be one third done in the dryer when the next load of washing is done. Matt Deres (talk) 02:07, 26 January 2018 (UTC)


 * North Americans place the upright spinning washer downstairs so that their screams of delight as they sit upon it as it vibrates do not annoy those in the dining or sitting room, or the bedrooms.


 * I had my mother run a full "extra large (volume)" wash at hot-from-the-main setting on my bedclothes (sheet, "wool" (synthetic) blanket and pillow cases (8)) with the blue towels from the guest bathroom I use today. She said it ran for 26 minutes, being: filling hot; agitation 12 minutes; spin/drain; second filling on cold-from-main (much quicker than hot); second agitation; final spin/drain.


 * This took all of 26 minutes. No wash would ever take longer.  The "Woolen" (synthetic) blanket was hung in the sun and dry in 15 minutes.  The remainder was placed in the front-loading drier, and done at the lowest temperature (basically, "above ambient") within 30 minutes.
 * Usually heavy items like towels, blankets, and jeans are hung to dry, while light cottons and gotchies and socks are dried on low temp, like delicates, for 30-50 minutes. This is not an issue, since two or three separate washes done by dark/red/light color can be dried together, so the different cycles are an issue of tactics, not shear stupid serial mechanics.  My drying reds have never turned my whites pink.


 * I think you Brits are being cheated by both your appliance manufacturers, and your state utility companies with this sill front loading, don't bend over to dry separately do goody-good bullshitt. μηδείς (talk) 03:46, 26 January 2018 (UTC)
 * We have not had state utility companies for over 25 years. AndrewWTaylor (talk) 10:43, 26 January 2018 (UTC)
 * We never had them.  We had the gas board, the electricity board and the water board. 92.19.172.194 (talk) 15:34, 26 January 2018 (UTC)
 * Yes, and they were all government run for many years before the Conservative government decided to sell them off. It was a policy of denationalisation started by Margeret Thatcher and completed by John Major's government. Richerman  (talk) 00:46, 27 January 2018 (UTC)
 * I think it's because Europeans care about using less water, energy and soap than Americans, since front loaders are much more efficient on this front. US top loaders might save time but our front loaders save us money and we tend to like that. Regards  So  Why  15:37, 26 January 2018 (UTC)


 * Our washer takes about half an hour per load, and the dryer about 45 minutes. Not "hours and hours". ←Baseball Bugs What's up, Doc? carrots→ 19:21, 26 January 2018 (UTC)


 * Restoring my comment:


 * Just out of curiosity, why are people supposing the drying time can't be shortened? I would guess that a clothes dryer on the ISS could work pretty fast if it vents the compartment to space. It might need a heater to avoid disruption to clothes fibers from freezing though... not sure. But the partial pressure of water vapor can be just as low on Earth, no? If I'm not misunderstanding the idea, we need merely create a super-Sahara blast of air for the dryer and you ought to be able to dry clothes like an astronaut. And, I mean, that's just engineering AFAICT. Wnt (talk) 03:40, 26 January 2018 (UTC)
 * Did anyone say there's no way to shorten the drying time? I haven't read the whole thread anymore but AFAIK most talks about drying time related to my point that if it's just the simple spin drying of a washing machine, you're not likely to get the same level of dryness from only spinning for 7 minutes compared to 15 minutes. I probably should have made clearer that I was assuming the same amount of clothes, fairly similar spin speeds and same type of fabric and same wetness. Also my assumption is that after soaking for even 5 minutes as I assume happens even for most fast American washing machines, the clothes aren't getting much wetter compared to NZ/Australian style. AFAIK this is one thing which doesn't vary so much between countries except that some machines do both, and that is after spinning in the automatic washing machine (if these are actually used) most people either line dry or use a clothes dryer or a combination of both. (I said tumble dryer above but I'm basically referring to anything in clothes dryer intended to completely dry clothes, as the article mentions there are multiple different methods of operation and time taken is one thing that varies.) The one exception may be if people have a spin dryer separate from the washing machine. Nil Einne (talk) 07:18, 27 January 2018 (UTC)

Who would have thought a simple discussion about washing machines would raise such passions? I'm not even sure what "sill [silly?] front loading, don't bend over to dry separately do goody-good bullshitt" actually means - but I do know it's not complimentary. We prefer front loading washing machines in the UK because they fit under the worktops in the kitchen without breaking up the workspace. The reason we have them in the kitchen in most houses is because we don't have such large houses as the Americans. Why? Because we are a small island and don't have millions of acres of land to spare and the green bits we do have left we try to keep that way if we can. And tumble driers have become popular because we have a maritime climate and if you put your washing on the line to dry before you go to work you can guarantee it will piss down before you get home to take it in. The simple fact is we do some things differently, sometimes for quite complex historical reasons, and it's not necessarily worse or better - just different. Richerman (talk) 00:46, 27 January 2018 (UTC)


