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Why do humans need such a variety of foods when animals usually only have one and get so much bigger and stronger then humans? | Different organisms require different vitamins/minerals in their diet. Some organisms can manufacture said items internally and some need to ingest them. Animals with highly specialized diets have evolved to function that way. Also as noted simply because humans have a variety of foods available to us does not mean we ... |
How can Man be certain we haven't cross-contaminated other planets and the moon as a byproduct of our exploration? | We don't know 100% that they are clean, but we do know 99.99%. The organisms here on earth simply would not survive on either surface. The environments are extremely hostile to organisms which require oxygen and water to survive. Furthermore, in the time frame of millions of years, it's much more likely we'll directly ... |
Why do currency exchange rates rise and fall? Who does the calculations for the changes? How relevant are the changes for me as an average (UK) consumer? | Currency exchange rates rise and fall based on the comparative pricing. If an oz. of gold costs 1000 pounds, and 100,000 yen, then 100 yen is equal to 1 pound. If the cost adjusts in either place, say, it is now 102,000 yen, then people will want to trade their 100 yen for a pound, in order to buy gold. When that happe... |
Why can't they/won't they extinguish the "door to hell" in Derweze, Turkmenistan? | They could extinguish it for example with some explosion that would momentarily consume all the oxygen. But it's in the middle of nowhere and Turkmenistan already is very rich in natural gas, so they really haven't had strong incentive to do anything about it. |
Why is it when you're drinking lots of beer your pee is clear but when you're dehydrated your pee is dark orange. Even though beer makes you dehydrated | The center of regulation for many bodily functions is the hypothalamus. When it detects that the body is getting dry, it releases a hormone called ADH which tells the kidneys to save water by concentrating urine. Beer is about 90-95% water anyways, so your body will naturally have to release that liquid. However, the a... |
Why do so many Americans claim to be of Irish heritage yet none of them claim to be of English heritage? | [This article goes in depth about possible reasons] which I'll try to tl;dr here in some bullet points * English heritage wasn't as bragged about post-revolutionary war* English heritage was also so common there was no reason to brag about it if everybody else was that way* Irish and Scottish heritage was exemplified b... |
I've always heard that email is not a secure form of communication, so how can it be a crime to read or forward an email which was not sent by/to you? | Passing out drunk in the street is not a way to secure your wallet, but stealing someone's wallet while they are passed out drunk in the street is still a crime. How easy it is to commit a crime doesn't have anything to do with whether it is a crime or not. |
How does salt kill bacteria? | Salt draws water of cells through a process known as osmosis. Where the cell membranes attempt to balance the salt-water concentration inside the cell and outside the cell. With sufficient salt, the bacteria cell is dehydrated. The opposite of that is water intoxication. _URL_0_ _URL_1_ |
Are there known evolutionary reasons that humans have a sense of aesthetics? Ex. Thinking that trees are beautiful, puppies are cute, art is beautiful, music sounds good, etc. | Several. The art and music builds group cohesion. You are attracted to your own group's art and music which makes you feel connected to other members of your group. Young animals and other "cute" species have facial proportions similar to our own young. We find our young cute so that we, you know, like them and that re... |
How do we know that prehistoric Earth only had one super-continent? | There are certain elements of rock strata that can be traced to a single development. For example the famous tip of the Matterhorn consists of metamorphosed granites and gneisses which is identical to the composition of parts of the Apulian plate which is part of Africa. It is incredibly unlikely that such identical co... |
Is there a difference in UV protection between cheap $10 sunglasses and expensive ones? I'm afraid the cheap ones will dilate my pupils and let in UV light. | If the sunglasses are certified as UVA/UVB protective, then it shouldn't be a problem. UV protection is cheap to apply. However, cheaper sunglasses may wear out quicker if you store them in an area where the lenses get rubbed a bunch , but I can't find any data on that. The main differences between cheap and expensive ... |
