Water

:''This article focuses on water as it is experienced in everyday life. See water (molecule) for information on the chemical and physical properties of pure water (H₂O) (dihydrogen oxide).'' Water (from the Old English language word ''w�ter'') is a colorless, tasteless, and odorless substance that is essential to all known forms of life and is known also as the most ''universal solvent''. Water is an abundant substance on Earth. It exists in many places and forms: mostly in the oceans and polar ice caps, but also as clouds, rain, river, and sea ice. On the planet, water is continuously moving through the water cycle involving evaporation, precipitation (meteorology), and runoff (water) to the sea. Humans consume "drinking water", water with qualities compatible with the human body. This natural resource has become scarce with the growing world population, and its availability is a major social and economic concern. ==A surprising substance== ===Changing appearances=== :''See :Category:Forms of water'' [[Image:Drinkingwater.JPG|thumb|Drinking water]] Water takes many different shapes on earth: water vapor and clouds in the sky, waves and icebergs in the sea, glaciers in the mountain, aquifers in the ground, to name but a few. Through evaporation, precipitation (meteorology), and runoff (water), water is continuously flowing from one form to another, in what is called the water cycle. Because of the importance of precipitation to agriculture, and to mankind in general, we give different names to its various forms: while rain is common in most countries, other phenomena are quite surprising when seen for the first time: hail, snow, fog or dew for example. When appropriately lit, water drops in the air can refract the beautiful colors of a rainbow. Similarly, water runoffs have played major roles in human history: rivers and irrigation brought the water needed for agriculture. Rivers and the seas offered opportunity for travel and commerce. Through erosion, runoffs played a major part in shaping our environment providing river valleys and deltas which provide rich soil and level ground for the establishment of population centers. Water also infiltrates the ground and goes into aquifers. This groundwater later flows back to the surface in spring (water), or more spectacularly in hot springs and geysers. Groundwater is also extracted artificially in wells. Because water can contain many different substances, it can taste or smell very differently. In fact, we have developed our senses to be able to evaluate the drinkability of water: we avoid the salty seas and the putrid swamps, and we like the fresh pure water of a mountain spring. ===Important properties for living organisms=== Water has many unusual properties that are critical for life: it is a good solvent and has high surface tension. Fresh water has its greatest density at 4°Celsius: it becomes less dense as it freezing or heats up. As a stable, polar molecule prevalent in the atmosphere, it plays an important atmospheric role as an absorber of infrared radiation, crucial in the atmospheric greenhouse effect. Water also has an unusually high specific heat capacity, which plays many roles in regulating global climate. Water is a very good solvent and dissolves many types of substances, such as various salts and sugar, and facilitates their chemical reaction, which aids complex metabolisms. Some substances, however, do not mix well with water, including oils and other hydrophobic substances. Cell membranes, composed of lipids and proteins, take advantage of this property to carefully control interactions between their contents and external chemicals. This is facilitated somewhat by the surface tension of water. Water drops are stable due to the high surface tension of water. This can be seen when small quantities of water are put onto a nonsoluble surface such as glass: the water stays together as drops. This property plays a key role in plant transpiration. A simple but environmentally important and unique property of water is that its common solid form, ice, floats on the liquid. This solid phase is less dense than liquid water, due to the geometry of the strong hydrogen bonds which are formed only at lower temperatures. For almost all other substances and for all other 11 uncommon phases of water ice except ice-XI, the solid form is more dense than the liquid form. Fresh water is most dense at 4°C, and will sink by convection as it cools to that temperature, and if it becomes colder it will rise instead. This reversal will cause deep water to remain warmer than shallower freezing water, so that ice in a body of water will form first at the surface and progress downward, while the majority of the water underneath will hold a constant 4°C. This effectively insulates a lake floor from the cold. Life on earth has evolved with and fine tuned itself to the important features of water. The existence of abundant liquid, vapor and solid forms of water on Earth has no doubt been an important factor in the abundant colonization of Earth's various environments by life-forms adapted to those varying and often extreme conditions. In fact, civilizations have historically flourished around rivers and major waterways. Large metropolises like Paris, New York, and Tokyo are easily accessible by water and thus, in times past, could easily be developed through trade. Islands with safe water ports, like Singapore and Hong Kong, have flourished for precisely this reason. In places such as North Africa and the Middle East, where water is scarcer, access to clean drinking water was and is a major factor in human development. ==Importance of astronomical position== The coexistence of the solid, liquid, and gaseous phases of water on Earth is perhaps vital to the origin and evolution of life on Earth as we know it. However, if the Earth's location in the solar system were even marginally closer or further from the Sun, the conditions which allow the three forms to be present simultaneously would be far less likely to exist. Earth's mass allows gravity to hold an atmosphere. Water