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hiwz7s
|
Biology
|
Why sometimes when I'm really full, I still feel hungry?
|
I can answer this one, the reason you feel pain right away is because it goes through very fast nerves, but hunger is not a nervous system reaction, it's a hormonal reaction, and hormones take more time to have their effect, they're "slow." that's why they advise you to wait 10 minutes after eating a meal and see if you're still hungry then.
| 4 |
gg0za4
|
Biology
|
Why does mens hairline start receding from the sides and not the middle? And why do women usually have staighter hairlines?
|
I know a bit of this since I read it a long ago somewhere, apparently it's because in our head we have lots of areas which need/are impacted by different hormones and nutrients, so for example when you see an increment in the male hormone (testosterone) the hairs in certain zones affected by that hormone start to shrink until they just... Can't grow anymore
| 1 |
6q6ftg
|
Other
|
How can companies give away free products and still make money?
|
Beyond hoping to attract customers and retain them by initially offering free products, companies can actually benefit financially (from an accounting perspective) by providing free products. This can happen in a few ways. 1. When a product or service is given for free, a company can reduce their tax liability. If a product costs $10 to produce and sell, but is given away for free, taxable income decreases. Let's say a company generated $100 in sales. If the cost of all the goods sold was $20, then $80 is subject to tax. But if they also gave away products that cost $50 to make, the revenue subject to tax decreases by the same amount. So the $100 in sales, minus $20 for the cost of generating that $100, minus the $50 cost of free products, reduces the taxable amount to $30 ($100-$20-$50). If they're tax rate is, say, 10%, they aren't losing the entire product cost...free to the consumer, but nominal savings to the company. 2. Goodwill. In accounting, goodwill is a type of intangible asset (one that cannot be seen or touched, like cash, property or equipment). In layman's terms, goodwill is value that exists in paper. Let's say a company has $1000 worth of equipment. They also have $9000 in intangible assets such as brand recognition, supplier relationships and patents. So total value is $10,000. If the company gives away free product and that helps to attract customers, that's also worth something. So let's say I decide to buy this company, and I pay $12,000 for it. They only have $10,000 worth of real assets, but I feel the free product giveaways are worth $2,000. I now own a company worth $12,000 on paper that in reality only has a "real" value of $10,000. I just generated a 20% increase in the company because I said so. 3. There can be a social component that can also add intrinsic value. Toms shoes is a prime example. For every pair of shoes purchased, another pair is given away for free to someone who needs shoes. Toms can charge more per pair because the customer is willing to pay more to know that they're helping someone in addition to getting a pair of shoes. Plus, donations of free goods, in the case of Toms, can be accounted for as charitable donations, which reduce tax liability. TL;DR - Something that's free for the customer doesn't equal an equivalent loss for the company.
| 22 |
bmuuep
|
Culture
|
why didn't Germany invade Switzerland?
|
There's a joke... a Swiss Bundesrat discusses with the german chancellor. Chancellor says if we invade we do it with 10 times the numbers you have. Bundesrat answers: good to know, so we hand out 10 bullets per soldier. Came to mind even though irrelevant.
| 16 |
5yeihr
|
Other
|
How do extremely mentally ill homeless people survive? I'm curious about how homeless people who are completely obviously unhinged survive day-to-day life. I mean the people that can't even speak or hold a conversation beyond yelling gibberish at random passerby. How does somebody seemingly incapable of even begging for change find food and water for themselves? I honestly have no idea since I have no experience with them beyond random encounters in the street.
|
I live in Winnipeg, one of the coldest major cities in the world; I am continually astounded that people survive the streets here. Most homeless people hit the relatively balmy West Coast for winter, but there are still those who stay, and deal with temperatures that can reach -50Celsius (-58Fahrenheit) on rare occasions, and frequently stay below -20C (-4F) for weeks. They mainly sleep in shelters, but some get banned for disruptive behaviour, and some cannot pay the minimal entry fee; the cardboard recycling dumpsters here have lids, and in the very worst pinch, they provide a relatively sheltered and insulated sleeping spot, if you can hazard the chance of getting accidentally dumped in a trash compactor truck. Sleep aside, no shelter provides day services, and so they must find ways to stay warm for at least half the day. In the downtown core, Winnipeg has built a series of insulated walkways between buildings, over streets and underground, to allow comfortable pedestrian movement. This helps business to stay alive in winter, but these walkways are also a way for the homeless to stay warm without being targeted for "loitering"; they can simply walk around in neutral spaces, where no store-owner can kick them out. All the same, there's only so many times you can do laps in the walkways before you need to find a place to sit, shit, eat, panhandle, or busk, and I can't say what they manage to do then. For many years, Winnipeggers have talked about our Frequent Flyers; a few homeless and mentally ill people, less than 20 of them, who rack up massive bills for the city by calling 911 and getting a free ambulance ride and checkup; 911 operators are bound by regulation to send an ambulance if the caller lists certain symptoms (which I will not disclose); they may be on first-name basis with the caller, and be fully aware of their ill intent, but if they didn't send paramedics, they'd lose their jobs. The Paramedics are similarly bound; if the "patient" lists certain symptoms, they must assume good faith and bring the patient to the appropriate hospital that specializes in the symptoms described; basically, this means that a free phone call can be used as a way to get social contact (fucked up as it is, they are often genuinely desperate for any kind of interaction), warmth, and a free ride to a few locations in Winnipeg. It's infuriating and ingenious at the same time; they cost us huge amounts of money, I've heard estimates in the hundreds of thousands all told, and it would be so much more affordable if we made some other sort of provision for them, like maybe bought them each a bus pass. Chances are, they'd lose or sell it though.... it is a pickle. Sorry if this was a little off-topic, I got carried away. Hope it's interesting!
