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ELI5: Why does inhaling steam seem to clear up clogged sinuses? | Think of your mucous as a kind of hydrophilic (strongly attracted to water) slime. If you're sick, suffering from allergies, exposed to irritants, etc... then it can be valuable to move that mucous along faster than it would normally. By inhaling water vapor, you increase the water content of the mucous, and it becomes looser, less sticky and more subject to being cleared.
Another reality of the situation is that often what we perceive to be clogged sinuses due to mucous are actually just inflamed. Steam and warmth can be soothing, especially since dryness or the presence of an irritant is often a cause of that initial inflammation. | 20 | 20 |
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[Superhero costumes] So superheroes have awesome powers and all, but how are their masks - like the ones worn by Spiderman and Deadpool - able to squint? | You would think that the masks would be great for concealing emotion in addition to identity, giving you an edge with your poker face. But I just saw Spiderman fight someone and his mask, particularly the eye area, moved the way you'd expect his eyes to move beneath the mask. What the hell kind if material is this? Same thing when Deadpool was fighting, well, everyone. | As noted by others, it depends on the Universe.
In the MCU, it's explained that Spidey's mask actually needs to do that because Peter is unaccustomed to dealing with as much sensory information as he gets after being bitten (which is why he wore goggles that blocked out some of his peripheral vision to begin with). Stark probably just gave him more sophisticated armor.
In the comics, where such squinting may happen, some of these costumes may be made out of unstable molecules created by Mr. Fantastic.
It's unclear how Deadpool's squinting worked in the Deadpoolverse, but we might imagine this his squinting is basically his facial expressions breaking the fourth wall of his mask. | 74 | 52 |
Why is diffuse reflection a hazard of working with lasers? | Moreover, how can surfaces that appear shiny be diffuse reflectors of UV wavelengths? Also, how can surfaces that appear dull be specular reflectors of IR wavelengths? What is about those wavelengths that allow them to act differently on those types of materials? | A surface consisting of microscopic features may work like a mirror for wavelengths larger than these features. So actually IR and UV are not special, they react the same way to surfaces structured relative to their respective wavelengths. | 20 | 31 |
Can a planet be 100% water? | Can a planet be completely made of water, or any other liquid? Or is some land and layers inevitable? | Liquid at what temperature and pressure? You could construct a planet made entirely of H2O, but it would have an ice core and at least some gaseous atmosphere. If it were another substance, the same would be true.
If it were a non-metal liquid, it would quickly evaporate into space from sputtering due to the lack of a magnetosphere.
This planet could not survive, and probably wouldn't even ever form naturally. | 19 | 48 |
Is terminating pregnancies to prevent genetic disorders immoral? | i.e., a mother getting an abortion after a positive Down’s syndrome screening. Is it eugenics? | It depends on what system of morality one might use. From a utilitarian perspective it may or may not be immoral because terminating the pregnancy would have the moral gain/loss for all (and generally speaking the fetus wouldn’t have any net gain or loss as it has no consciousness). | 38 | 82 |
If elements in groups generally share similar properties (ie group 1 elements react violently) and carbon and silicon are in the same group, can silicon form compounds similar to how carbon can form organic compounds? | Yes and no.
It is possible to create molecules with several Si-Si bonds just like with carbon, but those are less stable than Carbon bonds.
In addition Silicon Hydrogen bonds are pretty reactive.
Just compare Methane, a pretty stable and unreactive molecule, with Silane, which combusts in air without any help.
That's because the electronegativity of Silicon and Carbon are different, which affects the Si-H bond.
As the other people mentioned Silicon Oxygen bonds are quite stable, that's what Silicone (the polymer) is.
Still, Carbon is the only known element that forms "unlimited" amounts of different molecules where the Carbon is directly bound to another Carbon.
Adding a CH2 group to elongate a molecule does not make it less stable.
This is called catenation, and allows so many different carbon compounds to exist.
Silicon, ( and Sulfur and Boron) allows for limited amount of Catenation, while Carbon allows basically unlimited chain length and branching.
The longest silicon chain that is somewhat possible to create contains 8 Silicon atoms in a chain. Everything longer will decompose on its own, into unspecific Silicon hydride polymers.
Si8H18 is the sum formula for that.
In addition Carbon can form very stable double and triple bonds, the same bonds are possible with Silicon, but they are extremely unstable. the simple molecules ~~Disilane~~ Disilene and Disilyne are possible to isolate, but anything more complex falls apart.
**Tl;Dr** They are very similar, and both allow Catenation, but the addition of another electron shell in Silicon changes the properties (electronegativity) just slightly, so that longer chains get less stable, compared to Carbon chains getting more stable and bonds with Hydrogen have more of a hydride characteristic than the covalent bond between Carbon and Hydrogen.
Thus lifeforms in anyway similar to earth's life is impossible on a silicon basis. | 1,602 | 3,363 |
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CMV: We live in a society designed for "Morning People", but this system should be abolished and replaced with one that favors "Night People". | The idea that individuals have circadian rhythms that determine their sleep behavior is [well studied](http://www.ncbi.nlm.nih.gov/pubmed/17936039). For the purposes of this CMV, I'm assuming this phenomenon is at least semi-accurate for most of the population. I am also assuming we live in a society that is based around the sleep patterns of morning people.
However, my view is that society would be better off if it catered to so-called "Night-owls". Night owls are shown to be more intelligent, more personable, and more productive than morning people. [However, there is empirical evidence that they suffer from a kind of "social jet-lag" that results in less happiness, less white matter in the brain, and more self-reports of feeling tired](http://www.medicaldaily.com/night-owls-smarter-new-study-suggests-late-bed-late-rise-leads-greater-workplace-success-244753).
My hypothesis is that Night owls show increased aptitude *despite* suffering through unfavorable conditions. If presented with favorable conditions, such as a societal system of late-to-bed, late-to-rise, we would see an even more pronounced productivity and success from these people, which would benefit society as a whole.
We no longer live in a strictly agrarian society. "Business Hours" as they stand are arbitrary, and in an increasingly international business world, strict hours become even less reasonable. We have lived under the tyranny of morning people for too long. Their antiquated and inefficient system must be abolished. Long Live the Night Owl. Long Live the New Flesh. CMV.
Edit: Added more sources to support some of my assertions: [One](https://personal.lse.ac.uk/kanazawa/pdfs/paid2009.pdf) [Two](http://emilkirkegaard.dk/en/wp-content/uploads/Morningness%E2%80%93eveningness-and-intelligence-early-to-bed-early-to-rise-will-likely-make-you-anything-but-wise.pdf) [Three](http://marric.us/files/CSTA_learnjournal.pdf#page=76) [Four](http://cordis.europa.eu/news/rcn/30721_en.html) | How is society designed for morning people?
Aren't we just sticking to working in daylight because it makes things easier (e.g. construction work during the day vs. the dark night) and sleeping when the sun is down because it easier to sleep in the dark? | 33 | 32 |
ELI5: why do pregnant women experience specific cravings? | Is there any science behind pregnancy cravings? I remember being told in my youth that the concept is a myth, is that so? | When a woman is pregnant, her body starts to pump around all kinds of hormones (special substances that cause different parts of the body to do specific jobs, so that the body knows it needs to feed and take care of the child growing inside her womb). It's these hormones that cause women to feel emotions (or cravings) that she normally wouldn't feel - similar to how women can get more upset during their menstrual cycle: it's all got to do with hormones. | 12 | 18 |
ELI5 Scientology | What is it? Why is it so bad? or such a big deal? | Some governments have special benefits for religions, like not paying taxes. L.Ron Hubbard wrote Science Fiction, which didn't do so well, so he used the same ideas and started a religion.
This would be no big deal, it happens all the time (c.f. John Smith), but in this religion, Scientology, you have to give ALL your money instead of the more typical 10%, AND Scientologists believe that psychiatry is a scam, so some people who need help, and medicine, don't get it and get hurt. | 21 | 21 |
ELI5: How exactly does the skin healing ointment heal the cracks in the skin? | Ointments can work in a variety of ways depending on the ingredients and what you are trying to heal.
The most common ingredient is one derived from a type of oil, usually petrolatum. This can vary and some are wax based such as certain lip balms but they all provide the same purpose which is serving as a moisture barrier. It keeps the crack or break in the skin wet. In the case of cracked skin this is usually enough as the cracks are typically caused by overly dry air in the winter.
The second is to provide a barrier to foreign particles. Think of it like plastic wrap for food. It can keep dirt and dust out as well as bacteria. This keeps the crack or wound from getting infected so your body doesn't have to use energy to fight a bacteria off and devote more to healing.
Lastly are the specialized things that go in there. In burn creams usually its different substances which can cool or soothe the area. In first aid ointment it can be anti-bacterial agents. In the case of cracks usually its just some vitamins or other things that may or may not actually provide any real benefit. | 13 | 30 |
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ELI5: Where does wind come from? | pressure differences caused by temperature differences.
the best eli5 answer would be to just open your freezer about 4 inches and put your hand over the gap. You will feel the cold air come out of the freezer pretty quickly because the difference in room temperature and the freezer temperature cause the air to 'even out', moving the cold air in to the warmer air and thus, wind (on a very small scale :) ) | 21 | 18 |
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How much is the "lag" in the real world? | When playing multiplayer video games, we often experience lag. I think it can be defined as the length of time since the information is sent from the server until it is received by the computer being played on. The player then experiences the game a few milliseconds after it actually happens.
I was wondering how much lag is there in the real world? How much time does it take, for example, for the eyes to receive information send it to the brain and for the brain to "experience" what's happening? | We can actually measure how long certain signals take to propagate through the nervous system using a technique called evoked potentials. Using a set of electrodes on the scalp surface, you measure the response of the brain to a long set of stimuli and average them to get rid of all the random, moment-to-moment signals. Then you get a reproducible waveform.
For instance, there's a peak called N20 (sometimes N19) which corresponds to the arrival of sensory information from the wrist to the primary sensory cortex. This takes about 20 milliseconds. Arrival at the primary sensory cortex is just the very first step of sensory processing, but that means a sensory "lag" from your wrist is at least 20 ms long. From the foot it's more like 45 ms.
In the visual system, there are multiple identified responses and no clear agreement about what they mean. The N75 response is thought by some to represent the first arrival of visual signals to the occipital cortex, where visual processing begins. This would give a minimal visual "lag" of 75 ms; however, the P100 wave is associated with actual perception of visual stimuli, meaning the lag might be as much as 100 ms.
There are a lot of evoked potentials that have been described. There's a P300 that, to simplify, represents the recognition of a meaningful (as opposed to arbitrary or meaningless) visual stimulus. That's as much as 500 ms after the stimulus.
The idea of "lag" however is complicated by the fact that there is some sort of processing going on through the entire process. Even before visual signals arrive at the occipital cortex, basic processing in the retinal ganglion cells have started to define color opposition and contrast. That's within the first 10 ms. So the fact that it takes 50 or 75 or 100 ms to make it to the visual part of the brain doesn't make it a lag in the same way a server lag is a lag.
| 28 | 29 |
ELI5: How does mental stress affect the body? | So I know that sometimes people get headaches and stuff when they're stressed, but I've also heard that they can get other physical conditions if they go through a lot of mental stress.
How does that work? Could it affect your senses, like taste, hearing, or sight? | There are several mechanisms, related to the gut-brain axis and hormone/neurochemical reactions in the body/brain that influence behaviours. These are called Somatic symptoms. They are generally influenced by the environment changes experienced by your amygdala (fear, emotion) and hypothalamus (temperature, light sensitivity) in the brain, causing a side effect.
The gut-brain axis is an established correlative relationship between your digestive system function (including bowels and stomach) and your mood. Mood changes are reflected in appetite (my depressee mood makes me unable to eat, and nauseated), and vice versa (constipation or diarrhea or conditions like Irritable Bowel Syndrome can affect your mood)
Neurochemical and hormonal changes are due to chemicals shifting concentrations in the body, such as cortisol (stress) or serotonin (mood stabilizer). Cortisol is related to the effects of being in danger, such as fast breathing and heartbeat, and can even cause faster aging in your cells, for example.
