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ELI5: How do we actually reproduce the flavor of something? For example, how do companies go from an actual banana to creating something that is banana flavored, but contains no bananas, like gum? | Take an organic chemistry class and you'll likely find out in lab!
Basically, something's flavors and scents tend to come from only a handful of certain chemicals. If we're talking about food, these compounds are probably aromatic compounds, which means they have a benzene ring somewhere in there. Anyway, make these compounds and you've basically created the flavor and scent you're after. | 119 | 202 |
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ELI5: The Public Safety exemption to Miranda rights | According to CNN's Jake Tapper (twitter feed 4/19 6:34 PST), the police invoked the 'Public Safety' exemption to Miranda rights when they arrested the suspect in the Boston Marathon bombings. I found the FBI's page (see below) on it but I'm a five year old.
http://www.fbi.gov/stats-services/publications/law-enforcement-bulletin/february2011/legal_digest | The link you provided gives an excellent summary. As it says, "...police officers confronting situations that create a danger to themselves or others may ask questions designed to neutralize the threat without first providing a warning of rights." In other words, if you think that you or the people around you are in danger of being seriously hurt, you can take action to protect yourself before worrying about reading the Miranda warning.
There are some further details that go on to elaborate on when the rule can be applied. In one case, a man is arrested and found to have a gun holster but no gun. A police officer arrested him and asked him where the gun was. In another case, police and multiple suspects got into a gunfight. One of the men reached for a bag that was later found to contain bombs. Upon finding these bombs, police officers talked to a suspect and asked if there were other bombs and how to disarm them.
The article analyzes these examples further by explaining a few key patterns in cases where the public safety exception applies. Basically, the information at hand must relate to an immediate threat to the safety of the cops or the general public. The other key element is that the information must be provided voluntarily, not coercively. In other words, you can ask the suspect a question but you can't beat him up to get him to talk.
TL;DR: Information can be used in court without the Miranda warning if it meets 2 conditions. First, it must relate to an immediate safety threat (eg. "Where is the bomb?" or "Do you have any weapons on you?"). Second, the suspect must voluntarily answer the question without being forced. | 20 | 80 |
When we talk about "technology", why do we talk about high techs like computers & gadgets, artificial intelligence, bioengineering. But not plumbing, scissors, baskets? | Technology can be defined as "the collection of techniques, skills, methods, and processes used in the production of goods or services or in the accomplishment of objectives."
We speak of hammers, saws, pickaxes only when we discuss them in the context of *primitive* or non-modern period. But when we speak of it in today's context, we don't consider them as technology. Why? | This seems like a loaded question. What do you want to know about hammers, saws, and pickaxes from a social scientific perspective?
The definition of technology that you provide is nice and general and pretty consistent with the way it is used across a broad variety of kinds of research. For example, historians, anthropologists, and archaeologists would all use the term technology in reference to the kinds of "primitive" tools that you mention because the development and use of such tools at particular times or by particular groups is of especial interest to those disciplines. In the field of organizational behavior, one might see the term technology applied to management or human service techniques as a way of explaining how organizations accomplish their goals of getting people to do what they need them to do. Generally, sociologists and other social scientists who study modern or contemporary society are going to focus on those technologies that are most socially transformative. Arguably, a lot of "high technology" fits the bill. That being said, one could make a strong argument that some important low technologies, like plumbing, are grossly understudied.
All of these things are technology. Whether or not lay people call them that is a separate question. Sometimes people make the distinction between "high technology" or "high tech" and "low technology" or "low tech" in reference to the difference between computers and robotics, on the one hand, and simple, mechanical tools on the other. But these terms still draw on a broad understanding of technology. | 17 | 63 |
ELI5: Why was the historical development of beer more important than that of other alcoholic beverages? | Beer (and wine and mead) come first. All other alcoholic beverages are products of refining (properly "distilling") the various beers into stronger mixtures.
So to make vodka, for instance, one makes a potato mash, then ferments that mash into potato beer, then uses heat and condensation to separate the alcohol from the water, concentrating the beer into a liquor.
So beer isn't "more important" as a comparison of equals, it's a predicate. So the invention of the wheel is more _significant_ than the invention of the tire, because you have to make the wheel _first_ and wrapping that wheel with padding makes it into a tire.
Without the predicate the follow-on technology never happens.
So without beer there are no other alcoholic beverages.
In general the historians talking about this subject are talking about the "big three" - beer, wine, and mead - when they talk about the discovery of beer. Since wine needs specifically grapes, and mead needs the domestication of honey, while beer can be made from any grain or sugar in general, it's something of an understood generalization.
There is far more beer-making land throughout the cradles of civilization than there is wine or mead producing land.
So the beer is though to come before the domestication of bees for mead, the domestication of the grape for wine, the domestication and enrichment of fruit trees for cider.
So the various grain beers was likely first and foremost, and certainly lead to the invention of the other alcohols.
There is some evidence that it also lead to the domestication of yeasts and so the baking of leavened bread. | 1,954 | 6,282 |
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How exactly do electromagnetic waves carry data through the air? | I've been under the impression that radios signals are turned on and off rapidly to represent 1's and 0's. Am I correct or is data transmitted somehow else entirely?
Edit: To clarify, I'm talking about all wireless technologies, such as wifi and Bluetooth. | Turning the signal on or off (or more precisely varying the amplitude) is called amplitude modulation (AM) and is one way to transmit data. A more common way for high data rates is frequency modulation (FM), where the frequency of the signal is shifted a fraction of a carrier frequency. E.g. in WiFi the main signal is 2.4 GHz, and the signal will modulate a few MHz around that carrier. | 10 | 56 |
ELI5: Uses of complex numbers. | I recently got interested in the topic of complex numbers, I watched a few videos on YouTube about the subject and I think I got the general idea of what they are. But I still don't understand what uses they have in real life. | The original use of complex numbers was to solve the dilemma of the fundamental theorem of algebra. Way back in the distant past, mathematicians argued that every polynomial had a number of roots (places where the function crossed the x-axis) depending on the order (highest power) of the polynomial. Unfortunately for those mathematicians, there were a host of counter-examples to this very elegant principle. So instead of just taking their lumps, they decided to invent complex numbers so they could be right - with the addition of complex numbers, the fundamental theorem of algebra ends up being true.
However, a more interesting application of complex numbers is with respect to the concept of *rotation*. You can use a complex number to represent a vector in two dimensional space (i.e. a set of x,y coordinates). If you multiply two of these vectors together, you end up with a new vector whose angle is the sum of the angles of the original vectors and whose magnitude is the product of the magnitudes of the original vectors.
Rotation also leads into *periodicity* - things that repeat. So we can represent periodic phenomenon with complex numbers. Since waves - including sound, light, etc. - are periodic phenomenon, complex numbers are a way to model them. | 25 | 23 |
Why did Wittgenstein's first book make such a strong impact? | (talking about *Tractatus Logico-Philosophicus*)
Or did it not? It's considered a philosophical text but on the source side, I think it's lacking (he didn't cite anything, correct?), and yet again I find much of it compelling. However, I've found lots of arguments compelling that I or others, apparently, don't consider to be compelling. Is it because he was helped by the introduction written by Bertrand Russell, who I understand was his friend at the time? Or something entirely different?
Is this a sign that the world has changed what it considers to be philosophy? Thank you | From a historical perspective, Wittgenstein's *Tractatus*, with its focus on the logical analysis of language, was received at the time as a hallmark text that helped sketch out the principles and methods (e.g. the "linguistic turn") of what we now call the analytic tradition of philosophy. Since the *Tractatus* directly responded to and expanded on many of the thoughts of Russell and Gottlob Frege, philosophers who by then had become famous figures, it became widely discussed among those who regularly interfaced with philosophy by way of logic, language, or the natural sciences, especially since it received Russell's glowing endorsement. In 1924, for example, John Maynard Keynes noted how the work "dominated all fundamental discussions in Cambridge," where Russell taught. (See Peter Sullivan and Michael Potter's *Wittgenstein’s Tractatus: History and Interpretation* for more on that.)
Perhaps most emblematic of its influence, the *Tractatus* drew the attention of the Vienna Circle, a group of philosophers who catalyzed the rise of logical positivism, itself one of the most notable movements in 20th century philosophy. For members of the Vienna Circle (e.g. Rudolf Carnap, Moritz Schlick), the *Tractatus* represented a sort of (second) logical positivist manifesto, laying out the movement's empiricist agenda while rejecting the traditional problems of philosophy (e.g. metaphysics, as in proposition 6.53) by demonstrating their disappearance. As Martin Puchner (2005) puts it:
>One sentence \[of the *Tractatus*\] in particular was almost immediately appropriated as the central slogan of logical positivism and thus became a chief weapon against metaphysics: "7: Whereof one cannot speak, thereof one shall remain silent." Reiterated innumerable times, this sentence became the rallying cry of the most militant wing of the Vienna Circle, the final command through which the battle against metaphysics, riddles, astrology, Heidegger, and the allied reactionary forces of Europe would be won.
Though Wittgenstein would later criticize the Vienna Circle for misreading his work, it remains that the *Tractatus* was treated as foundational. At the Circle, they would often read the text line by line, carefully interpreting what Wittgenstein had wrote through their particular lens and eventually incorporating Tractarian interventions in their own works. Given the later influence of figures like Carnap, it's easy to see why the *Tractatus* remains so influential nowadays.
On a more fundamental level, however, the *Tractatus* is an extraordinary text simply due to the size and boldness of the intervention it makes, effectively repudiating centuries of past philosophy by casting the problems they seek to answer as "misund\[erstandings caused by\] the logic of our language" (Preface). It may not explicitly cite many other philosophers, but it shows a deep understanding of the longstanding questions it wishes to take apart, needling at ideas pointed to by figures ranging from Plato to Kant to Schopenhauer and transforming them to fit its own general theory.
And it does all this in a meditative yet impenetrable manner, listing out just seven primary propositions and offering a book full of "nonsensical ... elucidations" (6.54) that touch on not just language and logic, but also on knowledge, ethics, metaphysics, science, nature, and so on. Michael Morris, author of the *Routledge Philosophy Guidebook to Wittgenstein and the Tractatus*, notes that "for the range of \[the *Tractatus*'s\] concerns and the depth of its thought its closest companions are two unfinished works: Heidegger’s *Being and Time*, and Wittgenstein’s own *Philosophical Investigations*," which is essentially to say that it encompasses nearly every typical philosophical concern in its writing, in spite of its brevity. No matter your interest, there's something you can glean from the *Tractatus*, just due to its sheer scope — and that, too, makes it enduring in a way unlike many other philosophical works. | 46 | 29 |
ELI5: How does allergy medicine work? Does it suppress the immune system in some way or does it use another mechanism? | Antihistamines (Benadryl/diphenhydramine, Zyrtec/cetirizine) block the effect of a pretty specific part of the immune system, the histamine released by mast cells and basophils in response to allergens. Mast cell stabilizers like cromolyn prevent release of histamine to begin with. These are sort of technically suppressing a little bit of immune function, but it's a part of the immune system that mostly defends against parasitic worms, not bacteria or viruses. Leukotriene receptor blockers like montelukast stop some of the signals that make airways clamp down in asthma.
Corticosteroids definitely suppress immune function in a broad way, though how much they suppress depends on where they go. Nasal steroids like fluticasone are targeted narrowly and have few side effects, while a steroid like prednisone taken by mouth goes everywhere and can do pretty much anything. | 13 | 22 |
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Prof invites me to travel with her for research but unpaid. Should I take it? | Currently an undergrad finishing school at the end of this year.
A professor who has similar research interests as I told me about his trip to country X next year for a research project when I visited her office this week.
I had been wanting to go to country X for a while, was originally planning to go on my own.
The professor mentioned that the cost for living could be subsidized but she have no fundings for my other expenses. Since the country is very underdeveloped, the transport and all other expenses in total are estimated to be around 5k USD for 20-25days.
At the same time. I do have job offers lined up after graduation which could help pay off my 15k in student loans.