| 17 |
chkaep
|
Biology
|
how does helium change your voice? Also does it effect everyone the same? i heard this little girl at the supermarket that sounded like she was already on helium. if she breathed some would she get squeaky-er or does it cap off? B
|
When you speak normally your vocal cords vibrate at a certain speed or frequency this is usually the same when you are breathing air. Helium is a much lighter gas than air, which is why balloons filled with it float so well. When it passes over your vocal cords they vibrate faster which makes the voice sound squeaky because of the frequency of the movement of the vocal cords. Yes it will make a little girl or boy sound squeakier but as children's voices are naturally more high pitched, the effect will be less pronounced so you might not notice it as much. *Putting my fun police hat on now; it can be very dangerous to breathe in helium and other gases, so whilst funny it's not recommended, particularly for children, as they might suffocate and no one wants that.* Edit: Autoincorrect Edit 2: Safety
| 1 |
86tu22
|
Technology
|
how this is possible: "Your PIN will be texted to you...for security the message will be automatically deleted two days later" Received my new bank card and with it the instructions to get my PIN for it. > After a short while your PIN will be texted to you. For security reasons the text message with your PIN will be automatically deleted two days later. How is this possible? **edit:** the text itself - a perfectly standard, normal text: > "Your PIN number is *xxxx*. Please memorise or change it before deleting it. This text will be automatically deleted in 2 days time.
|
There is a set of functions in your phone called the SIM application toolkit. It allows for a text message to trigger various things as well as being automatically deleted. Below is a link to the wiki article on the toolkit. URL_0 You can access the toolkit via an API I Android or iOS
| 3 |
igrrbv
|
Other
|
How can they make some fruits seedless, but not every fruit such as cantaloupes or cheeries?
|
Some plants can prevent seeds just by restricting pollen from interacting with the fruit/flower, marijuana for example. . . Others have more complicated methods
| 1 |
67yzov
|
Biology
|
Fast little water jet is expeled from under my tongue? Why sometimes I pull back my tongue a fast little water jet is expeled from under my tongue? Is there a saliva channel? which is its name and where it comes from?
|
Yes there is. The gland is called the submandibular gland and you can most often see the ducts as [two small openings on both sides beneath your tongue]( URL_0 ). You have more salivary glands, the parotid gland and the sublingual gland. The parotid gland is located on [both side of your head (just in front of your ears)]( URL_1 ) and the ducts are located in your cheeks, across the second upper tooth from the back (can sometimes be seen as salivary flow when you press at the location of the parotid gland). The sublingual gland is just under your tongue and have several tiny ducts.
| 3 |
idpwal
|
Other
|
Why do you get that sudden body chill when you listen to good music?
|
A 2019 study further established the relationship between dopamine and enjoying music. Listening to music that gives you pleasure releases dopamine into your system to increase your happiness. URL_0
| 2 |
8wm2bz
|
Biology
|
Why do you get tired after you eat?
|
To the best of my knowledge, due to evolution. Now it's easy to eat when you're hungry, but that wasn't always the case. You had to hunt down your food and you were never sure when your next meal was coming. Thus, your body enters a conservation stage after eating. As the food starts to break down, your back into a state of looking for your next meal. I'm sure there will be others that come in with a much better explanation though.
| 5 |
l7ckr5
|
Economics
|
Stock Market Megathread There's a lot going on in the stock market this week and both ELI5 and Reddit in general are inundated with questions about it. This is an opportunity to ask for explanations for concepts related to the stock market. All other questions related to the stock market will be removed and users directed here. How does buying and selling stocks work? What is short selling? What is a short squeeze? What is stock manipulation? [What is a hedge fund?]( URL_0 ) What other questions about the stock market do you have? In this thread, top-level comments (direct replies to this topic) are allowed to be questions related to these topics as well as explanations. Remember to follow all other rules, and discussions unrelated to these topics will be removed. **Please refrain as much as possible from speculating on recent and current events.** By all means, talk about what has happened, but this is not the place to talk about what will happen next, speculate about whether stocks will rise or fall, whether someone broke any particular law, and what the legal ramifications will be. Explanations should be restricted to an objective look at the mechanics behind the stock market. EDIT: It should go without saying (but we'll say it anyway) that any trading you do in stocks is at your own risk. **ELI5 is not the appropriate place to ask for or provide advice on stock buy, selling, or trading.**
|
What will exactly happen to the hedge funds? Those billionos of dollars they're losing, do they go back to the investor?
| 489 |
c9s14u
|
Other
|
What are the criteria by which scientists decide whether a seismic event is a new earthquake or an aftershock?
|
Hey /u/gsnow! I just relayed that one amazing post of yours to another grieving friend. I've been doing this ever since you first posted it. So, I decided to see if you were still posting and how you were doing. I'm happy to see that you just posted this. I feel like I can safely say /u/TheEarthquakeGuy can probably answer your question. Thanks again for the years of comfort you've given me and my friends with that one comment. I hope you're doing well!
| 1 |
dicxi7
|
Culture
|
Why does multiculturism work in canada, but fails in europe?
|
Go to a big city in Europe. You'll see all sorts of people from all sorts of backgrounds. Everyone's getting along fine. White right wingers are just terrified little bitches. Once they grow up and get out of the house they'll realize people all just want the same thing.
| 2 |
6122cs
|
Other
|
Why is it that we can remember some childhood memories so vividly, and others not at all?
|
From a psychological perspective we are more likely to remember memories that are associated with high emotion- usually negative emotion. So if you think of your earliest childhood memory it is usually a negative memory like being violently sick or getting in trouble.
| 3 |
c6vmm3
|
Technology
|
How are ratings measured? Is there some sort of signal sent to the network after I tune in to watch?
|
They don't *know*, exactly. Ratings are an extrapolated statistic based on some fraction of the population who has volunteered to have their TV fitted with a device which does indeed send such a signal. If 7% of the people that have devices like that are watching something it's estimated that 7% (plus, minus, and/or multiplied by a *bunch* of statistical corrections to adjust for the age groups and viewing habits of people that decide to get a ratings box installed) of the overall population is watching, so about 20 million. Note: this is for traditional broadcast television, for online streaming each viewer does send back a signal.
| 1 |
ne13im
|
Biology
|
Why are there many plants that can be grown in a greenhouse, but some, like ramps and truffles, that can only be grown in nature with conditions that can’t be mimicked in a greenhouse?
|
Truffles can be cultivated, and regularly are. The catches are: * They're very picky about the environment they're growing in which includes the soil, trees, etc. and that's a lot of factors to cover. You can't just build a greenhouse or just plant them wherever you are. Some places just won't work. * They take several years to develop, so you need to go through a ton of work and money to get set up and then you might find out 10 years later that they didn't grow after all. Womp womp.
