Questions tagged [water]

A chemical substance with the chemical formula H₂O, and an important biological solvent.

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222
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4answers
27k views

Does hot water freeze faster than cold water?

Is it true that hot water freezes faster than cold water and if so, what practical applications have there been found for this phenomenon?
81
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2answers
12k views

Is drinking water during a meal bad for you?

I have heard that it will "wash away the nutrients", that it dilutes stomach acid and all kinds of things. Is this just an old-wives tale?
58
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1answer
13k views

Does anybody spend 6 hours each day just to get water?

During the 2018 Super Bowl there was a commercial advertising a campaign to help bring fresh water to people in developing countries. It argued that fresh water is grossly easy to attain in developed ...
55
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1answer
50k views

Do laws exist that say restaurants must serve customers who request tap water?

My mother claimed the other day that it is a "state law" that any restaurant must serve customers tap water upon request, therefore not requiring customers to buy a (flavored) drink or (overpriced) ...
53
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4answers
12k views

Does water swirl the opposite way on the other hemisphere?

I have heard this one several times but was never given a convincing explanation. Is this a real phenomenon? (Bonus points for a good physical description of the behavior or reasons it couldn't occur....
50
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2answers
4k views

Do people need to drink 8 glasses of water a day?

Since I was a kid, I can't remember how many times I've heard that a healthy person needs to drink at least 8 glasses of water a day. There are definitely plenty of reasons to remain well-hydrated. ...
44
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3answers
25k views

Is watering plants under a hot sun bad?

A couple of people have told me that it's a bad for plants to be watered in the middle of a sunny day, i.e. it's not just that you waste more water due to evaporation, but that there are actually bad ...
41
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3answers
3k views

Can microwaved water explode?

Some time ago I read a warning that microwaved water can "explode" under certain circumstances. There was one case as an example where someone heated water in the microwave, took it out and then it "...
41
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1answer
22k views

Does Disney have the third largest navy in the world?

Does Disney really have the world's third/fourth/fifth/sixth/seventh largest "navy"? I've often seen this claim being bandied about on trivia sites and the like. But there are never any credible ...
41
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1answer
4k views

Is refilling water bottles bad for you?

On a lot of bottles of so called mineral water, it is advised not to refill the bottle (with ordinary tap water, or any other drink e.g. cola) as doing so may present a health hazard. Is there any ...
40
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2answers
56k views

Is there a place in the world where two oceans meet and they don't mix?

This picture is currently being spread virally: Some Muslims were saying that this is mentioned in the Quran where it is said: He has set free the two seas meeting together. There is a barrier ...
38
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3answers
4k views

Is water fluoridation harmful?

There’s a controversy going around whether the benefits of water fluoridation outweigh the potential harms. What is the evidence for the harm this may cause and what evidence supports the health ...
37
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2answers
9k views

Does drinking distilled water remove needed minerals from your body?

Claim: Drinking distilled water can actually remove needed minerals from the body, due the lack of minerals in the water, and therefore do damage to the body. I have a hard time accepting this due ...
36
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1answer
12k views

Is it beneficial to drink alkaline water (aka Kangen water)?

At a friend's house the other day, some sort of contraption had appeared near the sink since the last time I had been there. It was a filtration-looking device with one input hose connected to the tap ...
35
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1answer
4k views

Has it ever rained fish?

There have been several reports of "raining fish" where fish fall from the sky (usually during a rain storm). An example such as this 2010 video from National Geographic seems unlikely at best. Has ...
34
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2answers
40k views

Do magnetic water softeners work?

I'm extremely skeptical of the idea of magnetic water softeners (strong magnets attached to pipes), but desperately wish it were true because I hate lugging 40# bags of salt out to my well house in ...
34
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2answers
6k views

Should we drink water before we feel thirsty?

The claim is that we should be drinking water routinely to the point that we never feel thirsty, and that to not be doing so is to our detriment, at least enough for the notion to be popular amongst ...
33
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3answers
26k views

Do knives get dull in dishwashers?