Even though the research project really fits with my future endeavors and will perhaps boost my grad school application and resume. A part of me just don’t feel right about working for “free”.
Should i deny this offer or take this as an “opportunity”?
Thanks in advance. | Before you throw in the towel, talk with the researcher about your concerns, especially if you are really interested. Also, depending on your school, sometimes there are awards or other funding (not loans!) that you can receive to help with living abroad to conduct research. | 66 | 36 |
ELI5: how can an iPhone be so hard to hack when entire banking systems and other massive companies can be successfully targeted? | Big companies have many separate systems, many of which have to talk to each other, which means many potential vulnerabilities (often the employees themselves) and you just need one. Compare that to a single hardware device with strong encryption that has a single owner/user. | 29 | 15 |
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ELI5: Why does 100% humidity not mean water everywhere? | Atmosphere, which is a collection of gasses (including water vapor), has physical properties (temperature, pressure, etc) that let it hold a certain amount of moisture. Anything past that limit, and you can't add more moisture to the air. It's holding as much moisture as possible. So 100% doesn't mean you're walking around underwater, it just means the air is fully saturated with moisture. | 127 | 140 |
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ELI5: Why does food that is bad for people taste good, while food that is healthier tastes worse? | Our bodies instinctively like foods with high energy contents: fats, oils, and sugars. It's a survival mechanism that isn't really helpful any more. Cavemen who ate animal fats and oils tended to live longer through the cold winters than the cavemen who ate kale. We've evolved to favor the foods that would keep us alive longer. | 36 | 52 |
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Why can some animals, like turtles, develop in to different sexes after conception based on environmental conditions, while in humans it's fixed in genetics? | What is different in a turtle's DNA, and why don't humans have the same ability? Or do they? | Still waiting for a more detailed answer but:
In general we have genes that relate to a certain sex. But that genes still need to be expressed to actually define a sex. For turtles the environment and especially the temperature determine how strong which sex genes are expressed.
In humans that's not possible to such degrees. But there are some exceptions with people who have hormonal or genetic issues resulting in a unusual expression of those sex genes resulting in a blur between the lines in some cases.
NOTE:
-Im only a live since bachelor student don't take anything for bare truth.
-Im purely talking about the literal expression of biological sexual traits, for discussing social or psychological gender aspects pls find someone else. | 25 | 27 |
Why does contemporary work in ethics within the Analytic tradition seem so far removed from the ethical problems that each of us face in our lives? | I have taken a number of graduate courses in contemporary metaethics. I can't for the life of me give a damn about the discussion being had about global hedonist theories of Crisp. But when I read the classics in ethics like Kant, Mill, or Aristotle, I absolutely love it. I even love reading Spinoza's Ethics, or Hume. Why is it that the ethical theories that derive from these great thinkers seem so far removed from their original sources? For me, when I read Kant's moral theory I get the sense of the importance that ethics has for our overall conception of what it means to be human with limitations and hopes and ideals. Contemporary writings, for me at least, lack that gravity and just appear as pedantic and unimportant. Am I just thinking about things wrong, or have I been given the wrong material to read?
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What do you recommend I read to engage with contemporary ethics in a more sincere way?
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Edit: To clarify the "problems that each of us face" part: When I read Kant, or Spinoza, or Aristotle, I deeply want to change myself to be a more virtuous, ethical, and happier person. But when I read about whether moral claims are truth apt... well I feel not that... | Analytic philosophers publish all sorts of stuff about the ethical problems that we confront in our daily lives.
The issue is that you took a course on meta-ethics, but your interests are clearly in applied and normative ethics. | 22 | 18 |
[The Expanse] What are the major differences between the cultures of Earth/Earthers and Mars/Martians? | It’s important to distinguish *perception* versus *reality* when we talk about the differences in Culture between Mars and Earth.
If you ask a Martian about Earther culture they might describe a culture of decadent, wasteful, lazy people who live on a government handout led by a group of corrupt autocrats who are out to hurt Mars in every way possible.
Equally, if you asked an Earther about Mars you’d hear them described as an overly aggressive and militarized culture of people who are constantly seeking to harm Earth’s interests and undo the carefully balanced peace that keeps the system sane.
And if you asked a Belter they’d probably say that both suck and should go the fuck home and leave the belt.
The reality on both sides is somewhere in between. Are there lazy people on Earth… yes. But that comes from a planet that is so overpopulated that there is no possible way to provide everyone with meaningful work. “Basic” is just that, the bare minimum to keep you alive and for many that’s all they’ll ever be good for. But the cream rises to the top, and Martian Marines and Sailors will tell you that an Earther is just as hard as their Martian equivalent.
Equally, Martians are products of their planet. A planet that is not habitable but may be someday. They are militarized and focused because even a small slip up might mean everyone around you dies. There is no Basic on Mars because there is no room, no resources, and no capacity for it.
In the end, both sides are human… and if you look more than skin deep they are actually pretty similar. | 42 | 36 |
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What would happen in mathematicians decided to change the order of operations? Would math still work if everyone agreed, or is something about it intrinsic? | Mathematics doesn't depend on the order of operations. That concept is just something we need for the way we typically write down operations. If we were to change the order of operations, all that would be needed is for existing texts to be rewritten to add parentheses to formulas that were affected, but nothing would fundamentally change.
Note that there are other ways to write down mathematical operations where something like the order of operations isn't even a thing, because the notation is unambiguous. One such example is the "Polish notation". This notation places the operator in front of the operands. So instead of "1 + 2", one would write "+ 1 2".
Combining operations is easy too: "(1 + 2) * 3" becomes "* + 1 2 3".
To evaluate expressions in Polish notation, you always evaluate the innermost expression first and work your way outwards. There is no need to decide on whether multiplication or addition takes precedence or where to include parentheses. There is only one way to interpret this notation. | 185 | 131 |
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CMV: Anyone who supports trans-women (MtF) in competing in women’s sports either doesn’t understand their biological advantage, or simply doesn’t care about sports and consequences this would create | Recently the news about trans weightlifter from New Zealand competing in OI were trending. She used to compete in men’s division, and now at 43 after transitioning for about a decade is going to compete against female weightlifters.
I simply don’t get how people are oblivious to potential implications this precedent will bring into women’s sports.
Is there any other possible reason for supporting this other then not believing in advantages a male body has, or simply caring more about trans rights then the future of sports? | To be fair, sports scientists, ethicists and stakeholders have been debating this issue for two decades now and the proposed guidelines for participating in women's events on a scientific basis were met by Laurel Hubbard.
One of the major factors was testosterone levels, and Hubbard's levels were sufficiently low for long enough.
The people coming up with guidelines presumably came up with them out of care, and know more about the issues than anyone else. They may turn out in time to have got some things wrong, but neither of your contentions that they are ignorant or don't care are accurate. | 177 | 349 |
ELI5: What are RAW images and how do they differ from normal images? | I’ve listened to many tech reviewers and photo editors saying that RAW images are better and have been intrigued by it. Also what are it’s merits and demerits? | RAW images = what your camera sensor sees, normal images = what your screen shows.
There are a few differences: A sensor doesn't really record colored pixels. Color is achieved by placing a filter in front of it - so some pixels will record only red light, some only green and some only blue. While your monitor does works in a similar way, generally there those "subpixels" are grouped together to full-color pixel units. This translation has to be done before an image can be shown.
And there are other things that have to be done in between the sensor recoding an image and a monitor displaying it. A camera would typically remove image noise, correct white balance (basically, remove any tinting that the lighting of your scene might have), and a lot of other different things. RAW images don't include all of that and are taken directly from the sensor data, including more details about some over- or underexposed areas, that would just appear "completely black" or "completely white" in a processed image.
That means that RAW images aren't really "better", in fact they themselves are much worse pictures than a processed JPEG. They just allow you the freedom of doing those processing steps yourself (and adjusting the parameters to your liking) to get an even better end result - assuming you and your software are more capable than your camera (which might make some wrong guesses about how you want your photo to look). | 34 | 24 |
Can there be such a distance function? | I want to know about a special distance function. I know the properties of a normal distance function, in any space, but one has recently drawn my attention: the triangular inequality.
The triangular inequality can be explained the following manner (if I understand correctly):
given A,B and C 3 points in some space and D a distance function in this space, than the following statement is true:
D(A,B) <= D(A,C) + D(C,B).
My question is: can there be a distance function for which the following statement is true:
given A,B and C 3 **different** points then
D(A,B) **<** D(A,C) + D(C,B)?
If yes, which one, how?
If no, why?
**Edit:** Thanks everyone for the answer. I didn't realize so weird distances and metrics can be useful, I just thought it is a weird question to think about. Well, you learns something everyday! | Yes. But before we start, first the 4 properties that a function must have in order to be a distance function:
- D(x, y) = 0 if and only if x = y
- D(x, y) = D(y, x)
- D(x, y) >= 0
- D(x, z) <= D(x, y) + D(y, z)
the last one being the triangle inequality that you already mentioned. You're looking for a distance function where the triangle inequality is a strict inequality when the 3 points are distinct.
Let D(x, y) = 0 if x = y and 1 otherwise.
Verification that this function has the 4 required properties is straightforward, property 1, 2 and 3 follow directly from the definition. For property 4, we distinguish distinct cases:
- x = z, but x <> y and y <> z. We find: D(x, z) = 0, D(x, y) + D(y, z) = 2, OK.
- x <> z, x = y, y <> z. D(x, z) = 1, D(x, y) + D(y, z) = 1, OK.
- x <> z, x <> y, y = z. D(x, z) = 1, D(x, y) + D(y, z) = 1, OK.
- x <> z, x <> y, y <> z. D(x, z) = 1, D(x, y) + D(x, z) = 2, OK.
For your requirements, the 4th point of the above applies. We see that the strict inequality clearly holds.
The name of this distance function is the "discrete metric", with metric being the term commonly used instead of distance function. | 18 | 15 |
CMV: All public funding for neonatal circumcision should cease | As an intactivist sympathizer I do not support neonatal circumcisions at all -- the only exceptions to this are when a baby provably has a foreskin infection that circumcision can prevent. But absolutely no government money can go towards circumcisions. All neonatal circumcisions, or circumcisions given to anyone under 18 (who cannot give informed consent), must receive no public funding and should be fully fronted by the requesting parent(s) (or a charity as long as that charity is not funded by the government). Medicaid, medicare etc -- absolutely none of these services should fund circumcisions *unless* there is provably an infection that has or will occur in the baby that a circumcision is sure to prevent.
If you think that circumcision is so great that you are willing to do it to a baby incapable of giving consent, then you should be willing to pay for it -- an unwillingness to pay for it is an appalling contradiction in this regard. I think it would be *very* telling if, after this were to be hypothetically instituted, circumcision rates in states that cover circumcision would fall.
To make this debate flow easier, I will say that you can boil my view down to "neonatal circumcision, outside of special cases, is not medically valuable enough that it should be covered by government subsidies".
CMV
**EDIT**: To add in, I will expand it to include *any* major medical issues with the penis that may be resolved by circumcision. So developmental, infectious, long-term issues etc..
**EDIT 2**: Since charities are tax exempt, I'll exclude any tax exempt groups from the criteria
_____
> *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!* | Your premise here is the assumption that the government only has an interest in sponsoring procedures that will save a life or improve one's general health. This is not supported by any precedent or judicial ruling in the United States. Government-funded programs exist covering birth control, erectile dysfunction medication, surgery for cleft palates, wisdom tooth extractions, even acne-medication. Any argument about what the government "should" or shouldn't subsidize is subject to the broader questions of the government's established interests and roles in society. This varies a lot by different countries, so it's hard to know exactly what you're arguing for and why you think this issue is different from any other non-lifesaving thing the government pays for. | 23 | 122 |
ELI5: How is it that, say, Lebron James and Danny DeVito are considered to be the same species despite being so physically different, but a brown bear and a black bear are considered to be completely different species despite being so physically similar? | Defining species is a tricky and often subjective part of the various scientific disciplines which interact with it.