 * Oh, please. You've got all of Canada, Australia, and Ireland (oh, yeah, you did that) to colonize.  So your problem seems to be with George III, the parliaments that backed his denial of the rights of Englishmen to the Americans, and the lyrics of Pink Floyd.  Every time I do a 26 minute mega-hot-no-overbending-wash, I'll think, Up yours, Georgie Boy!"  (Although I am quite happy to pay and tip the lady who runs the lavanderia across the street from me. μηδείς (talk) 02:27, 27 January 2018 (UTC)


 * The UK stuff is weird since my impression is Count Iblis does not live in the UK anyway. (I could be wrong, but in the fact that someone could be asking the same question despite not coming from the UK or any part of the Commonwealth is a given.) Also as I mentioned, top loaders are common in NZ and I'm pretty sure Australia albeit as I said with longer cycles, not as long as many front loaders but to a degree it also shows why making this a UK vs US thing is dumb. Although to be fair, bending over to use a front loader is one common complaint at least here in NZ and again I think Australia where front loaders are also fairly popular although except for the elderly or those with recognised problems I suspect unless you're stupid it's actually better for you . Interesting enough, the inability to add straggler clothes mid wash (not always true) is another thing that commonly comes up when discussion top loaders vs front loaders but it doesn't sound like that's much of an issue in the US since by the time you find something your washing machine may already be rinsing. [//www.canstarblue.co.nz/appliances/washing-machines/washing-machine-type-staff-decide/] Incidentally besides efficiency another common mentioned advantage of front loaders is it's easier to stack it with a dryer (couldn't find a ref but did find [//www.appliancesonline.com.au/academy/laundry/stacking-kits-how-to-organise-your-washer-and-dryer/]) here where it's common for washing machines to be in a at least semi separate laundry room/area. (Many houses here only have one storey. Also this is one case where I'm not thinking of Australia even if the previous ref was for Australia.) Despite bending or kneeling, some people actually find it easier to particularly to remove clothes. (See earlier ref.)Nil Einne (talk) 07:18, 27 January 2018 (UTC)
 * When I was in Australia I noticed that the older houses had separate laundry rooms and all had flyscreens over the windows (essential as there is a huge variety of insects).  I don't know if there is greater use of air conditioning/double glazing now.   In Britain, there used to be flies buzzing about all day long, but now we never see them. 2A02:C7F:BE3D:8000:C5A6:F576:B94F:852F (talk) 11:59, 27 January 2018 (UTC)


 * Here in New Zealand, most houses have dedicated laundry rooms which usually have enough space for the washing machine, a tumble dryer, and a tub with hot and cold water connections. This room often also contains the (usually electric) hot water cylinder, so that dry laundry can be stored on the shelves above the cylinder so that they get mildly warm storage. Basements are rare in NZ, but basement garages are common, and sometimes the laundry is built into a corner of the garage. The concept of a washing machine built into a kitchen would I think, fill most New Zealanders with horror. All washing machines I've owned in the past 30 odd years have been top loaders with total wash,rinse,spin cycle of about 50 minutes. A wash+rinse implies two water fills; on my current washer each fill takes 4-5 minutes, so there's 9-10 minutes out of the cycle; I cannot comprehend the claims above of 15 minutes total. Akld guy (talk) 18:36, 27 January 2018 (UTC)


 * I wonder if a person with a collection of good 22nd-century non-shrinkable fabrics could wash clothes in supercritical fluid, first steam perhaps, then washing with CO2 maybe, hence washing/drying the entire load almost as quickly as his robotic assistant can close and reopen the chamber. Wnt (talk) 19:24, 27 January 2018 (UTC)


 * (1) Count Iblis lives in Uqbar. Second, my experience comports exactly with Akld guy.  Who wants to wash diapers in the kitchen?  My parents' laundry room is basically a wide hall with three doors.  You enter it from the rec-room, on the left is a door to the garage, on the right are the washer, dryer, and tub, all behind two-three panel folding doors that can be closed when guests are coming, the water meter is on the left after the garage entrance and straight ahead from the rec-romm entrance is the downstairs toilet, with a sink, and a window that would be embarrassing were it not for the rather dense 60-year old honeysuckle that grows their.  One can enjoy watching the tits sheltering there in the winter. μηδείς (talk) 21:26, 27 January 2018 (UTC)


 * Ha, lots of comments after I return here, thanks! I did know know about these top loader washing machines at all :) . Count Iblis (talk) 15:59, 29 January 2018 (UTC)