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Why would sampling distribution tend to be normal distribution in large sample sizes even though the population distribution is not normal? I know that it happens but why does it happen? I am not very math heavy so i need an explanation in easy language | ​
https://preview.redd.it/e5zg7d7gh8w51.png?width=1045&format=png&auto=webp&s=ad859d056d48376ed4555df5794f2920baf0eefb
https://preview.redd.it/tldsog2ih8w51.png?width=841&format=png&auto=webp&s=2c1752698d1158f221104f26fbec9c9156911b71 | Imagine a uniform distribution. Let's make it real simple, its just the numbers 1-6.
Now think about picking two of these numbers at random to make a sample. Then, let's take the mean of that sample. Here are all the options:
1,2: mean = 1.5
1,3: mean = 2
1,4: mean = 2.5
1,5: mean = 3
1,6... | 16 | 16 |
ELI5: What is the difference between poison, venom, and toxin? | *Toxins* are substances which have a profound negative effect on the body, which may be produced by the body or from an outside source.
*Poisons* are toxins which are ingested, and often are produced by plants. Potassium cyanide is such a poison. Lead and arsenic are examples of inorganic poisons (they have no carbon... | 27 | 31 | |
Is Maths a branch of Logic or is Logic a branch of Maths? Why? What does it mean to be a "branch of" a discipline? | A branch of another discipline would mean everything contained in the branch is a subset of the parent discipline. This would be like calculus being a branch of mathematics since everything in calculus is math but math is more than just calculus. Neither math not logic is a branch of the other since both has a scope be... | 38 | 46 | |
ELI5: Turbo in an Engine. And the difference between Turbo, Turbo-charger and super-charger and how these differ from just a regular old combustion engine. | First, understand that the mix gasoline and air combusts best in a fairly narrow range of ratios. So for a given amount of air, you have to have a proportional amount of fuel to make the engine work well. The more fuel-air mix you can burn, the more power the engine will produce. It's reasonably easy to get more fuel i... | 57 | 132 | |
ELI5: How do new allergies develop? | How do people start developing allergic reactions to things they weren't previously allergic to? | I was taught to think of the immune response like a police traffic stop.
An unknown protein is driving along, and gets pulled over by a police officer because it "doesn't quite look right". Everything is fine and the protein is allowed to continue. The officer files a report that they did the stop and this is put on t... | 11 | 20 |
ELI5: Why do male athletes in sports like baseball, hockey, or football rarely debut before about age 20 and typically peak around age 25-27, but female tennis players can reach the top rungs of their sport at age 14/15 (Austin, Capriati, Hingis)? | You never see a 14-year-old male competing in competitive sports. Yes there was a 15-year-old baseball pitcher once, but he did very poorly. Typically superstars in these sports don't have even decent seasons until age 18 at the absolute earliest.
However, women in tennis sometimes burst onto the scene as 14 or 15-yea... | Male athletic performance depends on muscular strength and power, which for most guys doesn't fully develop until their early 20s or even later.
Female athletic performance isn't juiced by testosterone like male performance, and so those extra 5 years of the body maturing doesn't bring increased performance like it ... | 39 | 23 |
Can many small, quieter speakers produce sound equivalent to a single larger, louder speaker? | Say I have 200 phones playing a song, does the volume increase when coming from many sources? | Yes, due to a principle called constructive interference, the sound waves with matching and in phase frequencies will build on eachother, making the amplitude higher and the volume louder.
Think of a crowd cheering in a stadium for a simple example.
However, from an engineering point of view the sound would probably ... | 38 | 70 |
I don't understand virtue ethics at all. Why is it considered an ethical theory on its own and not a supplementary psychological theory to consequentialism and deontology? | MacIntyre in After Virtue wants to illustrate virtue ethics by the example of a child playing chess. If it's just after the reward (e.g. a candy for winning), it will have an incentive to cheat. However, if it's genuinely interested in playing chess, it would only rob itself by cheating, instead of playing properly, le... | >Who makes the decision when someone is considered virtuous? What's the underlying principle?
This seems to be your underlying question here. For virtue ethics, it's based off of what Aristotle calls the 'function argument', which illustrates a key concept in virtue ethics: *telos*, a term for the end sought by an ... | 25 | 23 |
Does a fish see clearly when out of the water? | Anytime I open my eyes underwater, everything is blurry, but I can see fine otherwise. Is it the same way for a fish? Can they see fine underwater and then have trouble seeing out of the water? Is there even any way to test this? | When light moves from one medium to another, it refracts (distorts). The eye evolved underwater, so it evolved to have fluid inside it so light would move from the water into the eye without refraction. Your eyes have adapted to compensate for the refraction that happens when light goes from the air to the fluid inside... | 17 | 20 |
How the US education system works. | Following on from a post about the British education system I saw a few days ago, how does the American system work? In particular: What is the SAT and the ACT? How does the college admissions system work? AT how old do you leave high school? | The details vary by school district (which can be as small as a few dozen students in one school to hundreds of thousands of students in dozens of schools), but generally:
Ages 5-10: Elementary school (called Kindergarten through 5th grade)
Ages 11-13: Middle school or (less commonly now) junior high school (calle... | 20 | 17 |
ELI5: How do people undergo psychiatric testing for court purposes? Don't they know the are being tested and can influence the results? | Psychologists administer a test known as the MMPI (Minnesota Multiphasic Personality Inventory). The MMPI is approximately 500 questions (the short form is approximately 320 questions). The MMPI consists of several scales that measure several psychological disorders. This includes schizophrenia and other psychiatric di... | 11 | 34 | |
CMV: "Free Speech Zones" and "Protest Permits" for political rallies are in direct violation of the Bill of Rights | The 1st Amendment to the US Constitution (Bill of Rights) is written as such:
> "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Go... | It comes down to the need to balance the right of various to individuals to assemble and speak, and the necessity for public property to actually be accessible to the public. The courts have ruled time and again that, while Constitutional rights are natural rights which cannot be removed from an individual without due ... | 12 | 52 |
ELI5: Why is climate change believed to be false and lumped with the theory of evolution even though it has nothing to do with religion/God? | Recently read the front page article on how Alabama now has to teach evolution and climate change and was just wondering why they are put together when climate change doesn't involve religion in the way the theory of evolution does. | Believing in climate change, like evolution, comes with a few assumptions/related beliefs: 1) the success of humans is thus far only a blip on the overall timescale of our planet and is by no means guaranteed; and 2) altering an environment that has allowed humans to flourish could lead to disastrous consequences.