Your brain is a control center, but if the control center has a change, the whole body feels it | 21 | 59 |
Why is it that the inside of fresh water pipes that feed houses don't need regular cleaning? | They are designed so that there are no blind ends or dead angles, where bacteria or deposit could build up. An example of how this failed was a case where the cooling system of a power plant had a blind end in their piping. *Legionella* bacteria found the place, made a little colony and then spread around the area with the mist from the cooling tower, infecting many people.
Second, tap water is chlorinated, even if it's pure at the source, exactly in order to avoid bacterial buildup. Small concentrations of chlorine are good enough to prevent growth, even if they can't be used for desinfection as such. A little ammonia is added, because when chlorinated, it forms more persistent nitrogen chlorides that retain the active chlorine in the water better than plain chlorine, which gives only a chlorine solution. If there's a breach of the integrity of the piping or a problem at the source, a "shock chlorination" is done to actually desinfect the pipes.
Even so, buildup is a thing. Fortunately, much of it is inorganic, like calcium and iron salts. Because it's washed continuously with water, it attains a pseudo-steady state where it releases little material into the water. However, over time, it can build up to such a point that it affects the water pressure. | 14 | 15 |
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CMV: someone being my family member doesn’t mean I should give them a pass on bad behavior | With the holiday season, it’s the time of year where racist uncles and thrice divorced aunts start showing up, and the age old argument will be thrown out: “I know you don’t like them, but they’re family so you need to get along and give them a pass.”
My opinion is that someone being family doesn’t earn them anything. If nothing about them was different except for that they weren’t my family, would I still have to respect them and like them? I think no. I think there need to be more reasons. I think family gets a pass too much.
I’ll never forget the time my brother gave me a black eye and bloody nose but I was the one in trouble for staying mad about it and wanting to file a police report. I was rightfully afraid, but my parents talked me down. “He’s your brother”, they said, “and we treat family differently. You need to give him more chances. You two have to get along because that’s what family does.” I’m sad to admit they guilted me into letting him get away with knocking me out with his fists. I don’t think I’m the first person or the last who was guilted into giving family members a pass on bad behavior.
I think if anyone, family or not, is to get a pass on bad behavior, better reasons need to be given. I don’t think there’s any legitimate moral obligation to put family on a pedestal and a think doing so is dangerous and unhealthy.
My view could be changed if I can be convinced that someone being a family member is the only reason there needs to be to let someone get away with behavior you otherwise would call out or do something about. For example: if someone at the dinner table was overtly racist, convince me that I should only call out the racism and comment on it if the person isn’t my family.
CMV.
Edit: I’ll define giving a pass: giving a pass includes taking no action that could lead the offender to think they’ve offended. If someone beats you up, giving a pass means you tell them it’s all good and that you’re not mad about it. If someone is racist, giving a pass means you will agree, nod your head, stay silent, etc so long as the speaker is able to keep thinking nobody has a problem with their comments. | I think there are valid reasons why we should treat family members differently than strangers. The main being that you share a connection that won't be easily severed. That person will remain connected to you, and your kids, siblings, etc... They in all likelihood will continue to orbit your life in a significant way, and for that reason they can't be dismissed as casually as just any person.
That said, this means that sometimes one must react more severely to a family member. If you're gay, and your father is a homophobe, that needs to be confronted because it is going to be a problem unless they can change their view. If you're gay, and a grocery store cashier is a homophobe, it's less important. Likewise, you need to find a way to make clear that violence isn't cool, so it doesn't keep happening. | 249 | 2,202 |
ELI5: why do harmonicas come in different keys? Does this mean that to be able to play any song which you like , you need to purchase a set of harmonicas? If no, does a chromatic harmonica capable of playing any song? | Wind instruments generally rely on perfectly sized holes to create musical notes, and as such the given notes they can produce are fixed.
With large instruments like flutes you have enough 'space' to make holes for lots of notes, so you can create all of the semitones within a given octave. That means all of the little sharps and flats between can be played at any time.
Because harmonicas are small, they economise by using only the notes within a given Key, typically C.
This has meant that the harmonica is easy to play in key, because all of the notes are in key, so it's a simpler instrument to learn to play, and that the Harmonica is a good name for it.
It also means that you get the harmonics of two or three notes playing at any one time, since it's tricky to play just one note on a harmonica. | 27 | 63 |
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I still don't understand when it's proper to use *affect* vs. *effect*. | I still don't understand when it's proper to use *affect* vs. *effect*. I have googled it so many times, and yet when it comes times to use the words I have no clue. Please ELi5 it to me and explain it so I never have to question this again. | Affect means to influence or change. Think "a for alter". Barring some psychology-specific lingo, it can only be used as a verb. Think "a**v**ect for verb".
An effect is a result, think "e for end". To effect is to cause an effect. | 114 | 212 |
What causes the blood vessels to constrict or tighten which leads to high blood pressure? | Additionally, is that the only reason our blood pressure rises? I'm trying to understand the underlying mechanisms that cause blood pressure to rise and fall. | Blood pressure is determined by 3 factors:
- **Blood volume**. The more blood you have, the higher the blood pressure. Blood volume increases when you drink more than you pee (for example, kidney disease).
- **Heart function**. The faster and harder the heart pumps, the higher the blood pressure. Heart activity increases in response to adrenaline (fight or flight).
- **Vessel diameter**. The narrower the blood vessels, the higher the blood pressure. Vessels constrict in response to adrenaline, or due to plaque buildup (cholesterol). | 17 | 35 |
What makes Influenza airborne and Ebola not airborne? | If I get a droplet of saliva of someone contaminated with the flu, I can get sick, the same way, if I receive a droplet of saliva with Ebola viruses inside, I can get sick; So why is the flu more contagious? | Each pathogen spreads in different ways that are related to the physiology of both the host and pathogen.
Let's look at HIV. the virus is very fragile, and cannot survive outside the host for long. the viral load is only significant in bodily fluids. you can't contract HIV from a sneeze because the viral load is not significant in the nasal cavity, and because the virus cannot penetrate your passive defenses (skin, mucous membranes).
The Flu is way different. the viral load is quite high in the mucous membranes, and the virus is not so fragile; it can spend a bit more time outside of the host without dying. While the exact mechanism of contracting the virus is not well understood, it's clear that the virus is much better at getting past passive barriers and infecting a host cell.
So now lets look at ebola. most infections are due to direct contact or contact with contaminated medical equipment. remember that one of the biggest reasons that the number of infections climbed so high is due to the lack of really basic infection control measures. Things like disposable gloves, antimicrobial soaps and running water, bleach, goggles and masks, disposable paper gowns, hot-water laundry machines- All common to modern medical practice- are often lacking where these outbreaks occur.
Now back to saliva- there's still a lot of questions. if you inhale a droplet of saliva from an infected person, will you get sick? Well, we don't know, honestly. now say the person has bleeding gums and coughs or sneezes, the chances of spread are much higher.
But ebola is not nearly as contagious as influenza. | 13 | 23 |
How are phones able to reach the towers while using far less power | Lets say we have an LTE signal.
The towers use a very strong signal to get it to our phones. But how are our phones able to reach the towers to request something (Like a website)? | The general idea: the larger the antenna, the weaker signal it can receive.
The antennas on a cell phone have to be small, so they can only pick up stronger signals. The antennas on a cell phone tower are very large so they can pick up weaker signals. | 41 | 70 |
ELI5: Why are Google, Microsoft, Yahoo, and Cisco all supporting CISPA when most of them vehemently opposed SOPA? | Source: http://www.theverge.com/2013/4/13/4220954/google-yahoo-microsoft-technet-cispa-support/in/2786603
edit: Thanks for the response everyone! Guess its true they'd rather protect themselves than you, tough to blame them for that | Also, it gives them legal safe-harbors for giving your info to the government. Without CISPA, they were stuck in a nasty place between not appeasing government requests and some liability for not treating your information properly.
Souce: various Techdirt articles. Warning: good blog, but they definitely have a point of view. | 496 | 1,628 |
ELI5 Do animals and humans have the same blood? | Do animals and humans have the same blood? If not
.. why? What makes them different? | No, they do not have the same blood.
The specific thing that makes makes them different is our different genes. More broadly, it’s our different needs that make us different.
You will find that most creatures have the same basic elements to their blood - plasma, platelets, red blood cells, white blood cells, etc. But what those cells look like and what they can do is very different in different animals. Camels, for example, have oval-shaped red blood cells where we have disk-shaped red blood cells. This is so that camels can drink and take onboard huge amounts of water all of a sudden without their RBCs bursting. Dolphins and whales have red bloods cells shaped in a way that maximises oxygen carrying capacity, more than ours do. This allows them to hold their breath far longer than we do. | 25 | 18 |
eli5 how are soaps able to clean away germs when washing things? | Hello everyone. I have always wanted to know how exactly are dishwashing soap, hand soap, cleaning soap are able to kill or remove harmful bacteria from whatever we are using it for? | Many bacteria and viruses have an outer membrane that's made mostly of oil molecules (lipids).
Soap in hot water breaks up oils and carries them away.
Not only does this help remove the germs from surfaces, it also causes some of the germs to just pop and die; all their insides come out and are washed away. | 51 | 47 |
[Star Trek] Dose Starfleet know what's at the edge of the Milky Way Galaxy and/or beyond it? | Just looking at all the series, we have the 4 Quadrants.
But nothing beyond that. | The four quadrants are just what we use to divide the galaxy into components that are easy to reference. Like the hemispheres of the Earth.
We know that there is a harmful energy barrier surrounding the edge of the galaxy (much like the one surrounding the galactic core). | 23 | 25 |
Blood bank pioneer Charles Drew was killed in a car crash in 1950. His injuries were too severe for him to be saved. Per wiki a passenger says a blood transfusion might have killed him sooner. Are there any reasons/conditions why a blood transfusion could kill a trauma victim sooner ? If so, how ? | By 1950, the major blood groups and RH would surely have been known for transfusion, (eg in North Carolina where the crash occurred) | Blood transfusions increase blood pressure. Since his superior vena cava was blocked, blood flow from the head/neck/chest was blocked. But blood flow to the head/neck/chest continued. This causes a spike in blood pressure localized to these regions. A further increase of blood pressure from the transfusion could result in a cerebral edema, throat swelling, or hemorrhaging | 2,419 | 3,245 |
Is a patch of grass one singular organism? Or is multiple? How can you discern one specific organism of grass from another? | A patch of grass can be a collection of individuals or, since grass is rhizomatous, a single individual can grow shoots from its root and become its own bunch. These are known as bunch grasses. So the answer to your question is sort of, "it's both!" | 4,950 | 7,082 |
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ELI5: If nearly all the countries are in debt or in a financial crisis, where is all the money going? | Like say how the U.S. is in debt to China. And if China has a debt to Japan. And Japan to France so on an so forth. How is there money circulating if we're all in the red? | Countries owe money to other governments, their own government, and people (both within the country and elsewhere). The majority of US debt (for example) is owed to US government and private American citizens. Only about 9% of the US debt is held by China. | 78 | 214 |
ELI5:Why is high blood pressure bad for you (due to the damage to the arteries and blood vessels) but regular exercise, which also increases blood pressure, doesn't cause the same damage? | 1. High blood pressure leads to enlargement of your heart (because it needs to pump harder in order to overcome the resistance of your narrowed/blocked/damaged arteries). This leads to all sorts of heart problems, particularly dilated cardiomyopathy.
2. Exercise leads to a *transient* increase in blood pressure. People who exercise excessively tend to have larger hearts too (particularly left ventricular hypertrophy) and this also has the potential to cause problems, however, you would have to exercise *a lot* for this to happen. There are two key differences between transient high blood pressure from exercise, and high blood pressure from clogged vessels. Firstly, exercise only raises your blood pressure momentarily, however, the longer-term effect of exercise is reduced fat clogging your arteries leading to an overall reduced blood pressure for the majority of the time. The second difference is that in exercise whilst your heart needs to pump harder (to move more blood around), however, this is against low resistance. This process of pumping harder makes the heart stronger. By contrast, when you have high blood pressure your heart needs to pump harder *against resistance*, leading to dilatation which is far more problematic. Dilatation is like filling a balloon with water - the balloon expands, but it does not get stronger/more elastic.
3. High blood pressure causes damage to the heart and the kidneys. However, high blood pressure also indicates clogged arteries and/or kidney disease (amongst many other things). These things that you have when you have high blood pressure cause damage too, damage somebody who exercises well does not have.