| 5 |
brhj5t
|
Biology
|
Why are mentally intensive tasks sometimes more tiring than physical ones?
|
Because adjusting neural pathways takes huge amounts of energy; your brain takes a lot of energy to keep running at an optimal level.
| 9 |
k2iewn
|
Earth Science
|
What is 'high-pressure' and 'low-pressure' in weather and how do they form? I'm having trouble wrapping my head around something I feel should be so simple, but I'm lost when I look up the weather and see low-pressure cells and high-pressure cells and how some bring rain and others don't, while some are hot and others cold.
|
Not a meteorologist but my understanding is that there are currents of airflow the go around the world. Mostly caused by heating and cooling of the atmosphere from the sun. As these pockets of air move around the run into each other and move away from each other. This causes high low pressure areas.. because water vapor is heavier than air itself it tends to collect in low pressure zones. As more water vapor collects it starts to form clouds and eventually rain..
| 1 |
5tairy
|
Physics
|
What would it theoretically take to create artificial gravity?
|
Artificial gravity can be created by either acceleration or mass. Mass is difficult to manage with a spaceship (you need to move around a moon or something) but you can easily get acceleration just by spinning something around in a circle. Stand on the inside of the spinning object and you have an apparent acceleration downward as you try to be thrown away and are stopped by the floor. This can feel weird if the circle is too small and the speed of your feet and head is too different, but a reasonably sized spinning ring or tube would provide usable "gravity" while not consuming much energy. You probably don't want to throw projectiles without practice though as they will behave oddly.
| 2 |
acim2d
|
Engineering
|
Why do zippo lighters stay lit? Normal lighters go out after you stop pressing the release button.
|
A "normal" lighter is full of compressed butane. When you hold down the button, it lets a stream of flammable gas out of the lighter & that burns. A Zippo is more like a candle or oil lamp. There's a wick soaked in flammable fuel that will burn as long as there's fuel & oxygen to make it work.
| 2 |
l0coo2
|
Biology
|
How do eucalyptus/mint scents clear up a stuffy nose?
|
Aussie bush on the summer rain is my all time favourite smell as an Aussie. I love the smell after a sun shower that comes from the earth mixed with the big gums and iron barks. It's amazing.
| 6 |
l52uv9
|
Biology
|
Why when you cut an onion you cry? When my mom cut onion and I go near him and I suddenly cry..I want explanations about this
|
Onions have chemicals in them that irritate your eyes. When your eyes are irritated, they produce extra tears to wash whatever is irritating them out. It's the same principle as something like pepper spray, although much less intense.
| 3 |
clr8c7
|
Biology
|
What causes natural death?
|
It means that the cause of death was internal rather than externally. So it's a very broad meaning to be honest. Sickness is technically natural death. So sickness and organ failure is natural even cancer. And something like being hit by a car would be unnatural death
| 4 |
8pusfc
|
Repost
|
In real life we can create a green paint from the combination of blue and yellow paints. Then why is it different in the electronic world where green is considered the primary colour, and yellow is the combination of blue and green?
|
it’s called additiv and subtractive colors.. if you mix all physical colors you get some kind of black. If you mix all colors from light it’s white
| 6 |
af4szi
|
Biology
|
If it takes the body 24 hours-ish to digest food, why do you have to use bathroom so soon after eating things like Mexican food?
|
After we eat, the stomach and intestines dilate and expands, which trigger this reflex called the gastrocolic reflex - where basically ur intestines increase bowel movement to empty any food you had before to make space for the food you just ate. Furthermore, certain food like spicy food increase gastric emptying, which increases bowel movements even further :)
| 10 |
6r6xqt
|
Culture
|
Why does every show with two people in the title end with the person with a Y in their name? that question may sound really confusing but let me give an example. Max & Ruby Rick & Morty Zack & Cody. I've always wondered why shows always have the person with the Y at the end. ((I meant shows who have a person with the letter Y) i know shows exist that don't have people with the letter Y.))
|
Meter. We tend to find regular meters more pleasing and/or memorable. One well-known poetic verse meter is called "trochaic." A single "foot" of trochaic meter is a stressed syllable followed by an unstressed one. (Think of the words "FA-ther" and "MO-ther"; one of those would serve as a trochaic foot, for example.) Well, a one-syllable name followed by "and" is going to read as stressed-unstressed, and two-syllable names scan the same way. (Also, two-syllable names ending in "y" are really common.) So it's an easy way to establish a memorable and pleasing pattern to the name: MAX and RU-by RICK and MOR-ty ZACK and CO-dy EDIT: Formatting EDIT 2: I *really* want to go in depth here with some of the other comments here, because a lot of the counter examples demonstrate either a similar or different type of metrical pattern, but I don't have time to right now. Sorry.
| 5 |
8j6pba
|
Other
|
Why is tickling essentially torture? You would think something that doesn't "hurt" and makes us laugh would be a good thing.
|
Zones which are most ticklish (armpit, bottom of feet, waist, neck) are also the areas most susceptible to predator attacks. Tickling probably evolved to train children through play. Grandad torturing kids through tickling is torture, but it’s also training them to survive animal attacks. Not 100% sure, but there was an article while back arguing that the context of the stimulus determines whether we experience tickling or not. So Grandad attack will be fairly similar to predator attack, as both are trying to attack the vulnerable (ticklish) areas.
| 5 |
dofc3i
|
Chemistry
|
Why do some chemicals drastically change their properties when forming a molecule?
|
This depends on the properties in question, but for sodium and chlorine it is because they behave as near-opposites. Chlorine really wants to take your electrons, so it is dangerous. Sodium really wants you to take its electrons, so it is dangerous. When mixed, you get a rather mundane salt, since each atom satisfies the other's needs.
| 1 |
8sbxi4
|
Physics
|
How come on an airplane, I'm able to look down the aisle towards the front of the airplane with all windows closed and I'm able to determine whether the plane is pitched up or down? Noticed this on my last flight. Without any reference point (aka the ground), I'm able to determine correctly whether the plane is pitched up or down. It just *looks* like it's pitching up/down without any need for a reference point (like the horizon or similar).