vapor and carbon dioxide in the atmosphere provides a greenhouse effect which helps maintain a relatively steady surface temperature. If Earth were less massive, a thinner atmosphere would cause temperature extremes preventing the accumulation of water except in polar ice caps (as on Mars (planet)). According to the solar nebula model of the solar system's formation, Earth's mass may be largely due to its distance from the Sun. The distance between Earth and the Sun and the combination of solar radiation received and the greenhouse effect of an atmosphere ensures that its surface is neither too cold nor too hot for liquid water. If Earth were more distant, most water would be frozen. If Earth was nearer to the Sun, its higher surface temperature would limit the formation of ice caps, or cause water to exist only as vapor. In the former case, the low albedo of oceans would cause Earth to absorb more solar energy. In the second case, a runaway greenhouse effect and inhospitable conditions similar to Venus (planet) would result. It has been proposed that life itself may maintain the conditions that have allowed its continued existence. The surface temperature of Earth has been relatively constant through geologic time despite varying solar flux, indicating that a dynamic process governs Earth's temperature via a combination of greenhouse gases and surface or atmospheric albedo. See ''Gaia hypothesis''. ==Water in everyday life== All known forms of life depend on water. Water is a vital part of many metabolism processes within the body. Significant quantities of water are used during the digestion of food. (Note however that some bacterium and plant seeds can enter a cryptobiotic state for an indefinite period when dehydrated, and come back to life when returned to a wet environment) About seventy two percent of the fat free mass of the human body is made of water. To function properly the body requires between one and seven liters/quarts of water per day to avoid dehydration, the precise amount depending on the level of activity, temperature, humidity, and other factors. It is not clear how much water intake is needed by healthy people.[http://ajpregu.physiology.org/cgi/content/full/283/5/R993] Water is lost from the body in urine and feces, through sweating, and by exhalation of water vapor in the breath. Humans require water that does not contain too much salt or other impurities. Common impurities include chemicals or harmful bacterium. Some solutes are acceptable and even desirable for perceived taste enhancement. Water that is suitable for drinking is termed potable water. Because of the growth of world population and other factors, the availability of drinking water per person is shrinking. This issue can be solved through more production, better distribution, or through less waste. ===A rare resource=== :''See water resources for information about fresh water supplies.'' Water is a strategic resource for many countries. Many battles and wars, such as the Six-Day War in the Middle East, have been fought to gain access to it. Experts predict more trouble ahead because of the world's growing world population, increasing contamination through water pollution and global warming. UNESCO's World Water Development Report (WWDR, 2003) from its World Water Assessment Program indicates that, in the next 20 years, the quantity of water available to everyone is predicted to decrease by 30%. 40% of the world's inhabitants currently have insufficient fresh water for minimal hygiene. More than 2.2 million people died in 2000 from diseases related to the consumption of contaminated water or drought. In 2004, the United Kingdom charity WaterAid reported that a child dies every 15 seconds due to easily preventable water-related diseases. Some have predicted that clean water will become the "next oil", making Canada, with this resource in abundance, possibly the richest country in the world. ===Water for everyone=== There are three ways to improve the availability of drinking water: produce it more, distribute it better to the needy, and waste it less. Drinking water is often collected at spring (water) or extracted from artificial borings in the ground, or wells. Building more wells in adequate places is thus a possible way to produce more water. Other water sources are the rain or the seas. This water however is not adequate for human consumption, and water purification is needed. Popular methods for purifying water are Filter (water), boiling and distillation. More advanced techniques exist, such as reverse osmosis. The distribution of drinking water is done through municipal water systems or as bottled water. Governments in many countries have programs to distribute water to the needy at no charge. Others argue that the market mechanism and free enterprise are best to manage this rare resource, and to finance the boring of wells or the construction of dams and reservoirs. Reducing waste, that is using drinking water only for human consumption, is another option. In some cities, such as Hong Kong, sea water is extensively used for flushing toilets citywide in order to conserve fresh water resources. Water pollution may be the biggest single misuse of water; to the extent that a pollutant limits other uses of the water, it becomes a waste of the resource, regardless of benefits to the polluter. ==Water in human culture== Water is considered a purifier in most religions, including Christianity, Islam, Judaism, and Shinto. For instance, baptism in Christian churches is done with water. In addition, a ritual bath in pure water is performed for the dead in many religions including Judaism and Islam. And in Islam, the daily Salah can only be done after Ablution (Wodoo), that is, washing parts of the body in clean water. In Shinto, water is used in almost all rituals to cleanse a person or an area. Water is often given spiritual powers. In Celtic mythology, Sulis is the local goddess of thermal springs; in Hinduism, the Ganga is also personified as a goddess. Alternatively, gods can be patrons of particular springs, river