Everybody keeps telling me don't put knives in dishwashers. And if I ask them why, nobody seems to have an answer or an argument to support his/her advice. So I thought I'll shoot the question to ...
30
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1answer
37k views

Did the Nazis maliciously fluoridate drinking water?

Firstly, I think this is a stupid unbelievable question. However, for the sake of getting on S.SE, is there any evidence to for the Nazis using fluoride maliciously for example, to make prisoners more ...
28
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1answer
4k views

In California, is water from the north diverted into the Pacific Ocean?

Possibly addressing the Californian wildfires, president Donald Trump claims that in California "water coming from the north" is "being diverted into the Pacific Ocean". Governor Jerry Brown must ...
28
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2answers
2k views

Does dowsing (aka Water Divining) work?

Also known as water divining, the more general term is dowsing. Practitioners claim to be able to detect minerals and even specific objects. I first became interested in dowsing in my teens, when the ...
25
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1answer
2k views

Can anything be 'more hydrating than water'?

Some sports drinks, and even vegetables claim to be 'more hydrating than water'. What does this even mean? How is 'hydration' even measured? If I ate enough cucumbers could I survive without ever ...
25
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1answer
14k views

If you put your hand in water while sleeping/drunk, will you pee yourself?

This is like an urban myth and a classic prank, but I never saw it in action. Supposedly if someone is passed out or sleeping, the contact with water will make him pee. Is this true? If true, why ...
24
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2answers
12k views

Has 99% of the western continental Europe banned water fluoridation?

I keep seeing this claim about the unpopularity of water fluoridation parroted. Despite dental pressure, 99% of western continental Europe has rejected, banned, or stopped fluoridation due to ...
24
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1answer
19k views

Is it dangerous to mix boiled and unboiled water?

There is a popular belief in Russia that mixing boiled and unboiled water (say, adding cold unboiled water to a cup of tea to cool it) can be dangerous for one's health, even if it is safe to drink ...
24
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2answers
13k views

Can boiling water break car windows?

A friend of mine in Australia has heard from several of her friends that it's unsafe to pour boiling water on car windows in order to defrost them. Online examples of people claiming it's unsafe ...
24
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4answers
6k views

Are slick bicycle tires more slippery in the wet?

I always assumed slick (tread-less) tires were more prone to loss of traction in the wet. That is until I read this answer on the bicycles SE which claims that bicycle tires are too thin, round and ...
23
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2answers
3k views

Do fruit/vegetable washes effectively remove pesticides?

Is there any evidence to suggest that commercially available fruit/vegetable washes can effectively remove pesticides from produce? Here are some example claims: Veggie Wash uses natural cleaners ...
23
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2answers
2k views

Is bottled water more contaminated than tap water?

According to some NPO's such as the Australian Centre for Independent Journalism and the Environmental Working Group: Bottled water is constantly promoted as pure and natural, but research by the ...
21
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2answers
12k views

Is water calcification bad for your health?

I have a friend, who adamantly believes that water calcification causes a number of problems, including poor health. He also said it made the water taste disgusting. He had recently installed a ...
21
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1answer
4k views

Does Masaru Emoto's experiment show human consciousness affects the aesthetics of water crystals?

Japanese author and doctor of alternative medicine, Masaru Emoto claims that water can react to intentions. Talk nice to water and you get nice looking ice crystals from it. Mention Adolf Hitler near ...
20
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1answer
6k views

Does one hamburger take more water to produce than 2 months worth of showering?

One hamburger requires 660 gallons of water to produce – the equivalent of 2 months’ worth of showers. Per http://www.cowspiracy.com/facts/ from Catanese, Christina. “Virtual Water, Real Impacts.” ...
20
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1answer
18k views

Do hot baths damage skin or nerves?

I like to take showers and baths hot enough to leave my skin pink when I come out. One of my friends has a much lower tolerance to hot water and has said that that soaking in hot water can damage the ...
20
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2answers
15k views

Is drinking hot water more beneficial during hot weather?