|
You can't, really. What you can sense is the direction of acceleration, the amount of acceleration, and changes in acceleration. However our senses are not optimized for this. Without instruments or outside reference it's very easy to get acceleration confused with pitch up, or deceleration confused with pitch down. Add in a little roll and you get a [Graveyard Spiral]( URL_0 ). Basically, you're feeling the extra throttle the pilot added to keep airspeed up on the climb, or the reduced throttle to keep airspeed down on descent.
| 4 |
7ux221
|
Chemistry
|
Why does glue harden so quickly out of the bottle relative to inside?
|
it is subject to some air... but very little, with minimal surface to contact that air. Most glues work by either evaporating a liquid carrier like water or some sort of solvent (or reacting with air/water in the air, so that liquid quickly reaches equilibrium with the humidity content of the air in the bottle.
| 2 |
jfjof9
|
Physics
|
What force is creating new spacetime (and at an accelerating pace)? I recently learned that the expansion of the universe means that everything is moving further away from everything else as new spacetime is fabricated between objects (rather than the universe's edges expanding). What I can't find, is the process by which this expansion is happening. If the vacuum of space is considered spacetime, then spacetime can be devoid of all energy. So how does it get made if energy cannot be lost in its creation?
|
Dark energy is what causes the expansion. We aren't completely sure what dark energy is. It could be a result of how gravity works or it could be its own new force. Either way from what we can tell is empty space contains dark energy at a constant energy density. This means as new space is created so is new dark energy. This new space and dark energy also contribute to the expansion giving a run away effect that we see today.
| 1 |
ddz92f
|
Technology
|
How are computer languages created?
|
Computer languages are really just a system of rules. You can create a computer language in your mind right now if you want to. Just create some rules for creating variables, making loops and functions, conditionals, classes etc.. Of course to make the language practical, you need to write a program that can transform a text file which contains text that conforms to the rules you created into machine code that will be understood by the computer. Thats what we call the compiler or interpreter. If you ask how do you create a compiler, then the answer is its just a program like any other program. You create it with another existing language like python or c++ or whatever is your favorite. If you ask how was the first compiler created, then the answer is it was written in machine code. machine code doesnt need compilers because computers already understand it. They understand it because their circuitry is hard wired to understand it.
| 2 |
bqe3ge
|
Biology
|
How is it that our brain can perform complex calculations sub consciously for an action, such as calculating the angle and force of a perfect long throw, but struggles to calculate the actual numbers in our head?
|
It doesn’t. A computer scientist might describe it like this: The human brain almost invariably uses heuristics for almost everything. Heuristics are basically computational shortcuts which get very close to the right answer without much arithmetic. Heuristics suffer from a tradeoff between highly accurate performance in specific contexts, and good performance across a large range of contexts. In humans, we may have different sets of heuristics to get the best of both, that is, you don’t even have to think about not tripping over on a flat surface, but you don’t apply the same approach to a rough and difficult surface, where trying to walk as if it was flat would probably cause you to break an ankle. These heuristic methods have gotten very powerful for specific things, but the limits of that tradeoff still apply. A baseball pitcher can throw a nearly perfectly consistent 90mph fastball but struggle to make free throws — both are generally actions of throwing right? well yes, but the baseball player will have developed a very specific heuristic which only handles the context of baseball, including every detail of it from the topography of the pitchers mound, and the handedness of the batter etc. That same heuristic doesn’t work at all in the context of basketball free throws. In the same way, arithmetic is one of those things for which that tradeoff is the most true. Many school children are able to accurately and quickly answer basic multiplication questions like 6\*7, but that won’t generalise. Knowing how to solve 6\*7 won’t ever tell you how to solve 373958372\*3882638420. But then knowing how to solve that won’t tell you how to solve an integral. Through evolution, the human brain has developed an incredible capacity to develop new heuristics which can solve a particular problem with a very high accuracy, every time, but that heuristic is actually much more narrow than most people think. All of the basic stuff you expect to happen in physics doesn’t happen in a vacuum, when you get to completely alien scenarios, we’d be completely stuck (hence why quantum mechanics has been consistently quite impossible to understand. The only consistent way that even the best physicists had is mathematics, we couldn’t form ideas about how we’d expect “particles” or “waves” to behave at a quantum level, because even that simple delineation breaks down)
| 17 |
795hvd
|
Technology
|
Fingerprint scanner (Touch ID) hashing Specifically, explain it like I completely understand hashing. I understand that when you change the input to a hash function a tiny amount the entire output changes. This is what I don't get: if a hash of the fingerprint is stored then doesn't a tiny variation on the positioning, lighting etc of the scan completely change the output which is then compared with the stored version, thus marking it as incorrect???
|
Your fingerprints contain a lot of little details that make them unique, that's how we're able to consistently identify different people using them. These details are called minutiae. When the scanner picks up your print, it identifies the various minutiae and can use those to create a consistent hash. Most computer fingerprint systems will do this by comparing the presented fingerprint against a database of fingerprints, but in order to maintain security, a biometric security system shouldn't do that, instead a minutiae point called the pattern, the overall shape of the fingerprint, can be used to indentify the center and rough orientation of the print, from there the computer can then check the other minutiae points relative to that center to calculate the hash and ask the computer to compare the two.
| 2 |
79nwze
|
Other
|
what is the difference between treason and conspiracy against the united states?
|
Conspiracy against the United States is committing a crime as part of a group that would otherwise be named something, if you were acting solo. So if you commit tax fraud solo, you can be tried and convicted of tax fraud. If you do it with someone else, you can also be charged with conspiracy against the US. Treason is a much more specific crime. It requires actually making war against the US, or joining and giving aid to those making war on the US.
| 1 |
8ixeo2
|
Other
|
If church attendence is declining so fast why are there still churches everywhere? I was thinking about this recently. We keep hearing about how church attendence plummets in the US. Based on that you'd expect churches to be closing, after all look at all the retail stores closing in face of onlime competition that probably didn't have as sharp of a drop in sales. But even in my hyper liberal neighborhood churches are still more prevelant than fast food restaurants and a single one closing is often a local news story. How are they holding up when their "consumer" base is so much smaller than decades ago?