or lakes: for example in Greek and Roman mythology mythology, Peneus was a river god, one of the three thousand Oceanids. The Greek philosopher Empedocles held that water is one of the four classical elements along with fire, earth and air, and was regarded as the ylem, or basic stuff of the universe. Water was considered cold and moist. In the theory of the four bodily humours, water was associated with phlegm. Water (classical element) was also one of the Five Elements in traditional Chinese philosophy, along with earth (classical element), fire (classical element), wood (classical element), and metal (classical element). A common misconception of water is that it is a powerful conductor of electricity. Any electrical properties observable in water are due to the ions of mineral salts dissolved in it. Water does self-ionize, but only at a very slight, almost immeasurable level. Many bottled water companies exploit another common misconception, advertising both purity and taste, but, as stated above, pure water is tasteless. == See also == * dehydration * desalination * dihydrogen monoxide * double distilled water * drought * evapotranspiration * flood * flume * fresh water * heavy water * holy water * hydrography * hydrology * irrigation * mineral water * precipitation (meteorology) * rain * sea water * transvasement * wastewater * WaterAid * water (molecule) * water quality * water resources * water industry * World Ocean Day * World Water Day == External links == *[http://www.greenfacts.org/water-disinfectants/index.htm Scientific Facts on Water disinfectants] A faithful summary by GreenFacts of a leading scientific consensus report on Drinking Water Disinfectants published by the International Programme on Chemical Safety of the WHO. * [http://www.hkc22.com/residentialwater.html Residential water problems and markets] Study paper from Helmut Kaiser Consultancy * [http://www.hkc22.com/watermarketsworldwide.html Water markets worldwide] Study paper from Helmut Kaiser Consultancy * [http://www.worldwaterforum.org/ World Water Forum] * [http://www.unesco.org/water/wwap/ World Water Assessment Program] * [http://unesdoc.unesco.org/images/0012/001295/129556e.pdf United Nations' World Water Development Report] * [http://www.gemswater.org/ United Nations GEMS/Water Programme] * [http://www.lsbu.ac.uk/water/ Water Structure and Behaviour] * [http://www.wateraid.org/ WaterAid] * [http://www.sahra.arizona.edu/newswatch/ SAHRA—Global Water Newswatch] * [http://www.siwi.org/ Stockholm International Water Institute] (SIWI) * [http://news.bbc.co.uk/2/hi/science/nature/3752590.stm BBC: The water debate] * [http://www.geocities.com/tapvsbottled/ Tap Water Vs Bottled Water] - Interesting site providing facts about tap and bottled water. * [http://www.emagazine.com/september-october_2003/0903feat1.html E the Environmental Magazine piece on bottled water] (Oct 2003). * [http://www.iapws.org/ International Association for the Properties of Water and Steam] * [http://ga.water.usgs.gov/edu/watercycle.html US Geological Survey: Comprehensive discussion of the water cycle, in many languages] Water Beverages Hydrogen compounds Hydrology Materials Natural resources Nutrition Oxygen compounds als:Wasser bn:জল ga:Uisce la:Aqua lv:Ūdens ms:Air nah:Atl nds:Water simple:Water th:น้ำ vi:Nước vo:Vat

Water

== Display in Opera == The page doesn't display correctly in the Opera (browser) browser. I think it has something to do with the image or table floating. It works fine with Opera v7.52. However, the "Thermochemistry" table on the right site doesn't display correctly in IE6SP1. == the "ice skates liquify ice" myth == Should we mention this myth in the article ? http://www.eskimo.com/~billb/miscon/miscon4.html#ice http://www.princeton.edu/~lehmann/BadChemistry.html#Skating Well, the criticism is partially wrong. True, you need more than pressure to liquify ice. I guess is has more to do with friction. But take head: ice skating is only possible because you liqify the ice under your skates. At about -40 celzius, you can't do that any longer, and skating becomes very tough. If not for that effect, Scott's mision to the south pole might have came back alive. User:mousomer > Furthermore, pressure applied to ice will liquefy it, which makes ice skating possible. I don't think this is actually true: it is a common instance of folk-science. Consider, ice is still very slippery even if you're not wearing skates. Also, it's possible to "skate" with ice skates, or shoes, along cement (though quite a bit more difficult because of friction). I certainly agree that ice will phase transition to a liquid under higher pressure, evidenced by the negative slope of its phase boundary curve. I think the bit about ice skating should go, perhaps even replaced by a note to dispell this myth. More data also welcome, as I'm not completely positive. User:MimirZero 04:26 Sep 13, 2002 (UTC) :I think the sentence is correct. The reason that ice is slippery without skates is that you press on it; the reason that it's more slippery with skates is that the pressure is higher. Cement is not liquified by the body's pressure, so you can't skate on it: normally, pressure increases the frictional force, but in the case of water it reduces it. But I'm also not completely positive. User:AxelBoldt 02:01 Sep 14, 2002 (UTC) Nope, the sentence above is quite false. It's true that pressure does decrease the melting point of ice, but it would take ''tons'' of pressure to melt ice at temperatures routinely skated at, so that's not what makes skating "possible". There's actually not much good research in this area, but the best prospects so far include a phenomenon known as "surface melting" where the atoms at the surface of a solid behave in liquid-like ways, regardless of the temperature and pressure; and possibly some heating of the ice by the friction of the blade. One ''can'' skate on dry Teflon, BTW. :We would need the force per area that melts water at skating temperatures; even if the force is large, the small area of the skate could do the trick. Also, the Teflon