What are antioxidants and why are they so praised by food labels? | Antioxidants are just vitamins. A, C, and E specifically. There was some research that these helped fight free radicals in your body . Then the dying blueberry industry went "HEY!! Blueberries have those! Hey everyone, look! Antioxidants will save your life! Eat blueberries and don't get cancer! We're a superfood!!" Th... |
what is the difference between a scripting language, markup language, and a compiled language? | The difference between compoled and scripting language is much smaller than between those and a markup language. So scripting languages are interpreted and executed on the fly every time you execute your script. A compiled language is prepared for execution once and then just run every time you use it. Markup languages... |
Why isn't there any way for me to live without being ruled by some government? | [You can.] If you live with any number of other humans you'll form some sort of a societal structure. Before long, you'll have yourself a primitive government. |
Why are my old smartphones (2013) so slow today doing simple stuff like photos and internet browsing when it could run Playstation 3 graphics games with ease? | Planned Obsolescence. _URL_0_ Basically, if you make the perfect product, then people would not need to replace or buy a new version. However, if you ensure that your product degrades over time, then you'll force your customers to make repeat purchases. |
Why does a blood pressure cuff inflate to a much higher pressure than my blood pressure? | They do this because they are listening for the first time, and then the last time that they can hear your heart beat through the stethoscope. basically inflating it to well over your blood pressure just makes it easier. If they only inflated it to 100 the first time they would have missed it. |
what are the biological, psychological, or other scientific explanations as to why humans seem to be so attracted to violence? | The capacity to do violence effectively is pretty much a life-skill of every other animal on earth. We are lucky that lots of smart humans came before us and set things up so tons of us get to just sit on our asses and enjoy our lives but that doesn't mean we aren't still hard coded to fight. Play and sport are both ju... |
the benefits and drawbacks of the UK leaving the EU | Pros * We would stop sending money to the EU each year, which is in the £10 - 15 billion range.* We would no longer be obliged to allow unlimited movement of nationals from the EU to the UK.* We would be free to pursue our own trade policies .* We would no longer have to follow a variety of EU directives and legislatio... |
What would be the environmental impact if everyone who drank cow milk switched over to vegan milk (coconut, almond, cashew, etc)? | I did some back-of-the-envelope calculations and found that almond milk still uses far less water to produce compared to cow's milk. --- Standard commercially available almond milk contains about 2% almonds. [Source 1], [Source 2] 1 almond weighs about 1.2g. [source] There are about 28 grams of almonds in a 48oz bottle... |
Why is there a cannabinoid receptor in our brain? | The human body produces [endocannabinoids], which are molecules that bind to those receptors. It just so happens that several species of plant, the most notable of which is cannabis, also produce variations of cannaboid molecules that can bind to those same receptorsThat's kind of like asking, "Why are there capascin r... |
How does the reusable gel heating pads work? | There is a chemical mixture inside, that when excited produces a self-sustaining exothermic reaction. What this means in layman speak is that the reaction, once started, will continue on its own until it runs out of material, and that the reaction releases heat. When you heat the pads afterwards, you are using heat to ... |
How does modern agriculture work? How do various factors lead to large yields i.e. 200 bu./acre for corn. | Pesticides remove organisms growing there which we do not want. Using herbicides removes unwanted plants that compete with the crops for sunlight, water and nutrients in the soil, and insecticides and fungicides kill organisms which damage the crop and reduce the rate at which they grow. Biological controls can also be... |
why do I see servicemen in their Camo "gear" around college campuses? | They might be ROTC cadets wearing their uniforms. Is there a military installation nearby? I wore my uniform when I went to class on my lunch break. I went back to work afterwards.Army and Air Force ROTC will wear ACUs on days when they have to go to a lab and/or class. ACUs are the camo variety. Navy dresses up a lot ... |
How do people make those celebrity face collages made out of pictures of people's faces? | Either they spend a long time getting the colouring right, or they use a computer program to do it for them. Probably the second one. Also some of the pictures have tones of colour added to them to make them fitThere are multitude of programs that can do this for you. Essentially it lays out a grid of pictures based on... |