Difficult, but great question! | 86 | 159 |
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I am a graduate student who is in desperate need of help (throw-away account). | I'll try and give as much info as possible, but mainly I'm just hoping someone has been in my shoes and can help me. I am a 6th year PhD student in chemistry. I have passed every requirement throughout my graduate career, but as it stands my adviser (P.I.) is unwilling to discuss anything graduation. I have met with the dean and she was as unhelpful and non-committal as one could expect from someone in her position. At this point I don't care about a letter of rec. or keeping any form of a relationship with my adviser. All I wan't is that stupid piece of paper that says I have my PhD. I have tried discussing things with my adviser and it turned into a verbal assault in which I stood their and was called horrible names for bringing the subject up (this doesn't begin to describe the level of abuse that my adviser exhibits over myself and other students). I am most certainly not alone, there are three other students in my lab that are my year and going through the same experiences.
What I am really asking is does anyone know of a process by which I can force my graduation. Whether it is petitioning or speaking to a certain representative. The dean that I spoke with said that the only way for me to graduate is with my advisers signature, but I cannot believe that the university does not have a fail safe to protect its students from sociopath professors. Especially considering I have passed every bench mark asked of me (besides my thesis defense of course).
Any help would be appreciated. | If the chair of your department and your graduate advisor are unwilling to help, the next step is an advisor in either graduate studies or the college of natural sciences, depending how your university is organized. You can also get in touch with the ombudsman and start escalating if you feel like you are being verbally abused. | 13 | 31 |
[Mister Rogers’s Neighborhood] Where is Mister Roger Coming From and Where Does He Leave to? | During the intro, Mister Rogers enters the building with a suit that he takes off. He later puts it back on as he leaves.
Where is he coming from and where is he leaving to? I always assumed he was coming home from work and later leaving home to go back to work, but that is a long break his job is giving him.
His real jobs before the show was being a Presbyterian Minister and as a producer, but I am not sure those are the jobs he is returning to and from. Especially since being a Presbyterian minister would probably be Sunday work and would not require a suit on the other days, unless he is attending a wedding, funeral, or dedication ceremony everyday.
So what is he returning home to and where is he leaving off to? | While being a minister has short scheduled hours they're both longer than you think (many churches offer daily services even though attendance is low on weekdays) have required support work (there's a building to maintain, and every service is slightly different and must be planned for), and just plain being available if anybody wants to talk.
Coupled with the fact that he's probably scheduling his own hours, it makes sense for him to be giving himself a long break in which he goes home between tasks, unwinds for a bit, then heads back to work. | 41 | 44 |
ELI5: If the human body already rejuvenates itself by replacing dead cells by new ones, then why isn't eternal life possible/happening? | Why does this process eventually stop so people get old and die? Isn't it possible in theory for the body to keep replacing every dead cell in every body part so we people wouldn't age? | The tips of your chromosomes are composed of a protective coating of meaningless code called a telomere. You can think of these telomeres as the protective plastic caps at the ends of your shoelace, their purpose is to protect the actual meaningful strands of DNA. When DNA replicates in a cell (during the process of creating new cells) some of the code at the tip of one strand is lost every time. The telomeres protect the meaningful code of the DNA but overtime they are stripped away. The less telomere code a cell has, the older it is, and eventually the cell will die rather than keep replicating its DNA without the telomeres. This occurs to prevent mutations as a result of lost meaningful DNA. Some cells actually have the ability to regenerate their telomeres using an enzyme called telomerase. An example of such a cell would be a germ line cell like sperm or an egg which necessarily need to be protected from cell aging. They say aging and cancer are two sides of the same coin because tumour cells also have access to telomerase which sadly prevents their aging and death. | 28 | 32 |
Why does light move? | Light moves faster than almost anything in the universe, so how does it always move that incredibly fast regardless of what its being emitted from?
Is the speed of a light particle/wave always constant?
What is the mechanism through which light is emitted from something at light speed, why is it always emitted at light speed?
Thanks, looking forward to the answers. | Light is composed of an electric and a magnetic field both oscillating sinusoidally. Ampere's and Faraday's laws say that if an electric or magnetic field changes, then the other kind is generated and also changes. It turns out that a sinusoidal change in an electric field will generate a sinusoidal change in the magnetic field. Then the sinusoidal change in magnetic field creates a sinusoidal change in the electric field and the process repeats indefinitely thus creating a light wave.
There are two properties of the universe called electric permittivity and magnetic permeability. These values affect how resistant an area of space is to a changing electric/magnetic field. In a vacuum, these properties have characteristic values which we have empirically measured.
Permittivity and permeability work together to restrain the propagation speed of light by resisting light's changing electric and magnetic fields. In fact, the speed of light can be derived as simply equal to:
**sqrt(ε0 * μ0)^-1**
Where ε0 and μ0 are permittivity and permeability of the vacuum respectively. So, the speed of light in a vacuum is due to the values of these universal constants. | 28 | 46 |
[General fantasy] So, is evolution a thing in fantasy? | Like, did species naturally evolve, like on real world earth, and creation myths are just that, myths? The khajit never came from elves, they were just bipedal felines. Orcs, elves, and average humans are all just hominids that split at different times, etc? Or is it all magic? | It depends.
A couple of examples:
There are hints that evolution does occur on Planetos - some of the Maesters have fossils of creatures that are no longer known.
All the evidence is that Arda was indeed created by Eru Iluvatar. However Hobbits seems to have evolved - over a remarkably short time - from Humans, rather than being created as a species themselves. | 27 | 16 |
ELI5: Why does it seem like verses of the Qur'an are always sung as opposed to spoken? | I'm on the [Qur'an website](http://quran.com/) at the moment, which contains a feature where you can click into a section, press the play button there, and a narrator says the verses to you, but they're all sung instead of spoken. And then I realized that in any movie or TV show that features Muslims praying, they're always sung too.
Is there a reason for this? Is it just a case that these verses are the equivalent to Christian/Catholic hymns and they have separate prayers? | Its worth remembering that the Koran is the product of a culture that emphasized the oral tradition and that has a language that is expressive of that; Arabic lends itself to melodic sound, and that it is a mark of high historical esteem, in Islam, to memorize long passages of, or the entire Koran itself. The structure helps with that memorization, much like you remembering the words of a song you haven't heard in 10 years, but not remembering what you said that same day when you ordered lunch.
| 29 | 41 |
What is the evolutionary advantage of seeing in the "visible spectrum"? | Is there any reason we see in the spectrum of light we do? For example, why not slightly extend to see IR and UV, since they affect us every day? Are we slowly evolving those capabilities, or would that be useless.
I'd think having something close to thermal vision like seeing IR could provide some sort of hunting edge back in the day. Am I wrong? | If you look at the wavelengths of light that penetrate our atmosphere, they fall in the visible spectrum.
We evolved to detect what "lit-up" the world
IR thermal vision is really useful for hunting at night. We didn't do that though. | 11 | 21 |
I have come to the conclusion that socialism is the best viable form for an economy to take. Does anyone care to CMV? | Socialism is defined as a democratic control of the means of production by the working class for the good of the community rather than capitalist profit. The line of thinking being that when the working class becomes their own executives (supervisor, factory owner, company owner, manager, etc.) workers will be able to receive pay proportionate to the work they do and their usefulness to the company. Workers will no longer be a simple piece of machinery, designed to assemble the components and make pennies on the dollar compared to the supplier of the components, the large shareholder, and the factory manager, all of whom are able to sit back and let their wealth generate more wealth. Socialism is about the community, not the individual, and will ensure meaningful and relevant work for anyone who is willing to learn a profession.
| Why should a factory worker putting parts together be as valuable to a company as the engineers who make the company's existence possible? Why should people want to strive for more if they're equally served doing less? A full transition to socialism removes all reason to excel and advance past pure intellectualism, which, while nice, isn't very fast because not enough people pursue it.
Why not have a partial change instead and move towards being a social state where everyone is supported equally and able to survive and be happy, but the more useful have more than the less useful? | 13 | 24 |
“If a company can’t afford to pay their workers a living wage, they shouldn’t be in business.” What does economics have to say about this? Is that an economically sound argument? | That statement is a normative statement. Economists like to deal with positive statements such as "if a company increases wages by X per cent, it would lose Y per cent in profit and respond by reducing employment by Z per cent".
As to answering such a question, it isn't well defined. You have to figure out what a living wage is and what "should be in business" means. If you then implement policies that do that, the specific mechanisms of those policies could convert it into something measurable or simulatable. | 370 | 216 |
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ELI5: Why does a saltwater rinse help wounds in the mouth heal faster? | Shouldn't the salt irritate the wound, causing it to heal slower or get re-injured from swelling? | Salt water works in three ways. First, it dehydrates the bacteria due to osmosis - that is, the water in the bacteria gets "sucked" across the cell membrane into your salt solution due to the concentration differences of the solutions to the point where the bacteria is no longer functional, effectively killing it.
Second, it serves to physically remove any of the bacteria from the wound, and is able to penetrate deep (giggity) into the wound to get any bacteria that may be lurking below the surface.
Third, it also dehydrates your cells in the wound, effectively killing off the surface cells that have been damaged by the bacteria, and washes them away so that the cells underneath can be regenerated and heal more effectively.
Any irritation that is caused simply causes inflammation to redirect the healing processes of your body towards the wound, which also contributes to the healing process. | 22 | 15 |
CMV: Homeless spikes are just plain wrong. They should never be installed. | I believe homeless spikes are wrong.
http://www.channel4.com/news/londons-anti-homeless-spikes-criticised
http://www.independent.co.uk/news/uk/home-news/homelessness-spikes-outside-london-flats-spark-outrage-on-twitter-9506390.html
http://www.theguardian.com/society/2014/jun/09/boris-johnson-calls-removal-anti-homeless-spikes
I think homeless spikes should be removed. I believe you will always have rough sleepers (although we could probably drastically reduce the amount in the UK) and as such should not introduce such measures.
I just don’t get the justification.
EDIT: Anybody who wants can sleep in my garden, or outside my house. If I didn't live with someone else who'd be worried about getting his stuff pinched I'd let anybody who asked sleep in my house, although I wouldn't let them have my room n I'd keep the door locked. There is very little to steal that I own.
I've never owned a car, never will, I just cannot justify it morally because of the environmental damage they cause. If I did own one I would let people sleep in it.
I do see a massive difference between putting spikes in what is a pubic place (regardless of who 'owns' it) and not letting homeless people sleep in your house though. I think it's moot.
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> *Hello, users of CMV! This is a footnote from your moderators. We'd just like to remind you of a couple of things. Firstly, please remember to* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! If you are thinking about submitting a CMV yourself, please have a look through our* ***[popular topics wiki](http://www.reddit.com/r/changemyview/wiki/populartopics)*** *first. Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | You get certain rights that apply to physical property that you own. One of those rights is the right to keep other people from using that property. If someone doesn't want homeless people sleeping on their property they are completely within their rights to do whatever they want to discourage that short of physical violence.
Some homeless people are totally harmless. Some have dangerous mental health issues. Some do drugs. Some piss in the street. It's completely reasonable to not want homeless people on your property because you don't want to deal with the latter three cases.
Homeless people do need *somewhere* to go. But no individual property owner is responsible for giving them that place.