skating seems to work completely differently, since no melting is involved. It would be more interesting to know if it is possible to skate on materials with comparable melting point to water, but which do not show the pressure-melting point relationship of water. Frozen hexane, maybe? User:AxelBoldt :Data from CRC, 77th ed. : water: ice I - liquid phase boundary: { pressure (MPa), melting point (°C) } : {0.1,0.00}, {1.,-0.06}, {2.,-0.14}, ... {50.,-4.02}, ... {100.,-8.80}, ... {150, -14.40}, ... {200, -20.69} :Data from www.ice-rinks.com/FAQ.htm : ice temperature { hockey, -8.8°C }, { figure skating, -3.3°C } :Data from www.angelfire.com/sd/scsa/scsa.html : speed skates : dimensions { width, 1.1-1.4mm }, { length, 330-457mm } :Assume 65kg adult. Assume -5°C ice and ambient. Assume 1.2mm x 400mm skate blades. :Use g=9.8m/s², F=m*a, P=F/A, A=l*w. :Derive: P = m*a/(l*w) = 1.33 MPa. :Extrapolate ice's MP from data for 1.33 MPa: ~-0.09°C. :Conclude: -0.09>>-5.0°C: Human mass is vastly insufficient to melt ice. :Action: removing skating reference from article :Question: maybe post myth-dispelling math somehwere (and find non (C) source for data?) :User:MimirZero 04:57 Sep 14, 2002 (UTC) ::Conclude: User:MimirZero is possibly a robot. ::Action: Get horribly confused. User:Pmcm 16:32, 19 Sep 2004 (UTC) :::Conclude: User:MimirZero is possibly an alien from a parallel universe known as a ''physics teacher''! :::Conclude: User:Pmcm is a typical physics student : ''constant state of confusion'' :-)
:::I thought it was a good presentation, but I'm a chemistry teacher. I think a discussion of this would be good in a skating or ice article rather than in water. See this also [http://amasci.com/miscon/ice.txt for a good discussion of the phenomenon.]--User:Vsmith 19:46, 19 Sep 2004 (UTC) You are assuming constant pressure across the area of the blade. If the skater's weight is not evenly distributed, perhaps it's conceivable that you could routinely get 50 times the pressure you calculated. Also, hockey skates are concave, so only the two outer edges are ever in contact, which makes the area much, much smaller, and the pressure correspondingly higher. --User:P3d0 19:53, Sep 19, 2004 (UTC) == desert survival == > Desert survival Why is this whole section here? Seems like it should be under "Desert Survival" or "Construction of a Still" not "Water". And I don't think Wikipedia should be a repository for how-to-build-it's either, but that's just me. I'm voting to remove this section. User:MimirZero 05:25 Sep 13, 2002 (UTC) :Procedural information has its place in Wikipedia, but I agree that it's out of place in this article. User:AxelBoldt 02:01 Sep 14, 2002 (UTC) > Warning Ok, maybe I'm just in fanatical-cut mode, but I also don't think Wikipedia should be in the buisiness of prescribing certain behaviors and admonishing others. I think the warnings should be reworked to simply present the facts preferably in the main body of the article. And the alcohol warning should really go under "Alcohol" not "Water" IMHO. I propose that the warnings should instead be dropped: consider if we started putting in things like "Do not use water on a metal fire" "Do not try to breathe water" All these are true, but Wikipedia is not an MSDS database. :Or the discussion of "desert survival" should be shifted to an article on the topic. User:Robert Merkel 05:35 Sep 13, 2002 (UTC) ---- Drinking water on this page links to the same article as Water (resource). User:Ellywa 09:20 20 May 2003 (UTC) ---- What's the bond angle of water? Would it be appropriate to put a 3D model of H20 on this page? I'm just playing around with POV-ray modeler and I was trying to make a molecule using the "blob" feature. But then I needed to know the bond angle of H20. That brought me here, and then I had the idea to put a 3D picture of H20 on this webpage. If I can think of a consistent way to translate empirical bond length/bond angle stuff into a 3D picture then that would be cool. Although there are speciliazed programs which can do this already, like RASMOL, but POV-ray code seems so damn simple. User:Dgrant == potable == along the lines of what was mentioned earlier... but clicking on "Potable" in the article (something like "water that is fit for human consumption is called potable") links to this article... that seems kind-of not helpful, but I really don't know what else should go in the potable article... thoughts? :In the dutch wikipedia the article on potable water contains info on dutch regulations on drinking water, in addition, the history of the devolpment of drinking water might be added in future. User:Ellywa 21:07, 14 Aug 2003 (UTC) ::So... somebody should probably translate the Dutch article (and probably put some regs from other countries in as well), yes? -- User:SS 19:05, 14 Sep 2004 (UTC) == Thermal properties of Water == I forget the terms as it was a long time ago, but should there not be details on the thermal properties of water here - heat needed to raise 1 kg by 1 degree C (or whatever), and also that needed to change phase (solid-liquid, liquid-gas) ? A note on the definition of the calorie/Calorie may also be appropriate. Any "qualified" volunteer ? == Amused? == ''The water dipoles hydrogen bond to the dipolar regions of the sugar molecule and allow it to be carried away into solution. "HELL YEAH"'' I must be the only that finds this anon's enthusiasm about aqueous solutions amusing, right? -- User:SS 18:57, 14 Sep 2004 (UTC) == Pressure-temperature state chart == A pressure-temperature chart showing the regions where water is in each state would be awesome, and make the triple point discussion more obvious. The colour could even add some extra info, such as density. Does anyone have relevent formulas that could be used to produce such a graph, if not such a graph itself? User:Dcoetzee 00:26, 19 Sep 2004 (UTC) == Freezing salt water??? == I'm uncertain about the following:
"Note that this effect only applies to fresh water: sea water contains sufficient salt that the density minimum occurs at the freezing point (approximately -1.9 oC)."