Why are there glaring, unfair salary differences among race in America? | There is almost no salary difference *at the same level/job*. That data is the median income for a family based on race. The problem is that many Black and Hispanic people are working lower income jobs, dragging the median down. Asian people tend to work higher paying jobs so their median is higher. |
How do we find out who exactly died in an air strike against terrorists? | The answer to this question falls to the US Intelligence Community and its partners throughout the world. There is a lot that goes into "targeting" a suspected terrorist - I mean a LOT. Targeting analyst teams may very well spend years focusing on and tracking one individual, or his/her close circle. This process invol... |
What do you know of the Order of De Molay? | I wasn't a member, but I know a bit about it from its association with the Freemasons as a Master Mason. From what I could tell after checking Wikipedia, it's a bit like a cross between the Boy Scouts and the Freemasons. Members of deMolay are boys between 12 and 21 years of age, and the adult supervisors are “Dad” and... |
If the quality of film is so good, then why is it dying? And if so many filmmakers prefer film to digital, then why aren't they sticking with it? | Simply put, digital is a lot cheaper. When you record something on film, all of it goes onto the film, even the mistakes the actors make, which you then have to cut and try again and again until they get it right. With digital it's no biggie, you can record as much as you like and it won't cost much extra. Digital is a... |
why is private education in England called "public school"? | A small number of older private schools are known as "public schools". When they were founded, the name made more sense because it indicated that they were open to the general public rather than being tied to membership of a particular church or other organisation. Other private schools tend to refer to themselves as "... |
How do "framerates" make a difference in videos? | simplifying u/Ging1721 's answer, Got a slow blinking light? even a car's indicator will do now start it and blink your eyes in such a way that when you open them it seems like the light isn't actually blinking but is constantly on This is exactly what happens in the video you saw! The camera which records at 30 - 60 f... |
How does the fuzzing of Up- and Downvotes protect against (Spam)Bots on Reddit? | By obscuring the true vote counts, a bot doesn't know if they've been banned or not. Reddit has a type of ban where your account is banned from voting, but you're still able to login, view content, etc. They use this type on detected bots because it stops the bot from knowing it's banned. If you detect a bot and ban th... |
Why do high schools even bother teaching second-language classes with methods that are demonstrably completely ineffective at teaching even a basic level of competence? | For the same reason tests are given as multiple choice, rather than short answer, and education is given as a, "memorize these facts and regurgitate them later,": the system is poorly designed from the bottom upI really wish that the one method of learning that public schools taught students from a very young age/grade... |
If you regenerate all your cells and, get a new body, so to speak, how come scars don't disappear? | Tissues are groupings of cells. Scars occur when there is damage to the structure of the tissue, so that, when the cells are replaced, the new cells are in a different "structure." That is, the cells are the same, but the way the cells are placed in the tissue is changed because of the damage to the skin/body. The diff... |
Mini ice age and irreversible global warming | We have known about the effects of solar activity on our weather. The Sun is in a 11 year cycle with lower and higher solar output. And these cycles does create some fluctuations in global temperatures. We are currently in a stage in the cycle when activity is reducing. And the current cycle have been smaller then the ... |
Why do the numbers on a digital clock appear to shake when I'm brushing my teeth? | It's due to the nature of the LED display. The Light Emitting Diodes flash on and off, virtually imperceptibly, so they appear to show a constant light. However, if you vibrate either your head or the light source fast enough, it will cause an optical illusion similar to how you would perceive movement in a dark room w... |
How did Russia become so much bigger than any other country? | They conquered *a lot* of sparsely populated land in Northern Asia. Much of the landmass of today's Russia is still very sparsely populated and inhospitable. Prior to the 16th and 17th centuries no major nearby settled state had a particular strong interest in these areas. *In Asia, control over populations was general... |