Furthermore, you can't even be sure that someone putting in homeless spikes is a bad person. What if they volunteer at soup kitchens, donate to homeless shelters, and advocate for getting homeless people the help they need, but still don't want random people sleeping on their property? | 43 | 33 |
Are supposedly "habitable" exoplanets that have 5 times the mass of Earth really habitable? | I just read a new article stating that a habitable exoplanet has been found. However, it states that it has 5 times the mass of Earth. Doesn't that mean that it will have 5 times as much gravity? It seems like that would make the planet inhabitable, having the much gravity. Am I wrong? | Habitable usually means that the surface could support liquid water (assuming the atmosphere is right for that). In terms of mass and gravity, a planet 5 times the mass of Earth would actually probably have surface gravity closer to twice that of Earth, because the greater radius of the planet reduces the gravitational pull you feel. | 27 | 16 |
ELI5: What exactly is Stem Cells treatment and why is is so beneficial and so frowned upon. | Stem cells are cell that can be turned into just about any other cell, which makes them nice to help repair damaged cells. The problem people have with them is the way they were collected. They can collect them from a variety of sources now, and mostly through non-invasive, non controversial means. They used to be only from aborted fetuses. | 15 | 20 |
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ELI5: What makes Snopes the authority on whether claims are true or false? | I see Snopes referenced a lot when it comes to the validity of claims on the internet and it never seems to be questioned. How are they confirming these claims and why is their word taken so seriously? | They reveal their research process, cite their sources, constantly update their articles when they find new information and most importantly they are not afraid to correct any errors they've made. Basically they practice what good researchers are suppose to do. | 172 | 107 |
What exactly makes things "cute"? | What is it about puppy eyes or sleeping kittens that are appealing to humans? Why can it also apply to inanimate things? (i.e. A "cute" hammer) And why, when I see a really cute picture do I sometimes feel that it's "too cute" to stand, and I want to physically grab/eat/coddle it? Does the base idea of cuteness apply to all humans? Was it like this in the, say, 1500s? | In human evolution, natural selection favored parents who had strong, positive feelings for their infant children. Puppies and kittens have similar geometric shapes to their faces as infants. It's a simple matter of mistaken affection that actually worked out pretty well for all parties involved. | 16 | 27 |
Why are humans so disproportionately weak compared to the rest of the great apes? | Our strengths are long distance running, tools, and very high level cooperation. To be effective these do not require the same physical strength as a gorilla. Since we split from our common ancestor we've relied on these things (obviously) to great effect so the cost of maintaining a gorilla's stature isn't a benefit.
| 50 | 27 |
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Is protein from meat "better" than protein you get from other sources? | Proteins are made of chains of amino acids. If you take apart the protein, you get a certain amount of each amino acid. Meat/dairy is more "efficient", because the ratios of the different acids are the same from one animal to another. Plants will usually be short on one or two amino acids, so you don't effectively get as much protein as it says on the label.
You just need to have more than one kind of grain/nut/legume in your diet, which you probably have already, unless you're a farmer going through hard times in 1400. | 1,386 | 1,419 |
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Why is a 2l coke cheaper than a 0.5l coke? | Doesn't make sense. They use more coke and more plastic to make the product and it's still cheaper. | Supply and demand. People are willing to pay more for the portable .5L bottle when they are out and just want to grab something to drink. It's an "impulse buy." But the 2L cokes are to be brought home and put in the refrigerator and drank over a period of time.
So, it is less about the materials and more about the state of mind of the person buying it. | 291 | 277 |
Why do Scientists Bombard Specific Elements to Create New Ones? | For Oganesson, it was Calcium and Californium: 20 + 98 = 118. But why not just Praseodymium and Praseodymium? If you bombard element 59 with element 59, shouldn't it also give you element 118? | There's a lot of things to consider when designing these kinds of experiments. They're fixed-target experiments, so you have a beam and a target, and you have to choose materials for both that are convenient/possible to use.
Also, you have to consider what nuclides are likely to be produced by the reactions. The typical way that these experiments are done involves heavy ion fusion-evaporation reactions. That means that the beam energy is in the range such that the two heavy ions can fuse together and create an excited compound nucleus. The compound nucleus then "evaporates" particles (primarily neutrons and gamma rays, but also protons, alpha particles, etc.). You want to maximize the probability that the final product is the nuclide of interest.
There's some relatively narrow range of energies that will work, because if the energy is too low, the Coulomb barrier will make the fusion-evaporation cross section too low to finish the experiment in a reasonable amount of time, and if it's too high, the compound nucleus will be more likely to just fission rather than ideally losing a few neutrons and remaining a superheavy element.
Since the Coulomb barrier energy is proportional to Z*_b_*Z*_t_*, where those are the atomic numbers of the beam and target, it's worse when the two have roughly equal Z. You get the benefit of a lower Coulomb barrier, so more manageable cross section, if there's a big asymmetry in the beam and target Z.
So with all of that in mind it turned out that for this particular case with the accelerator available, it was determined that a calcium-48 beam (a doubly-magic, effectively stable nucleus with a bunch of extra neutrons) with a californium-249 target (a heavy nucleus with a lot of protons to bring the charge of the compound nucleus up to 118) was the optimal choice. | 360 | 774 |
[MCU] What does Stark Industries do since it's out of the weapons business? | Like it says on the tin | Alternative energy, advanced manufacturing, computer sciences, and bioengineering of different degrees. Most of how Tony makes the suits work is also applicable in the civilian realm.
Take for instance his armor fabrication, his multiple AIs, or his tower's arc reactor on the seabed in Avengers 1. | 75 | 60 |
Understanding of language by a computer, couldn't we make it work through linguistics? | Let's first define understanding of language. For me, if a computer can take X number of sentences and group them by some sort of similarity in nature of those statements, that's a first step towards understanding.
So my point is
-We understand a lot about the nature of sentence structure, and linguistics is pretty advanced in general.
-We have only a limited amount of words, and each of those words only has a limited amount of possible roles in any sentence.
- Each of those words will only have a limited amount of related words, synonyms (did vs made happen), or words that belong in same groups (strawberry, chocolate - dessert group)
So would it not be possible to write a program that will recognize the similarity between "I love skiing, but I always break my legs" and "Oral sex is great, but my girlfriend thinks it's only great on special occasions"? | There's a lot more to language that people realize. Assuming we're dealing with just text, parsing is only around 85% accuracy these days, maybe pushing 90%. Dealing with speech, etc. is far more complicated.
To make matters worse, there is no agreed-upon model of grammars -- there are a range of models some of which are really good at describing language but really hard to use for NLP, and others are really good for NLP but not very good for describing language.
Still further, the study of meaning (both literal and non-literal) is fairly new, and what we know is vastly eclipsed by what we don't know. Further, a lot of what we say is caught up in world knowledge (it's not a fact about *English* that dogs are mammals) and about our knowledge of human capacities (using turns of phrase, metaphor, allusion, etc. are done because we expect people can *figure out* what we're saying extra-linguistically).
Language -- strictly pure language itself -- doesn't cover nearly half of what you're aiming for. To get the rest, you need something bordering on artificial intelligence. | 28 | 25 |
Discrete Mathematics Topics For Learning Algorithms and Data Structures | Hi all ,I need to know what topics should i study first in discrete mathematics before i study data structure and algorithms | Understand mathematical induction well is important. It's a standard technique for proving algorithms correct. Induction and recursion should become synonymous things when you are working on algorithms.
It's also probably useful to conceptually understand a little graph theory, especially trees and directed acyclic graphs. | 10 | 18 |
ELI5: I'm baffled, how is it even possible that this many unarmed people are being shot down by police? | * As the internet becomes more deeply woven in everyone's everyday life and it reaches lower and lower into the socioeconomic latter, issues can disseminate from a class of people that never hadn't had their narratives matter before
* This in turn means that more people can do something about these issues they previously hadn't had much experience with
* This fuels the media creating a positive (if you would call it that) feedback loop in reporting of racial issues
Its likely that unarmed deaths at the hands of police has not risen heavily in the past few months vs the last twenty years, however the level of communication has dramatically increased to people who couldn't potentially afford it before. As people organize and take a stand together that creates attention from the national media.
TLDR we just know now how often it happens and the people are getting fed up | 55 | 26 |
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CMV: The definition of asexuality is too broad and invites more ridicule and less acceptance of the LGBTQ+ community as a whole | I started thinking of this after seeing this tweet. It's an asexual model advertising an asexual-themed lingerie line. [https://twitter.com/SophNar0747/status/1453702975222919168?t=2zXdqNmFzX5C8xV7pUL99A&s=09](https://twitter.com/SophNar0747/status/1453702975222919168?t=2zXdqNmFzX5C8xV7pUL99A&s=09)
Apparently the accepted definition of asexual has broadened to include people that enjoy sex, seek out sex, yet say they feel no sexual attraction. That they feel sex as an asexual person is essentially like masturbation, just involving another person.
[https://www.healthline.com/health/what-is-asexual](https://www.healthline.com/health/what-is-asexual)
Now, I have a friend that identifies as asexual, is married but has never had sex with her husband. She's sex repulsed, which is what I think most people think of when they see the term asexual. I understand that kind of asexuality being included in the broader LGBTQ+ community. It's unusual and opens you to ridicule in a society that pressures people to lose their virginity and advertising often with sexual themes. I can see that being surrounded by sex when you're repulsed by sex would be distressing, like when your friends family and coworkers talk about sex. I can see that the other kind of asexuality, where you're simply not interested in sex, would also contribute to reduced acceptance in society.
However, I don't see the functional difference in how you're treated in society and conform to societal expectations if you label yourself as asexual but regularly engage in sex, whether casually or in a relationship. People with strict paraphilias can only be aroused when non-human elements are present and are attracted to those non-human elements (like leather, shoes, food, etc). They're not considered automatically part of the queer community. They engage in sex and enjoy it when their partner accommodates those fetishes.
I think this new broad definition of asexuality is confusing to the average person, and contributes to the perception that being LGBTQ+ is "trendy" and "attention seeking." This attitude contributes to queer issues being taken less seriously, like discrimination and violence on the basis of your sexuality or gender identity. I just don't see any example of, and can't imagine, oppression that would be leveled against a person that identifies as asexual yet regularly engages in sex with other people.
My argument is that the definition of asexuality should be limited to people that are not interested in sex, either because of repulsion or simply non-interest. I'm not setting the bar that they all have to be virgins, because there are plenty of gay people that married and had children with people of the opposite sex to fit in and avoid discrimination. I can see someone not fully accepting that they don't feel sexual attraction until they try it out. I'm not suggesting the label of asexual should be ruled out for masturbation either, as it's very different than sex with another person. But, I think actively seeking sex should be disqualifying for labeling yourself as asexual. There's no functional difference between having sex because you're attracted to someone and having sex just because it feels good.
TL;DR: The label of asexual makes no sense for someone that actively seeks out sexual partners, and engages regularly in sex. Asexuality is understandably being included in the broader LGBTQ+ community, but I think people that identify as asexual yet engage in sex shouldn't be included in that. It's confusing and leads to people taking queer issues less seriously.
EDIT: What would change my view is if someone could provide an example of discrimination or distress a person would experience if they identify as asexual yet still engage in sex regularly and actively seek it out. | It's not clear why you think the definition is too broad or too complicated. It is really quite simple:
* Heterosexual people experience sexual attraction to people of the opposite gender within the gender binary, and no or little sexual attraction to people of the same gender.
* Homosexual people experience sexual attraction to people of the same gender within the gender binary, and no or little sexual attraction to people of the opposite gender.
* Bisexual people experience sexual attraction to people of both genders within the traditional gender binary.
* Asexual people experience little or no sexual attraction to people of any gender.
Just like all the other sexualities, asexuality is about the attraction one experiences, not about the actions one performs. An asexual person can choose to seek out and have sex with others in the same way that a straight person can choose to remain celibate. The definition of "asexual" is no more broad than the definition of "heterosexual" in this regard. | 101 | 114 |
What are researchers and scientists primarily doing on Antarctic missions? What have been the most significant discoveries or advancements from this study? | One of the most historically significant discoveries made in Antarctica was the work of Joseph Farman (and many others after him) on the ozone hole over Antarctica and its relationship to CFCs. Farman begin collecting ozone readings in Antarctica in 1957, although his work was largely dismissed by the scientific community at the time. It wasn't until 1974, when two American scientists showed that CFCs could destroy ozone in the stratosphere that anyone begin paying attention and a dangerous ozone hole was theorized. In 1985, Farman and colleagues published a paper in Nature showing that ozone levels over the Antarctic had decreased by 40% since 1975, and that the ozone hole was a very real problem. The discoveries of Farman, and many others over the years, lead to the Montreal Protocol, an international treaty intended to phase out the use of ozone-depleting industrial compounds. The Montreal Protocol was signed by 24 countries in 1987, and has been signed by more than 200 today. The story that begins with Farman's work in Antarctica and ends with the Montreal Protocol, which has effectively eliminated CFCs and stopped the expansion of the ozone hole, is one of the greatest success stories in the history of modern science. | 44 | 73 |
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CMV: Popular educational Youtube channels like VSauce, SciShow and MinutePhysics cause more harm than good | These channels are often advertised as "better" alternatives to TV, especially here on reddit, and it bothers me because I really don't think that they can enrich your life in any way and might even cause people to find themselfs on [Mount stupid](http://blogs-images.forbes.com/chrisbarth/files/2011/12/Mount-Stupid.gif).