T... | 27 | 25 |
[Toy Story] Under what circumstances can toys break the "rules" and reveal they are alive to people? | If Woody and the gang went far enough to expose themselves to Sid just to save Buzz's life, would they do it under other circumstances?
If their owner was about to die and it was in the toys power to save them, even though the toy revealed itself to the owner in the process, would they still do it?
How much do we kno... | There are some conditions that need to be met before a toy can reveal themselves as living. First, and most importantly, there can only be one human around. Secondly, this human must have personal experience with the toy or toys, whether this experience is good or bad. Thirdly, this human must be in a consistent state ... | 17 | 20 |
ELI5: what is the difference between the different forms of Chinese? (Mandarin, Cantonese, Simplified, Traditional) | Mandarin and Cantonese are often refered to as dialects. However this doesn't really doesn't show how different they are from each other. For example American English and British English are considered dialects of the English Language, but they can understand each other. This is not true with the Chinese Dialects. A pe... | 49 | 36 | |
ELI5:Why is Israel pissed off with the Iran Nuke deal? | I would think that a deal saying Iran can't produce a nuclear weapon would be something Israel would be all for, but yet they seem pretty upset about it. | As with almost all foreign policy pronouncements, you should consider what audience is being targeted and what the speaker's incentives are. In this case, there are good strategic incentives for Israel/Netanyahu to appear hardline on this deal.
First, Netanyahu's domestic political situation is dependent on him being... | 141 | 226 |
ELI5:Can someone help me understand how crossing the legs impacts when measuring blood pressure | Crossing legs, crouching, or otherwise increasing peripheral vascular resistance will cause a slight increase in blood pressure due to the increased pressure required to force blood through slightly crooked arteries. | 39 | 74 | |
[X-Men] why is Forge considered superhuman for his intelligence, but Richards and Stark generally aren't? What are the upper limits of his "powers"? | Edit: so I understand now that he creates things intuitively. But can he decide what he makes, or does he just put things together and then find out at the end what he made? Abs if he can decide, does he need all the parts easily available, or can he also intuitively know that he needs to buy 8 Tesla coils, 944 screws,... | Richards and Stark understand the underlying science behind their inventions. They could teach a class on the things they've discovered, if there existed other people who could keep up.
Forge cannot do that. He couldn't teach you how to build one of his machines anymore than Cyclopes could teach you how to turn your... | 257 | 278 |
I am sorry if this is inappropriate to ask but are PhD salaries enough to sustain your living? | I am so sorry if this is inappropriate to talk about but especially in the US, are PhD salaries enough? If this is inappropriate, just tell me and I’ll delete the post.
Or do I might need a second source of income?
And if so, how would it be with the visa? I think 20hrs/week is given by visa and would just working i... | It can depend a bit on field and where the school is. In general, if you’re getting a salary from the school, it’s intended to be enough to live on, but, especially in big cities with a high cost of living, it can be a bit short. It may mean living with a lot of roommates far away from campus to find an affordable rent... | 25 | 20 |
ELI5:Why, when I've done nothing wrong, do I feel guilty when passing by a cop? What's the psychology behind it? | You evaluate a threat using two criteria: intent and capability. "Does this person want to harm me? Does this person have the ability to harm me?"
Law enforcement officers score high on both these scales. In terms of intent, the police might not have any desire to harm you physically, but they are motivated to harm y... | 459 | 458 | |
ELI5: How does quantum computing work? | Regular computers store the values of 0 and 1. To represent a series of numbers, they must store them all, like this.
000
001
010
011
100
101
110
111
Quantum computers store numbers as 0, 1, or 'superposition', which is 0 and 1 at the same time (Q). This means that they can save the same range of numbers as QQQ.
This... | 15 | 39 | |
ELI5: In quantum mechanics, what does it mean for something to be "observed"? | [This post](http://www.reddit.com/r/funny/comments/1krtbt/so_thats_how_usb_plugs_work/) made me wonder — what does it mean for something to be "observed"?
I tried Googling around for it and ended up more confused than when I started, so hopefully somebody here can help shed some light. Thanks! | The word observed is used because typically we're measuring a property of something very tiny, which tells us about it. We "observe" its existence by measuring it's velocity or position.
The trouble is, to get that information, to measure it, we have to interact with it in some way. Since the world of quantum mechani... | 19 | 91 |
Why is good quality vision called '20/20' vision, and not 100% vision? | 20/20 basically just means you can see what a 'normal person' should see at a range of 20 feet, from 20 feet away. It means you have normal eyesight.
Perfect eyesight can be a lot better than 20/20. You can have 30/20 vision, meaning you can read what a normal person sees from 20 feet away, from 30 feet away, for ins... | 25 | 17 | |
CMV: I believe people are capable of being prejudiced against robots or artificially intelligent beings, and that that prejudice is a type of racism. Racism against robots is a social issue we will have to deal with in the future. | First, I will acknowledge that robots are not a human race, and that you might think it's silly to call prejudice against robots racism.
However, sociologists consider islamophobia to be a type of racism, despite Islam not being a race. In this way, prejudice against robots could be considered a type of racism, as it ... | I would probably use the word prejudice to describe it instead of racism.
But this is a very hypothetical question. We do not have any artificial beings which have anything close to sentience and sapience. Certainly nothing which is self directing and has free will.
Whether that discrimination were immoral would ... | 86 | 165 |
ELI5: How are animals able to drink water from puddles from the road, dirty ponds, etc. etc. But if we were to do it, we'd fall terribly sick? | In part it's immunity gained by getting ill once, or a few times and surviving it. The immune system remembers what foreign organisms it encountered before and fights them a lot faster and efficiently when an infection happens again (with exceptions from the rule, not all pathogens produce a lasting immunity).