Some will say that the viability of offspring among groups of sexually reproducing organisms is a good test, and it does offer some utility, but it is by no means exhaustive. Polar bears and grizzley bears are a famous example of two types of organisms which are generally considered different species, but which occasionally mate in wild, producing reproductively viable offspring. Mosquitos can become behaviorally different enough that they don't know how to entice mates between groups and they are often considered diferent species despite the reproductive viability of offspring created by human intervention.
Archaeological evidence throws in additional wrinkles. Although we generally consider domesticated dogs to all be of the same species, if the only record we had of them were bones (ignoring DNA) we would likely consider great danes to be a completely different species from pugs. This problem rears its head when examining hominids which co-existed as it is difficult to say if these are divergent groups of one species or two separate species; some the scientists involved usually prefer the latter result as it is more prestigeous to discover a new species than just a member of an existing one.
Non-sexual reproducers add additional problems as the detectable differences in species has a lot to do with how they look and how they behave around other similar organisms.
DNA has added an additional tool which allows us to statistically compare gene differences between two organisms. This has been done to create base-lines of what we already feel are different species and how much their genetics deviate from each other and then we can use this to compare other similar appearing organisms, both those we can observe today and those from the relatively recent past. If they are too similar, it is a strong mark against it being a different species and if they are quite different, it is a strong mark in favor of it.
In the end, the idea of 'species' is only important when it is useful in describing our world. It's useful to differentiate between predators and prey, or the reproductive viability of populations of organisms, or tracking forms of organism through the archaeological record. It is important to recognize that the walls we put up around species are not entirely sound and if we aren't careful we can make mistakes, but in so far that they are useful tools for helping us to grapple with the complexity of the world, they are just fine. | 3,164 | 3,391 |
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Any tips for reading research papers? | I am trying to read and understand research papers at the moment regarding path finding algorithms. I find a lot of research papers to be a bit hard to get through. Does anyone have any tips on how to tackle them? | Read them over several sittings. Take notes. Try to rephrase/reproduce the main arguments. Discuss it with others. Read related material and references.
It’s ok if you don’t understand every detail the first time. Just try to get them with time. | 19 | 28 |
How close does the energy of a photon have to be to the energy jump of an electron for it to absorb the photon? | If an electron can only absorb all or none of a photon and can only jump up to specific energy levels, the energy of the photon would have to be equal to the energy level of the electron. But, I am assuming that there can be some error, otherwise it would rarely happen. What is this error and why is there one? | The answer is if you are going to transition between two bound states (energy levels) the energy of the photon and energy of the transition must match *exactly* for non-scattering interactions.
That being said its not "rare" because we are typically measuring ensembles of many many atoms. These ensembles have statistical broadening effects, as well as uncertainty effects in the light field that make them more probable. For example the precision something can measure a frequency of light is going to be inversely proportional to the time it can interact with that light field. Meaning most systems can only interact for a set amount of time before the light field is turned off. This innately gives the light field some uncertainty in frequency.
These uncertainty effects give both the atom/molecule and the light field a distribution of available frequencies. Now the probability that the light will interact (be absorbed) but the object will be proportional to the overlapping area of the two frequency distribution functions. There are more factors at play here but thats the basic point.
Additionally you can have scattering events where only part of the photos energy is absorbed due to induced fields. | 12 | 16 |
CMV: Terminally Ill Individuals Should Be Able To Elect For Assisted Suicide | While the right to die is of course a very sensitive subject and can involve a lot of controversy; I feel that narrowing the scope of the subject down to the terminally ill makes it much easier to discuss. Whenever we, or at least I, think of death, I always think of my loved ones, which is why I think the subject matter is so sensitive. We as a collective rarely ever want to admit defeat to even the thought of losing someone precious to us; so, I feel that there is this societal pressure that makes it feel like it is unacceptable to let go. Given this; given the fact that we truly care for our loved ones, we might, or even should, be obligated to consider our loved ones' right as an individual to decide their fate. This is otherwise known as "self-determination'. Maybe, we are obliged to allow a person, especially one who's terminally ill and fated to die within the foreseeable future anyway, the right to choose when and how they would like to die. A more suitable term that I've seen used is "death with dignity". This may be especially pertinent when considering an individual who may be facing what they may consider particularly horrible deaths, such as morphine resistant pain. So, I consideration of this, though it may not feel right; perhaps giving terminally ill individuals the right to die, as other modern societies have, may be the more ethical option.
&#x200B;
Thank you all for your thoughtful input, as someone new to Reddit I never expected such a high response rate. This has been really nice. :) | "I feel that narrowing the scope of the subject down to the terminally ill makes it much easier to discuss."
Couple of problems with that sentence. First, who gets to decide what constitutes terminal illness? If you have a rare disease that is terminal in 99.6 percent of all known cases within five years, what about the 0.4 percent who survive longer than that? Also, if we say people with terminal illness can commit assisted suicide, when? Do they get to do it when they still feel reasonably well, or do they have to wait till the agony sets in?
Further, mental illness is just as much an illness as any physical illness, and can also be incurable. Who gets to decide whether incurable mental illness which often results in suicide constitutes "fatal" illness?
Also, if self determination is a right, why is it only a right of people in pain?
I feel these questions, among 100 others like them, make a strong case for ALL individuals having the right to assisted suicide. | 34 | 211 |
ELI5: Langrangian points | Lagrange points are special points found within what is called a three body system, where there are 3 different massive objects. These are points where if two of the objects are orbiting each other via a barycenter, the third, if placed at one of those points, will orbit the same period as the other two without entering into their orbital paths.
So how do they work? First, let us establish that the closer an object is to a massive object, the stronger the gravitational pull. The stronger the gravitational pull, the faster the orbital period
This is going to use the Sun and Earth ad the objects, but really anything can be used.
First of these points is L1. This is found slightly (1/100th of the distance between the Earth and Sun IIRC, if they are the other two objects) within the orbit of the Earth and is directly between the Earth and Sun. This ends up with the Sun pulling on the object, but the object also has a slight pull from Earth in the opposite direction, weakening the sun's grasp on it, boosting it's orbital period to that of the Earth.
Next is L2. This is found on the opposite side of Earth than L1, but this time both the Sun and Earth are pulling in the same direction, boosting the pull, enough to lessen it to the point where it matches the orbital period of the Earth. So the goal here is to have the pull of the Sun, coupled with that of Earth, be the same as the pull of the Earth from the Sun.
Then is L3. L3 is found on the opposite side of the Sun, slightly outside of Earth's orbit. Since they are aligned, both the Sun and Earth pull on it from the same direction, compensating for the more distance from Earth's orbit, to the point where it matches the Earth's orbital period
Then come the interesting ones, L4 and L5. They are both found in such a way that the distance between all 3 objects is identical and makes an equilateral triangle. L4 is found ahead of the orbit of the Earth though slightly inside its orbit. This has the effect that the pull by the Sun should be more than that of the Earth, because if is found closer, thus the orbital period should be faster, but the Earth is found directly behind the direction of travel, which pulls the object back, slowing it, making the orbital period the same. L5 is the opposite, it is found behind but slightly outside the orbit of the Earth, slowing it, but it is sped up because the Earth is ahead of it, pulling it behind it slightly, boosting the orbital period.
Only L4 and L5 are stable (if something leaves it, it will pull back), the rest are unstable and require correctional maneuvers to compensate. The interesting thing about Lagrange points is that it is possible to orbit the actual points due to the fact that if an imbalance occurs perpendicular to the line they are on in L1 through L3, or somehow else in L4 and L5 (I forget how), it pulls it back to the Lagrange point, which can be used to make an orbit, an orbit around nothing, called a halo orbit. | 11 | 15 |
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ELI5: how the Nazi identify the Jews in the holocaust | I mean, just by accusation? Did they had a census or anything? In the common cold war dictatorships delation or previous political activities were the cannon for getting people into trouble, but in the Nazi regime the idea was to delete an entire ethnical and cultural belief, so I can't figure it out. | The Nazi party in Germany identified Jews through military records, census records, tax returns, synagogue membership lists, parish records (for converted Jews), routine but mandatory police registration forms; the questioning of friends, relatives, neighbors, businesses was also used, as well as Jewish community membership lists, individual identity papers, captured census documents, police records, and local intelligence networks.
When we think about the holocaust, or read about it, or hear about it, the focus is usually on the apex, the peak of the horror...but you have to understand that this happened gradually over a period of years. There were a number of methods employed to identify and exclude European Jews (amongst others), and it began with giving the power to Hitler and those who would follow him. In 1933, Germany passed the Enabling Act, which essentially ended democracy in Germany, giving the government the power to enact legislation by decree. This gave them the legal ability to make the discriminatory policies that were to come. It also meant Hitler was allowed to make legislation that violated the Weimar Constitution without the approval of the parliament. They began by suspending the licenses of Jewish doctors and others in service industries. They forbade Jews from taking the bar exam, thus preventing them from becoming lawyers. They used a claim of overcrowding in schools and Universities to prevent Jewish students from attending public schools. They then taught students to love Hitler, obey authorities, and hate Jews. All of this happened in 1933, and it was just the first steps. By 1934, Jews were prohibited from slaughtering animals, which prevented them from obeying Jewish dietary laws. Nearly every aspect of Jewish life was subject to arbitrary-seeming legislation. In 1935, the Nazi leaders announces the Nuremberg Laws. These laws (among other things) excluded Jews from having citizenship, from marrying or even having sex with German women, denied Jews basic political rights including voting, denied Jews the right to hold political office. They also made it nearly impossible for Jews to make a living, reducing Jewish-owned businesses in Germany by two-thirds.
And so it went, until things finally got so horrific the rest of the world was forced to stand up and take notice and, more importantly, to act. It took far too long for that to happen, with a near global Depression making for hostile times all around. | 41 | 32 |
[DC/Marvel] What keeps the DC universe earth from having their own "Civil War"? | Compared with the Marvel earth, the DC earth has just as many events of destruction, if not more because of the advanced power of their heroes and villians. In some continuities San Diego was sunk, and a whole city (coast city) was completely destroyed as examples. What is keeping the DC earth governments from going SRA on their heroes? | Consider this: Earth has an Amazon warrior, a man many times faster than the speed of light, three honest-to-God *aliens*, a man wielding the ultimate weapon in the universe, and a guy in bat-shaped pajamas that *must* be some kind of big deal if he's got a seat at the table with the big hitters.
Do *you* wanna be the guy to tell them "No"? | 122 | 92 |
eli5: Why does it sometimes get harder to fall asleep the longer you stay awake? | Tiredness and wakefulness are two independent states influenced by your circadian rhythm.
Your body produces melatonin to help induce sleep, as controlled by the circadian rhythm. This peaks around 3am for a normal adult lifestyle. Past this peak, melatonin production ceases and your liver breaks down what was produced. Your body becomes more alert, though is still fatigued. | 47 | 58 |
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ELI5: Why does the US have military bases and constant presence in other countries, but other countries don't have military bases in the US? | In Germany and Japan, it has to do with agreements that the Germans and Japanese agreed to when the peace treaty was signed to end World War II.
In countries or areas like Britain, Diego Garcia, Australia, Spain, Italy, it is because the bases are usually a joint-alliance agreement (e.g. NATO).
In countries like the United Arab Emirates, Kuwait, it is because the United States has negotiated agreements with those countries to have a presence there. Usually the United States pays a monetary amount or agrees to provide something (military aid or defense) in return.
In countries like Iraq (very small presence now) and Afghanistan, the answer is because of military action.
It should also be noted that even though countries don't have military bases in the United States, there are many foreign service members in the United States under joint agreement for training with US military forces. | 954 | 1,264 |
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ELI5: Why does food have to be labeled "not a significant source of ___" | I knew my diet green tea wouldn't be a significant source of calories from fat or iron. I figured that would be a given. Is there a reason they have to include that label on everything? Also why not do it with everything else rather than just the limited few? | The FDA requires all food items to have nutrition labels. Certain substances are required on these labels, like fat, protein, carbs, sodium, cholesterol, Vitamins A and C, iron, and calcium (I am unsure if this is a complete list). If a food item however has no significant amount of any number of these items though they are allowed instead of listing zero to list that, it can help to save space especially if it is true of many of the required categories. | 89 | 306 |
ELI5: how does going to war make a country richer? | It doesn't usually make the country as a whole richer, but it might make the small group of people in charge richer, especially if they own or have investments in industries that would profit from war (weapons industries). Additionally, war can be a way of getting new land and resources which can also add wealth. Again, usually this wealth only gets earned by a small already rich group while the common people don't profit from their country being in war. | 16 | 17 |
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ELI5: Why can't the whole world switch to one currency? | What would happen if it was attempted?