Let's use this MinutePhysics video to illustrate my point: [What is Quantum Tunneling?](https://www.youtube.com/watch?v=cTodS8hkSDg).
What has the viewer actually gained after watching this video? He obviously doesn't understand quantum tunneling, but might you argue that he now at least want's to actually learn about it? I'd say no.
The problem I have with the video, I think, is that it doesn't inspire learning at all but rather just exists to make the viewer feel as if though they have gained some understanding. He gives you an explaination and a person who does not currenty study physics will probably just accept what is said here.
What's worse is that the person watching might even feel as if he has actually understood the concept and could actually "have a say" about it. Think of people who like to say that "Biologically a tomato is a fruit, not a vegetable".
So in the end the person has not only gained basically nothing but he might actually feel satiated with the simpified answer and walk away feeling as if though he now understands the concept and has actually spent time "learning" and not just mindlesly watched a youtubu video.
Edit: Sorry for writing such a shitty motivation for my view. Most newer comments seem to bring up issues I have already commented on.
#Please post in threads when possible.
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> *Hello, users of CMV! This is a footnote from your moderators. We'd just like to remind you of a couple of things. Firstly, please remember to* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! If you are thinking about submitting a CMV yourself, please have a look through our* ***[popular topics wiki](http://www.reddit.com/r/changemyview/wiki/populartopics)*** *first. Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | How else do you explain quantum tunnelling to people without spending several hours explaining the Schroedinger equation and how to apply it, and before that spending a year explaining all the mathematics that is required to understand Schroedinger equation.
You cannot just sit atop "mount excellence" and yell at the people in the valley below "No, you are too uneducated for me to give you an explanation of quantum tunnelling to, you will have to wait until you've had a formal education in physics and mathematics". That doesn't work. People who want answers will seek answers and that video isn't a bad answer for 1 minutes requiring no prior knowledge of the subject. | 125 | 49 |
ELI5: When an animation studio like Pixar has multiple dozens of people, all with their own styles, working on a project, how do they keep everything uniform? | Usually in animation we have model sheets and motion bibles (terms vary from studio to studio) that tell us how each character expresses themselves, reacts, and moves. Everything from how they look over one shoulder, how they smile, where their centre of balance is, what they do when surprised, and so on.
This helps keep all the work uniform. | 8,725 | 11,723 |
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[Avatar] Where are the water and earth shamens? | We know that the Air Nomad monks are responsible for identifying the Avatar when the rebirth cycle is on air. We know that the Fire Shamans are responsible for identifying Avatar's when the cycle is on fire and that they're supposed to be helpful and loyal to the Avatar, no matter which nation they're born into. Yet, when Aang travels to the Water Tribes and Earth Kingdom, he never even considers tracking down their Avatar temples.
This is especially strange since the Water Tribes should be on call to try to find the next Avatar after Aang went missing.
What's up with that? | The four nations are each culturally distinct. While the Avatar plays a role in every nation's spirituality, how that manifests is different for each group.
In the hundred years war the Water Tribe has sort of drifted away from their spirituality. They maintain traditions, but mostly for traditions' own sake. Not that the people aren't strong spiritually, just that their society has shifted. (This is a plot point addressed in Legend of Korra)
The Earth Kingdom is huge, and has many culturally distinct states. If the Avatar was born there it would be up to local authority figures to put the pieces together. Kyoshi's Avatar-hood wasn't discovered until she was 16. That's probably fairly common among Earth Kingdom born Avatars. In Ba Sing Se, the institution that would take on that role is the Dai Li. (So, not exactly helpful to Aang)
There are temples to the Avatar all over the world. Visiting them each individually doesn't really serve much purpose to the Gaangs' larger goals. There's also something to be said for subtlety; Sozin ordered a genocide of the Air Nomads to wipe out the Avatar. Azulon did the same thing to the Southern water tribe. The idea of Aang showing up was so inconceivable that Ozai used finding the Avatar as a way to banish his son. At what point do the organizations whose sole role it was to find or serve the Avatar just disband? | 59 | 53 |
How would waves be any different if there was a superocean like Phantalassa. Would they be larger and more dangerous or calmer and would anything else be different? | The amplitude of waves in the ocean somewhat depends on the wavelength of them. For a longer unobstructed path, wind can have a larger compounding effect, leading to larger waves. The southern ocean is a good example of this, as it encircles the lower latitudes of earth (up to Antarctica) pretty much unobstructed. As a result, you'll routinely see 20 meter or higher swells going through there. Any scientist stationed at McMurdo has certainly earned his or her sea legs lol. | 3,645 | 8,363 |
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ELI5: How does a salt water rinse work for toothache/inflamed gums? | I had my wisdom teeth taken out and I've been using an anti-bacterial mouthwash (chlorhexidine) but I've found a salt water rinse actually works better for getting rid of the pain/inflammation/aching.
So why does something as simple as salt and water work better than a dentist recommended antibacterial mouth wash? | warm Salt Water works well because it's a hypertonic solution, means that the osmotic difference between the solution and the tissues is such that it will pull water OUT of the tissues. The inflammed tissues will have excess water in it, and the hypertonic solution will calm it down by pulling out the water, allowing it to thin down and not be so "angry". It also acts as a mild disinfectant because the salt solution does the same to any bacteria that are around. | 184 | 108 |
All religious debate between atheists and theists is pointless. CMV | It seems to me that whatever the argument, the two parties clash on the issue of "faith". Atheists in general require some proof or logical set of reasoning that leads to a religious conclusion (which they haven't found), whereas theists don't - they simply "believe". Arguments boil down to people shouting "I need proof or I don't believe" at people shouting "I have faith, I don't need proof". Whenever I see the debate I find myself rolling my eyes, because the participants don't have a shared logical framework to operate in. It's like a hockey team taking on a football team with a shuttlecock. No one's scoring any goals.
It seems like if you can't agree on if there is/isn't a god, then there's no meaningful debate to be had. Meaning of life? Don't bother. Inherent moral values? Nope. Just accept that your if your belief values don't match, you can't get past "faith" to discuss second level questions.
To clarify, I mean specifically the debates held between people of different viewpoints on the "God - for and against" debate. I think that a lot of "what if...?" questions, if approached from a neutral perspective, can lead to meaningful discussion, because you're not dealing with the belief issue.
So change my view, is there a point in debating it? | These debate type things are about two things.
1. hearing a new point of view or clarification on it. Maybe you will hear some thing that will stick with you or change the way you think.
2. formalizing your view. If you have to explain it you start to think about it more.
Either way if you are not open minded then yes it is a pointless but if you have even a crack of openness then its not an entire waste. | 18 | 38 |
Professors: what questions do you wish prospective/new PhD students would ask you? | I am visiting the campus of a PhD program that has offered me admission. Since their offer, I have Skyped for an interview, corresponded via email with various faculty members in my field of interest, with current graduate students, and with the GPD. So my basic questions about funding, research, resources etc have already been answered. This Open House is a two day event where I will be interacting with potential advisors and peers for most of the day each day. I was wondering what kind of events take place, what kind of questions I should be asking during one on one conversations with faculty as well as during panel sessions. Please help! Thank you!!! | If you haven't already discussed this with your potential supervisor, I'd definitely make it a point to ask them and other students--How often does your supervisor contact their students? How often do they meet with their students? What's their average turnaround time for comments on a chapter draft? Do they usually initiate contact with their students, or is it expected that you will be the main driver of the relationship? How many students have they graduated, and where are they now? Do they co-author with their students? Do they bring students with them to conferences? What's their position on mental health issues in grad school/academia? | 112 | 127 |
ELI5: Recently my hometown got 9" of snow, and the forecast was 8-12 inches. How can this (and other weather) be predicted so accurately so far in advance? | Centuries of record keeping helps us see patterns and trends, decades of tracking weather patterns and results and feeding into ever-improving computer modeling, better data collection using radar and satallites, and every day we understand better the sciences behind weather which allows us to improve our computer modeling and amount of data we can track and document.
And for all that we still get it wrong. A lot. | 22 | 18 |
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[Avengers] Are the Avengers or Agents of Shield paid for their work or do they simply have all their expenses from food/board taken care of? Are they eligible for benefits, what about their families? | Agents of SHIELD are either federal employees or employees of the UN, depending on the continuity, so they are paid and receive benefits fitting of their profession.
Avengers are either employed by SHIELD (like in the early MCU) or are part of an independent foundation (like in the Comics/ late MCU). The Avengers do get food and board, but mostly so they can go into action faster like you would see with Firefighters but more luxurious. | 79 | 71 |
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ELI5: Once you have an idea, how do you get it into production? | IE. investors, app development, protection from others blatantly stealing your idea? | 1. Have money to invest in the idea
2. Find other people to invest in the idea
3. Legal costs to know if you're actually the first to have the idea
4. Legal costs to patent idea
5. Make more business contacts, potential customers
6. Finding a manufacturer
7. 100/0 split on costs & profit for you & manufacturer **or**
8. x/y split on costs & profit for you & manufacturer
9. Realize you have no business plan
10. Make more business contacts & start begging
11. Find a new project
12. Sell out & be rich **or**
13. Accept failure & the $100k you threw into the money pit
You cannot stop someone stealing 'an idea'. Ideas are free, always. You need a 'something' to protect & get the right legal protection for. If you have a great idea and don't know the industry you think would benefit the most from the idea, your only hope is to be really lucky because if you don't succeed immediately, someone else will solve how to work around / improve / undercut your idea.
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If chlorine is supposed to kill microbes in tap water, why is it safe to drink? | Chlorination in drinking water is low enough not to cause any significant harm to humans due to our size and ability to deal with small amounts of toxic material. Given that microbes are microscopically smaller than us, the amount required to kill microbes in water is resultantly lower.
It can be likened to air in the city being 'safe' to breathe. While it won't knock you down dead, it does carry the potential for long term health risk. The benefit/cost of chlorinating water is generally believed to have an overall positive effect in that the number of deaths from waterborne disease prevented outweighs the possible increase in risk for cancers, for example. | 13 | 21 |
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Is it okay to do research in a field outside of the subject I eventually want to get a PhD in? | I graduated in 2019 with a degree in Cognitive & Behavioral Neuroscience. I did a year of part time psychology research in undergrad. I then worked as a full time RA for a psychiatric research lab from November 2019 to December 2020. I moved across the country in September, and was applying to jobs over the last 4 months. I now landed a job doing Cardiovascular research paying me 25% more than my last job. I also had a job with a neurology lab lined up, but went for the cardiology one because of the pay, which is more important to me for now. I wanted to know, was this a bad move in terms of research experience if I want to study Clinical Psychology? Is it helpful to have research experience in an unrelated field? I can't find any discussion on this anywhere. | I don't see it as a problem, particularity if they are part of the same overarching theme (medical research). Even very established researchers go outside of their field either for fun, to get a fresh perspective, or out of necessity. Having experience in both fields might even be a benefit in that you will likely have a broader set of skills and it might stimulate some cross disciplinary ideas.
I would suggest that if a future interviewer asks why you have experience in a different field you say something about getting more experience and/or trying different things. Sometimes academia can be judgey if you do things for money (which is a silly perspective, but common) rather than "for science". | 23 | 52 |
ELI5: How can NASA tell the structural layer of a planet without digging into it | Firstly, they have mass. An ice planet will have less mass than a planet made of rock or iron, and more than one made of light gasses. Mass can be very accurately calculated if it has a moon or other satellite, as the period of the orbit, the time one orbit takes, is proportional to the mass.
We also have knowledge of how elements react under certain pressures, and we know the temperature or the outside of the planet, and knowledge of fluid dynamics tells us what the internal temperature will be.
Additionally, we have our understanding of the solar system. Rock, iron and other metals predominates from the sun to the asteroid belt, gas from there to the Neptune, and the Kuiper belt and beyond.
And we have good information about the Earth, which can be extrapolated. Slowly we will obtain information from seismic studies of planets.
So, take Mars. We know its size and its mass. We know the surface is rock. Knowledge of its size and mass tells us how much of it is light rock and how much heavy nickel/iron. As seismic sensors that are part of probes sent to Mars give us more information, we will learn more.
But there is a fair degree of conjecture. We know we are not far wrong, but expect further evidence to refine our understanding about the construction of the planets. | 28 | 73 |
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[MCU] Why don't they give all of the Avengers Falcon wings or War Machine suits? | Or at least more than one of them?