In par... | 5,369 | 14,511 | |
What exactly is information? | In regards to the holographic principle, when physicists state that information is conserved in a black hole, what do they mean by "information?" How is information different than energy? | The existing answers address what information is in the context of information theory, but do not address what is meant by physicists when discussing whether or not information is conserved in black hole dynamics. This is actually something a little different.
In quantum mechanics, an initial quantum state evolves ov... | 12 | 15 |
ELI5: If insider trading is illegal, how are CEOs allowed to trade shares of their own companies? | Most executives are governed by rules regarding insider trading, which are set by the company through bylaws or individual agreements with the executives. Normally, they state the times when you can and cannot trade in reference to when certain pieces of information are about to be released. For example, you are prob... | 40 | 100 | |
If the heat death occurs, how can time itself stop? | Since space and time is the same thing, how can time stop if the heat death occurs? The low energy particles evenly distributed in the universe would still be distributed in space, with space between them. Right? | Love this question!
This is where metaphysics and philosophy blend. Also, a classic question becomes metaphysically/philosophically beautiful!
If a tree falls in the forest, does it make a sound?
Most people answer yes. What you're saying is that it exists independent of our observation.
Relating back to the bigger... | 17 | 20 |
[General]When it comes down to the core 'Science' in Science Fiction, which universe has the greatest integrity in its fictional physics and application? | I don't want to exclude iterations of 'magic' from this, but it seems when it comes to most instances that have it magic is simply an unexplained, or vaguely explained, thing that isn't questioned. This could also be applied in same aspect to far off science fiction wherein everything works because its just 'technology... | A lot of Michael Crichton's books have at least some foundation in real world theories and possibilities. Some of the books are simply conversations about the implications of a new technology that just happen to be set in a thrilling narrative. | 15 | 21 |
ELI5: If the first living beings reproduced asexually, how did diverse species came to be? Also how did sexual reproduction started? | I understand that the first living beings were unicellular organisms, prokaryotes, which reproduce asexually. If DNA was only "cloned" from one organism to form an offsrping, how did different species appeared? I'm guessing it has to do with some kind of genetic mutation, but even then I can't wrap my mind around how s... | Well it helps to look at species that have various forms of reproduction between asexual and our form of sexual reproduction.
For instance prokaryotes can't go through meiosis but can incorporate new DNA from other prokaryotes.
Then there are some yeast cells that can reproduce asexually or sexually when under grea... | 42 | 157 |
[General Discussion] How are spaceships built in space? | That's a very broad question, but the short answer is "in pieces".
At our kind of technology level, the quintessential example is the ISS. We built it in "modules" small enough to transport up to orbit using existing rockets, and then just bolted the modules together once they were up. This has the advantage of using ... | 24 | 25 | |
CMV: All the US flag apparel people wear and use around July 4th disrespects the flag itself | Background:
-US Federal Law Code says the flag isn’t to be used for clothing. The code isn’t enforceable because of the 1st amendment.
-American Legion says it’s okay to have the flag resembled on clothing.
The flag is something to be honored and respected. It’s colors and design is not something you should use to c... | > Background: -US Federal Law Code says the flag isn’t to be used for clothing
The code is that you don't take an **actual US flag** and cut it up to make a shirt, not that a shirt can't have stars and stripes imagery like the flag's design. | 567 | 1,204 |
ELI5: If the affordable care act requires that people with pre-existing conditions can not be denied by private insurers, why wouldn't everyone just wait until they were sick and then purchase insurance? | You can only apply for insurance during "open enrollment periods" (the 2015 one ends February 15th) or under certain specific circumstances called "qualifying life events" (get married, be born, change jobs, things that might require you to change health insurance basically). If it's not an open enrollment period, and ... | 45 | 73 | |
When genes change expression is this change simultaneous over the whole body or could genes in only certain cells change expression? | No, genes can be expressed in some cells but not others. This is how you get differentiation of cells, to create organs etc. It's not just in something large like the body that this happens, genes can be turned on in certain portions of a embryo, but not in others. | 32 | 109 | |
Economist roles in private firms - what does the job actually entail? | So.. i've recently graduated (a degree in pure economics) and keep seeing economist roles in a range of firms from visa the UK arts council.
I would assume theres a good bit of statistical modelling in the job role, but that was a tiny part of my undergraduate degree and i certainly couldn't perform reliable regre... | Unfortunately what they want is for you to turn the data into meaningful **quantitative** information regarding their performance or forecasting future conditions. This requires knowledge of statistics or econometrics and statistical software skills, programing skills, data cleaning and visualization, etc | 10 | 15 |
Why does squinting seem to improve our sight? | For people who don't have perfect eyesight, squinting is the substitute for getting contacts or glasses. How does this help our eyes focus on something we couldn't before? Is it because there's less surface area for our eyes to cover or??? | Squinting helps eliminate non straight light rays entering the eye, this means the need for refracting or focusing of light which is non straight is reduced.
In other words squinting acts like glasses by correcting refractory errors, someone who squints should be assessed to see if optics will helps their vision
Edit... | 412 | 458 |
ELI5: how does the body regenerate blood after donating? | Also when the blood that has been donated is regenerated why/how does the body know it is back to its needed amount? | After you donate blood, the number of red blood cells in your blood decreases. Red blood cells are responsible for carrying oxygen and this decreased oxygen in the blood is a stimulus for the kidney to secrete the hormone erythropoietin. This then travels to the bone marrow and stimulates the production of more red blo... | 112 | 162 |
ELI5: How are private prisons legal? | I've been wondering how it's legal for a private organization to incarcerate a federal/state prisoner (or any prisoner of the government for that matter). | How is the government hiring a company to manage prisoners different from the government hiring guards to manage prisoners?