EDIT: Why so many downvotes?!? | The advantage of multiple currencies is that if one country has economic booms or busts they can tweak their currencies so they are worth more or less to either slow down or speed up their economies.
Take Greece as an example. If they were still on the Drachma, they could devalue their currency and make their exports cheaper for other countries so it would get more people back to work. | 1,291 | 1,623 |
ELI5: The Simpson's Paradox | Just saw a comment on it on /r/askreddit and I cannot wrap my head around it. Is it just bad methodology in studies (at least for the kidney stones)? | The classic example is something like comparing exam pass rates for boys and girls. It's possible to find that, say, girls have a better pass rate overall but when you look at the results for individual subjects the boys beat the girls in every subject. At first this seems impossible because combining several subjects where the boys always have a better pass rate must surely mean that the boys will have a better pass rate overall. It's possible because there aren't equal numbers of boys and girls taking each subject. There are, say, lots of boys taking physics which has a low pass rate and lots of girls taking English which has a higher pass rate. The boys taking physics have a higher pass rate than the few girls taking physics, but a lower pass rate than both the boys and girls taking English. | 94 | 175 |
ELI5: How do refrigerators, coolers/cooler rooms and freezers work? | They are powered by electricity (obviously) and sometimes the back of a fridge is warm. But what is going on inside that makes the temperature inside the fridge/cooler cold? Thanks! | Refrigeration works on the rule that turning a liquid to a gas sucks up heat, and turning a gas to a liquid releases heat. An example of the first is that wearing wet clothing makes you cold. This is because your body heat is being sucked up to turn liquid water into water vapor.
In a refrigerator or freezer, this happens inside a pipe, with a chemical that boils at a much lower temperature than water. As it passes through the inside of the refrigerator, it turns from liquid to gas and sucks up heat. Then, outside the refrigerator, the compressor uses electricity to squeeze the gas back into a liquid, which releases heat. Then it gets pumped back through the inside, and so on.
If you have a large space, like a walk-in freezer, or air conditioning in your house, air is circulated over the pipes to get the heat sucked out of it, and then the cold air is blown around inside the space. | 10 | 26 |
How close would lightning have to strike to you in a body of water to fatally shock you? | I have no idea what variables would come into play here, but assume the following:
* Freshwater Lake
* You're swimming on the surface
* Take an "average" lightning bolt
How far would lightning travel once it's hit the water? And for how long of that travel is it strong enough to kill? | Resistance of Fresh water 0.055 µS/cm at 25 °C. An average bolt of negative lightning carries an electric current of 30,000 amperes (30 kA), and transfers 15 coulombs of electric charge and 500 megajoules of energy. Large bolts of lightning can carry up to 120 kA and 350 coulombs.
Just need a math/physics guy to tie it all together | 27 | 121 |
ELI5: Why is cancer so hard to cure? Will we ever find an infallible cure? | Usually, cells that cause disease are very different to your cells. Bacterial cells have very different characteristics to human cells and so we can use treatments that exploit those differences to only eradicate bacteria.
However, cancer results from mutated human cells, so cancer cells and human cells are overall very similar. Therefore, methods that eradicate cancer cells will often also eradicate human cells and we must rule them out. That makes it very hard to find a treatment. | 3,006 | 2,126 |
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Theoretically, if one could double a male's X chromosome, could one produce a female clone of the man? | Assuming all social aspects were taken care of, is the genetic material there to possibly create a female clone of a man? | The X and Y chromosomes contain genetic information beyond sex determination. You would end up with a female, but not a clone of the "original". The resulting specimen will be closer-related genetically than a sibling, but still won't be a clone due to the genetic differences encoded in the X and Y chromosomes. | 459 | 1,152 |
ELI5: What happens to urine and fecal matter after we flush the toilet? | How is it treated and, in particular, where does the solid waste end up? | That's a question with a ton of detail.
There are two types of sludge treatment; primary and secondary. Most of these processes require a press of some sort or a drying bed to assist in removing water content. After that, the sludge is most often used as a soil treatment, just like manure, after another facility processes it.
As far as water, there are multiple types of treatment, plants and results. The basic rundown is that the water goes through a device called a clarifier. This separate the liquid, floatables and setables. Floatables are anything that floats to the surface and setables are essentially the sludge. The water then goes through a series of processes to remove bacteria. Some of those are natural trickling, some are chemical, and some are a combined force.
The water can end up being crystal clear and reused as clean water, mostly clear and used as reclaimed water, or still very dirty and sent to a disposal site where the earth is the last stage to making clean water again.
And i could go on for hours... | 103 | 159 |
Since children are growing and constantly have dividing cells, why do they have lower cancer rates than adults (who are not growing)? | Cancer develops when cells malfunction, and when the malfunction is not handled by the immune system.
Cells can malfunction for three reasons: cell was faulty to start with (genetics), cell was exposed to something that causes malfunction (a carcinogen), or cell randomly malfunctions.
Of those three reasons, genetics and carcinogens are much more likely than random errors. Genetics typically lead to childhood cancers (because cells are faulty from early in life), whereas environmental exposure typically leads to adult cancers (because damage from carcinogens keeps accumulating).
Also, adults also have constantly dividing cells, even if they aren't growing (but the rate of division is lower than in children). | 21 | 17 |
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ELI5: Why it is unsafe to drink rubbing alcohol? | I know this sounds horrible, and I will never do it, but It is just alcohol isn't it? Why isn't it possible to mix a drink with it? | Alcohol is just a class of organic molecules that has a hydroxyl group attached to a single carbon (methyl alcohol) or a chain of carbons. When alcohol enters your body it get metabolized to form a ketone or an aldehyde. What metabolite is produced is dependent on what alcohol is being metabolized. Regular drinking alcohol (ethyl alcohol) gets metabolized into acetaldehyde which isn't very toxic to humans but is part of the reason you feel hungover. When rubbing alcohol (isopropyl alcohol) is metabolized it forms a ketone called acetone, also known as nail polish remover. Acetone acts as a central nervous system depressent and will lead to headaches then dizziness then vomiting then a coma if taken in large enough quantities.
So it's really not the rubbing alcohol that hurts you its what your body does with it. If someone drinks rubbing alcohol or antifreeze which contains methyl alcohol (metabolizes into formaldehyde) of course the best thing to do is get them to the hospital. If that's not an option for some reason, getting them drunk and keeping them drunk for a while will also save them. This is because ethyl alcohol has a higher affinity for the enzyme that metabolizes all alcohols so your body will be too busy metabolizing the ethyl alcohol to metabolize the other alcohol. Eventually the isopropyl or methyl alcohol will be excreted in the urine and no harm will be done. | 80 | 53 |
[astronomy] If the universe expanded at the same rate during the Big Bang why are there areas of high mass density( galaxies) and areas of low mass densities? | That is actually a great question, but very hard to answer. It touches on many different parts of cosmology and there is still a lot of debate around this.
One part is basically the question of initial conditions. What did the universe look like at the beginning? And why? Answering this involves topics like: string theory, inflation, pre-heating, baryogenisis, primordial nucleosynthesis. (In ascending order of how much we know about them). Some of this is very controversial and theoretical, so I'll leave it out.
What we do know *really* well is how the universe looked after those processes. At this point the universe is around 400 000 years old and filled basically with a neutral gas (mostly hydrogen). (We know this because of the Cosmic Mircowave Background). The gas is *almost* perfectly homogeneous, with fluctuations of about 10^(-5). Those initial fluctuations grow with time: denser areas have stronger gravitational pull, attract more gas and get even denser. Eventually they form galaxy clusters, galaxies and on the smallest scale gas clouds collapse to form stars. Therefor fluctuations are the seeds of the large scale structure we observe today. This is of course *way* more complex! Cosmologists use massive computer simulations to understand how exactly tiny fluctuations evolve into the universe we observe today. (There are many feedbacks/non-linear effects, dark matter...)
I hope this rough overview is somewhat helpful. Please ask if you want more details. | 16 | 25 |
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ELI5: Why isn't there a "life skills" class offered in highschool to teach kids how to change tires, get credit, and other necessary information to function in the real world? | we had one in high school (not in the US) it included:
* Checkbook balancing - basic financial skills. (loans, debts etc..)
* Cooking.
* Sowing and knitting. (You can't imagine how useful it is to know how to hem or fix something!)
* Basic vegetable gardening.
* Basic electricity. (how to wire a plug etc.)
* Basic car stuff. (change tires/check pressure, check oil, add wiper fluid etc..)
It was awsome!
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How can TSA/Airport security workers stand next to X and T ray machines all day everyday without any ill effects? | I know the people walking through the machines have nothing to worry about, but are there any precautions in place to stop the workers absorbing these rays? Do the machines focus the radiation into one area?
Thanks in advance. | Like any radiation worker, they apply ALARA. That means that you should take steps to make your radiation exposure "As Low As Reasonably Achievable". The ways to do this are the maximize distance from the source, minimize time near it, and use shielding when possible.
If you pay close attention when passing through security, you'll see that they rotate between positions throughout the day. So the people operating the x-ray machines rotate around to other positions as well.
You may also notice that some employees are wearing badge dosimeters. These are little badges that you wear on your body. Over time they will accumulate on average the same exposure density to radiation that your body does. Every few months you send them in for testing to see if you had an abnormally high exposure within that time.
I don't know much about the manufacture of their machines (I'd guess it's not something they want the public to know much about), but it's not hard to add some shielding to strongly attenuate x-rays. | 143 | 238 |
How does carbon dating work? | I wanted to know the process and the equations involved in carbon dating
| Carbon dating (like any other method of radiometric dating) uses the ratios of specific isotopes of (in this case) carbon to assess the age of the material.
**Process:**
A sample is obtained. Paleolithic charcoal from a fire, lets say. This sample is ground and processed through an accelerator mass spectrometer, where the exact isotopic content (weight%) is determined by the machine. Then some math is done.
**Principals:**
* Carbon contains one radioactive/unstable isotope; Carbon-14. Carbon-14 naturally occurs in all organic life (as it occurs as a random percentage of all carbon on earth). Carbon 14 occurs as cosmic rays strike atmospheric Nitrogen, and this has happened as long as nitrogen has been in the atmosphere, and at an equivalent rate.
* All radioactive isotopes have a certain half life. Carbon-14 has a half life of 5,730 years. From the half-life, the mean life is determined using the equation T_1/2=tau*ln(2), where T_1/2= half life and tau=mean life.
* Radioactive decay (of all elements) is governed by the equation N=N_0 exp(-lambda*t), where N=number of atoms left, N_0=original atoms, lambda is the decay constant (reciprocal of the isotope's mean life, in this case 8267 yrs)
* This equation is reduced to t=8267*ln(N_0/N) (for C-14 only)
* From the data obtained in the mass spec, we then use that ratio to calculate the time (in years) since the sample stopped accumulating C-14.
However, in thorough scientific work, there are many variances in the calculation. Variations in the C-12/C-14 ratios locally and temporally complicate this, as well as isotope fractionation (from weight) are all problems that can happen. | 10 | 28 |
ELI5:How do Persian rug shops stay in business? | I understand that rugs can cost in the tens of thousands but I pass by these places in my city and they always look shady and empty. The rugs always cover the windows so you can't see inside the shop. Are these places fronts for back door dealings or legit businesses? How often does someone walk in and drop $20 000 on a rug? How do these store fronts afford thousands a month for rent? | High end retail stores such as rug shops, expensive antique stores and so on have very high markup. 300% minimum, and up to 1000% in many cases. These rug shops are selling 20 rugs a year at $20,000, unlike a high volume discount stores which might sell 20,000 rugs at $20 each a year. You don't have to sell a lot of rugs a year if you are purchasing them at $2000 each, and sell at $20,000. | 172 | 510 |
Why does Agile get so much training geared towards it? | So I’ve just started a new job, after a 3-month training course in Java development. I already had about 6 months of experience working in what was basically Agile for a much smaller company.