why do cowboys say "yeehaa"? | It's really kind of a mistake that we think that. People driving horses would say "gee" and "haw"; the same way people on boats use port and starboard instead of left and right. _URL_0_It carries well so the cattle can hear it. Kind of like sooeee with pigs. At least with goats and sheep, people got wise and used a hor... |
The difference between uninstalling a program and deleting all the program files? | There are a few extra pieces of information that your computer stores, called registry entries. Uninstallation removes these, while deleting program files does not. The extraneous registry entries don't take up much space, but they make it harder for your computer to find a useful registry entry among all the junk. |
Why aren't there more Asians in MMA and UFC in the Western world? As the birthplace of many martial arts, you'd think there would be a much higher participation by Asians? | a couple reasons. Number one, talented Asian fighters stay in fight in Asia. They make more money and have better prestige there. Also, Asian fighters are actually pretty well represented in the lower weight classes, but they don't fight far below their weight like a lot of other fighters do, because, well, they can't.... |
What is the federal funds rate, and why does it have such a significant impact on things such as the strength of the dollar, the selling-off of government bonds, and the global economy? | It's basically the interest rate at which the federal reserve lends out money to banks . Why is it important? Well, first because a lot of other metrics are tied to it , and banks will often loan money at a rate of "fed funds plus X" or "LIBOR plus X." Generally, lower fed funds rates makes it easier for banks to borro... |
How come animals we keep around the house can't catch the common cold? | Colds are caused by viruses which generally try to get the cells to accept them by binding to proteins on the surface of the cell. Think of the protein as a lock and the virus as a burglar who managed to steal your keys: the lock doesn't know the difference and lets the burglar in. Your pets have slightly different cel... |
Who makes malware, viruses, and trojans? | Pretty much anyone with a knowledge of computer programming and code. As to why they make viruses/malware/trojans and their motivations really varies from person to person and could be for a multitude of reasons .I've always assumed it was bitter Eastern Europeans.There are alot of malware/spyware programmers who have ... |
Why is Spanish the only language that uses upside down exclamation and question marks? | In Spanish, unlike English, questions and statements are often worded identically. For example consider, "You like apples" versus "Do you like apples". Even without punctuation, you can tell the first sentence is a statement and the second sentence is a question. In Spanish, both the statement and question would be wor... |
Hot/Cold water piping. What made it so flushing the toilet while somebody was in the shower got hit with either really hot or really cold water, and how that is fixed in modern places. | One of the most common plumbing configurations is a trunk and branch system. This is where a larger diameter pipe runs from one end of the building to the other, and smaller diameter pipes branch off to supply rooms or individual fixtures. If any of the branches demand water , there is less water available to all the o... |
why does sleeping help cure a hangover, when if the same amount of time passes whilst awake you will feel little to no difference? | Sleeping off a hangover; sleeping itself doesn't really help. What is happening while you sleep is that your liver is scrubbing the toxins from your system. The best way to address a hang over is to take vitamin B6 and B1, drink lots of water and avoid Tylenol.I wouldn’t be able to prove this but doesn’t your body reco... |
Cell Cycle and Mitosis? | The cell grows and grows through the G1 phase. When it gets big enough, it enters the S phase, where the DNA replicates. Then it goes to the M phase, mitosis. This is where it splits. The two daughter cells repeat this process. |
What makes people in crowds at live shows feel the need to clap along with a beat? | Let me break the answer down into two parts. Music is founded upon a beat, or rhythm. Certain types of rhythms or beats cause enjoyable sensations. This is basically why people enjoy music. The human mind, as complex as it may be or seem, has many very primitive aspects toIt. As a bumblebee communicates through dance, ... |
Whenever a singer is really into a song, why do they flail their fingers around the microphone like its a flute? | When you are "feeling the music", a number of involuntary and semi-voluntary body movements will develop. These will show in any working musician or others who work with music whenever there is no choreography something else to make them not do it. They'll also show in anyone who is enjoying the music. If you watch a s... |