The company does not decide who goes to prison or for how long, the government does. The government also sets the standards for how prisoners are to be treated, and has a responsibility to enforc... | 11 | 18 |
I have a cold and am curious, what defenses will the virus encounter (in order, from entry)? | First, there are physical barriers. Skin, for example. Then, assuming you got it through contact between your mucous membranes (mouth, nose, eyes) and particles containing the virus, there are antimicrobial agents in these mucous membranes (though most of these are geared toward being antibacterial, not antiviral) as... | 19 | 18 | |
CMV: If it comes to climate-induced migration, the nations with the highest emissions have a moral obligation to admit their share of refugees. Not doing so would be morally reprehensible. | In 2017 The Guardian wrote:
​
>Climate change 'will create world's biggest refugee crisis'.
>
>Tens of millions of people will be forced from their homes by climate change in the next decade, creating the biggest refugee crisis the world has ever seen, according to a new report.
>
>“... | If you have a nation that pollutes more due to geographic/economic/cultural factors, all other things equal, then by moving people into that nation you are increasing pollution more than you would otherwise. If there is already a feedback loop to pollution, then it's possible that by increasing the share of refugees to... | 14 | 35 |
What does the Schrodinger equation mean and what does it tell us? | I am beginning quantum mechanics and we have been studying the Schrodinger equation pretty extensively. But I am confused about what this equation represents and why can't we derive it? | The time-dependent Schrodinger equation tells you how a quantum state vector evolves with time. It says that the Hamiltonian operator is the generator of translations in time. If you know the state vector at time t = 0, the Schrodinger equation and the Hamiltonian tell you what the state vector will be for all time.
Y... | 16 | 21 |
CMV: It's not sexist to think that there are traits more common in women versus men and these same traits make you more likely to succeed in certain jobs and industries. | Modern psychology acknowledges differences in the mental functions and behaviors of the sexes. For example, males show greater affinity for violence. Studies have shown women are more empathetic.
[https://en.wikipedia.org/wiki/Sex\_differences\_in\_psychology](https://en.wikipedia.org/wiki/Sex_differences_in_psycholog... | I think it has more to do with the rationale behind believing certain traits are more common. Feminists would absolutely tell you that men have learned some traits and women have learned others because of the way culture has historically viewed men and women differently, and they would say that's a bad thing.
It's ki... | 24 | 32 |
ELI5: Why smartphones can't capture decent pictures of the moon/stars. | There are two main characteristics of a camera. How much light it collects, and for how long. In mechanical cameras, these are aperture size and shutter speed, respectively. Smartphone cameras do not have a shutter, but likely have something analogous.
When the cameras are designed and manufactured, the engineers have... | 15 | 27 | |
ELI5: why is blood pressure an important health metric? And how does sodium affect it? | High blood pressure can often indicate blockages in blood vessels, or hardened vessels, and this makes the heart work harder than it needs to. More work means the heart wears out faster.
Sodium affects blood pressure because it pulls water from the body into the blood. More water means more blood volume, and that's hi... | 16 | 22 | |
[Dc comics/Batman] What kind of certifications does Batman need to to fly the Batplane and what FAA rules does he break whenever he goes up? | Let's go with this version of the Batplane: http://imgur.com/a/tG0Na | Well in addition to pilot's license, whether it be Private or Commercial, the FAA requires a specific type rating to fly any aircraft weighing over 12,500 lbs and/or having a turbojet powerplant. Since the Batwing is a crazy bat-prototype a type rating probably doesn't even exist so Batman would be flying it illegally ... | 24 | 24 |
Why does an excess of neutrons make an atomic nucleus unstable? | From what I've learned on the net, larger nuclei are less stable than smaller ones. This is apparently because larger nuclei have more protons, meaning that their compounding repulsive forces eventually overcome the strong nuclear force that 'glues' a nucleus together.
So why is it that increasing a nucleus' size with... | For very large nuclei the models become more complicated and nuanced, but for intermediately sized nuclei a relatively simple model called the shell model works pretty well.
According to the shell model protons and neutrons in nuclei occupy energy levels similar to the electron energy levels in a hydrogen atom. Howeve... | 33 | 63 |
How detailed are reflections in mirrors? | If you were to zoom in on a mirror, just how detailed could the reflection be? Would it get blurry and fuzzy like when you try to zoom in on a picture? Or could you zoom in far enough and see atoms?
(this is all assuming you have a mirror with 100% reflectivity and a good enough camera or microscope to zoom on atoms) | For most practical purposes (looking at light and visible things) the answer is that the mirror is infinitely detailed, given your assumption that the mirror is flawless.
Hypothetically speaking, you couldn't zoom in to the mirror to the atomic scale, you'd end up looking at the atoms of the mirror. However, you could... | 10 | 25 |
Eli5: How come humans need around 1,500-2000calories for basic survival of the Body but people suffering from severe anorexia can carry on for years eating a lot less. | 1500 to 2000 calories is what the body needs to remain healthy. Less than that and the body begins cannibalizing non essential things. It starts with fat stores, then it goes to muscles. All in the name of keeping energy supplied to the vital organs. Severe anorexics will consume just enough calories to keep their brai... | 47 | 22 | |
CMV: Racial color blindness does not advance racial justice | There seems to be a widespread opinion, on both the right and on the left, that political discourse that is about racial groups or policies that are constructed around racial categories fundamentally undermine a project of social justice. The idea is that by talking about race, we are perpetuating racial division, and ... | > Simply put, race matters.
Right, but it *should not*.
That should be the ultimate goal: a society where race does not matter.
Sure, in the short term, we should still consider race. But in the short term only - as a way to remedy past wrongs.
We should not lose the endgame of a colorblind society. | 38 | 125 |
How is it that my computer can load multiple files at the same time, if there's only one "needle" in my hardrive? | How can you see everything around you when you only have 2 eyes?
The read head only picks-up chunks of data at a time. Any software that requests for an entire file in one go will lock your system, so they don't do that. Since they only ask for chunks at a time it means any number of files can be read or written to ... | 21 | 44 | |
Recommended Reading on Consciousness, Self Awareness, and Intelligence | I hope this is an OK question.