My training period contained a bunch of training on Agile, and then in my first month at the new job I got another 16 hours of it over four days last week.
The one thing I can’t work out is why so much time was spent on training me and my colleagues to work in Agile. It’s so simple to me, and honestly I think “Agile is small bits added over time” could have replaced the whole thing. I simply do not understand why so much training exists to get across such an easy and simple concept.
Edit: A word | Wellcome to corporate software development, where 5 minute youtube tutorials get converted to 3 days of training seminar. Yes, i had similar trainings where a professional teacher was hired to tell us 8 hours about "listen to what the user wants".
But 10-20 years ago agile was not realy a thing and most companies has a waterfall model where you just wrote technical documentation and requirements for the first months and then realized that you have to rewrite everything after 80% was done. So agile(SCRUM) came in as the new cool kid everybody liked and it was what the silicon valey did, so we all have to adapt it! So managers hired professionals to teach their coders the way of the agile. | 37 | 33 |
Do quantum mechanical effects have any physiological consequences for how our brains work? | Aside from quantum effects being at the core of physics and chemistry as per the other comments, there are also some, lets say, less supported, theories.
Roger Penrose, the physicist, proposed that quantum effects are the direct mechanism (that is not via normal biochemistry) that drives consciousness. The consensus is that this is not plausible.
Then there is Deepak Chopra who likes to produce word salad with the word "quantum" thrown in. Complete garbage but hard to argue against - bacause how does one argue against random gibberish. | 76 | 61 |
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ELI5: Why do muscles swell and look larger during workout? | The blood vessels in the muscles dilate to allow more blood (and thus oxygen) to go to the muscles when kts needed.
This causes them to hold more fluid for a limited time, making them look bigger than they actually are. | 11 | 16 |
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ELI5: How do we determine if an animal has feelings, is self aware, or is sentient? | On the topic of animal cruelty... I feel like it isn't bad to eat animals, and birthing an animal just to be eaten may seem harsh, but are the animals even aware of their own existence?
Edit: Wow! Thanks for all of the responses, I have read many but I'm gonna start reading the rest! I'm starting to feel guilty for my opinion up there, but I know you all just wanted to help!
Edit 2: I came here to see if I should feel bad eating a burger... Now I'm back to the question my sentience phase. Thanks Reddit.
Edit 3: While I would like to get more comments if anyone has anything to say, but I feel as though this has been answered the best it can. I got a little ethics lesson in as well. | This is an interesting question and there is no single answer. It's not really a question of is an animal "self aware" or "not self aware" and more, "how self aware" is an animal. Even though it is a bit more complicated than this you can think of there being levels of self aware.
The standard test is called the mirror test. It's very simple but really clever. You put a mark on an animal (when it is asleep or not paying attention) in a place that it can't see it, like on it's head. Then you put the animal in front of a mirror.
If the animal sees the mark in the mirror and reaches up and grabs the mark then it recognized that the animal in the mirror was itself. If it doesn't do that then it doesn't realize that the thing in the mirror is itself and then probably doesn't even have an idea of "self".
You can look up lists of animals that can pass the mirror test. Great apes can definitely pass it. Elephants can, probably some types of birds but it is a little less easy to test a bird.
There are some other tests too, some are "easier to pass" than the mirror test meaning they show a lower level of self aware, and some are more difficult. | 18 | 32 |
ELI5: if judges are just supposed to interpret and uphold the law, how can there be some judges that are 'friendlier' to left or right politically? | So the thing is, when it comes to interpreting the law, there are different ways that reasonable people would interpret the same laws. These aren't as simple as "left-wing or right-wing" interpretations but often come down to some degree of legal positivism vs. natural law.
Let's take the classic case of Roe v. Wade for example. You're a judge and a plaintiff is arguing that she has a fundamental right to have an abortion. How do you interpret the law?
Judge #1 says that our constitution was clearly intended to establish a limited government and the Bill of Rights establishes that. Even if the Constitution doesn't explicitly say so, there's an inherent recognition that humans have bodily dignity that the government cannot violate. As such, the woman has the right to decide what to do with her body and the government cannot stop that.
Judge #2 says that in a democratic society, the people make the laws. The Constitution says nothing about abortion or bodily dignity so we shouldn't assume that it applies unless the people make a law saying so. Instead, the people made a law saying abortion should be illegal and we should respect that until the people change their minds and repeal that law.
Both of these are reasonable interpretation of the law and come down to how that judge interprets our legal system. The by-product of this is that one judge's interpretation favors traditionally liberal policies while the other judge's interpretation favors conservative policies. | 67 | 32 |
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Why can't we use salt water in our toilets? | Would the salt erode the pipes at an alarming rate? | The plumbing issue is minor, and can be countered with an appropriate choice of materials. Boats and ships use saltwater to flush their toilets all the time since its readily available unlike fresh water. However, on land you would need to run both a saltwater supply line **and** a second saltwater sewer line at massive expense.
This is because sewer waste is treated before discharge, and combining salt and fresh wastewater would result in brackish sewage that couldn't be discharged in normal locations. *If* you had a septic tank, you would be salting your fields. | 331 | 328 |
CMV: We don't live in a patriarchal world anymore | Firstly it has to be said; before modernisation, the system was not fair to women at all, they didn't have the vote and on top of that they weren't able to further studies in univesities. They were basically stay at home wives with the lucky few able to venture into business. But ever since the invention of birth control and mass production of sanitary pads, women took control over their lives, more control then they previously had. Now we they can do anything their mind sets them to do it. Unfortunately, discrimination does occur but thankfully laws have been able to reduce it and hopefully stricter measures can help remove it completely.
I just can't understand how people still think we live in a patriarchy, one of example often used is the gender pay gap, [which does exist](https://ec.europa.eu/eurostat/documents/3888793/8979317/KS-TC-18-003-EN-N.pdf) and has more to do with social and economic factors than discrimination. A valid arguement for this is perceived barriers to choices in occupation and thankfully this is being mitigated with quotas.
It is true, there are more men at the "top" then there are women. This includes Ceos and executive positions but this can be attributed to men putting more hours, being more likely to relocate and many other characteristics that are required in competitive [environments](https://hbr.org/amp/2015/09/explaining-gender-differences-at-the-top). Why do men have to work so hard? If they don't they would likely find themselves in the bottom: [70% of the homeless are men](https://endhomelessness.org/demographic-data-project-gender-and-individual-homelessness/#:~:text=Sixty-seven%20percent%20of%20all,by%20women%20(29%20percent)).
I understand that we ALL have our issues and that life is hard for some of us. But I don't get how we still live in a patriarchal system. I am ready to CMV, I'm not looking for a fight.
NB: In 3rd world countries and the middle east this is a reality. This post is talking about the western world.
Edit: CMV, we still live in a patriarchal world but are slowly getting out of it. | If the gender pay gap exists due to social and economic factors, why can’t social and economic factors be part of the system?
Social and economic factors can and do change and have an enormous effect on gender roles within society and the balance of power.
When people talk about patriarchal systems, they usually are not excluding social and economic factors from that system. The term comes from anthropology and sociology, so the focus is particularly on the social.
If you don’t want to refer to the social and economic factors that keep men in power as patriarchy, is this because you would prefer calling it something else? | 39 | 54 |
We know that there are Suns in the visible spectrum, are there suns that exists purely in the gamma or radio ranges? | As you make an object hotter, the peak frequency of the emitted light shifts towards the higher frequencies. However, the intensity of the source will increase for every given frequency. This means that any object hotter than a few thousand degrees will emit radiation in the visible spectrum, no matter how hot it gets.
I don't know enough about the classification of stars to know if one can be cold enough to not emit a noticeable amount of visible radiation, whilst still being classified as a star. | 51 | 135 |
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ELI5: What happens when we recycle things, and how do we turn it back into usable products? | It depends on the material
What happens is they first get sorted into different basic types of materials like paper, metals, plastics etc. Within these groups there might be different forms of further sorting, such as magnetic from non-magnetic metals, or different types of plastics.
In the case of paper products, it's broken back down into fibers where can be rewoven back into weaker papers. So its diminishing returns, good paper products might be turned into things like toilet paper, paper towels, or tissues, but you can't really recycle a tissue into new paper, it's already been processed too much.
Metals and glass products can basically be melted down and remade into new metal and glass products almost indefinitely, they are the "Best case" things to recycle.
Most plastics aren't really truly recyclable and the market for recycled plastics is weak. Best case is you can grind them into a dust and "Blow" that dust into fibers for clothing. Things like fleece jackets can be made from 100% recycled soda bottles. Or you can compress the dust into things like decking, chairs, or picnic tables. Unfortunately the market for these products is so weak, the cost is so high, and quality of recycling (your average person doesn't really understand how to separate their plastics properly) is so poor that the vast majority of recycled plastics are either just collected and thrown away in landfills, shipped overseas where *they* throw it away, or burned on cogeneration plants (a power plant the burns trash as fuel). | 27 | 23 |
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Why are professional philosophers dismissive of Slavoj Žižek?—Is there documentation of the former's views on the latter? | Zizek is fun to listen to (lots of videos on YouTube), but at this point I am looking for information that is able to situate his writings within (or possibly against) broader contemporary philosophy. For example, I already know Noam Chomsky is no intellectual ally of Zizek, whereas someone like Cornell West is comparatively much more supportive. However, these are just the attitudes of well-known public intellectual philosophers, out of a large and diverse field. My curiosity is around the more general question: how do the major practicing schools of philosophy view Zizek's thinking (or lack thereof)? If some (e.g.) analytic philosophers are dismissive of Zizek, what rationale do they provide? If there's an article documenting this space of views, that would be helpful.
(*Clarifications*. Please note that my question is a literature research question (boring!! [*Metaclarification*: no, this is not a homework thing, I graduated years ago]), namely if anyone might suggest any journalistic articles documenting the existing criticism of Zizek, or academic papers/articles constructing critical arguments about Zizek. They would have to be of philosophical salience and yet useful for a non-professional like myself. I can tolerate some difficulty but would prefer a text that is not overly abstruse. Also, I am emphatically not looking to debate the merits of Zizek in this thread, because that's probably been done elsewhere. My comments above should not be construed as asking to do that.) | > If some (e.g.) analytic philosophers are dismissive of Zizek, what rationale do they provide?
Generally, no one is going to take the time to write an article on something they find unworthy of their consideration. If a philosopher writes a paper, they are already considering the work or person worthy of their time and consideration.
Philosophers, including academic analytic philosophers, have a finite amount of time in a day and deadlines. Even if they find Zizek's work interesting, it may not be relevant to their work and thus why they do not write on his work. | 19 | 33 |
Eli5 Why is kelp not classified to be a plant but moss is? Kelp seemingly have more plant parts but it is classified as a algae, but moss is a plant? | Down at the cellular level, algae and plants are different. There's a ton of confusing overlap so it's not really clear cut but, basically, although kelp has parts that "look plant-ish" like "stems" or "leaves" or "roots", if you look at the individual cells that make up those parts kelp and plants look really different.
Meanwhile, although moss might not look much like a palm tree, they both have stems and leaves and roots and if you get down at the cellular level they're basically the same types of cells.
Basically, plants are using one set of building blocks and algae are using another. Imagine plants are Lego...you can build all kinds of sizes and looks of Lego models but the individual building blocks are all basically the same. Algae are some other building set that's not Lego-compatible, let's call that Algo...you can also build all kinds of sizes and looks of models out of Algo, but you can't connect Algo to Lego. | 68 | 43 |
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I'd like a simple explanation of what is String Theory. I don't get it. | String theory is the idea that a particle isn't a pointlike object, but an extended object like a string. String theory was first introduced as a model of the strong interactions. It was found that such a theory could describe specific cases of particle scattering observed in the strong interactions. The theory had some success before it was realized that quantum chromodynamics described the strong interaction much better.