what's going on with Russia and Ukraine? | The are russian-speaking Ukrainians that want their communities to be united with Russia but the Ukrainian government wont let them. So they are protesting in a hard form and heavily armedI like to think of it like Texas and MexicoA long time ago. |
What actually happens when you set YouTube to "4K" then play it full-screen on a 1080 display? | It gets downscaled from 4K to 1080p. This doesn't mean that the video will look identical to the 1080p version though. It's still possible for the downscaled 4K version to appear better quality than the 1080p version . That's because videos are encoded and heavily compressed before distribution online. It's possible th... |
How come when you can't get to sleep you can hear things that you wouldn't normally hear? | Well at that point you are likely to be in a place where lights are out or low, which gives your eyes less information so your other senses, hearing for example, get sharper. There is usually pretty quiet too so you can hear all little things easier because of fairly small distractions. |
Why do some sounds make people shudder/cringe? | I believe that would be because of [Sensory Overload.] Where when one of the body's senses gets so overwhelmed by stimuli, it is unable to handle what it's processing. Some people have sensory processing disorder, where this sort of feeling can be easily caused by other things, such as a crowd of people talking, or the... |
If black holes are perfectly symmetrical, why do they exhibit frame dragging? | > Rotating black holes exhibit frame dragging. And rotating black holes don't have spherical symmetry. Instead they are *axially* symmetric about their axis of rotation. Only a non-rotating black hole is spherically symmetric. > Is there an alternate mechanism to frame dragging in black holes than in other massive obje... |
What is the advantage of Uber/ Lyft over traditional cabs? | I'm in Eastern/Central Europe so this may be different, but: - uber is cheaper- traditional cabs worked like mobs for a very long time, they still have a lot of shady practices - not all cab companies have mobile apps- with uber you don't have to wait around to pay, you don't have to take out your wallet, cabs will som... |
Where did the phrase "I give you my word" come from? | It comes from the era that we swore oaths for things. Giving your word is swearing an oath that you are telling the truth. |
Why don't hostages in execution videos put up more of a fight or struggle when they know they are going to be killed anyway? | Because they actually don't know they are going to be killed. Most of the time these hostages are dragged out in front of cameras and made to read stuff or stand as a prop many, many, many times over the course of their imprisonment. Not only are they regularly beaten and threatened but they are also told that they wil... |
Why are some people attracted to different 'types' of women/men? | Aside from an incomprehensibly complicated web of interaction between nature, nurture, self and influence, not all mates make for ideal combinations. As one example , the scent that comes off of person is subconsciously more attractive to people with complementing immune systems. Man A might have an immune system that ... |
What mystic wood are electric poles made of, and how is that they never need to be replaced? | I worked for a utility in the department that was responsible for inspecting the wooden poles. Here's how they test if the pole is still sturdy enough. First, they hit the pole with a hammer, listening to determine if it is hollow. Poles usually rot from the inside out. They then drill small holes in the pole near the ... |
How are undersea internet cables repaired? | There are many reasons that under sea fiber-optic cables can get damaged - under sea earthquakes, damage by ship's anchors & fishing trawlers, chewing of cables by sharks, etc. The cables can be as deep as 8000 meters and laying these cables is a very expensive affair. When damaged, the operator needs to first ascertai... |
How does nuclear fission work? | Nuclear fission is where protons, that were grouped into atoms, break apart to form new atoms, each containing fewer protons, but with the same total number of protons. In heavier atoms , there is a lot of energy available to hold the large group of protons together. When this group gets broken into smaller pieces, tha... |
Why are Phone companies improving screen resolution/size/aesthetics when currently the big problems with phones are battery life/low volume limits/poor reception/sturdiness? | Increasing battery life, volume limits, reception & sturdiness only appeal to users that treat their device as appliances. They buy new phones when their current product is obsoleted, more than a year after their last purchase. The fashion user meanwhile will flock to the shop for the thinnest or newest phone just mont... |