 
I am helping to teach (TA) a course on machine learning and artificial intelligence where we go over some compare and contrast with nature on a more "hard science" level (natural neural networks vs. artificial neural networks / AI's performance on simple cognitive tasks vs. a... | (1) David Chalmers - *The Puzzle of Conscious Experience,* David Chalmers *- Facing Up to The Problem of Consciousness,* Thomas Nagel - *What Is It Like To Be A Bat?,* David M. Rosenthal *- Two Concepts of Consciousness,* Dennett - *Consciousness: How much is that in real money?*, Putnam - *The Nature of Mental States,... | 10 | 41 |
ELI5: If my body gets a fever to fight and kill an infection in my body, why is it OK to take Advil to reduce my fever? Doesn't that counteract what my body is naturally doing? | First, some background: Advil is an inhibitor of the cyclooxygenase pathway, which normally creates prostaglandins (some of which are pro-inflammatory, some of which are ant-inflammatory). Prostaglandin PGE2 ultimately induces the fever portion of your body's immune reaction, so when you take Advil or other NSAIDs, you... | 18 | 59 | |
How can chip manufacturers like Intel, AMD, and Apple keep giving huge improvements on performance every few months by changing the architecture? | I recently saw the comparison chart for the new M1X chips which give 50% improvement over the previous generation. I'm wondering if the semiconductor size remains the same and the die size is the same as well, then how can they manage to just keep changing the architecture every so often. If the architecture change tak... | There's a lot that goes into a new architecture (or micro-architecture as we usually call it).
You can also play a lot of games with "50% improvement" (for example, is that power/performance?)
Part of it is smaller transistors. It can come from a bigger die size (although that is more expensive).
Other than that, you c... | 12 | 18 |
ELI5: What is the point of the "do not write in this shaded area" thing on tests? | I recently took the act, and on the first page there was a tiny box that said "do not write in this area" with nothing else in it. What is the point of that? | Most of those tests get pumped into a machine that scans it and marks your test, if there are pencil marks where the machine is not programmed to look it will probably mark it as an incorrect answer or cause an error in the machine | 22 | 76 |
[Star Wars] How bad is life under the Empire for the average joe? | It depends a lot on what planet you are on and what species you are.
If you're on Coruscant, it's probably indistinguishable from the heyday of the Old Republic, but with more racism against non-humans. If you're non-human, you're more likely to get shunned to the slummy lower levels.
If you're on a fairly important ... | 49 | 21 | |
[Superman] What is Superman's relationship with Metropolis PD like? | We know Batman's relationship with the GCPD. Has an ally with Gordon most of the time. Some officers don't like him but most of them support his actions. Is it the same with Metropolis? Are they receptive when he flies down with a baddie for lockup? | It varies over time, though tends towards the positive. By the time his career is in full swing, he's gone a long way to build credibility with local authorities as a guy earnestly trying to help. Another advantage he has is Clark Kent, Ace Reporter; while Batman doesn't really have an excuse to be shoving his nose in ... | 27 | 20 |
ELI5: Why doesn't a garden-hose eventually explode even when the tap is on and the nozzle on the other end is shut-off/closed? | Like when you're watering your lawn and plants, then forget to turn it off, and don't notice for a couple of days, why doesn't the hose or anything eventually explode? Probably has to do with the plumbing, if so, how? | Your plumbing supplies water at a certain maximum pressure. That pressure is lower than the pressure required to stretch the hose. So it's less like blowing up a balloon, and more like blowing through a pinched straw. No matter how hard your lungs can blow, the straw's not going to explode. | 38 | 22 |
ELI5: How do night vision goggles work? | There are several ways:
* Infrared: There are electronics that can see "color" lower than red. As things and beings radiate those colors as heat, you can use it to see in the dark. Also, as infrared is invisible to the human eye those night vision devices can be enhanced with a "infrared flashlight". It works like wit... | 16 | 52 | |
Same school for PhD | Currently, I’m an undergrad in STEM. I’ve been thinking about staying at the same university for my PhD (right after undergrad) but I want opinions on whether the benefits outweigh the detriments.
I love my university, it’s a great fit for me and a great university (R1). I love this city too, and my partner’s family i... | It's no issue at all, as your undergrad really isn't factored in to your "Research career". It's your PhD and subsequent post-doc placements that are your "research years", and where its beneficial to have moved around. | 45 | 16 |
ELI5: Why does fountain soda from the gas station seem to taste way better than bottled or canned soda? | Soda is created by taking a flavored syrup and carbonating it, which means adding carbon dioxide to create the bubbles.
When it's bottled/canned, it's carbonated at the factory and sealed, sent to a store, and then you buy it, open it, and drink it. When you buy it from a fountain at a gas station or fast food place, ... | 26 | 38 | |
[Marvel/DC] Why is acid always stored in giant open vats? | The overwhelming majority of the time, hazardous chemicals used in large quantities are stored quite safely; you only really end up hearing about the few isolated incidents where they aren't and some accident results. The fact that they exist at all is a result of substandard working conditions in most low-paying facto... | 96 | 120 | |
How does cuteness work in humans? Why are people often more willing to protect cuter animals? | Basically, why do people find certain animals so cute? Why will some people sometimes take unnecessary risk to save an animal they find cute? EG a kitten over like a possum, or rat, or something.
I've heard it's because they look like human infants, which is often true, but how about that baby duck, or even some inse... | There's a relevant ted talk by daniel dennett that says essentially "cuteness is what we find cute, and cute is the quality of being something we want to help, like a baby. People who didn't find babies cute had their babies die so here we are" | 27 | 56 |
CMV: trying a child as an adult makes the protections offered to children irrelevant and is downright vengeful | This is an issue I feel passionate about, but I also understand my views are not that developed. Very curious to say what the responses are!
Juveniles are given special treatments in trials, there is a focus on rehabilitation an integration back into society. This makes a lot of sense to me, children are still learnin... | The ability to be able to try a juvenile as an adult is an example of taking the law on a case by case basis which is a good thing. In general it is not reasonable to think the law is going to work effectively for every person.