EDIT: Holy crap, guys, I get it, chill.
/u/imariaprime says pretty succinctly what about three sextillion other people have said:
> without a minimum level of technical expertise (which most don't have), the suits [also presumably the Falcon wings] would actually be a danger to them if anything went wrong and they couldn't troubleshoot it on the fly
Or, as /u/metallink1 put it...
> flying that shit is hard as fuck
Also Stark and Pym are paranoid dicks.
[/u/ZombieFeedback also has a very in-depth explanation.](https://www.reddit.com/r/AskScienceFiction/comments/8jdi78/mcu_why_dont_they_give_all_of_the_avengers_falcon/dyzbnj7/)
Edit 2: GUYS I GET IT. STOP EXPLAINING WHY.
Edit 3: I feel like I've entered some obscure circle of the afterlife where a bunch of my fellow nerds constantly explain why the Avengers can't all have Iron Man armor to me. GUYS. I UNDERSTAND. | All of the Avengers have been outfitted with gear that best compliments their own unique abilities, skillset, and preference.
There's no reason to trade in a preternaturally skilled sniper for an incompetent pilot, and sometimes a discreet infiltration asset is better than a tank. | 406 | 467 |
Can a gravitational locked planet outside the Goldilocks zone support life on the side facing the star? | I have read that based on a stars size the Goldilocks zone will differ from star to star.
I have also read that if a Planet has one side locked facing the star with in the Goldilocks zone it wouldn't be able to support life because it would be too hot.
So what if it is outside the Goldilocks zone but the side facing the sun has all the things needed for life.
Would the science support the possibility that life could be possible?
Would this planet also need a moon orbiting around it to help create tidal currents on the liquid side and helping the tectonic as well?
And perhaps if the planet also needs to turn would it be possible that instead of turning in relation to the sun like our planet does but on a tilt it spins in a way that one its poles are facing the star.
Yes I have no idea what would cause a planet to rotate like that, but my question is basically can a planet outside the known habitable zone with a single side always facing the star support life and does the math allow for this? | There are multiple definitions for the habitable zone around a star, depending on various assumptions. The classical model doesn't include atmospheric effects, which obviously have a significant influence on surface temperatures. It also doesn't account for a tidally-locked planet, or the possibility of alternative types of biochemistry (meaning life based on a solvent that is not water).
All that to say, the habitable zone concept is more of a loose guideline than a precise limit on where life could exist. The planet you are describing is theoretically capable of supporting life, despite not being exactly within the habitable zone. Since we have yet to find extrasolar life, there's no validation for any version of the theory, so take it with a grain of salt. It's more of a best-guess as to where life is likely sustainable that a hard limit on where life can reside.
Regarding requiring a moon, that delves too far into speculation to be really meaningful.
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CMV: I believe that a Bachelor's Degree for office type positions are simply to weed out the large amount of candidates and that it isn't practical since you can simply train on the job. | I always believe that you can take average performing high school students and train them to work in office jobs like Accounting, Auditing, Marketing, and etc.
Just for example, I am not academically driven but I became successful in my current workplace because I develop practical general translatable skills.
Skills such as good written and verbal communication, how to ask questions and extrapolate information for future references, and just skills that helps with more of the macro.
Micro changes frequently since you always learn completely new things when you transition to newer positions.
Average performing high schoolers aren't that different from college students. Given that they have taken the SAT, written large amount of essays, have to do presentations, and surely would have develop skills that can translate to more professional oriented jobs.
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> *This is a footnote from the CMV moderators. We'd like to remind you of a couple of things. Firstly, please* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | Degree requirements for most jobs have very little to do with hard skills learned in school. They're mostly to demonstrate the soft skills and socioeconomic class associated with becoming a college graduate.
You're right that it's to narrow down the graduate pool, but it's not arbitrary. | 42 | 152 |
[Star Wars] Is there a canon explanation for why so many aliens are humanoid? | For most, such as Sullustans and Abednedo, convergent evolution. Species in the galaxy that evolve into intelligent toolmakers tend to have the same basic body shape.
The species that have human shaped heads with colorful skin or other small differentiators (like Twi'leks and Mirialans) are "near-humans" who have human ancestry but adapted to life on other planets or interbred with aliens. | 23 | 15 |
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ELI5: How does something like a complex theoretical equation get turned into a real world application? | This is such a brain-smoother for me that I don't even know how to really easily word the question, so I'll try to give an example of what I mean:
In some books I've read in the past, there have been things where they've said stuff along the lines of "If we figure out the necessary equation, we could potentially fold space for faster than light travel."
So, let's say you have your equation, and its principles are sound - how do you then USE this to actually do something? How does it take the jump from theoretical to practical? | >real world application?
Let's... Use a real world application as an example, rather than FTL travel.
Let's say you want to build a wall, and to prevent it from falling over you want it to be vertical.
If there isn't any wind, you can hang something heavy from a string to show you what vertical is, but if you'd like to be able to work on windy days you'll need a guy named Pythagoras to come up with a handy equation for how to put together three pieces of wood in a way that makes sure the angle between two of them is always *exactly* 90°, as long as you know how long each piece of wood is relative to the two other.
All you have to do to turn it into a real world application is a bit of measuring, cutting, and arithmetic.
Or let's say Pythagoras figured that out thousands of years ago and now you'd like to know where you are even if you're lost in a place without streetsigns (such as the middle of the ocean).
You have the technology to put radio transmitters in space, but just using the triangulation that Pythagoras figured out and other people refined *doesn't work* until some guy named Snell figures out how to predict how fast light moves in various mediums, and some guy named Einstein figures out how fast *time* moves at different accelerations and velocities.
All you have to do is fit a battery powered supercomputer in your pocket that can do billions of calculations per second, launch a bunch of satellites, build insanely accurate clocks, and BAM just like that you've turned thousands of years of mathematics into a real world GPS system. | 43 | 72 |
[Star Trek] if I had no knowledge of holodeck programming and wanted to create my own, what would the process be? | Unless you need something particularly complex or obscurely specific you can simply request what you want in plain speech and the computer will attempt to render it for you. Describe the setting, the characters, and the activity or plot. No programming skill necessary, the only limits are your ability to articulate what you want and the vast resources that the computer can reference. | 18 | 27 |
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ELI5: How does a company decide a job requires X-Y number of years for a particular position? | Just scrolling through job postings. I'm qualified for a lot of jobs with the exception of 8-10 years in business XYZ or 4-5 years in industry ZYX. I know what they want and could probably hop right in and do it, but I learned many of my skills from the military or from night classes while doing a completely different job.
Why not just put, "A solid understanding of ____, ____, and ___ in the ZYX industry." Give interested candidates something more specific and can be proven in conversation or written test.
Anyone know how they come up with the required number of years? | When it all comes down to it, they are guessing.
They know who last did the job and about how much experience they had coming into it, and in general they know that someone with more years experience will be better at it.
Besides, they can afford to discriminate. If you post a job with no experience required then you get thousands of recent grads applying for it. Better to ask for 3-5 years experience and then you get people for not much more who have already proven they can do the work.
I find that the 'experience required' restriction is never a deal-breaker. It is just there to narrow the field of applicants. The company will find out in the interview whether you know what you are doing or not, so go ahead and apply. | 27 | 34 |
CMV: Any Relationship Between Any Set of Consenting Adults Ought to Be Legal | **Breakdown:**
* **Any relationship:** I mean any form of relationship, whether that be polygamy, incestuous thrupples, polycules, plural marriages, interfaith swinging, or any other configuration you can think of.
* **Any Set of Adults:** I mean that everyone that is party to the relationship is an adult^[1] at the time they become party to the relationship.
* **Consenting Adults:** I mean that every person that is party to the relationship gives their informed consent and maintains their informed consent for the duration that they are party to the relationship.
* **Ought to Be Legal:** I mean that for any relationship that meets the aforementioned conditions, there should be no law prohibiting dating, marrying, cohabitating, fucking, and so forth. Further, that any relationship that meets the aforementioned conditions should be treated with legal equality to any other relationship to the extent that is possible.^[2]
[1] *Adult or of the relevant legal age for any pertinent activities.*
[2] *Understandably, there will be relationship structures that are too complex to accommodate in a standardized way and should be navigated case by case to achieve the spirit of the idea of legal equality.*
**Why do I want my view changed?:**
As I am tired and can think of no solid arguments against this, I feel that I must be missing something.
Please change my view. :)
Edit: Due to the opacity and inherent power imbalance, I feel that it is reasonable to say a relationship between parent/guardian and child will be highly unlikely to ever meet the demand for informed consent. | Nations define marriage for the purpose of establishing parental responsibility and inheritance rules. US law arises from English common law. Dual marriage is an ancient common-law right that has existed “since the memory of man runneth not to the contrary.” Plural marriage has never had that status in English common law, so it can be regulated by the states (which have responsibility for handling marriage as a legal relationship).
The factual answer is that many people consider it immoral, so it’s outlawed for that reason. And polygamy is often used as a way of abusing young women, semi-forcibly marrying large numbers of them off to men.
From a purely pragmatic standpoint, it complicates inheritance rules considerably, and nobody wants to try to untangle that knot. It would be a nightmare for everyone. And it brings no benefits, since polygamists are an almost insignificant percentage of the population. | 152 | 366 |
ELI5 why inbreeding causes problems. | It's general knowledge, as far as I know, but what actually happens? | Certain diseases are related to genes. Now for every gene in your body it has a partner. You have two sets of genes, one from mom and one from dad, and need both to live.
Some times a defect or change in the gene causes a disease. Now here is the tricky part: if the change is only in one of the two copies of the gene and you get the disease, it is called Dominant. If you need the defect in both copies it is Recessive.
Lets make up a gene, called DERP1. Remember you have two copies of DERP1, mom and dad versions or DERP1 (m) and DERP1 (f). Your DERP1 (m) is defective, i.e. it doesn't work and cannot be used to make proteins, but DERP1 (p) is just fine and there is no disease. You are a CARRIER for a disease of DERP1, but you do not have it, because it is Recessive and you need both copies to be defective to have a disease.
Now DERP1 defects are rare, so if you marry some random woman, the odds of her and you both having a DERP1 defect are small, and you won't pass along the disease to your kids.
But your sister may also be a carrier for the defective DERP1 from mom. So if you mate with here the odds of your off spring getting both defective DERP1s (one from you and one from her) is 25%.
As a general rule of thumb, most family trees contain one to two Recessive diseases in their genes, most people are carriers and without genetic testing would never know that a whole gene was broken. But by inbreeding the chances of recessive disease genes linking up are vastly increased. Its funny that incest is probably the only universally reviled practice in human history (I had a anthropology teacher tell me this) and that even animals will usually avoid inbreeding.
Edit: Fixed mistake with % | 19 | 20 |
ELI5:Why they don't teach how to do taxes, credit cards, insurance(health and auto), loans, investments in general public schools. | It seems like these are all important things everyone person will have to deal with in their life and yet, they barely scratch the surface on teaching these in schools. | They teach the underlying skills you need to figure these things out on your own. Reading comprehension, a bit of research, and some basic math is all you really need to figure out how all this stuff works. If schools had to teach you every life skill you'd need, we'd be in school for the entirety of our lives. The purpose of education is to teach you how to reason about the world around you so you can better face the vast variety of challenges life will throw at you, not to tell you the solution to every problem you will face in your lifetime. | 74 | 103 |
Could someone explain band gaps? | Its been brought up in a couple of my classes, but I've never really understood it. | So when you have one atom you have distinct energy levels that electrons can occupy. The electron can have these allowed energies, but not any others.
When you have two atoms bound and sharing electrons, the energy levels combine in such a way that two atomic orbitals of similar type end up going from orbitals of similar energy to molecular orbitals, one of lower energy and one of higher energy. In the simplest case you have a homodimer where two atomic orbitals of energy E combine to two molecular orbitals of energy E-g and E+g. Of course the electrons are going to roll downhill and land in the lower energy molecular orbital (E-g, known as the bonding orbital) and leave the other (E+g, antibonding) empty. As a result the electrons in the molecule end up with lower energies than the electrons in the separate atoms. See Molecular Orbital Theory for more of this.