- What is the difference between a cappacino, frappicino, a machiato, and others? | Here are your standard hot beverages:_URL_0_ A frappucino is basically a latte blended with a bunch of ice and sugar. Edit: But if you order a caramel macchiato at Starbucks, you're really just getting a caramel latte. Don't know why they do that.All the drinks start with espresso, the difference in names comes from wh... |
If we're so close to having self driving cars, where are all the (presumably simpler) self driving trains and trams? | I can't speak for other cities, but in London, the Docklands Light Railway has been running without drivers for a couple of decades. And Transport for London, the government organisation responsible for London's urban transport, has just announced a contract to buy a couple of hundred new underground trains which can o... |
In the US, why do nurses get paid CONSIDERABLY MORE than paramedics? | Nurses have a lot more A & P and clinical knowledge than paramedics. Also relevant is the relative youth of EMS as a field. There are still people working who were around for when EMT and paramedic training became a standardized thing. Nurses have been doing there thing for a lot longer, so of course it's a more estab... |
Why do American pharmacies use those orange containers? | It is to designate it as prescription medication, and because original packaging is not given in the prescription sizes that doctors issue. Original packaging is large containers of pills. You may need 10 you may need 100 to fill a prescriptionThe orange tint is to protect the pills from sunlight in the same way that b... |
Is there a such thing as 'catching up' on sleep? | There is such a thing as "sleep debt" . This is the cumulative effect of losing sleep as the body becomes more fatigued mentally and physically. To "catch up" on sleep, then, means to rest until the body is no longer experiencing fatigue as a result of the previous sleeplessness. This could result in a longer sleep per... |
What is the difference between a male and female condom? | Same difference there is between males and females, in general: one is an innie and one is an outieA male condom is designed to fit snugly over the penis. A female condom is designed to sit inside the vagina through the use of a ring that holds it in place. |
Can somebody,please explain to me this email , especially the first part | It means when you respond, use Reply-All. They want everyone they cc'd to get your response. |
ELI15 Apple's "recognize a phone number in text" patent | To get a patent, you only have to convince a patent officer, not a judge. To have your patent survive a lawsuit, you might have to convince a judge, but if you have a lot more money than your opponent, they will probably settle out-of-court to avoid going bankrupt funding their own legal teamPatents can be revoked if t... |
why are funeral processions allowed to block traffic and display flashing lights? | Laws vary from state to state. In most states them putting lights on their own cars is illegal, but it may be different depending on where you live. In many states you can hire a police car to specifically drive with and block traffic for the processionIt is illegal to attach those lights to an non-emergency vehicle. V... |
How do grocery stores like Whole Foods, KaDeWe Berlin, etc. make a profit with such a massive amount of expensive perishable inventory? | Something I can answer! I work at a chain grocery store and essentially the short term items that we make and sell are customer draws. Unique items and store made goods that look attractive and sell decently. We probably break about even on those items except around holidays. However it gets you the customer into our s... |
How does "catching up on sleep" work, and how long does it take? | Well, you can't catch up on sleep. But you can reset your self. The fastest way is with an alarm. It sounds strange, because you feel tired, but more sleep isn't the answer. Related sleep is. If you normally need eight hours for optimal rest, set an alarm for that much time, then get up. Sleeping extra messes with your... |
What is ionizing radiation, and how does it differ from non-ionizing radiation? | Ionizing radiation is radiation that has enough energy to remove an electron from an atom. As chemistry is all about bonds made by the electrons, this means that ionizing radiation can change the chemicals that make up things, including living things. As life is a chemical reaction, changes to the chemistry of living t... |
Why does splashing cold water on our faces help us wake up? | Some will tell you this is due to the Mammalian Diving Reflex. When water below 20°C contacts your face, the body reacts by changing heart rate and redistributing blood flow to allow you to remain underwater for longer. However, for such a short period of time, it's more likely that the cold water simply provides a sti... |
If I'm wearing gloves and I touch something hot why does still burn me but not go through the glove? | it does, essentially what's happening is the molecules in the hot thing are bumping into the molecules of the glove, making them more jiggly so they in turn bump into the molecules of your finger, the point where it hurts your hand is far lower than the point of ignition for the glove. |