|
Most churches own their buildings outright. Most retail stores pay rent. When you own a building that was paid for by previous congregations, cost to operate it are largely independent of attendance. When you rent retail space, the rent doesn't go down because you have fewer customers, so you fold and a new store takes over.
| 5 |
hoe2xg
|
Biology
|
Why is water so highly recommended for burns? Even very minor burns?
|
When you cook a delicious steak the grill and take it off when you're finished, even though it no longer on the flames, it remains hot. You are a delicious steak. Once the original heat source that burned you in the first place is removed, that heat is still there in your flesh. Cool water (never use cold water in a burn) will help carry that heat away and stopping the damage.
| 1 |
7830od
|
Chemistry
|
Why is it so hard to duplicate the taste or resteraunt food?
|
Not sure, but I know 2 things that might actually impact the dishes: 1 - restaurants often use *way* more fats/sugars than you'd use at home. 2 - the ingredients aren't necessarily the same/the same quality Restaurant suppliers tend to have better quality ingredients for some dairy (e.g., thicker cream), meats, and produce than what we get in the grocery stores. (Although, yes, a lot of the packaged products are the same brands - just a lot cheaper and in bigger volumes). But even if the ingredients **are** exactly the same, the food you cook at home may not taste as good simply because of your perception. When you cook at home, you have to do all the work, and you're serving the food yourself on your own everyday dishes... doesn't have quite the same experience to it as eating in a restaurant, and that can mess with your perception.
| 2 |
nx0kky
|
Technology
|
why does it take "up to 10 days" to be removed from an email list if it is all electronic? You'd think it be instant
|
It may not be all electronic. We keep our list manually. Both subscribe and unsubscribe requests are handled by a live human being who somehow needs to sleep, eat, take vacation etc. it is a small list and there are few requests (five a week maybe) so there is little value in automation. The manual system is also a nice way to ensure more “enthusiastic” colleagues don’t have easy access to the list.
| 3 |
lxf7v1
|
Technology
|
In a world full of VPNs, how do governments and corporations point a finger at a certain country for hacking their infrastructure?
|
Some methods of identifying the origin of the attackers could include looking at the code of the malware; what languages are used? Although this has been used by attackers in the past to pose as another nation (the creator of the Mirai botnet wrote "i love chicken nuggets" in russian as a comment in the code, and the americans were looking at russian sources for a few months. the creator was american). Other methods include looking at the TTPs (tactics, techniques, and procedures) used during an attack. For example, if a certain APT (advanced persistent threat) group was observed using a specific technique in terms of reconnaissance, followed by another specific technique to gain initial access, then we can build activity patterns. If we see similar activity being conducted towards similar targets (let's say, all the targets are in the finance industry within the same country) then it is widely believed that it is safe to assume this was the same group. Personally I don't much agree with this last one, as it is easy to copy techniques and attack vectors. I asked this exact same question to a superior of mine in the cyber industry who has worked for NSA and he told me that in most cases, secret government agencies have wiretaps, moles, and compromised / insider sources that give them reliable info on who the source of the attacks is. This is why you'll never see a detailed article explaining how they know that a certain country has allegedly attacked another. My follow up question was "then how do we, as civilians, know for a fact that this country really has attacked this other country, without just blindly accepting what we are told?". His answer, "you don't".
| 2 |
670sb9
|
Technology
|
Why are Scuba Suits mainly black? I know that some fish tend to have their underbellies white and the tops dark (some rays), is there some relation of this with scuba suits? Or to do with absorbing heat, being seen, etc. Thanks!
|
The purpose of a wetsuit is to keep you warm. They do this by trapping water between the suit and your skin. Black is the best color to absorb sunlight - and heat the suit up. There may be some other reasons but I believe this is the main one..
| 2 |
havu5d
|
Psychology
|
Why can our brains see words that are spelled correctly, but we think they are spelled wrong?
|
It’s called jamais vu. It can happen as a result of mental illness or intoxication, but it also happens when you repeat or look at a word often. It’s unclear why it happens, but it probably has to do with your brain ceasing to recognize the *word* and only recognizing the shape or sound of the word.
| 2 |
gzuovq
|
Chemistry
|
Why do some alcohols have a high calorie content While others have zero calories. Are calories removed in the distillation process?
|
there is absolutely no such thing as a zero calorie alcoholic beverage. Alcohol gets treated more or less like a carbohydrate by the body. It has calories. I'm curious as to whatever gave you the idea that there was such a thing? is some manufacturer out there lying and claiming to have such?
| 2 |
csdj6l
|
Technology
|
What are the differences between different types of picture formats (jpg, png, gif, etc)? Are some better than others?
|
JPEG is a lossy-compression image format. What this means is that when the image is compressed, some of its details are discarded in order to make it take up less space. JPEG is designed to work on more natural pictures, mainly photographs, where close pixels tend to have similar colors, and compression artifacts are less noticeable. GIF uses non-lossy compression. The main "feature" of GIF files is the limited palette - instead of supporting the full 2^24 colors, GIF uses only up to 256 different colors at a time. This allows each pixel to take up less space (only 1 byte instead of 3, before compression). GIF is mainly useful for images with a small number of colors, such as charts or icons. GIF is not recommended for photographs. GIF has two additional features: layers, which allow you to have more than 256 colors by layering two or more images with two different palettes (where the top layer has one "transparent" color, which lets you see the bottom layer), and animation, which simply lets you store a series of images inside the same file, which are played sequentially. This is mainly intended for use in simple short animation (like a blinking smiley face), not full on videos. The reason animated GIFs are commonly used in place of an actual video format is that until a few years ago, GIF was the only animated format that was supported on every possible platform. PNG is a modern file format, intended to replace GIF. It uses non-lossy compression and supports the full color palette instead of just 256 colors. It also supports transparency (unlike JPEG). PNG images take up more space than JPEG, but they preserve the original image quality since the compression is non lossy.
| 1 |
a7eb10
|
Biology
|
Why do animals taste differently?
|
They taste differently because they have different likes and dislikes, as well as different physiological aspects of their nervous systems. A rat might find a eucalyptus leaf to be bitter, but a koala bear would find it sweet and enjoyable.