If there was a 17 year old serial rapist would you really want them to have their record w... | 21 | 72 |
What do the symbols connecting the elements mean? | http://upload.wikimedia.org/wikipedia/commons/b/bc/Nitrogen-iodide-2D.png
In this picture, there are three types of bonds. What should I search for to learn what they mean? | These bonds show the 3 dimensional structure of the molecule. The plain lines are in the plane of the page. The solid wedge shape signifies a bond coming out of the page towards you. The dashed line signifies a bond going into the page away from you. It's as simple as that. Chemists use this to show a 3D structure in a... | 41 | 15 |
CMV: science and religion can perfectly co-exist | I feel like a lot of people think science or religion provide all the answers to a problem, that either of them holds the 'universal truth'. I believe they just provide a different viewpoint. Science will perfectly explain how I'm able to live (how does my heart beat, why is the air breathable, what do I need to eat in... | It's not that science and religion can't coexist, it's a question of whether there's good reasons to believe each of them individually. Science is an itterative process that produces tentative conclusions that attempt to predict how the world works from observation and testing.
Religion is a mix of subjective claims ... | 30 | 89 |
Introductory books for understanding Kant, Hegel, Marx, Lacan, Zizek, Semiotics, and post-structuralism? | Hi everyone, I have a (very) basic understanding of all of the above, however it is very unstructured and based on bits from here and there. What are your recommendations on books that introduce the above, preferably in an organised sistematic manner? Books that would pave a way for further development by helping to se... | Some general recommendations:
*Kant* by Guyer
*Hegel* by Beiser
*The Philosophy of Marx* by Balibar
*The Lacanian Subject* by Bruce Fink
*How to Read Lacan* by Zizek
*Critical Semiotics* by Genosko
*French Philosophy in the Twentieth Century* by Gutting.
One could probably list hundreds of more books, but... | 22 | 42 |
ELI5: Why does Vitamin B have so many variations? | Vitamins are grouped together based on their function within the body. B vitamins are mostly associated with metabolic functions, as well as DNA synthesis. Because of the wide range of different molecules we can metabolize, there are a large group of associated B vitamins compared to other groups. | 133 | 119 | |
How did engineers build the Shahara Bridge? | I saw [this photo](http://imgur.com/LmyFZ) of the Sahara Bridge in Yemen. Since this bridge was built quite a while ago, how did they do it? | For arches a wooden form is usually put in place until the stones are properly arranged. Presumably they started with ropes, then a wooden scaffold and form, then removed everything once the arch was in place. | 22 | 26 |
What are the functional differences between a Universal Basic Income, Negative Income Tax, and a Guaranteed Minimum Income? | Sometimes those terms are used interchangeably.. and sometimes each type has different models of how it operates..
But generally, Universal Basic Income is a flat amount granted to every individual regardless of income..
For example, every citizen receives $1000 per month..
With Negative Income Tax people below a cer... | 26 | 73 | |
[Charlie and the Chocolate Factory] How dangerous was it actually for the Oompa Loompas in Loompaland? | Wonka claims that the reason he took the Oompa Loompas away form their homeland is that Loompaland is full of whangdoodles, hornswogglers and snozzwangers, that would have eventually wiped out the Oompa Loompas.
Is that true? Were the Oompa Loompas really that maladapted for life in their own home environment? | There is one important thing to remember when thinking of evolution:
You don't need to be the fastest, toughest or strongest, you only need to survive until you get old enough to multiply.
Seeing that they are pretty plentiful, they might just have been eeking by by pumping out more small Oompa Loompas than got kill... | 26 | 29 |
Why aren't bullets cone shaped? | I can't seem to understand why some rounds (eg. [9mm](http://upload.wikimedia.org/wikipedia/commons/9/96/9mmLuger.jpg)) are rounded not cone shaped. Isn't a cone the best shape to pierce air? | Intuitively, it may seem that a cone is the best shape but keep in mind that there are multiple factors in play. One of which is torque.
- A blunt object is subject to less destabilizing torque than a pointly one by having the leading edge closer to the center of gravity.
- Spin is induced to resist torque. It is eas... | 16 | 29 |
[General/Superheroes]Are heroes judged "street class" because of their abilities or feats? | My friend and I were discussing what constitutes a street class superhero. My friend said it was based on their powers, I said it was based on their feats. Then he brought up a good point.....that if they were judged by their feats, then Squirrel Girl is a World/Cosmic class hero.....
Thoughts? | It is usually actually based on the scope of their operation. Many heros go from street to world class over the course of their story, few transition in or out of cosmic because of what being a cosmic hero entails. For example, Ben Grimm is a world class hero because he travels all over the world with his friends stopp... | 19 | 16 |
How does a hard disk create space for new files after deleting old ones but is still capable to recover those deleted files? | As soon as I empty my recycle bin my windows PC tells me, I got now more space to put new files in to. I can even limit out this space. Still with apps like Windows File Recovery I can see files which has been deleted months ago and recover like they were never gone. How is this possible? | The operating system uses a file system which is the schema used to store the files on the disk. Different file systems have different capabilities: file name length, maximum file size, encryption, etc...
The general idea behind a file system is that it creates a table somewhere on the disk that it uses like an index ... | 29 | 16 |
ELI5: Why are there "colleges" for specific majors inside of large universities? | Ex: College of Engineering @ University of X; Also, for undergraduate applications, do you apply to these specific colleges, or the larger one? | The first universities, as we understand the term, came into being when multiple smaller institutions (colleges) joined together under one name, but retained their individual identities and traditions. Oxford, for example, is made up of 38 colleges. They all teach the same stuff, but they all have their own flavor. Kin... | 23 | 40 |
What is the difference between an aeroplanes 'air speed' and its 'ground speed'? | The wind.
The airspeed measures how fast the aircraft is moving with respect to the air. This is an important piece of information since the dynamics of flight depend on the speed of the aircraft with respect to the air. For example, the amount of lift generated by the wings depends on the airspeed.