"Beer Bellies." How do they form and why do they look different from normal overweight ones? | Different people store fat differently, but having a large amount of excess body fat in the abdominal area is actually worse for your health than fat distributed in other areas. "Beer bellies" or "guts" often involve visceral fat surrounding organs, as opposed to just subcutaneous fat. It can lead to cardiovascular pro... |
How do athletes that require huge amounts of calories fit all that food in their stomach? | First, they eat extremely calorie dense foods. Second, they spread their meals out across the span of the day, often having three big meals plus several snacks.Lots of calories doesn't equal lots of food. The simple truth is a bottle of cola can replace a whole meal if you just look at the calories. The bigger problem ... |
Why some people request their posts are not voted? | A few reasons 1. They want answers or comments back, but they don't want to make it to the front page. A good example of this would be a very specific post in /r/relationships. You would want the help of the community, but you also wouldn't want your significant other reading the post. 2. Some people use it to see if t... |
What exactly happened in Greece to result in the current economic crisis? | shortest answer: hardly any taxation, more inportantly the shipping industry which is massive in greece payed hardly any taxes. Country fell in debt. Was unexpected because the earlier greek government filed false documents to the EU saying their economy was alright so they could join the EU. Currently Greece is paying... |
Why can a piano go years without being tuned, but you need to tune a guitar every time you use it? | Piano strings are strung on a cast iron frame. Guitar strings are strung on a piece of wood . Environmental variations will cause much greater variation in the wood in the guitar than the cast iron of the piano. In addition, guitar strings are under about 18 lbs of tension, whereas piano strings are under about 180 lbs... |
Why does language policy/planning almost always end up being about education? | When you're promoting a minority language, the absolute best-case scenario is to create a generation of native speakers -- as in, children who are raised speaking the language. For that, you need to get people reasonably proficient in the language, and dedicated enough to raise their children in it, before they become ... |
Why is the flushing mechanism different in a household toilet compared to public restrooms with multiple toilets? | Public restrooms get more use, and more frequent use. It is not uncommon for it to be occupied almost immediately after a user leaves the stall. As such it is more efficient for them to have a tie directly to the water main rather than to fill a tank. Also it means there is less for someone to tamper with, which will h... |
Why is it when you feel like you're going to sneeze and you look at the sun you automatically sneeze? | While this isn't exactly the photic sneeze reflex it's the most similar condition to what you're describing that I can think of. The exact mechanism behind it is not well understood, but we know it affects some 1 in 4 people. |
Why do Stand-up Comedy specials have directors? Aren't the comedians on stage completely in control of their own material? | The directors are generally the ones that deal with production of the special, not so much the jokes the comedian saysThey are control of their material, they are not in control of the cameras, the microphones, the lighting, or any of the dozens of other things you need to produce a showSomeone needs to choose all the ... |
Why don't we distill water for drinking? wouldn't it be a lot more pure than spring or filtered? | Distilling water takes a lot of energy for a marginal benefit.Water distillation requires evaporation and condensation. To do this on a large scale requires a lot more power than it does to filter it, and you would also have to constantly clean the condensers due to various deposits that would form on them. Distilled w... |
why the American Civil War happened. | The Northern States and the Southern States had incompatible business models. The Northern states were opposed to slavery, an essential part of Southern agribusiness, but they were not willing to compensate the Southern slaveholders to get them to free their slaves. As new states were formed, a huge debate took place r... |
Why does molten cheese stick to things so effectively? | Cheese is mostly protein and fat suspended in a little bit of water. Protein molecules are like long chains that have been coiled and twisted, and then coiled even more. Fat molecules are usually like straight chains but may have some branches. When protein molecules get heated, the chain begins to uncoil and untwist, ... |