People still worked on the theory and discovered that one of the vibrating strings acted like a massless spin-two particle. The only massless, spin-two particle that can exist is the graviton, the hypothetical force carrier for gravity. It was then found that one could use string theory to derive Einstein's equations for general relativity. People then shit themselves when it was realized that string theory contains all the fundamental particles and their interactions. Dreams of unification spread throughout the world.
Then nothing happened for a while and people got angry and mostly abandoned string theory. Someone then realized that 4-dimensional field theories could be rewritten as 5-dimensional gravitational theories. It turned out that in this framework easily solvable gravitational theories could be used to do calculations in hard to solve field theories.
And that's where we're at right now. | 121 | 133 |
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ELI5: Why does electricity "want" to be grounded. If there was a bigger planet then Earth here would electricity jump to it instead ? | The more general rule is that a system will tend to minimize its potential energy. For example, a ball on the top of a hill "wants" to roll down to minimize its gravitational potential energy. Similarly, a circuit "wants" to minimize its electrical potential energy, or voltage (technically voltage is electric potential energy per charge aka electric potential). *Ground* is defined as voltage=0, so a circuit being grounded is like the ball reaching the bottom of the hill. | 51 | 85 |
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ELI5: Roman Aqueducts | So i understand how the romans made water go up, by using gravity
but Im still confuse how they do it,
The diagram I made below shows my confusion, the romans uses gravity and hills to transport water, but how did they managed to bring the water up to the 1st hill??
[diagran](http://s12.postimg.org/xu194me6j/Untitled.png)
Im sure not all cities have mountains with a spring right at the very top,
so some cities should use lakes as their water source like the one in the diagram | All cities in antiquity had a higher elevation water source nearby. The nature of primitive civilization is that it formed along rivers and streams, which flow naturally from a higher place to a lower place. This is how such cities acquired fresh water, and without one the city never could have formed in the first place.
Follow any river upstream and each step will raise your elevation, if only a little bit. The aqueduct starts upstream where the land is higher than the city, and remains level until a certain height, then flows down towards the city. | 72 | 91 |
Build a project in Python or c++? | I’m a student looking to add personal projects for resume. I wasn’t which subreddit would be best to ask this on, but is there anyone that would like to brainstorm a project and develop a program together preferably in python or c++?
TL;DR: looking for a couple people to partner up with on project!! | Depends on which kind of project
If you need something fast, low level stuff, or learning deeply about class, object, pointer, then go with C++
If you want to process of data, like Computer vision, or Machine Learning, etc, then go with Python
Ps: i dont mean C++ can't do what Python can, i mean it's more suitable. Choose right tool for right job. | 16 | 22 |
[40k] How are women incorporated into the Imperial Navy? | Are there many women in the IN? Are they treated any differently than the multitudes of men? What ranks do they usually inhabit? Are there any notable female figures in the IN? Any other information relevant stories/information would also be appreciated. | The Imperial Navy is composed of both men and women, as is the Imperial Guard and the Adeptus Arbites. Women and men are treated equally, for all are equal who pledge their service to the Emperor. Women are not barred from combat or holding any rank congruent to their service level. For example, Anastasia Arkelius, Lord Admiral of the Imperial Navy, currently serving with Battlegroup Cerberus. There is also Sylvia Locke, Lord Captain of the Dauntless Class Light Cruiser Aegis, on extended long range patrol in the Koronus Expanse. | 54 | 32 |
ELI5: Why does vision in darkness have grain? | You have two types of receptors in your retina. Cones are good at picking out fine detail and color while rods are better with picking out contrast and movement. In low-light settings, differences in light coming to your eyes are much more subtle and the cones don't function well. So you don't get fine detail, and what you do see can have some variance, causing your brain to register a grain. | 25 | 34 |
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ELI5: Why are humans and most other species dependant on water? Is it just coincidence that 70% of earth is covered in it? | We need a liquid that can act as a medium for our bodies to do all the important things it does.
Water is an easily accessible one that is made up of two commonly found atoms. It's electrically neutral, non corrosive/toxic/flammable and doesn't react with a lot of stuffs. It's melting and boiling temperature range is just right to not damage the structure of cells at the distance that the Earth is from the sun.
There is no other liquid that fulfills all of the aforementioned criteria. | 25 | 29 |
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Can a pair of binary planets share an atmosphere without exceeding the Roche Limit? | Can the distance between a pair of binary planets be close enough that the gasses making up their atmospheres could mix at the L1 Lagrange point, without either planet being pulled apart by their partner planet's gravitational field? | It depends on what you want to count as an "atmosphere". If you're willing to let it be thin enough, sure. Anything of substantial density would require the planets to be too close, and would also cause too much friction for them to remain in orbit for long. | 27 | 36 |
Why is torque a vector? Right hand rule is a bit arbitrary isn't it? What does the direction of the torque vector signify? | Torque causes an object to rotate, and rotation in 3 dimensions is determined by an axis, the direction of rotation about that axis, and an angle. The torque vector direction determines the axis and the direction of rotation about that axis. (Since we are talking about continuous rotations, the angle part isn't really given by anything, but the magnitude of the torque is used to determine the rate of rotation.) If you point your right hand thumb along the direction of the torque vector, then your fingers will curl in the direction of the rotation induced by that torque. | 20 | 19 |
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[ATLA/LOK] Does God exist is ATLA/LOK? | In the ATLA episode “The Waterbending Scroll” (and probably other episodes that I’m too lazy to look for) Katara says “Oh my gosh” gosh being an alternative to God. In LOK I believe there was an episode where Tenzin blesses the food. So is there some kind of god in the Avatar universe or some kind of spirit that they worship? | They worship (although in this context "worship" seems more akin to respect/reverence) various spirits and spiritual deities. Spirits range from the very powerful like Raava and Vaatu, which represent harmony and chaos respectively, to minor nature spirits and there are various ones in between. | 284 | 261 |
ELI5: How do regexes...work? | So, have you ever run into a programming concept that you just *couldn't* learn, no matter what? Regexes are that for me. I can't tell you how many times I've read up on the basics of regexes, looked in books, seen websites, used tutorials, and even copy-and-pasted regexes into my code...and they're still fucking magic to me. For some reason, my brain just shuts down when I'm looking at them. I think one of my profs scarred me in university or something.
I put to you a possibly impossible task: can you explain the basic principles behind regexes (how they work, why they work) in a way that I can remember and makes sense? Possibly with a few basic examples, building on each other?
You'd really be improving my life.
EDIT: I'm happy I posted this; hopefully other people benefit from it in the future! | (Edited to fix formatting and make a clarification.)
Regular expressions are just a way to say "match things that show up in a particular order."
Let's say car manufacturers all start painting the first letter of their brand names on the sides of their cars to make them easy to identify. Dodges get a big "D", BMWs get a big "B", Toyotas get a big "T", etc.
Let's also say you're standing the side of a road with a flag in one hand. Your job is to watch traffic go by and every time you see a Dodge ("D"), point at it and wave the flag. So you sit there for awhile not seeing any Dodges and you do nothing. Then a Dodge goes by with its big D painted on the side, so you point at it and wave your flag like a madman. Congratulations, you've become a regular expression engine and have just evaluated your first regular expression:
> /D/ (D. The slashes are sometimes used to denote regular expressions.)
What you've done is called "finding a match." Easy enough, right? You can sit there and point at Dodges all day. That gets kind of boring, so your overseers give you a another assignment, find Dodges followed by an Audi. That's a more complex regular expression:
> /DA/ (D followed by A)
So you start by looking for a Dodge, and when you find one, you look at the car that follows it. If the second car is an Audi, you've found a match and you start pointing and waving your flag. If not, you start over and look for a Dodge.
One more assignment, a Dodge followed by an Audi followed by a Chevrolet followed by another Chevrolet:
> /DACC/ (D followed by A followed by a C followed by another C)
What's important to note here is that you don't start looking for an Audi until after you see a Dodge and Chevrolets aren't on the radar until after you've found the Audi. You progress across the expression starting from the left and not waving the flag until you fall off the right edge. If you fail somewhere in the middle (say, a Dodge followed by an Audi followed by a Ferrari), you go back to square one.
The pattern you should be seeing here is that you're being given a list of "things" to look out for. That's really all there is to it. Where regular expressions get complex is in defining what a "thing" is.
Individual characters are easy, but you can use certain special characters to give things special meaning, such as a dot that matches anything:
> /DA.T/ (D, A, anything, T)
This means that Dodge, Audi, Hyundai, Toyota (DAHT) will match, as will Dodge, Audi, Dodge, Toyota (DADT) or Dodge, Audi, Mercedes, Toyota (DAMT), all because any car can fit in the blank where the dot is. When you wave your flag and report a match, you report the sequence that matched.
Other characters, like the asterisk, plus sign and braces, apply special meaning to the thing before them to indicate how many you want:
> /DA*T/ (D followed by zero or more As followed by a T)
>
> /DA?T/ (D followed by zero or one As followed by a T)
>
> /DA+T/ (D followed by one or more As followed by a T)
>
> /D{3,5}AT/ (Between 3 and 5 Ds followed by an A and a T)
Brackets make up a compound "thing" that can be any of the things inside it:
> /D[ABM]T/ (Dodge followed by a Audi or BMW or Mercedes followed by a Toyota)
So can parentheses:
> /(DA)?T/ (Optional D-followed-by-A followed by a T, so T or DAT will match)
>
> /(DA|TH)F/ (D-followed-by-A or T-followed-by-H, followed by F, so DAF or THF will match)
The pipe symbol within the parens means "any of these regular expressions is considered a match for this thing."
Some special characters are called "anchors" that mean you find the expression at the very beginning or the very end of the string:
> /\^DAT/ (Dodge, Audi, Toyota being the first cars you see that day)
>
> /DAT$/ (Dodge, Audi, Toyota being the last cars you see that day)
There's a lot of punctuation flying around a complex regular expression, but the key to understanding it is to break it into individual "things" and treat them like items on a checklist. There are also a lot more complex things, but what I've outlined above are the basics that get used 90% of the time.
HTH, and here's looking forward to your sixth birthday. :-) | 30 | 31 |
CMV:Water is wet | The Google definition of "wet" is: "covered or saturated with water or another liquid." I don't understand how a molecule of water that is surrounded by other molecules of water in not surrounded by water. If you simply Google "Is water wet," it will come up with an article from The Guardian. I feel that the text that is shown at the beginning of the article manipulates the definition of "wet." I think that people tend to just look it up like that and trust that source. Some people will say that water can't be wet even if it is surrounded by other water, because it's water. I don't understand that logic.
_____
> *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!* | Water is not always wet, but it _can_ be wet. Here are some illustrative examples:
* Frozen water is not typically wet. When you take ice out of your freezer, it's usually not wet.
* Take that same frozen water and put it in a drink though, and now it is wet. It's wet because it's covered by a layer of liquid water. Even if you don't put it in a drink, and just leave it outside to melt, it will soon _become_ wet.
* Gaseous water is, practically speaking, never wet.
You can tell the difference between water that is wet and water that is not wet because water that is wet is slippery, much more so than non-wet water.
| 20 | 18 |
Eli5: What makes human memory unreliable? | Human memory is synthesized when first formed; you sometimes create it even before you’ve processed all the sensory input you attach to it. And then to keep a memory stored, you re-play it and store the result. So each time you remember a memory, you have a chance of corrupting it with new false information. | 30 | 19 |
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Can an educated patient with a rare disease present and publish self researched interventions? | I am not a scientist or healthcare professional. I do have a very rare genetic disease with no therapy or cure. I am university educated ( arts degrees) and self researched and applied lifestyle interventions that were unexpectedly successful. As I track all data regarding my interventions, my medical team and I, as first author, published an article this Spring.