I heard from various sources since I was growing up that during hot weather one should drink warm or hot drinks and during cold weather one should rather drink cold drinks, but a quick google found no ...
20
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0answers
28k views

Does adding a dry towel to a load in the dryer make it dry faster?

Is there any truth to the claim the a dry towel can actually speed up the drying process? There are numerous different sources that I've heard claim this, here is one on voices.yahoo A few months ...
19
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1answer
15k views

Did an elite Kenyan athlete help an armless runner drink, losing $10,000 prizemoney as a result?

From WTF Facts A Kenyan elite runner passes water to a dehydrated disabled Chinese runner who was suffering. This slowed her time. She came in 2nd in the race not only costing her the win but ...
19
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2answers
1k views

Does hydraulic fracking endanger the drinking water supply?

According to an industry website the process of Hydraulic Fracturing (or "fracking") is safe. According to an article in the Huffington Post the process is not safe. At least, there is evidence the ...
19
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2answers
12k views

Does drinking warm or hot water aid in digestion?

One of my brother-in-law's coworkers claims that drinking hot water (straight from the tap) aids in digestion. I've been able to find a debunking of cold water causing cancer, but can't find anything ...
18
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1answer
33k views

Will fluoride and chlorine dissipate from tap water left to sit overnight?

One common recommendation for watering house plants with tap water is to allow the water to sit overnight before watering, so that the fluorine and chlorine that are commonly added to tap water (which ...
17
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2answers
9k views

Can you breathe underwater using bubbles of air?

A very popular videogame character, which is famous for his sonic speed, is depicted breathing underwater by using air bubbles. Now since I've never heard anyone complaining about this, despite the ...
17
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1answer
3k views

Can magnets be used to clean laundry?

According to the Magnetic Laundry site, magnets can be used instead of detergent to clean laundry! For a "scientific" explanation, their video states: These magnets work at an atomic level to ...
16
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3answers
6k views

Is there any reason to use cold water over hot water for boiling?

I was always told that boiling cold water in a pot is better for you then boiling warm or hot water (from the sink). Is there any truth to this statement?
16
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1answer
2k views

Does it take 200L of water to make a latte?

I just saw this Youtube clip that claims it takes 200L of water to make a latte. Is that true?
16
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3answers
3k views

Can an electronic device reduce scale buildup in waterworks?

I have recently received an ad for a device attaching to my inlet water pipe and a power socket, and claiming to massively reduce the scale build-up. This compact, computerised limescale remover ...
16
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1answer
837 views

Is urine the cause of redness of eyes (in swimming pools)?

According to abc13.com, Chlorine in swimming pools don't make your eyes red, it's the urine. Quoting from the article: One of the most shocking revelations the CDC shared was the truth behind what ...
16
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2answers
12k views

Does Indian Water Therapy have healing effects?

Indian Water Therapy is an ancient practice which involves drinking 1-1.5 litres of water every day as soon as you wake up, then not eating anything until 40 minutes has passed, at which point you can ...
15
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1answer
25k views

Are there any benefits to drinking 1.5 liters of water first thing in the morning (water therapy)?

I'm not sure the origin of this "water therapy", but I've seen various websites that claim that drinking 1.5 liters of water right when you wake up is great for your body/mind, heals all diseases, etc....
15
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1answer
10k views

Is chlorine in water absorbed quickly through the skin?

I recently saw a demonstration of a water filtration and purification system. In one of the demos two glasses were filled with tap water and then someone put three fingers into one of the glasses and ...
15
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1answer
4k views

Does it take 20000 L of water to produce 1 kg of cotton and 130 L to produce 1 cup of coffee?

http://everylastdrop.co.uk/ says "When you consider the water required to produce all the stuff we consume, we actually guzzle a massive 4,645 litres every day". It then lists several specific cases, ...
15
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2answers
19k views

Is it better to water lawn in the morning or in the evening?

Some gardening sources recommend watering lawn in the morning, with the reason being water is needed for photosynthesis, and the grass can use it straight away after watering. Some sources say the ...