Why does ball sweat smell different than regular sweat? | The simple answer is bacteria, it's the same reason your armpits smell different than your sweaty feet do. You have many types that live all over your body, and they are the ones that produce the fragrances you smell. |
What does the 'Bagel' button do on my toaster? | It toasts the bagel only from one side. You're supposed to cut the bagel in half first and place the halves in the proper direction.Toasts the top of the bag only because toasting the bottom is pretty pointless.While I don't care for half toasted bagels, I find I do often use it to toast hamburger buns |
Why does your face get red when embarrassed or flustered? | The simple answer is blood flow. Blood is red, and when the flow volume to your cheeks goes up, the red coloration is more noticeable in your cheeks. The more complicated answer involves your *sympathetic nervous system,* and the fight-or-flight response. Embarrassment prompts the release of adrenaline as your body pre... |
What is this "pop" or "crack" sound that my pc monitor and tv make? | > only if they're off. They are cooling down. When they were turned on they heated up and the case expanded . As they cool down the case shrinks and at some point a joint will shift under the pressure and cause a popping sound. |
Why do aircraft use flaps to take off? Doesn't it create drag? | The fact that the larger wing surface creates more drag is precisely why aircraft use flaps. Flaps allow the wing to only be that shape at certain periods of flight. At the slower speeds of take off and landing, the lift it generates is much more beneficial than the drag it creates. At higher speeds the drag would beco... |
Central Limit Theorem and Normal Distributed Variables, in statistics | I'll give it a shot. First the book definition: Central Limit Theorem: For any population with mean μ and standard deviation σ, the distribution of sample means for sample size *n* will have a mean of μ and a standard deviation of σ/√*n* and will approach a normal distribution as *n* approaches infinity. First you have... |
Why can't we block one side of a magnet to make it only attractive on one side? | What you're asking for is a [monopole magnet], which [until this year] was strictly theoretical .That square magnet would have both north and south, there by making the excercise futile. Anyway, the magnetic field is a closed loop. It has north and south poles. It is not possible to "cut off" the field. The lines need ... |
If in the summer the sun never sets very far up north, how does the temperature not get extremely hot? | This is a little complicated so I'll try to boil it down. At higher latitudes the angle that the sun's rays hit the earth is much greater than the angles nearest the equator. Because more oblique angles cover more area with the same amount of light and heat energy, the energy in any one place isn't very strong. Less en... |
Why is it a good/bad thing the US doesn't have a direct election for president? | The electoral college also aims to give the smaller states a greater say than they would have if the vote was based purely on population . Arguably that's still desirable, so the concept of electoral votes should stay. Certainly the smaller states that benefit would oppose an amendment to the Constitution, so you can't... |
the purpose of tracer round | Tracer rounds are there to let the shooter see where the bullet is going. Especially with low to medium caliber "inert" bullets , there generally won't be any easily visible sign of the point of impact, especially at night. So, tracer rounds allow the shooter to see the bullet's path, and correct their aim. They also a... |
What would China, Japan, or wherever do if they wanted to collect U.S. debt? | They would buy the government bonds and then wait for their money. That's how it works. You can't just go, "Give me my money!" just like how a bank can't give you a loan and then a week later decide it wants all $200k backSovereign debt generally exists in the form of bonds. A bond is basically saying "If you give me $... |
Why must emergency contraceptive pills be taken within 72 hours of sex? | Apart from stopping ovulation, it also inhibits implantation or can stop it all together by changing the way the eggs and sperm can travel. 72 hours is doctors being careful because with medicine the rule is better safe than sorry. The entire Plan B pill is just a large dose of the active chemical in standard birth con... |
Why is it more common than not to have gaps at the bottom of toilet cubicles? | It is easier to clean, increases air flow, is less expensive to construct, and if a toilet overflows or breaks it allows a single drain to protect all the stalls. Edit: and my top rated post of all time is about the logistics of toilet stalls. Edit: few other reasons people have pointed out: Ability to access if a chil... |
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