| 3 |
6bezrp
|
Biology
|
Does genetic engineering work on living animals? For example, it works on newborn babies but does it work on an adult living human? Another eg: I want my kids to glow in the dark(which is possible), but can that also work on me or do I have to be in my mother's womb to have my genes manipulated?
|
It's possible and it's been done, though it's usually called "gene therapy" in this case. The best example that comes to mind is a study where colorblind monkeys were provided with a gene allowing them to see color properly. Because you have to add a gene to lots of cells rather than just one that divides, the genes usually have to be added via a virus that infects the cell and splices in the gene.
| 2 |
bz25wa
|
Physics
|
How do we accurately measure temperatures near absolute zero?
|
There are a few different ways of measuring temperature close to absolute zero, but here I will just explain one of them. & #x200B; We can start by reminding ourselves that temperature is really just a measure of how much energy something has. So a hotter atom will have more energy and move faster than a colder one. One common way to measure temperatures close to absolute zero is by measuring the kinetic energy of the atoms at that temperature. Usually when performing experiments at very low temperatures (just a few milli-Kelvin), the experiment traps the atoms with some type of field (usually magnetic) and forms a condensate, or cloud. So you can imagine that as each atom in that cloud is cooling down, the cloud becomes more and more dense because each particle does not have enough energy to escape. Then the experimentalist can turn off the trap and the atoms/particles will fly away and the cloud will expand ballistically. The cloud size increases with time, and this increase is a direct observation of the velocity of the atoms and therefore their temperature (there is some fancy math that tells us that the temperature is proportional to the square of the size of the clouds shadow if we continue this analogy). & #x200B; The technical term for all of this is the Bose-Einstein condensate. Here is a more indepth review of this topic using the same analogy: [ URL_0 ]( URL_0 )
| 4 |
j9plke
|
Biology
|
How come certain plants are able to survive when you put them in just water but the same plant dies when you put it in soil and over water it?
|
Sometimes it's not the water that kills over watered plants, it's the mold that overly wet soil allows to grow
| 5 |
a8foqg
|
Other
|
What is the difference between an architect and an architectural enginner? Is there even any difference?
|
An architect says “Wouldn’t it be cool if my building looked like *THIS*?” And the engineer says, “Yeah, here’s how to make it not fall over.”
| 1 |
mjrna3
|
Physics
|
if atoms never touch that means we never touched anything basically, so how do feel the texture of something?
|
With the same poles facing each other, try to get two magnets to touch. They will repeal each other. So even without touching, you can "feel" the other magnet by the way it repeals. Same kind of thing happens when you "touch" anything. You are feeling the repulsively forces.
| 3 |
ac6fd9
|
Physics
|
How can the same side of the moon always face earth? Doesn't it rotate? The fact that the Chinese just landed on the dark side makes it seem stranger.
|
Let's assume the moon was rotating at a different speed than it is now (e.g. faster). Then the force exerted on the portion of the sphere closest to the earth would have the strongest attraction. This effectively acts as a "glue" where the portion closest to the earth continually gets pulled the most and thus slows down the rotation. Eventually the rotation will slow to a stop and the objects will be tidally locked.
| 115 |
k5zm7k
|
Technology
|
How can the Task Manager in Windows or Force Quit in macOS close frozen, suspended, unresponding programs instantly. What do they do different than clicking the X button in the corner?
|
They forcibly stop allocating system resources to the program, instead of politely asking the program to relinquish those resources once it’s finished. It’s the difference between asking a drunk patron to leave the bar vs grabbing him by the collar and tossing him out the door.
| 4 |
67l0pk
|
Biology
|
Why does our body produce lactic acid when we exercise?
|
Not enough oxygen to go around. Normally, any of our cells with mitochondria (which is most of them) would prefer to undergo aerobic respiration. It's very efficient, allowing you to get a buttload of ATP (an energy carrier) out of each molecule of glucose. The thing is, you need oxygen to do it. At rest, that's fine. During intense exercise, however, cells are undergoing aerobic respiration at a breakneak pace. They're using oxygen as fast as it's being supplied, and still need to make more energy. So, they start undergoing fermentation, which is way less efficient than respiration, but doesn't require oxygen. Breaking down glucose without oxygen can make a couple of things, and the one our body makes is lactic acid. Lactobacillus, one of the bacteria in yogurt, does the same thing with lactose in milk, making yogurt pleasantly sour with the acid. Yeasts, on the other hand, use the same process to make different products from simple sugars: Ethanol and carbon dioxide. Thus, beer.
| 1 |
82dpua
|
Biology
|
How does exercise actually reduce the risk of diabetes? And how does too much sugar in a diet cause a person with no diabetes to get the disease?
|
Type two diabetes is effectively caused by having a higher than normal blood glucose level for a prolonged period of time. When you eat, most carbohydrates are transformed into glucose and absorbed into the bloodstream. Simple sugars are digested and absorbed into the blood very quickly, causing large spikes in blood sugar. Insulin is released by the body to control blood glucose levels, and to enable cells to absorb and use glucose. Higher than normal glucose levels needs more insulin to control it. This ends up causing insulin ineffectiveness/resistance, which means tat your insulin is less able to control blood glucose levels. In response, the pancreas creates and releases higher and higher levels of insulin. This effectively makes the cells that produce glucose run out. Simple sugar is one if the things that causes this. Exersize does two beneficial things. Firstly, it reduces your blood glucose. It helps you control it without relying on insulin. This reduces the strain on your insulin and can prevent insulin resistance and diabetes. Secondly, exersize makes your insulin more effective. Combined, this reduces the chances of getting diabetes.
| 1 |
chkvej
|
Biology
|
What keeps oceans and seas from spreading viruses and many other contagious illnesses?
|
[Red Tides]( URL_0 ) is what popped into my head first. I witnessed one last year in Florida. Dead fish, jelly fish, and even huge turtles were washed up on the beach. Very sad. We had to call some people about a four foot turtle that had washed up near our condo and some guys in a golf cart came to assess and let the heavy lifting guys know where it was. We were advised to not get in the water. Another vacationer in our rental unit ended up pretty sick because he thought the warning was a joke and decided to dunk his head under the water. To sorta answer your question, red tides are usually naturally occurring and can’t be prevented or fixed. If there is any warning about ocean water please listen to it and take precautions.