This short note by itself would seem to imply that the Arctic Ocean should be frozen solid top to bottom! We need to include a bit here about salts "freezing out" as salt water freezes. The resulting ice is less salty and less dense than the salt water it freezes from. I'm not familiar enough with the details to feel qualified to edit it until I have time to delve deeper into it. --User:Vsmith 01:48, 19 Sep 2004 (UTC) : (User:William M. Connolley 08:49, 19 Sep 2004 (UTC)) OK, will do. (User:William M. Connolley 08:52, 19 Sep 2004 (UTC)) Oh no I won't... its been done. Should have checked. == Was this major split & rewrite needed? Maybe discuss first. == I think this split & rewrite just made things more confusing. Many parts of the orig version need to be included in both of the new splinters - and quite a bit is in the wrong place. My first impulse was a quick revert, but maybe we need to discuss it - as would have been appreciated before this split.--User:Vsmith 21:17, 19 Sep 2004 (UTC) :I disagree with the rewrite altogether. The chemical properties of water are very closely tied to our daily experiences with it, and the text went out of its way to discuss these ties. Just because you're not a chemist doesn't mean you don't care why the lakes don't freeze solid, why salty water boils hotter, or whether water conducts electricity. :More controversially, I think a featured article candidate should see only relatively small changes until after it's featured. :While I'm not suggesting an outright revert, I do suggest that we revert and that anything the new editor added be merged into the reverted article. I'd like to hear the editor's voice on this though. User:Dcoetzee 22:40, 19 Sep 2004 (UTC) ::Actually, this major rewrite was discussed in the WP:FAC page, where the candidacy was mostly opposed. The consensus was that the page was confusing as it was, and no satisfactory structure had been found. It seemed that the only way out was to clearly distinguish "water for life" and "water (molecule)". I believe that these are 2 very different concepts: drinking water, and pure water. (sorry for the lack of advanced warning in this talk page. I'll learn to be more careful in the future) . Please consider that this is work in progress: feel free to move things from one page to the other, or rework as you wish. User:Pcarbonn 06:30, 20 Sep 2004 (UTC) ::: I withdraw my objections. This seems like it was a pretty good move, as long as there's a prominent link for people with more chemistry background. User:Dcoetzee 00:32, 2 Oct 2004 (UTC) ---- Here is the discussion from the WP:FAC page: (self-nomination) This article covers a lot of ground (or should I say "water" ?), and anybody can learn something from it. User:Pcarbonn 15:10, 18 Sep 2004 (UTC) * Oppose: none of my suggestions were even commented on in peer review. Specifically, I'm confused with the :Image:Water_molecule_dimensions.png. What does it mean? Could you add more information onto the actual image itself? Could we also fix up the 1 sentence paragraphs? Some of the paragraphs could be fleshed out, say for instance "The Mpemba effect is the surprising phenomenon whereby hot water can, under certain conditions, freeze faster than cold, even though it must pass the lower temperature on the way to freezing." - give a bit more info (not the entire article it references, just some more info to make it more complete). Also, the history seems tacked on as an afterthought. I mean, there's water->History->Mythology and water->Water in practice->Water in religion... get my drift? Otherwise, this is a really well researched, well-written article! I would be happy to support it if you can sort out these things (especially a structural organisation). - User:Ta bu shi da yu 16:26, 18 Sep 2004 (UTC) ** Woops ! Somehow I lost your feedback in peer review. Sorry for that. I think that some of your objections have been fixed. Still working on the others... About "expanding 1-sentence paragraph": I'm afraid that the article would be much too long if we did that. It's already quite long as it is. What do you think ?User:Pcarbonn 16:53, 18 Sep 2004 (UTC) ***Hmmm... better, but I still object to one sentence paragraphs - doesn't look that professional. But not too bad. Seems there are a few more objections we could work on though. Now that I'm not concentrating on my exploding whale story so much, I can look into this story. - User:Ta bu shi da yu 13:57, 20 Sep 2004 (UTC) *Support: Very good article. I just re-arranged a bit, joke section & religion - hopefully an improvement. Always work to be done, red links ... etc. --User:Vsmith 16:38, 18 Sep 2004 (UTC) *Object--until the following fixes are made. 1) The Mpemba effect does not belong in the "Water properties" section--because it is not clear what water property causes the Mremba effect. Perhaps you should move the Mpemba effect to a section "Oddities about water." 2) What do you mean by "Water in practice"? This heading sounds like "Communism in practice" as compared with "Communism in theory." Come up with a better heading, please--Maybe something like "Water in everyday affairs." 3) The anthropic principle has no place on the Water page. Take it off. The special properties of water apply to all lifeforms--not to just to anthropoi men. 4) The content of "Systematic Nomenclature and Humor" has nothing to do with the Physics and Chemistry of Water. So you might move it to "Oddities about water." 5) Fire, air, earth, and water is not mythology. That theory by Empedocles was "the theory" used by Aristotle to explain the difference between water and wine. Empedocles's theory was an early form of the idea that matter was formed from unseen Atomism that were not created and will never be destroyed. [http://classicpersuasion.org/pw/empedocles/empalleng.htm] Perhaps you should retitle this section as "Water in early philosophy." 5) The order of the First section (which I will call "Water in everyday affairs") does not make sense; the sections are disarranged, with no logical order. Perhaps you could reorder this section to fix it by sequencing the sections from personal data toward Universal data to give the following order: Forms of water, Water properties, Water in life, Drinking water and politics, Domestic and industrial use of water, Water on earth, Water in the universe. I like the potential of this article, and I think you have done a marvelous job of making this a very interesting page. Congratulations! ---User:Rednblu 20:28, 18 Sep 2004 (UTC) *Object: The article's organization seems very focused on chemistry. I think that someone with no chemistry background would get through the introductory paragraphs of the article, and then founder on "Forms of Water". The chemical information is definitely important, but I think that there's a lot more that can be said -- I think information about the ecology, biology, etc. might want to go first. I think that you should split the "Properties of Water" section -- some of the basic