Add more and more atoms and more and more molecular orbitals get combined together. Each orbital has to be a tiny bit different from the others, so after you start piling lots of electrons in there you end up with just a band of bonding and a band of antibonding orbitals. The difference in energy between those two is the band gap.
Electrons in the lower band (bonding orbitals, known as the valence band) are basically stuck in place but those in the upper band (antibonding orbitals, conduction band) can move about as electron-hole pairs. If the band gap is small then ambient temperature is enough to promote electrons up to the conduction band, where they are free to move about, as in metals. If the band gap is huge, then there needs to be a big voltage put in to promote an electron to the conduction band for the electron to move and yield a current. This makes an insulator. In between are semi-conductors, where it takes a small voltage to promote an electron and yield a current. | 10 | 15 |
If the virtual particles exchanged to create forces don't really exist, then what are forces made of? | Hi, other /r/askscience posts I've read, such as [this one](https://www.reddit.com/r/askscience/comments/14qa1n/if_photons_are_the_force_carriers_between_magnets/?st=j4fix84s&sh=18e4b480), and [this comment](https://www.reddit.com/r/askscience/comments/14qa1n/if_photons_are_the_force_carriers_between_magnets/c7fvtq4/?st=j4fj1lqx&sh=d3302148) seem to imply that the virtual particles that are supposedly exchanged are more mathematical abstractions than literal objects. If that is the case, what are forces made of? | The "forces" -- in the sense that there are any -- are, like everything else, made of quantum fields. Strictly speaking, there aren't any forces in the sense of instantaneous interactions à la Newton; there are only fields, interacting locally (i.e. where and only where they overlap with each other).
The sense in which virtual particles are fictitious is that they correspond to just one way to decompose the global state of the fields into an orthonormal basis -- and that basis is especially inapt when interactions are turned on. They are just one route to grasping the quantum fields, which are the "real things". | 25 | 23 |
[Resident Evil] What’s up with Umbrella and bio-terrorism? | I mean, sure, it creates a lot of panic and casualties, but so could a normal militia. Why keep going for viruses and making monsters like Nemesis or Mr. X? | In the modern marketplace, diversification is the key to corporate survival. The company that only does one thing well will never be able to keep up with the company that does many things adequately.
Umbrella is the ultimate corporate juggernaut. They understand the importance of having interests in every field of human endeavour, from healthcare to video gaming to, yes, apocalyptic-level global bioterrorism. But you shouldn't be so quick to judge them based on just one part of their sprawling empire. Umbrella has countless products aimed at the betterment of humanity, and to dismiss them as just "the bio-terrorism guys who came close to exterminating all life on this planet" is to take a ridiculously narrow view. | 26 | 28 |
Why do "all-black" institutions still exist? Primarily, universities/colleges. | I was driving through an all-black college the other day and thought to myself in a very simple manner, "Why?" If colleges are really to prepare individuals for the real world, why shun certain races? Why purposefully surround yourself in only people that are similar to you? At the very least, shouldn't a university force us to interact with those that are far different from ourselves? I felt that during my time at a very culturally/racially mixed college, that it was the best thing I could have done. I found new ways to interact and learn from people who had very different backgrounds and cultures from my own. If I were to attend an all-white college, I would have been doing myself a disservice.
Can someone explain why these institutions still exist and possibly, if a redditor has attended one, what were your motivations for doing so? | Quite a few institutions which people think of as "all black", are actually HBCUs- Historically Black Colleges and Universities. While these institutions were historically places for Black students to attend (partly because HBCUs were created prior to to the Civil Rights Movement of the 1960s to serve Black students since segregation was still legal).
Currently, HBCUs allow students of all races to attend, but many still have high Black student populations. You can theorize all kinds of reasons for why this happens, including institutions being slow to change, HBCUs tending to have more professors of color, to it being nice to be part of a majority on campus. Location is also key, as HBCUs were originally located in slave states, so they are geographically situated near where large populations of Black people settled post civil war, and where their descendants still live today. | 157 | 193 |
How to talk to a grad student about productivity issues? | I'm paying one of my grad students for 40 hours of work per week, and I feel like I'm getting barely half of that. How do I politely approach her on this subject without sounding like I'm micromanaging? I'm fairly new to academia, so I haven't really had to deal with this before.
Most of what she's currently working on is funded from an internal pot of money, so it's not like she's missing external deadlines from sponsors. I will tell her that I want a certain model estimated by so-and-so, and when that time comes she'll tell me that she was having issues with the software, or the model was giving errors, or that it's taking longer to converge than she expected. I.e., nothing I can definitively call her out on.
This is a PhD student entering her third year, and I'm worried that she's slipping. I just don't know how to broach this respectfully. | Setting up tasks and keeping an eye on the progress is totally fair, just make sure that you realistically estimate the time those tasks need. Sorting out a package installation can take the whole day. Fixing convergence issues can take a week. On top of that, everything takes \*much\* longer for a student who is doing this for the first time. Maybe you should first see if she is actually putting in approximately a full time's worth of work, or if it's a motivation problem. | 395 | 252 |
ELI5: How are calories measured, and how accurate is it? | Calories can be calculated by the following equation:
Q = mc∆T
Q is energy in calories (not Calories, which is what nutrition labels use. 1 Calorie = 1000 calories). m is mass in grams, c is specific heat in calories/gram °C, and ∆T is change in temperature in °C.
Now how do we use this? Well we can use a device such as a bomb calorimeter. Basically, it's a chamber surrounded by water. Food we want to measure is burned and the heat from that process is transferred to the water (since energy can neither be created nor destroyed, only trasnfered).
Water has a specific heat of 1 calorie/gram °C. (Specific heat, btw, is the amount of energy needed to raise the temperature for 1 gram of mass by 1°C). So say in our device we have 20 grams of water and its initial temperature is 37°C. We burn our food and its temperature raises to 40°C.
We can calculate by Q = 20\*1\*3 = 60. 60 calories. Or .06 Calories as we'd see on the nutrition label.
**TL;DR** Burn shit and measure the energy from that | 22 | 60 |
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ELI5: how come we have computers that can beat chess champions since 1996. but now in 2014 video games AI are still horrible ? | Researchers have studied chess for decades. Chess, for all it's complexity, has a very well defined set of moves that can be made & options for actions.
The guy writing the AI for the new Halo is an overworked dev who would rather be doing something else & has deadlines to meet. He doesn't have a PhD in AI or access to decades of research on optimal strategies. On top of that, he has to keep his AI running in real-time without sucking up all the resources on a system. | 45 | 25 |
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If we can't see UV light why does a room get brighter if UV is used to disinfect it? | [Example of what I'm talking about ](https://www.reddit.com/r/specializedtools/comments/foepa1/the_autonomous_hospital_cleaning_uv_robots_were/?utm_medium=android_app&utm_source=share) | Since UV light is both harmful and not visible to our eyes, producers of UV lighting equipment ensure that their devices emit not only UV light, but also some light in the visible spectrum to show people that the device is turned on and to prevent people from staring at it for a prolonged period of time.
What you're seeing is now UV light, it's just regular visible light. | 72 | 23 |
What component/mechanism of a tree determines when and how it will branch off from the parent branch? | I was walking around my girlfriends cabin in the PNW, quarantining and all, and became fixated of the structure on simple moss/lichen & trees.
I recently dove into computer graphic generation and am now looking to figure out what mechanism forces a tree/moss to branch off from the parent branch and how? I want to recreate it with a graphic generating application - as I think it would be awesome to build a time lapse/simulation of the process. Plus, I have lots of time on my hand now.
Thanks! | The basic mechanism is controlled by two plant hormones. Auxin is produced in the apical bud of the main stem and existing branches and diffuses downwards from there. Sufficiently high auxin concentrations inhibit the formation of branches. Cytokinines, on the other hand, diffuse roughly from root to top and promote branch formation. Branching happens where those two overlapping gradients provide the right hormone ratio. | 17 | 65 |
Correct me if I'm wrong on Wittgenstein (I'm wrong) | What exactly does he mean by "language games"? Is it the claim that in inquiry, all participants need to have the same or similar experiences in traditions as well as fundamental beliefs (ie God exists for religious discourse, or reason can tell us about the universe in science) and as a result it makes no sense to base criticisms in science to attack religion because you'd be using language structures that make sense in science but make no sense in religion? | Wittgenstein uses the concept of a game to explain the idea of family resemblance. A set of things have a family resemblance if there are certain features which connect them, but no set of necessary and sufficient conditions shared by all. The people a a family reunion will not share any single feature which they all have, and no one else does. However, some will have the same nose, some will have the same eyes, some will have some of the same mannerisms the same, and so forth. These common links will ultimately connect all the members of the family.
A language game is some part of a language (where a whole language can be considered a limiting case), considered in association with the things which are done with it. Wittgenstein's point is that we do different things with language, and how we should go about trying to understand a certain statement depends upon what we would normally be doing with this statement. The upshot is Wittgenstein wants to reject the project of offering a logical analysis for all language.
On "Lectures on Religious Belief" says that an atheist can deny what the religious person says, but cannot really contradict it. Wittgenstein seems to think this means the statements as uttered by the religious person function differently that the statements as uttered by the non-religious person.
That leans a bit in the direction of what you're saying. | 13 | 18 |
ELI5: Where do those monster waves in the middle of the ocean come from? | Tsunamis get that big since the beach makes that the water has no space when going high up.
But those monster waves just exist on the oceans with hundreds of meters ocean dephts?? | Research into this is ongoing. We know what can cause them sometimes, but we don't know what causes them all the time. They seem to happen most reliably in places where a strong current moves in the opposite direction of the waves, but we don't even know if that's what always causes them.
Fortunately we found out that they happen way more frequently than we thought. So we should get more answers in the near future. For now though, there's no really solid answer. | 24 | 31 |
[Star Wars] Why aren't robotics and cybernetic implants more common in criminal and military settings? | Luke's hand is at least as good as the real thing, and the technology is obviously there to make it way better. Look at General Grievous.
Now Vader's huge cybernetic transformation could affect his force powers (maybe), but why don't regular folks and those who fight other humanoids make more use of this technology? | 1. Cost. Vader had the benefit of being saved by the goddamned Emperor of the galaxy, for whom cost is barely a concern. Most folks do not.
2. Religion. Even those who don't believe the Jedi had the magical powers they claim often believe in the Force, and that it flows through *living* things, not droids or cybernetics. Many people consider willingly taking on cybernetics to be like excising chunks of their own souls.
3. Pain. We...do not have fantastic anesthesia, here. This operation will hurt.
4. Widespread interference. Many smugglers and bounty hunters and the like do business in places where electrical interference would disrupts the control circuits of cybernetics. This is by design, as those same conditions make tracking more difficult.
5. Discretion. Since cybernetics aren't common, wearing cybernetics makes you stand out. For all their loud and brash style, most smugglers and other criminals have nondescript civilian clothes stored in case they need to blend in. A giant glowing robot eye will make that harder to do. | 65 | 77 |
ELI5: If IQ is standard deviation, why isn't there a ceiling that no IQ can surpass? | Standard deviations, and by extension, normal distribution, tell you data is likely to be distributed, but it doesn't impose limitations.
In fact, if data has a perfect normal distribution, it *can't* have ceiling, because the normal curve extends to infinity in both directions. At it can tell you is how unlikely it is for very high or very low values to be included in your data set. | 42 | 52 |
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Why do abusive parents abuse some of their children but not others? | I have my own observations based on anecdotal evidence, but I would like to hear what research has to say. | Bowen's family systems theory has some of the answer. Basically, you're born into a position that has an implicit script associated with it. Older brothers will always be older brothers, youngest sisters will always be youngest sisters. Abused kids grow up, seek out other people who they feel they can relate to, and clean up the abuse they received but still do a good amount of harm to their kids.
Often, you see families set up a "good child" and "bad child" that follow from how their system is set up. Think of an overly authoritarian parent who has kids that respond by being pretty passive. These kids might discourage their own kids from being authoritarian, not seeing how they could be harming them because they're responding to their own pain instead of what is best for the kids.