As I am acting outside the standard of care for someone with my disease, albeit with proven success, my medical team has now backed away from further research collaboration for ethical and liability reasons. As an informed patient, I am not bound by the same ethical or professional constraints of my medical team. Over the past year, I have progressed the interventions, still outside the standard of care, and I would now like to independently present the results as an N=1 study at a Conference in June.
I am uncertain as to the appropriateness of this effort but feel very strongly that the research would be immensely valuable to other patients suffering with the same disease. Currently, there is no cure or therapy for this progressive and debilitating disease and my research might offer some hope for others.
Any academic advice on strategies for navigating through the publication process would be very much appreciated. | Have you, as first author, and your medical team, as co-authors already published a case report in a peer-reviewed journal? Your post appears to indicate that you did so last spring.
If you've already get a paper out, even if it's a case report (that n = 1), then a conference is easier. Read up on the submission guidelines/requirements and prepare an abstract according to the req. | 95 | 133 |
Melanin protects from the sun, but does this extra melanin in your skin come at the cost of anything else? Is there any advantages to being paler? | Being paler helps with vitamin D synthesis.
That's not to say darker skinned people can't synthesize vitamin D, but paler skin lets you do more with less sun.
The basic theory is people started off in places with more sun, and so had darker skin. As they moved away to places that got less sun, they evolved paler skin, that let them get the necessary vitamin D synthesis done in less time. | 77 | 122 |
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If chimps held slaves would we be morally obligated to intervene? | Let's say there were chimp castes and those at the bottom were treated horrendously. | Look up the moral status of animals. A defender of the integral moral status of animals would claim they have the exact same rights as us. And if we are entitled to not being enslaved, and obliged to stop human slavery, it follows that we'd have to stop it.
Others believe animals have no rights, or at least not the same as humans. In the first case there'd be no moral obligation at all to stop chimp slavery, and in the first, a possibility of so.
It's interesting how the act itself suggests animal moral worth, especially for those that deny it. Many defend this moral anthropocentrism, the thesis that only humans have moral worth, by grounding moral status in rationality. And since humans are the only animal with an obvious rationality, it follows that they are the only ones with moral worth.
Still, some (like Descartes, famously) denied any kind of sentience to animals, usually for theological reasons (though whether or not that is his case is debatable). He famously insisted animals do not have souls and therefore do not perceive anything. A wounded dog only seems in pain, but it is a mere organic automaton. | 76 | 243 |
ELI5: Why is college tuition so high in the US? What does all the money go to? What would be the easiest, most effective ways to make it cheaper? | What parts of the school make it so expensive to run?
I've never sat down to figure it out, but it's hard to imagine it could actually cost $40k/year to give someone an education. Especially at a research institution - often, half of the grant money that professors get for research goes to their department (that's true for Northwestern at least).
Edit: it'd be great if anyone had numbers on this. Are there any university financial office execs out there? I went to a small school where nobody working there was making anywhere close to Ivy League money and the "list price" was still $28k/year. (Of course most don't pay full price, but the school still *gets* that money, be it from federal loans or some scholarship fund.) | The extra money goes to amenities (gyms, pools, food services, concerts, parks - basically anything that isn't basic teaching facilities and salaries). This makes the college more appealing to those applying, so they can raise tuition.
As colleges get more expensive, federal loans are made easier to obtain so students can still enroll. As federal loans are made easier to obtain, colleges are able to add more amenities and raise tuition. Positive feedback loops are bad. | 40 | 108 |
ELI5 - Why do packages of pork rinds have high protein but also say it's not a significant source of it? | There are a bunch of amino acids that go into proteins and your body can make most of them but there are 9 essential ones that you can't build and need to get from your food
Pork rinds have a lot of protein but they're missing 3 of the 9 essential amino acids so if pork rinds are your only source of protein you'll start running into issues which is why they are labeled like that | 189 | 80 |
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CMV: The idea that "Any Job is better than no job" is false | Last year I was laid off from my first "real" job at a Fortune 500 company with an outstanding (for my age) salary. I was unemployed for 9 months after that. I'm an IT professional with no degree (I'm not rich, I can't afford college. I couldn't afford college even if it was free, I got bills to pay)
During that period of unemployment, I had people, mostly boomers tell me that I should just get a job "anywhere" since "any job is better than no job" My problem with this logic is if "any job" doesn't pay the bills, then it's not better than no job. Let's say I got a job at Walmart, which obviously wouldn't be able to pay my bills. Whether I got "any job" or no job, I'll still be forced into bankruptcy, except I'll be wasting my time getting no real experience that matters while going further and further underwater. After a painful 9 months, I finally got an awesome IT contract that recently ended, so now I'm on the job search again. (I've been searching since about 4 months ago, actually) My fiance is in a similar ish situation. She has $22,000 in student debt, has never had any job and is trying to look for work in her field. She has an AS in human services. Like me, she's sending out applications, but no one's biting. Her parents are drilling into her head that she should just get a job at Home Depot or Walmart. I believe she's entitled to a job in her field and should just mass apply to as many human services related jobs there are (which there aren't many, tbh) | gaps in your employment history aren’t a good look especially if you’re seeing paid work that isn’t what you want as ‘a waste of time’
i understand how walmart has no relevance to your profession but i am sure there are many entry level jobs that are. even if they aren’t what you want, you’re getting paid, you’re doing something and you don’t know how useful the connections you make can be in later life | 75 | 156 |
Would a perfect game of chess end the same way every time? | As it stands right now, there are computers that can play chess, however, they do not play perfect games. If there were a computer playing a perfect game against itself, would the game play out the same way every time and have the same outcome? Would it be some sort of paradox? | By definition, if a game is "solved" that means that the *outcome* of a game of perfect play is known in advance--where "outcome" means that either white wins, or black wins, or draw.
The exact move sequence need not be the same every time. If chess is solved and it turns out that white wins, what that means is this: At any point in the game (given past perfect play), then *any* move that black makes, white has a response that guarantees victory (given future perfect play). There's lots of different moves that black can take, but none of them will stop white from winning (or even causing a draw). Any game states that could force a draw, white is always capable of avoiding. | 22 | 40 |
Can you get sunburnt behind glass? | Now that i found the right subbreddit..
Hey Askscience :)
It's coming up on summer her in Australia and have always wanted to confirm the suggestion by a friend that you cannot get sunburnt behind glass, as properties of the wave are changed once they pass through the glass?
When i drive around in my car on a warm day with the windows up i can quite easily feel the heat on my skin, however does heat on the skin always equate to sunburn? Or is the fact i feel more heat behind glass to do with the change in the wave?
| From the Wiki
>Ordinary glass is partially transparent to UVA but is opaque to shorter wavelengths, whereas silica or quartz glass, depending on quality, can be transparent even to vacuum UV wavelengths. Ordinary window glass passes about 90% of the light above 350 nm, but blocks over 90% of the light below 300 nm.[6][7][8]
UVA isn't as harmful but over extended time will give you a sunburn. UVA is 400-315nm.
UVB is your main Sunburn exposure and where most people get into trouble with skin cancer, it is 315-280nm. Glass blocks the smaller half of this very well, but leaves a sliver in the large end.
UVC is even higher energy, but the air itself starts to block most of this, it is a key component in the formation of the Ozone in the Ozone layer.
So yeah, you can get a sunburn from behind glass, but it will take a lot longer and it will be from larger wavelengths of UV compared to direct sunlight, so your cancer risk is lower (note: not gone). Obviously treated or tinted glass can be made to block all the UV. | 33 | 30 |
How to dissect a GitHub project in C | When you look at C code from GitHub, where do you start from? Do you look at all the header files first? Or do you look at the header/code pair with the least amount of imports? Or do you dive straight into main? | This is an advice for any codebase in any language. First get the code in your IDE of choice, when you're familiar with the structure take the debugger and try to understand the flow, then dig in , read and understand the code.
Reading code of a website which doesn't even have proper navigation mechanism will make things hard. Things are really easy when you can ctrl+click a symbol and jump straight to it's definition for example | 22 | 22 |
ELI5: What's that weird tingling sensation I feel in my crotch when I'm on a roller coaster or swing? | Pretty self explanatory. There's a weird sensation that goes through my crotch...like through the testicles to the upper abdomen whenever I have an experience of weightlessness, what is that? | Your body is use to certain pressures and changes in pressure, like when you trip. A feeling of weightlessness is a pressure you are not familiar with and the result is a unfamiliar tingle in your guts, which is rich in nerves. | 196 | 529 |
ELI5: Why can't psychologists prescribe medicine like psychiatrists, & how did the two professions come to exist as separate beings? | I'm very aware one can prescribe medicine and the other essentially is only there to talk with you about your life but if I'm not mistaken, both are doctors correct? So why can only one prescribe medicine when they both seem to have intimate knowledge of the mind? What I mean is, how did the two ever get distinguished? Were they ever just one profession?
Also, which one came first? (In a professional sense. I assume that people have been talking about their problems for a long time) | Psychiatrists go through medical school and (normally) 4 years of residency after receiving their B.S. They are the typical "medical doctors." Clinical psychologists usually have a M.S. or a Ph.D. in psychology. If their title is "doctor," it is because of the doctorate degree (like how professors may address each other). Keep in mind that there are other jobs you can take as a psychologist, such as research and counseling, some even with just a B.S. Whereas the psychologist has probably studied basic biology as an undergraduate and understands the general workings of the human body (outside of psychology), the MD has had extensive training on every organ system, dysfunctions of these organ systems, and pharmaceuticals + their effects.
Simply put, psychologists know how the brain and behavior work and what psychiatric medications do, but psychiatrists know how the rest of the body works, what effects the medications have on the rest of the body, and what non-psychiatric drugs/substances are contraindicted with these drugs. They are also required to have many more years of clinical experience before they are allowed to practice independently.
You can also compare it to eye care: an optometrist goes to optometry school and can do eye exams and prescribe limited medications for specific diseases. An opthamologist goes to medical school + residency and can do what an optometrist can, prescribe any medication to treat any eye disease, and perform eye surgery. | 34 | 45 |
What level of culture did Neanderthals have? | I know (now, through searching) that the sub is inundated with Neanderthal questions, but they mostly seem to be DNA and extinction related. So hopefully this is different enough. I wanted to ask what the current thinking is on the level of Neanderthal culture at the Upper Paleolithic boundary and beyond?
Last I remember (class in undergrad 10 years ago?), there are some indications of art, bone tools, harpoons (?). More reliable indications of caring for the elderly and for burial, and post-Mousterian toolset innovations. There seemed to be new findings about Neanderthal art and tools coming in occasionally, and they were always followed by Zilhao & d'Errico writing something like a "See! Told you *too* Neanderthals are super duper smart!" kind of interpretation and Paul Mellars writing something like "oh, it's misattributed and misdated, but if it turns out to somehow be Neanderthals, they prolly just stole it from a nearby sapien and didn't know what the hell it did". So did this question get resolved somehow? What's the general consensus on Neanderthals? Did they make cave paintings? Did they have music? Could they sew? Did they invent the Chatelperronian toolset or did they just steal all the ideas of the Aurignacian without figuring out what did what? Or does that even matter?
If you want to give me references, I'd be super happy! | Neanderthals made advanced tools, had a language (the nature of which is debated) and lived in complex social groups. The Molodova archaeological site in eastern Ukraine suggests some Neanderthals built dwellings using animal bones. A building was made of mammoth skulls, jaws, tusks and leg bones, and had 25 hearths inside. | 391 | 1,096 |
ELI5: Why does watching flash videos/streams in Google Chrome slow down other tabs? | AFAIK Google Chrome runs each tab in a separate process. So if something hogs one tab, other tabs remain responsive.
Why is it that watching twitch streams slows down my other tabs. For example it's especially noticeable when twitch.tv is open in one tab and i'm scrolling down reddit in another tab.
When i use another browser to stream twitch then Google Chrome tabs remain responsive. | I first had a very technical explanation which was very hard to understand i will now try it with an analogy.
Imagine your computer is a supermarket and every CPU core is check-out. Every customer is a process and the things they buy are the commands which every task needs to execute. If a task like the twitch tab needs to execute many commands it can block the check-out for longer therefore other processes need to wait longer and feel slower.