information would be appropriate at the beginning of the article, but things like electrolysis, the Mpemba effect, and other chemistry-specific information would be better later. Also, I think that having one of the photographs at the beginning of the article, and pushing the box of chemical information farther down the page, would make the article easier to read. Basically, remember that many of the people reading the article aren't going to be physicists or chemists; technical information that most readers won't be interested in should be sectioned off, or even put into its own article (Chemical Properties of Water, perhaps) -- User:Creidieki 01:28, 19 Sep 2004 (UTC) *Shouldn't "Water in religion" and "Water in mythology" be merged? -- User:Lord Emsworth 02:10, 19 Sep 2004 (UTC) :* Definitely. - User:Ta bu shi da yu 14:00, 20 Sep 2004 (UTC) *Object - This subject ''should'' be a feature article, but at the moment it shows strong signs of committee editing. Too much of the information is in short single fact sentences. To be considered best writing, many of these factoids should be grouped together and discussed in a more flowing style. I agree with many of User:Rednblu and User:Creidieki's comments, but: :#The anthropic principle should be mentioned in relation to the properties of water around 4�C. The problem is that too much of the rest of the article focuses on extraterrestial water. In particular, way too much in the lead section. :#The Mpemba effect: in or out - I could go either way. Perhaps in a 'see also'. :#A picture of an ocean, or waves crashing on a craggy shoreline would be good. :#The pictures are moving around, but I would have thought a pic or a reservoir would be better than the shower. :#Talking of showers, there is almost no mention of the use of water for washing and cleaning, except in the religion section. That's a little off. :#Talking of reservoirs, why no mention of them or aquifers or anywhere else we get our water from. Or bottled water. :#Water#History section is rather poor. Could be good to merge the religion and early philosophy subsections, along with various views on water as a life force. Similarly should discuss spiritual associations attributed to rivers and springs. E.g. Nile, Gangees and Sulis. :#No mention of the recreational use of water. :Of course, if you put in all these ideas, someone would say the article is too long and it has already had various sections split out. -- User:Solipsist 07:56, 19 Sep 2004 (UTC) *Thanks for the feedback. I'll split the article in 2 : water in (everyday) life, and water (molecule). I'll resubmit to FAC when done. User:Pcarbonn 16:15, 19 Sep 2004 (UTC) :* Cool! I sometimes miss these things, message me on the talk page when you do. Please :-) - User:Ta bu shi da yu 14:00, 20 Sep 2004 (UTC) ==Important properties for life== There have been several conflicting edits on fine-tuning and anthropic principle. I believe that all edits have a bit of truth, and that keeping only one explanation to the unusual property of life is NPOV. Shouldn't we have one short paragraph briefly explaining the various answers as explained in fine-tuned universe, with a link to fine-tuned universe for more details ? And move any further discussion to this article ? : It's not gonna be easy :) -- I personally see no reason for inclusion of ''anthropic principle'' or ''fine tuning for life'' as both imply a ''designer'' and are nonscientific and unfalsifiable. Evolution is ''about'' the ''fine tuning'' of life forms to their environment.--User:Vsmith 22:14, 23 Sep 2004 (UTC) :: Wikipedia is an encyclopedy, not a scientific compendium. It contains many philosophical or religious articles. I do not see why such issues would have to be removed from a "water" article. User:Pcarbonn 06:47, 24 Sep 2004 (UTC) :::OK, then put it in human culture or a Philosophy & Religion section. But, not in the main descriptive sections.User:Vsmith 16:52, 24 Sep 2004 (UTC) :: Neither the anthropic principle nor a fine-tuned universe imply intelligent design; they can only support it, and either may be irrelevant to the idea. They can be expressed scientifically, and frequently are, and they're "unfalsifiable" because they are true. You're certainly free to try living in a universe with different physics or composition, or on a random starless planetoid. In this universe, however, the peculiar coincidences of its existence make it very conducive to matter; the coincidence of Earth being where it is gives it conditions suitable for biological processes; and the aberrant behavior of water makes it especially conducive to life. :: The argument, boiled down, is: ::# The conditions in the universe favor our existence. ::# Small variations in the conditions would make our existence impossible. ::# In fact, almost any conditions would prevent us from existing. ::# This universe is freaking ''weird''. ::# Our universe is weird because we're part of it. :: Therefore the anthropic principle is your own fault, so don't complain. --[[User:Eequor|η">User:Eequor[ υωρ]]] 06:41, 6 Nov 2004 (UTC) :''... and they're "unfalsifiable" because they are true.'' Wow! That sounds like a religeous statment to me. ''It's true: all you gotta do is believe''. To be scientific an hypothesis must be testable or ''falsifiable''. No way to test or falsify = not scientific. -User:Vsmith 17:00, 8 Nov 2004 (UTC) :: Yes, well, observed facts are inherently true. Science is only concerned by why particular observations occur, not by whether the observations themselves have occurred. It cannot change the facts, only interpret them. :::Hmm... ''observed facts'' are not ''inherently true''. Observed facts are our current interpretations of our sensory perceptions or our instrumental measurements of those ''facts''. Thus these ''facts'' are subject to sensory and instrumental error and are not inherently ''true''. Facts, except perhaps the most trivial kind, are subject to re-interpretation and re-measurement by more sophisticated instruments. The facts can and do change with new interpretations based on new theories and explanations undreamed of in previous times. -User:Vsmith 00:56, 9 Nov 2004 (UTC) :::: What I mean is, an observation has a definite existence, regardless of our interpretations. Someone who observes the sky to be blue will always have that observation in their history. It is true that they observed a blue sky. --[[User:Eequor|η">User:Eequor[ υωρ]]] 17:13, 11 Nov 2004 (UTC) :: The anthropic principle is simply a truism. ''Because we observe only the universe, the universe must be in a state that allows us to observe it.'' Such a statement is self-verifying and cannot be false. :::A truism ... had to look that up as I don’t normaly use the term.
:::Found: ''A trite expression or idea: banality, bromide, clich�, commonplace, platitude...''
:::and ... ''Often the word is used to disguise the fact that a proposition is really just a half-truth or an opinion, especially in rhetoric.'' from the Wiki article.