| 6 |
esp804
|
Other
|
Does ketosis burn through fat at a faster rate once your in a calorie deficit with it, than your metabolism would normally burn through fat once your in a calorie deficit without keto?
|
Like 90% of the stuff people say about ketosis is nonsense mystic bunk. It's a diet that works to some degree because it's easy to eat a lot of carbs mindlessly compared to fat or protein (eating 700 calories of bread is something you can do without noticing, eating 700 calories of steak is a like a "this steak is too big" amount of steak.) but most of the claims people have about it are just fantasy nonsense.
| 3 |
74bsez
|
Biology
|
Why is it that we put ice on some injuries (e.g. black eyes) but want heat on others (e.g. sprains)?
|
Yeah for sprains you're still going to want to use ice. For muscle strains heat can be used, but mostly you can't go wrong using ice on an injury.
| 2 |
i9mxwn
|
Other
|
why do the moving parts of cartoons have a slightly different color? Like if a car for is about to open, it will be a slightly different shade of color until it opens. Then when it's closed/done moving independently, its color matches the rest of the car.
|
This was super apparent in the old Scooby Doo cartoons. Secret door? Not very secret since it was obviously a different color.
| 7 |
evxd1h
|
Technology
|
When you delete files permanently off your hard drive, where do they go and how does it work?
|
You can compare data storage too if you store a number with normal 6 sided dice. Take 6 dice and put them so they show 654321. If you erase data from a hard drive it would be like if you turn all dice with 1 up. Where did the number you hade go? The answer if philosophical and it the same as where do deleted file go. Data storage use binary so you store data with only two option 1 and 0. Erase in the data would be setting them to zero This is if you erase the data from the storage device. In practice that is not what is done except by special programs because it is a slow process. Think of a storage device as a large shelf with numbered drawers with dices you can flip. You use one drawer as an index and store that file X is store in drawer 569. When you delete a file you just change the index remove file X from it and store that drawer 569 is no longer in use. The content of drawer 569 is not changed. When you later store more data you might reuse drawer 569 and flip the dices to store new data. Between the point, you removed it from the index and when you reused it the data was still on the drive and can be recovered.
| 3 |
mk62gn
|
Engineering
|
why some racing tyres are slicks and working better than thoses with grooves but road car tyres works the opposite way??
|
Because race tracks are clean dry asphalt. The grooves in tires allow water to pass through a bit allowing the parts that stick out to make good contact with the road when it rains. Slick tires in the rain wind up hydroplaning almost instantly making them very dangerous. When cars are raced in the rain they swap out for grooved tires.
| 3 |
a9s3qe
|
Physics
|
Are two atoms across universe pulling each other? the gravity force can be 0.0000-Ten million miles 0s-00001 g Or the gravity force will be really 0?
|
> the gravity force can be 0.0000-Ten million miles 0s-00001 g Using High School level physics, I don't get ten million miles of 0s. I get 95 zeros. 0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000237 N Gravity Force = G m_1 m_2 / r^2 G = 6.67 m_1 = m_2 = mass of hydrogen atom = 1.66e-27 kg r = diameter of [observable universe]( URL_0 ) = 8.8e+26 m that gives you a force of 2.37e-96 Newtons. Whenever I get an answer that small, I start to wonder if there is anything neglected. Almost any other effect is going to swamp out this attraction.
| 4 |
bh7kl8
|
Technology
|
How can we measure blood oxygen saturation noninvasively but not blood glucose?
|
Blood oxygen saturation is very easy to measure. You're looking at two *very* specific wavelengths of light, which corresponds to the wavelength at which the haemoglobin molecule absorbs light either with or without a bonded oxygen. Compare the two and calculate. Since glucose contains a whole bunch of bonds (C-O, O-H, C-H) which are everywhere in your body, specifically identifying glucose by its absorption doesn't work.
| 1 |
5ys2t8
|
Other
|
What would happen if someone guilty admitted their crime after being found innocent?
|
Depending on any testimony they gave in court they could be charged with perjury. But in all likelihood they still get to walk.
| 10 |
c2c7l0
|
Biology
|
- Why do bugs squirm when they are being hurt, but don’t limp when a leg is cut off? Do they feel pain? Or do they just have a protective reaction to harm that is being done to them?
|
You know I always wondered about bugs my self... & #x200B; Mainly because it is so odd to me that if I full hardheartedly open hand slapped the living shit out of another human beings head (this person being my exact height and weight)...I could at the very least stun them. But at the very most knock them out, fracture, rupture or break something and possibly cause them to fall over and then possibly damage something or even kill this person. The latter part of that being the extreme. But still 100% plausible. Right? & #x200B; Now if I whole hardheartedly slap the living shit out of one of these flying green beetles that always crash into me while I am on the porch smokin...(me being over 100 times it's height and weight)...it would just fly away like nothing like it never happened. & #x200B; Hit a baseball hard enough and you can knock the cover off of it. Hit a beetle hard enough and it's probably telling its friends over lunch how much you hit like a pussy. LOL
| 8 |
l368so
|
Economics
|
Why is increasing corporate tax and income tax NOT bad? The convincing argument I read against it says: Corporations and people pass the tax increase they face on as higher prices, which are even higher than the tax increase due to the sales tax consumers pay on the higher prices. And then because the wealthy spend less of their income than the poor, it impacts the poor more because they have nothing left to save. Can you explain why this is not the case? Or if it is the case, why tax increases are still good?
|
The argument for higher corporate taxes is that they are at an all time low. Since the 1970's corporate taxes have kept getting lower through changes in the tax code and the abuse of loop holes. With some mega corporations paying virtually nothing in taxes. This is turn puts a burden on Joe taxpayer because those same corporations like Walmart and Amazon rely on programs like food stamps to keep wages low, so they are effectively subsidized by the very government they don't pay for. The problem is that only a handful of people (the share holders) really benefit from this. Lower corporate taxes are sold to voters using theories like trickle down economics which states that when the wealthy get more money, it trickles down to the workers with raises, benefits, and job creation while in reality it's nonsense. The rich don't spend their wealth they hoard it, while the poorest folks spend any extra money they get just to survive which in turn does more for the economy. Trickle down economics should be called trickle up, because lower corporate taxes causes tax dollars taken from lower and middle class workers and hands it to corporations which use it to maintain profitability rather than helping their workers. The problem with higher corporate taxes is that it affects the bottom line, and since big companies care more about their shareholders than their workers they'll likely increase prices and cut costs to keep the profitability as high as possible. If the pandemic has proven anything it's that the economy is more heavily impacted by working class people being out of work than rich people spending money.