One of the techniques to mitigate this problem (so that one process can't hog the CPU core for to long) is scheduling.
It works by setting a limit on how much goods at a time can be checked out so that other processes get some time as well.
I hope this makes things a bit clearer and feel free to ask questions and i try to answer them as good as i can. | 10 | 87 |
[Star wars] in attack of the clones when yoda intervenes count dooku fighting anakin and obi wan | Dooku pulls a space pillar down onto the pair of Jedi and Yoda struggles to hold it from falling on them....why doesn't yoda simply pull the two Jedi out from under it as that would involve much less effort no? | In addition to it being a split second reaction, the Force relies on concentration, *especially* for more difficult tasks. It's kind of similar to the "transporter problem" in Star Trek (2009). It's much easier to lock onto one rather stable thing than to grab two moving (and living) things at once. Yoda would have had to ensured he quickly focused on grabbing both his allies with enough force (pun intended) to pull them to safety, but not *too* much to risk harming them (like Force Pulling them into a wall or crushing their bones when Force Grabbing them). Yoda has a lot of skill with the Force, true, but in that moment with barely any time to think Yoda had the choice of moving two other Jedi at once (who could have regained consciousness and freaked out, tried to shake off Yoda's Force control instinctively not knowing he's saving them, and thus led to either of them getting *more* injured), or moving one rather sturdy pillar which can be damaged and tossed around for all Yoda cares. | 34 | 42 |
ELI5: How do very young or verbally challenged children get fitted for glasses if they are unable to verbally indicate that their vision is much clearer? | With normal vision, an object from the world should focus to tight spot on the back of the eye, known as the retina. One way to check this is to shine a beam of light and see how big of a spot it is on the retina. Someone with bad but correctable vision would have a large spot rather than a tight one.
By adjusting the properties of the beam, you can modify it so that it bends similarly to how it would go through a glasses' lens. By figuring out the necessary changes in the beam to make a tight spot, it's possible to recover the lens refractive power needed to correct their eyes!
This method is more complicated and expensive than just swapping lenses and asking a if it's clearer. But it's definitely worth correcting major errors in a baby or young child's vision or else their brain will stop using the nerves from the eye, causing irreversible vision loss. | 231 | 230 |
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CMV: The ROBOT9000 should be enabled on reddit. | The [ROBOT9000](http://blog.xkcd.com/2008/01/14/robot9000-and-xkcd-signal-attacking-noise-in-chat/) is a script invented by the XKCD author Randall Munroe. It ensures that every post is unique and deletes exact reposts. Reposters get banned for a short duration, but that duration doubles for every repost in a row.
In my opinion, the ROBOT9000 should be enabled on reddit. It stops a big part of the shitposts on reddit, like
- "this"
- "nice meme"
- "lol"
- "ayy lmao" .
The discussion quality would sharply rise as most of the twelve-year old mememasters would get banned.
Shitposting would still be possible, but you would actually have to put effort into it instead of just spamming various memes.
Subreddits like /r/ledootgeneration could turn it off, but the defaults (especially /r/askreddit) should turn it on because it would drastically enhace the comment and post quality on reddit.
EDIT: This post blew up and I would love to reply tp every post, but i have to do other things now. | Some very short sentences are quite valuable. For instance, this exchange on CMV is not too infrequent.
>**A:** Given your view on X, would you agree that Y is also true?
>>**B:** Yes.
>>>**A:** If so then you have consequence Z which contradicts X.
The response of "Yes." from user B would get removed and they'd get a tempban, even though "yes" is a perfectly valid response to a question. | 176 | 686 |
CMV: Apple only continues to thrive due to brand name status, not technological innovation | Technological innovation isn't solely about developing new features or pushing the limits on what things can do; it's also about taking new innovations and making it so that the average person can use them. Apple has always thrived at taking technological innovations and making it so that the average person can use them effectively, and continues to do so. | 105 | 287 |
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ELI5: Yanks - what on earth is a 'take a penny, leave a penny' jar? | It is to fill in differences in change when making purchases. Suppose you have $4.25 in change but the purchase costs $4.27; you can just take two pennies from the jar rather than break a larger bill. Alternatively if your purchase was $4.23 you would get two pennies in change, so rather than carry them around you could drop them in the jar for someone else to use. | 123 | 82 |
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Why should economists learn programming? | I’ve seen some economists on reddit suggesting others to learn programming. Why? | Any job that an economist is likely to have involves making statistical inferences using data. Now you're probably not going to do this by hand, as datasets will have observations running from a couple dozen to millions. Computer programming allows you to clean, merge, and analyze datasets at a reasonable speed. | 37 | 21 |
Mental Health and Philosophy of Mind | Any literature I've come across on "Mental Health" seems to implicitly assume an internalist philosophy of mind. Has any work been done by externalists on this matter? | It might help if you provide some examples of what you've been reading so we can see what you mean about implicitly assuming internalism.
Perhaps philosophical discussions specifically around mental illness might seem to imply internalism because mental illness is fundamentally an epistemic disconnect between mental states and facts. The process of belief formation is itself flawed, so we never even reach the starting point of externalist arguments. | 12 | 60 |
Why do medical professionals use Saline Solution as opposed to Distilled Water? | Saline seems to be the most universally used liquid in medicine. I've seen it used in IV drips, to clean out wounds, and to clean needles between stitches. Why is Saline used as opposed to simple water? Is it more sterile? Easier to make/cheaper? When did it become commonly used? | Saline solution is used is to maintain a balance of osmotic pressure between the body's cells and fluids. Cell membranes are selectively permeable which, in this case, means that water can enter and leave the cell freely but most species in solution cannot. Two systems separated by a selectively permeable membrane like this will seek an equilibrium, with water moving however it has to in order to make both systems roughly equally concentrated.
Using pure distilled water (hypotonic) would cause water to rush into the cells to dilute the contents and reach equilibrium, resulting in popped cells. Using more concentrated solutions (hypertonic) would draw water out from the cells and result in them being dessicated. | 26 | 15 |
How to think philosophically | How can I foster a philosophical mindset to be used throughout my daily life?
Are there methods of thinking that I can practice that would allow me to formulate arguments based on everyday observations?
In other words, what are the best ways to approach thinking with the goal of thinking like a skilled philosopher? | >In other words, what are the best ways to approach thinking with the goal of thinking like a skilled philosopher?
You read lots and lots of original philosophical work and it will come eventually. You might not always be right, but eventually you'll find certain parts of your life come to look like certain philosophical concepts, and might benefit from philosophical models or philosophical conclusions. Most of the time philosophy classes help people enormously in this process, but some people can do it on their own. That's really all there is to it. | 24 | 18 |
[Harry Potter/General] What is magic made of? | In Harry Potter, as well as many other fantasy series, magic is shown as a sort of spark/beam of light that shoots out of the wand. But what is that light? Is it plasma? Is is something else entirely? | In most cases, the light we see is the result of the magical energy exciting the electrons of the atoms which make up the air (and thus making the air glow). It's somewhat similar to an electrical arc, but there's more variety because the magic obeys different rules than normal physics.
If you could see into the Octarine, it would be even brighter and more prevalent. That's part of why more spells seemed to result in beams of light later in Harry's time at Hogwarts; as a wizard trains he becomes more adept at perceiving octarine light. Most of them don't even notice the change, it happens gradually and isn't mentioned much in the Hogwarts curriculum (unlike Unseen University, where it gets some emphasis). | 25 | 36 |
ELI5: What are the sources of income for a country/government other than taxes? | The government can directly own resources that they sell (oil, lumber, food, diamonds, lithium, titanium, etc).
The government can own factories or companies that make things that are sold.
The government can sell debt as a secure form of investment, this is normally done in the form of treasury bonds that have set maturation dates and interest rates.
The government can sell land to its citizen, or to other countries like the Louisiana Purchase.
The government can sell services that it may have, such as advisers to help write a constitution, or use of its military to protect a country that does not have a military of its own. | 30 | 44 |
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ELI5: How do all the different programmers working on the same piece of software arrange all their different lines of code together to form the finished working product? | Most teams use what's called a Version Control system which tracks individual changes to files (called "deltas"). When one programmer makes a change they push it to the VCS, the next programmer then either accepts that delta into their code and merges the two together then pushed the new version, or they ignore and overlay the version in VCS with their version. The exact process of how that happens is dependent on the mechanism of the specific VCS.
With every change pushed to the VCS the code should compile and deploy to a test environment (either a local server/PC, or a remote server/PC) at which point it is tested. Any defects/bugs are reported back to the programming team to fix, then they push the fix to VCS and the process happens again until the software is ready to be deployed/delivered to the customer.
Source: Am a DevOps Engineer | 11 | 15 |
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[Dungeons and Dragons] How conscious are most people of the alignment system? | Like, would a paladin consciously think of themselves as being Lawful Good? Would an anarchist specify that people wanting to join their revolution must be Chaotic? | Unlike a lot of abstract mechanics, alignment is something that can be reliably measured by characters in the world using Detect [Law/Chaos/Good/Evil]. While there's no guarantee that your average peasant would have any knowledge of such things, anyone with some magical aptitude -- Paladins, clerics, any arcane caster -- would at least be vaguely aware of the alignment grid as a concept. | 26 | 19 |
ELI5: What exactly is alcohol, and why does it kill basically everything? | 'Alcohol' describes a group of chemical compounds that are created by yeasts when they break down natural sugars in grains or fruits during a process known as 'fermentation'.
There are different types of alcohol (eg ethanol, methanol and propanol) but what they all have in common is a 'hydroxyl' group, which is a chemical structure that is very effective at bonding to other molecules. This tends to dissolve the molecules that it bonds to.
That's how alcohol kills microbes - by dissolving their protective membranes and then reacting with the stuff inside. | 7,697 | 7,243 |
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When a photon is red-shifted, (how) does it lose energy? | momentum, and therefore energy change based on frame of reference. a baseball thrown at 100 miles an hour has a decent amount of energy relative to a "static" observer, but if you were to drive by the pitcher in a car at 100 miles an hour, the ball would essentially be still in your frame of reference and have no kinetic energy. similarly, if you were to accelerate towards a redshifted lightsource in a rocket ship, you'd eventually reach a point where the light is no longer redshifted, since you and the light source are still relative to each other. | 26 | 49 |
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ELI5: What exactly happens when a music producer "masters" a song/album? | When most people hear the term 'mastering', they are think of the mixing process, aka balancing volumes and adding effects, etc. Mastering is actually a specialized subset of mixing that is a form of audio quality control or quality assurance. Only a relative handful of people and studios are capable of mastering, compared to the thousands of mix studios out there. The goal of mastering is to get every track sounding as good as possible across multiple systems, meaning that the end product should sound great through your car, stereo, headphones and laptop speakers. Along with this, many artists' songs are recorded and mixed in multiple locations, and it's the mastering engineer's job to get them to sound like they all are polished to the same standard. Lastly, mastering produces the final CD or vinyl format for distribution and archives the tracks (often separated into clean lyrics versions, a capellas and instrumentals) for the publishing company. | 339 | 492 |
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ELI5: How come Type O- (O negative. . . ) can be given to most other blood types but it can only receive it's own blood type? | When we talk about blood type, we're really talking about the different proteins in your blood. The biggest ones are the A protein, the B protein, and the Rh factor. If your body doesn't have the protein and you're given blood with the protein in it, your immune system will attack it. Someone with O- blood has none of these proteins, so if they get blood from someone with any of the three (either A, B, or +), their immune system will go crazy.
Getting blood that doesn't have a protein that you naturally have is fine, which is why someone with O- blood can donate to anyone. | 28 | 41 |
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Has there been any attempt to create one of the elements thought to be in the island of stability? | Is it even possible to create such large nuclei? How does one go about to create one? | The principle behind creating heavy elements is bombarding particles together to supply sufficient neutrons/protons. The island of stability is centered around very heavy isotopes, which require far more neutrons than protons. There is not enough access to the stable, heavy isotopes needed for synthesis to even come close to the number of neutrons required. | 26 | 148 |
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