:::So, why would we even use the phrase - as it is indeed either a trite expression or ''just a half truth''. I say be gone with it, not worthy of an article nor any kind of argument. -User:Vsmith 00:56, 9 Nov 2004 (UTC) :: ''Fine-tuned universe'' is a corollary to the anthropic principle. ''There is exactly one set containing every observation we have made or will make, in sequential subjective order.'' Essentially, one's observed universe is "fine-tuned" for one state -- exactly that state which is observed -- to the exclusion of all other possible tunings. It is unnecessary to refer to any specific properties of the universe; all other formulations of this idea concern the same set of observations. Again, this statement is a truism. :::The Universe we observe simply is and is not ''fine-tuned'' for anything. That would imply a tuner out there somewhere - an unknowable. The Universe is as it is. Life in the Universe has developed and evolved in and with the conditions of the Universe and has therefore tuned itself by evolution to the specific characteristics of the Universe that simply are. You state that ''fine-tuned universe'' is a truism. Again, be gone with the trite expression. -User:Vsmith 00:56, 9 Nov 2004 (UTC) :::: It is, however, worth noting that water is necessary to our existence. Thus, we can also make stronger statements about the fine-tuned universe. ''Since water is necessary for our existence, the set containing our history must contain water.'' --[[User:Eequor|η">User:Eequor[ υωρ]]] 17:25, 11 Nov 2004 (UTC) :: In other words, ''anthropic principle'' and ''fine-tuned universe'' are invariant truths for all observers. It makes no more difference whether one believes in them, than whether one believes in one's own existence. Each observer can verify the statements' truth by carefully conducting thought experiments about what, exactly, ''consciousness'' and ''self'' mean. ::: ''Thought experiments'', good mental excercise. Didn't think we were discussing ''consciousness'' and ''self''. Different horse, different ride :-) -User:Vsmith 00:56, 9 Nov 2004 (UTC) :::: But of course we are! ^_^ :::: Must not all observations be observed by a ''self'' and interpreted by a ''consciousness''? --[[User:Eequor|η">User:Eequor[ υωρ]]] 17:19, 11 Nov 2004 (UTC) :: The idea that falsifiability is somehow necessary to the scientific method is an unfortunate but widespread error. Science survived quite well before the 20th century. The possibility that an observer's interpretation of their observations is based on incorrect assumptions is irrelevant to their existence. If a reasonable observer does, in fact, observe their interpretation is flawed, they will discard assumptions which have been demonstrated to be incorrect. An unreasonable observer will discard the observation as spurious. Neither has any inherent interest in knowing in advance whether they will make a contradictory observation. :: In particular, thermodynamics and theory of relativity both refute the idea that "falsifiability" means anything at all. --[[User:Eequor|η">User:Eequor[ υωρ]]] 19:59, 8 Nov 2004 (UTC) :::''The idea that falsifiability is somehow necessary to the scientific method is an unfortunate but widespread error.''
:::Nonsense. A scientific theory or hypothesis is worthless if it cannot be tested. It must make predictions that can be tested, in other words - falsifiable - there must be a way to check its validity, to see if it is error. Other scientists must be able to either reproduce the results or falsify the theory if they cannot. Einstein’s relativity theory has been tested repeatedly on various points. It is a scientific theory because it makes predictions that can be and have been tested. But, then I gather from your responses that you really do not know what ''falsifiability'' means. -User:Vsmith 00:56, 9 Nov 2004 (UTC) :::: ''Falsifiability'' isn't the same as ''verifiability''. One can verify the truth of a hypothesis without needing to know whether it could be proven false with other knowledge. One can also act on the discovery that a hypothesis is false without prior awareness that it could have been false (and, at that point, "falsifiable" becomes a truism anyway). There is no particular reason one might need to know whether something can be proven true or proven false; one must only be able to state conditions which are ''sufficient'' (truth) or ''necessary'' (falsehood). :::: In the case of the anthropic principle, a sufficient condition for its truth is the fact that we observe the universe. One might say that ''fine-tuned universe'' is concerned with stating the ''necessary'' conditions for us to exist. --[[User:Eequor|η">User:Eequor[ υωρ]]] 17:01, 11 Nov 2004 (UTC) ==Fats in evolution== Also, could some one explain to me why the following sentence was "not making sense", and therefore removed ? ''"Fatty substances can also create membranes, separating an "inside" from an "outside". This allows the creation of individual cells, their competition for resources, and the process of evolution through natural selection"''. Life without cells wouldn't be life, right ? Thanks. User:Pcarbonn 18:24, 23 Sep 2004 (UTC) : I put back in -- makes sense to me. However, it may need a tie in sentence for clarification.--User:Vsmith 22:14, 23 Sep 2004 (UTC) : It's vague and makes unfounded claims: :: ''Fatty substances can also create membranes, separating an "inside" from an "outside".'' :# "Inside" of ''what''? :# How is this relevant to properties of water? :# Why must cell membranes be composed of hydrophobic substances? :: ''This allows the creation of individual cells, their competition for resources, and the process of evolution through natural selection'' :# This suggests that cell membranes are composed only of lipids. :# It jumps to the conclusion that cells compete for resources, and that competition at the cellular level is the basis for natural selection. :# It claims natural selection is required for evolution. :# The argument that evolution is required for life belongs in a different article; why imply that here? :# How is this relevant to water? :# If water ''is'' a significant part of natural selection, the connection probably deserves more than a single sentence. :: ''Life on earth has evolved with and fine tuned itself to the important features of water.'' :# Water does not evolve. :# This is the conclusion of the section; in what ways has life fine-tuned itself to water? The preceding paragraphs do not discuss that. :# This appears to be a misunderstanding of the