The groundspeed i... | 75 | 91 | |
[Star Wars] How is it possible to blockade a planet without an Interdictor type vessel? | Naboo: What kept ships from escaping perpendicularly from the blockade? Or even the other side of the planet. To make a ring of ships around a planet with intersecting lines of fire would take an enormous amount of ships. To make the blockade spherical is unthinkable.
AFAIK the Trade Federation did not have Interdicto... | I don't know a lot about how space travel works in Star Wars but there might be certain "angles of approach" or something similar that ships entering the planet have to take to land safely and it's much easier to cover those areas of orbit. That is just me speculating though | 38 | 44 |
What does Sartre in "Being and Nothingness" mean when he says that reducing an existence to its manifestations is not succeeding in overcoming all dualisms but instead converting them into a new dualism of finite and infinite? | There are infinite ways in which something can manifest itself within consciousness, but it can only be experienced one mode or way at a time. An egg is the source of an infinite number of experiences, but it can only give me one side of itself at a time. | 56 | 123 | |
CMV: Chipotle should not be directly blamed for their viral outbreaks | Please note that I frequently eat Chipotle so I do not have an objective view.
I don't think we can blame chipotle for these viral outbreaks. Yes, it happened, and yes there are some terrible side effects. These things happen, and we should be judging chipotle based on their response and action to the outbreaks.
So... | E. coli and Salmonella can be combatted by proper food handling, storage, and preparation techniques.
It's likely that the cause of those outbreaks comes down to improper food preparation. For example, under cooking the meat, or not properly cleaning surfaces that touch raw meat, etc. | 18 | 26 |
CMV: "Human sexuality is binary by design with the purpose being the reproduction of our species. This principle is self-evident.” | Hi folks, a biochemist here.
The quote in my title represents my view about human biological sex - that humans are a binary species. The fact that conditions like Klinefelter/Turner exist doesn't imply the existence of other sexes, they're simply genetic variations of a binary system.
The idea that sex is not binary... | How can there be variations of a binary system and that doesn't invalidate the idea that it is binary? It's like literally 'there's exactly two, except for those others, which are variations on the two'
At the very least the existence of XXY, XYY, XYYY, XXX, XXYY, XXYYY, X0, etc. would make it bimodal, not binary
Edi... | 725 | 1,104 |
ELI5: How does an internet connection become slow? | Lots of things can have an effect. If many people in your home are using the same WiFi network, the network may become bogged down. Interference can seriously degrade your signal, if there are any big sources of interference between you and the router. Walls, floors, etc can have an effect on wireless signal too.
A w... | 16 | 46 | |
Could it ever be possible to invent a bionic eye that allows people to see light outside of the visible spectrum, such as ultraviolet or infrared? | Your brain could probably handle the input anyway, experiments have shown that mice and new world monkeys are capable of comprehending the difference between red and green after having their natural red-green colorblindness fixed by gene therapy. | 81 | 234 | |
Does this study imply that people will live longer if they worked out *without* taking (much) protein? | Long-term low-protein, low-calorie diet and endurance exercise modulate metabolic factors associated with cancer risk1,2,3
http://ajcn.nutrition.org/content/84/6/1456.short
| I think the answers you are looking for are at the end of the paper. The authors say:
> In conclusion, our data show that the consumption of a low-protein, low-calorie diet; exercise training; and decreased adiposity are associated with low plasma insulin, C-peptide, FAI, leptin, and C-reactive protein and high SH... | 57 | 203 |
Are terrastrial and marine food chains disconnected? If they are connected, how and to what degree? | Does plankton end up in a cow living on a farm on a macroscopic scale? How about a terrastrial apex predator living hundreds, if not thousands of miles away from the closesr ocean? Is bottom of their food chain in the ocean? Is there research about this topic?
I can not imagine them being disconnected, and I would rea... | They are definitely connected in many areas, though not in the way you think.
The annual migration of Salmon up rivers to spawn plays a significant role in the forest ecosystems, moving nutrients and minerals into areas that would not otherwise have it. Given that some salmon swim well over a thousand km up the rivers... | 14 | 16 |
Why is reason so compelling? | This was a question my Epistemology professor and I were discussing. unfortunately we never resolved the question. So maybe you fine philosophers here could help.
It seems axiomatic that reason is the mode by which we arrive at the truth, but how is it and why is it the means by which we arrive at the truth? I used to... | Schopenhauer provides the counsel of despair: Reason is compelling because we appeals to the cognitive apparatus by which we understand experience. In a way, that's an inversion of the medieval conception of *adequatio*. We are not privileged by our capacity for understanding a reasoning that independently describes tr... | 19 | 29 |
I am considering going to grad school for philosophy | I am considering going to graduate school for philosophy. I have my Bachelor’s in math, which, as a career, would seem to offer fine job prospects, but I really don’t care much about mathematical problems. I like the argumentation aspect, writing proofs, etc., even though it was mainly an applied math school and that e... | Have you thought about how the social anxiety stuff may affect things like presenting in seminar, doing oral defenses, giving talks, and then later teaching and doing team work with colleagues? You wouldn’t be the first socially anxious phil student, but there can be rather a lot of public speaking and high stakes per... | 13 | 16 |
ELI5: Why does the virginity of oil matter? | The amount of benefits that first pressings give are much higher than subsequent pressings as far as nutrients, and anti-oxidants goes. Only so many to go around and the first press gets the majority of them. | 17 | 17 | |
CMV: The solution to (future) student debt is not to make the colleges free, but to make them more efficient. | I am seeing a lot of posts and news articles recently about lowering the student debt, most notably Bernie Sanders claim to make all colleges free. The debate seems to rage back and forth about whether this is tenable, and who would pay the cost, but for me, this seems to be totally the wrong direction.