Hurt people hurt people, and abuse can be on either side of a pole. Too much of one thing leads to too little of it. On mobile now, but Bowen's stuff is available for free online. Highly recommend. | 57 | 96 |
ELI5: What's the difference between HAM radios and "normal radios"? | In addition to the other good information here, there is a difference between ham radio and most other radios. On the ham frequencies we are allowed to select our own frequencies on which to operate, as long as it is within a certain range. Our radios usually have a "VFO" or variable-frequency oscillator which will let us tune to any old frequency. Most other radios, including business band, police, CB, marine, FRS, etc., have been restricted to work on certain frequencies, which are designated as "channels". Also, most ham radios are transceivers (2-way, like a walkie talkie or CB), where as most "normal radios" only receive (like am/fm). | 13 | 23 |
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How was Pi "discovered" and how was it plugged into formulae correctly? How was it able to be used before the invention of calculators? | Take a length of rope. Tie one end to a pole and to the other end attach a stick. Pull the rope taut and use it to draw a circle in the sand. Measure how many rope lengths the perimeter of the circle is. Get the answer "roughly six" (so about three times the *diameter*). Be happy for a while. Quoting the Old Testament:
I Kings 7: 23,
> And he made a molten sea, ten cubits from the one brim to the other: it was round all about, and his height was five cubits: and a line of thirty cubits did compass it round about
(KJV).
Time passes, more measurements are made because people are curious and besides more precise values for the perimeter-diameter ratio are useful in engineering, architecture, astronomy and whatnot. Come up with approximations like 25/8 (Babylonia ~1800 BCE), 256/81 (Egypt ~1600 BCE), and 339/108 (India ~500 BCE).
In the 3rd century BCE, Archimedes proves the inequality 223⁄71 < π < 22⁄7 by inscribing and circumscribing a circle with regular 96-gons. In the 2nd century CE, Ptolemy gives the approximation 377/120, the first one accurate to three decimals. By the sixth century, Indian mathematicians know the value of π to five decimals, and the Chinese to seven decimals.
After that, no further progress is made until the 13th century (probably because nobody needed that much precision anyway) when Indian mathematician Madhava discovers the infinite series for π and uses it to calculate an approximation accurate to 11 decimal places. Circa 1600 van Ceulen computes 35 decimals, in 1789 Jurij Vega 126 correct decimals, and in 1841 William Rutherford 152 correct decimals. I'll quote Wikipedia for the ultimate result before electronic computers:
> The English amateur mathematician William Shanks, a man of independent means, spent over 20 years calculating π to 707 decimal places. This was accomplished in 1873, with the first 527 places correct. He would calculate new digits all morning and would then spend all afternoon checking his morning's work. This was the longest expansion of π until the advent of the electronic digital computer three-quarters of a century later. | 93 | 53 |
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ELI5: How did we realise the mind is in the brain? | Most human cultures large enough to have major medical practices or dedicated healers were able to observe that injuries to the brain can cause changes or impairments to the mind.
It took more studies to get a more precise understanding, but the connection between the mind and the brain is pretty intuitive from just what can be observed. | 718 | 391 |
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ELI5: why do divers wear their oxygen bottles with the exit valve pointing up, but firefighters with the exit valve pointing down? | Shouldn't the pressure always force the air out of the exit valve, regardless of its orientation? What is the reason for this? | Divers are going to watch their heads and are in a mostly open area with very little heavy falling debris, so putting the oxygen valve up near the head allows it to be safer in the case of cramped spaces, and limits the hoses required to get the oxygen to the facemask.
Firefighters have to worry a lot more about falling debris and dangling wires and pipes, and worry less about the pressures of being underwater, so they use a longer hose and put the tanks on valves down, so a falling beam is more likely to strike the sturdy bottom of the tank and not the relatively fragile valves that release oxygen. | 363 | 163 |
Why was Immanuel Kant so captivated by Rosseau's "Emile" that he missed his afternoon walks? | I apologize if this had already been answered.
Kant is perhaps infamous for being rigid enough for his neighbors to set their clocks to the time in which Kant took his afternoon walks. However, I read that Kant missed his afternoon walks for several days after reading Rosseau's "Emile, or On Education." I'm not especially familiar with Rosseau's works other than "The Social Contract," but I was hoping someone could explain what was so captivating about this particular work of philosophy in Kant's perspective? | It was particularly the part called 'profession de foi du vicaire savoyard' that influenced Kant. Kant took from Rousseau the idea that virtue (being good) isn't a science, that morality doesn't depend on knowledge, that being moral isn't a matter of knowing some privileged moral proposition. This lead to Kant exploring reason as being a *practical* faculty, rather than just theoretical.
Rousseau taught him that although we're all unequal when it comes to our capacities for philosophical speculation and theoretical reasoning (for some people are more intelligent than others, never had the right education etc), we're all equal in our capacities to become *good*, we all share an equal moral and metaphysical dignity. Being moral is a matter of how we act, of the intention that forms our actions. In other words, it's not a matter of rationally knowing special moral truths that we become good, but rather by acting according to our conscience (which would become the moral law in Kants works). For Rousseau, having a conscience is part of being human, it's a natural feeling that inclines towards what's good, it's the feeling that pushes one to love and want the good, it's the inner voice of right and wrong that judges ourselves and others. 'One can be human (homme) without being a scientist (savant)' (Rousseau). | 98 | 161 |
CMV: After 90 years of age, the default resuscitation status of patients admitted to the hospital should be "Do Not Resuscitate" with an option to opt-out. | After working in the hospital for several years, I have noticed that families of elderly patients often elect full-resuscitation measures for their loved ones. I understand the decision, and I respect each and every decision a family member makes. However, in my opinion, and this is just an opinion, elderly patients above an arbitrarily set age, say 90, should be by default, "Do Not Resuscitate" unless the family wishes to opt out. Here are the reasons why.
When a patient's code status is set to "Do Not Resuscitate/Do Not Intubate" (DNR/DNI), many families falsely assume that doctors withdraw all care for the patient and do not assume appropriate treatment protocols. This is not true. Doctors treat the DNR patients with the same standards of care as all other patients, with the only difference being - in the event that their heart stops beating or the patient stops breathing, doctors let the DNR patients pass without any intervention instead of beginning CPR and advanced cardiac life support, and inserting a breathing breathing tube. The majority of DNR patients are treated and leave the hospital healthy. The difference comes into play only in the event their heart or lungs stop functioning.
Resuscitation measures include:
-Chest compressions
-Shocking the patient when the heart rhythm is appropriate
-Medications to restart the heart
-Inserting a breathing tube that connects to a machine to mechanically ventilate a patient
-Inserting a central line (long IV) into the neck to give further medications that maintain blood pressure
When CPR is performed, the frailty of a 90 year old body frequently results in multiple ribs being broken during chest compressions. Survival is usually accompanied by severe trauma to the body - many of these patients do not survive to hospital discharge.
The success rate of resuscitation is inversely related to advancing age. The following article provides a good overview of this:
https://www.reuters.com/article/us-cpr-survival-elderly/for-elderly-hospital-patients-cpr-often-has-poor-outcome-study-idUSKBN0DP1IH20140509
It states, "The researchers found that about 40 percent of the patients had successful CPR, or ‘return of spontaneous circulation,’ but more than half of those patients ultimately died in the hospital. For patients aged 70 to 79, the rate of survival to discharge was about 19 percent, for patients aged 80 to 89, the rate was 15 percent and **less than 12 percent of patients over the age of 90 were eventually discharged."**
Less than 12% of everyone over 90 survived until hospital discharge. Nevertheless, one must also consider quality of life after resuscitation. Yes, we can restart the heart and keep a patient alive - however, at what cost? Often, the patient stays in a vegetative state supported by blood pressure-maintaining medications and a breathing tube, never officially regaining full consciousness. Some patients that do regain consciousness and survive until discharge ultimately end up going to end-of-life care at nursing homes, they end up neurologically damaged due to the lack of blood flow to the brain during the resuscitation, they end up in significant pain, and they are no where near capable of performing their daily activities as they were prior to hospitalization.
That said, I bring this discussion back to my original opinion. I respect patients and their families who want everything possible to be done to keep their loved one alive. However, sometimes (and often), a patient does not have family when admitted to the hospital, or they are unable to be reached in the heat of the moment, and many times these elderly patients on the brink of passing are mentally incapable of making their own medical decisions. Currently as the law stands, everyone is "full code" until a DNR order is signed. I argue that it is for the benefit of patients to instate an opt-out option for patients above 90. I would like patients above 90 without any goals-of-care paperwork signed to be by default "Do Not Resuscitate" unless they are able to make their own decision to opt out, or if their health care proxy chooses to opt out and keep the patient "Full Code."
Let me hear your thoughts!
_____
> *This is a footnote from the CMV moderators. We'd like to remind you of a couple of things. Firstly, please* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | One problem with this approach is that the patient (or their proxy) may not be aware of this change. Most people probably assume that medical staff in a hospital will do everything they can to keep them alive unless instructed otherwise.
I think it would be better if hospitals (and perhaps insurance providers) encouraged patients to make an active choice before they end up in a hospital. This can for example be done by making it easy to register their choice and giving them a small discount if they do. | 16 | 29 |
[Star Wars] how do mynocks fly once they are in the vacuum of space? Their wings would only work in an atmosphere. | The organs contained within the Mynocks wings can interact with gravity and magnetic fields. Kind of like a biological version of the repulsor lift that you can find in any speeder. This lets them move around in a vacuum by flapping.
I suspect this is mostly just used to move from host/ship to host/ship they aren't going to be flapping between systems. | 23 | 17 |
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[ATLA] How much of bending power level is innate? | Clearly there are some benders which are innately more powerful than the rest of the world by a large margin. Namely these are the protagonists and villians. Is this to say every bender born comes with a different power level or skill ceiling to their bending ability, or is it a matter of dedication and practice to the martial fighting style? Is there something else at play that determines your innate bending power level like the spirit world? | Column A column B. Talent is talent. Hard work still matters. Katara is truly gifted as a waterbender. But she's also basically constantly fighting for her life and being forced to learn fast. She has passion and drive to boot.
Toph is true prodigy, arguably as much so as Azula is at firebending (if not moreso). She is a rare talent, one in a million and was able to develop seismic sense through earth bending on her own as well as discover metalbending. She is arguably one of the most powerful benders in the whole series (both).
Zuko is moreso on the other side. He is not naturally talented. He just works hard and still manages to be pretty solid. He's worse than Azula and only 'nearly' defeats her because she had lost her mind at that point. He's certainly good. But lacks almost any natural talent for firebending. However he improves drastically once his inner conflict is gone and he has his drive. So it's arguable that his difficulty and lack of raw talent is in part due to his inner turmoil. This is supported at least a bit by his inability to lightning bend.
Aang is the avatar. He's obviously going to be exceptional. | 28 | 19 |
ELI5: What causes air turbulence and how does it shake a plane? | To understand that, first you must understand how planes fly at all. In short, airplanes fly by sitting on a cushion of air. If you've ever stuck your hand out of a car window while it's moving and felt it try and move around on its own, that's the same principle.
This airflow is usually quite uniform: low pressure above the wings, high pressure below them, but sometimes something happens to break up that uniformity. It could be the wake of another nearby airplane, a sudden change in barometric pressure from a storm in the making, or even just a big patch of chaotic air going whichever way right in front of the plane (otherwise called "turbulent air"). There are alot of things that can cause turbulence.
Like rough waves for a boat, any rough patches in the air are going to affect the plane, but don't worry: we've come a long way from old-school Comets and DC3s, and modern planes are engineered to withstand all but the absolute most severe turbulence. | 27 | 26 |
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How do I improve at programming? | I've always wanted to pursue CS in college and get a job in it, and I was able to get into advanced CS for my final year in HS. It's really rewarding and I enjoy it like I thought I would. However, I'm really, really bad at it I think.
Originally, I thought It was just because I was new but 4 tests later and these are my test grades in order (70 - 40 - 20 - 50) (all out of 100). I was really confident in the one I took last week, however I'm almost positive It's going to come back terrible too after taking it.
Since this is something I want to devote my life to (and I also really can't fail this class), I have a simple question. How can i get better at CS? I feel like I understand the basic principles of what I learn, but the results never come back good. also we use javascript
thanks | Like most things, it comes down to practice. If you feel you understand the concepts, then try making up a practice exercise for each. If you learned how to do a for loop, then write a small program that uses a for loop or two or 10. And then check it on paper to make sure it lines up with what you expect. And if you got your tests back, go over what you did wrong and re-program them. Try to change things and see what changes and if it does what you expect. But the more you do it, the easier it gets! | 23 | 23 |
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