idea of a fine-tuned universe, and if that was the intent, it is backwards. The properties of water appear fine-tuned for the development of life; life is not necessarily fine-tuned for water (see extremophile). : --[[User:Eequor|η">User:Eequor[ υωρ]]] 05:46, 6 Nov 2004 (UTC) :No - water doesn't evolve (I didn't say that) - living things do. And they did evolve to utilize the many neat properties of water. This is an exact understanding of ''fine-tuning'' in the universe. Living organisms evolved with and fine-tuned themselves to utilize all the neat physical properties of their environment. Yes, extremophiles fine tuned themselves through evolution to adapt to and utilize some pretty bizzare environments where they had little competition. They still utilize water. -User:Vsmith 17:14, 8 Nov 2004 (UTC) == Unusual properties == Please note that water's part in the greenhouse effect is ''not'' unusual, nor due to its polar molecule nature, nor even necessary (despite its prevalence). One might easily imagine dust clouds which reflect, rather than trap, heat. --[[User:Eequor|η">User:Eequor[ υωρ]]] 05:52, 6 Nov 2004 (UTC) : This is incorrect. Water accounts for nearly all of the atmospheric greenhouse effect despite the fact that it is a trace element in the atmosphere. The reason is that it is largely transparent to visible light, but readily absorbs outgoing infared radiation. I cite /Global Physical Climatology/ by Dennis L. Hartmann --dikaiopolis :: Opacity to infrared light isn't particularly notable, is it? Lots of compounds block that. Is water unusually opaque to infrared for its transparency to visible light? --[[User:Eequor|η">User:Eequor[ υωρ]]] 06:51, 6 Nov 2004 (UTC) :: Incidentally, you've used the word ''extreme'' very many times, as well as a doubly emphatic ''extremely crucial''. --[[User:Eequor|η">User:Eequor[ υωρ]]] 07:03, 6 Nov 2004 (UTC) ::: Well feel free to edit my emphasis. But no, opacity to infared light is *the* mechanism of the greenhouse effect. And no, not very many compounds in the atmosphere *absorb* (not "block" -- energy is absorbed) infared, precisely because they have no dipole moment. If you look at common atmospheric compounds -- N2, O2, CO, N20... none of these have dipole moments, and have very low absorptivity in infared bands. If you want to learn about this, look up my reference which should be available in your local library. Page 48 shows a nice graph of absobtivity of atmospheric compounds as a function of wavelength. ::::The criterion for whether a molecule abosrbs infrared is not whether it has a dipole moment, but whether that dipole moment changes as it vibrates. For example, carbon dioxide does not have a dipole at rest, but some of its vibrational modes give it a dipole that fluctuates about zero. User:Shimmin 12:02, Mar 28, 2005 (UTC) ::: Also, you could take a look at the first hit on google: http://www.everythingweather.com/atmospheric-radiation/absorption.shtml -- "Absorption is mainly caused by three different atmospheric gases. Contrary to popular belief, water vapor causes the most absorption, followed by carbon dioxide and then ozone." I also know that carbon dioxide is orders of magnitude less absorptive because it only has a dipole moment when one of its degrees of freedom is excited, where as water has a dipole moment always. :::: Oh, I see. That's very interesting! Is water's absorption expressed by its dielectric constant, or is that slightly different? How is its permeability related? --[[User:Eequor|η">User:Eequor[ υωρ]]] 13:15, 6 Nov 2004 (UTC) ::::: They not really related. I'd be happy to explain to you the general message on IRC or E-mail. The short answer is that it has to do with electric dipole moment. Electric dipole moment may be related to dielectric constant in some tricky ways, but it is not really relevant here (that I can see offhand). Also, I took a look at the greenhouse effect page, and it has some info on the relative absoptive effects of the various greenhouse gasses. It's not a very complete explaination -- it turns out that it matters specifically *what* type of radiation water absorbs -- but the gross picture is there. -- user:dikaiopolis == Table == Howdy y'all, i havent edited this page before, so before i rush in and do something ill run it pass you all, in case there is some consensus about it that i dont know of. What do people think of the table on the (obviously translated into english) for this page? User:The bellman 00:37, 2004 Nov 30 (UTC) :Hi - check out water (molecule) the technical page that was split off this a month or so ago. It has that table - which used to be here. Seems someone thought it was too long so it was split. -User:Vsmith 02:23, 30 Nov 2004 (UTC) == Deltas == When describing a delta, it uses delta as a plural word. Is this correct? == Etymology == Are you sure the word is borrowed from Low German, isn't Old English w�ter a more plausible origin? ==Spelling Style == There have been recent edits switching back and forth between American and British spellings, esp. color/colour and odor/odour. Comments: # Failing to decide on whether we use American or British style can result in a lot of back and forth edits to no real purpose. Guidance: Wikipedia:Manual_of_Style#National_varieties_of_English # If we settle on British style, it should be consistent - hence vapour instead of vapor. ::--User:WCFrancis 14:54, 3 Jun 2005 (UTC) :Policy dictates that the first major contributor's spelling should be the preferred style of English. I would consider [http://en.wikipedia.org/w/index.php?title=Water&diff=7775&oldid=7651 this] to be the first major contribution, which would favor American English, but a case could also be made for [http://en.wikipedia.org/w/index.php?title=Water&diff=295602&oldid=295601 this] as being the first major contribution, which would favor Commonwealth English. :It seems now that we need to decide which version constitutes the first major contribution. Failing that, we could always try to reword some passages so that they need not favor any dialect of English. :User:Darrien 21:00, 2005 Jun 3 (UTC)

Water

Materials Inorganic compounds Natural resources th:Category:น้ำ

Water

I'm looking for a good sub-category name to encompass all aspects of the "water industry", from reservoirs through domestic water systems to :Category:Sewerage. The best I've been able to come up with so far is :Category:Water industry, which seems a bit lame. Any better ideas? --User:JTN 16:24, 2004 Nov 9 (UTC)

See other meanings of words starting from letter:

W