When I went to... | Colleges have an interest in their alumni being generally well educated in a variety of subjects. Smart, successful people usually aren't hyper-specialized - rather, they are knowledgeable on many subjects, and can recognize important relationships between subjects in order to find success where others haven't. Succe... | 21 | 35 |
How were archeological and paleontological artifacts dated before the "radio-carbon revolution"? | What methods did scientists use to estimate the age of artifacts before the advent of radio-carbon dating methods? I've read that radio-carbon dating led to a "revolution" in archeology, paleontology, and anthropology (probably geology as well, right?), but I'm totally ignorant about what methods were used before carbo... | A lot of dating came from and still comes from stratification methods.
Essentially, the deeper something is, the older it is. As you dig down you can usually see layers of dirt. Each layer corresponds to a different time frame, thicker layers usually mean longer periods of time. Edit: Though this isn't always true. A ... | 16 | 34 |
How do you forecast wind? I understand being able to forecast things like rain, snow, and sunny days based on cloud formations? But how can someone determine if a day in the future will be windy, and how strong that wind will be? | Weather forecasting actually \*starts\* with figuring out the winds: you need to know how hot and cold air and humidity are moved around by the wind before you can forecast temperature and rainfall.
It all starts with Newton's second law of motion "F=m\*a", and estimating the forces on any given mass of air to find ou... | 38 | 48 | |
ELI5: What made us, so many years ago, just being naked be seen as being indecent? | While clothing began as a "tool" to keep us warm, it quickly developed a symbolic meaning far beyond this. For example, it distinguished tribes/groups/nations from one another and indicated social status, wealth, and personality. It still does this.
In a society that developed cultural norms such as sexual restraint,... | 88 | 116 | |
[General "Hard-ish" SciFi] Wouldn't missiles be relatively useless in a space battle, considering the potency of future detection systems associated with laser point defense systems? | Considering Issac Arthur's "First Rule of Warfare" (there is no stealth in Space) and considering that missiles can never beat lasers for speed, I don't see how missiles could be used in space warfare, if we are talking about a relatively hard scifi story.
Is there something I'm not considering? | Depends on a lot of factors, including the relative sophistication of the missile and related technologies. In the most general sense a missile in the sense of a *kinetic projectile* has a lot of utility behind it: Force equals mass times acceleration, so even a little mass moving really fast (*a la* a rail gun or thor... | 71 | 46 |
If the active ingredient in Marijuana is THC, why are there different effects depending on the different strains? Are there more chemicals at play here? | Is this psychosomatic because of the different levels of THC or is there actually more to it? People say they react differently with hard alcohols but that's more in their head. I'm wondering if that's the same with strains of pot. | There are as many as 85 active compounds in marijuana, THC happens to be present in the highest concentrations and THC levels are used to measure potency.
The effects of many of the other compounds aren't well understood. (www.ncbi.nlm.nih.gov/pubmed/23386598) | 39 | 74 |
ELI5: Why does cat nip effect cats like it does, but not dogs or other animals? | Thanks for the help, I've always been curious. | Terms to know:
Nepetalactone - a compound in catnip
/ Olfactory system - the sensory system used for smell
In short, researchers are really unsure what exactly causes the cats to go into a craze like they do, thus they can't figure out why dogs / other animals aren't so easily affected by it. There isn't really an ans... | 23 | 48 |
ELI5: we already know how photosynthesis is done ; so why cant we creat “artificial plants” that take CO2 and gives O2 and energy in exchange? | Artificial photosynthesis actually is a deeply studied field of research, where you use sunlight to drive a reaction that releases oxygen from various solutions. The problem is, the components needed in the reaction are inefficient, degrade/deplete quickly, or are expensive to make/maintain. | 8,520 | 14,664 | |
I've read a lot of speculation about the future of the world's water supply. How serious is the issue, and what is likely to occur over the next decades? | The main thing to remember about this is the interconnectedness of resources in general. There's plenty of water in the world; it's just not potable. The availability of cheap energy would solve this issue, as that's mainly what makes it expensive to, say, desalinate seawater. | 45 | 185 | |
Would paddling a canoe work if water had no viscosity? | Viscosity is the frictional force internal to a fluid.
What would happen if one was paddling a canoe in a fluid with 0 viscosity? Would it just be the equivalent of throwing water molecules through a vacuum? | There are forces at work here other than fluid to fluid drag (viscosity). As you're swinging the paddle through the water, each water molecule in its path needs to somehow get on the other side of the paddle. Since the water has mass, and thus inertia, moving around the paddle requires some force. Specifically, getting... | 13 | 30 |
ELI5: What is the attorney-client privilege and when is it disregarded? |
Attorney-client privilege is a privilege - a protection allowed under law, that protects communication between an attorney and their client and prevents them from being forced to testify. This allows attorneys to do their job and be able to properly defend their client. It's very hard to come up with a good defen... | 21 | 27 | |
ELI5: In quantum mechanics, what do they mean when they say a particle takes "every possible path"? | I'm referring to Feynman's sum of all paths, which is often mentioned in layman physics books but rarely fully explained. What counts as a "possible path"? Often it is described as a particle travelling from point A to B could include a path in which it heads off to Alpha Centauri and back again. I know quantum physics... | A basic difference between classical physics and quantum theory is the fact that within the quantum world, certain predictions can only be made in terms of probabilities.
As an example, take the question whether or not a particle that starts at the time A at the location A, will reach location B at the later time B.
... | 20 | 49 |
ELI5: How does a graveyard stay in business after it's full? | Even after a cemetery is full there are still maintenance costs for things like landscaping and security. Cemeteries have a few ways to keep paying those fees.
In many states in the United States, cemeteries have to set aside a portion of each purchase for a perpetual trust. The interest earned on that trust is suppo... | 36 | 45 | |
Interview questions for faculty position? | If any of you serve on hiring committees, can you help a sister out and share some of the more commonly-asked questions when you interview people for full-time faculty positions? The only "real interview" for a faculty position that I've ever had was a phone interview with a hiring committee, and I can't remember any q... | These are slightly edited questions we've asked on skype for an instructor position. When you are face to face you should also feel comfortable repeating answers from one person to the next (they don't compare exact notes so it's not like it's "cheating" to re-use your good answer to professor 1 with the same question ... | 18 | 20 |
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