| 4 |
gee0dq
|
Economics
|
What is the difference between an MLM and a pyramid scheme? EDIT: Thank you for all the responses!
|
In an MLM scheme there is notionally a product that is being sold. But yeah, the only real way to make money is to sell in volume to those you recruit lower in the pyramid.
| 5 |
k3bpe1
|
Biology
|
Why do surgeries, especially transplants, take so long? I just saw a post about a doctor monitoring his patients vitals after a 23 hour long heart transplant surgery, with the nurses sleeping in the background. I understand that that may be one of the hardest things in the world to do, and requires an amount of focus I can't even imagine. But still, what takes **so** long in the operation room? Ninja edit: missspell
|
AST Certified and California credentialed Surgical Assistant here. Surgical procedures vary in length depending on how complicated the surgery is ( example - heart transplant 20+ hr VS a hip replacement 2-3 hr), the patients physical condition, and honestly the dr’s over all experience. In general anything having to do with the head, neck, or upper trunk is going to take significantly longer due to the fact there are so many vital organs packed into these parts of the human body. A wrong move in these areas can mean immediate and catastrophic results. The shortest procedures are usually the extremities. I’ve seen a foot amputated start to finish in about 20 min.
| 2 |
6jz1e5
|
Engineering
|
How come my car tells me when my oil is too low, but there's no gauge on my dashboard to indicate how much is in there all the time?
|
Unlike gas, your car isn't designed to burn through oil. Putting a gauge on the dashboard that *shouldn't ever move* is just adding cost & clutter to the instrument panel. You've already got an easy way to check your oil levels - the dipstick in your engine compartment. Check it every time you buy gas if you're worried about your oil levels.
| 2 |
m90qkz
|
Chemistry
|
Why are Diamonds the hardest rock but also easy to cut? So if Diamonds are a 10 on the Mohs scale of hardness which I understand they're super hard then why are they so easy to cut? After all shouldn't the hardest rocks be really hard to make jewelry and rings out of? How can you cleave or shear a diamond if it's so hard?
|
There's a difference between hardness and toughness. The harder the material, the less tough it is. Hardness is basically a measurement of how well something can scratch. If you rub a rock against a diamond, the rock will be shaved, though if you take the rock, and drop it on diamonds, the diamonds will shatter. As for cutting diamonds: The way the atoms are arranged make for weak points that you can use other diamonds, and high pressure water to cut.
| 2 |
aet32u
|
Biology
|
Why do certain wounds (like a cut on the lip) cause the injured area to puff up and become inflamed? I’ve been biting my lip like an absolute fool all night and now it’s gotten all swollen. I’ve never really questioned why that happens, so I guess this would be as good a place as any to ask. Thanks!
|
Not a doctor. shh When you have a cut on your skin, the body senses the problem and sends blood filled with special cells to help repair the region. This causes a large concentration on that part of the body and it keeps sending more blood until the cut is no longer detected which is why the swelling goes down when there is no longer any issue with that part of the body.
| 3 |
6300p3
|
Biology
|
how can muscles not seem to grow in size but can increasingly handle more and more weight?
|
Strength comes from how much energy the nervous system can produce (obviously the output being the muscle, which is how that energy is expressed). You don't need "big" muscles for your nervous system to produce a lot of energy
| 1 |
hw9aty
|
Other
|
Why did the plague doctors chose a scary bird mask? They could wear any type of mask but chose the scary bird mask, why?
|
At the time, they believed plagues were caused by bad smells, so they put a nose with lots of nice smelling things and they also made it hard for bad smells to come in. Though completely unintentional, it wound up acting similar to the face shields modern doctors wear. Combine with the gloves and wrapping, it was actually marginally effective PPE. That being said, [the real masks didn't look as cool as you're probably thinking.]( URL_0 ) The beaky masks you're probably thinking of date from hundreds of years later. They were made by people in Venice who wanted to make a mask that looked cool.
| 4 |
houssq
|
Economics
|
please: Why is a declining birth rate a source of panic for national governments?
|
It isn't an immediate problem. But once the population ages, the older folk start retiring or working fewer hours. Many of these rely on government programs to some degree. Those programs are typically funded by taxes from the work force. But with with low birth rate, it means you'll eventually start having a lower ratio of people in the workforce to the number of people retired and needing government assistance.
| 5 |
8cqug0
|
Technology
|
How does Powerline networking work? Like the Powerline Adapter Starter Kit from Amazon, it claims to gain network connectivity through your house's power grid. How does this work and/or is this possible?
|
Yep. I use a set to shoot my internet upstairs to a old WD wired-only live stream box. They work great in most cases with some caveats. The 120 volt AC stuff going through your house's power grid is a nice 60 Hz (or 50Hz if you're outside of North America) sine wave. All these things do is piggyback a small high frequency wave on top of that. The recipient box just has < blah blah boring electronics junk > that filters out or ignores the 60 Hz power signals and leaves them with the higher frequency signals which represent the digital stuff. As I said they work great, you just have to be aware that if there's any power line filtering between point A and B (like a UPS, a power conditioning AV power bar, or I'm guessing a PowerWall or something similar) will filter out your powerline ethernet signal. But most of us don't have anything like that _within_ our house, so it will probably work. The adapters will usually have some companion software that will test for that and/or basic connectivity between the two, as well as let you setup some basic security etc.
| 4 |
9v6l0b
|
Other
|
When cops go undercover and pretend to be prostitutes or drug dealers, how is that not entrapment? Okay, so my knowledge of police stuff is limited to my mom being an officer for a few years(but she couldn’t answer this question), and TV. But like, whenever an officer pretends to be a prostitute undercover, and then arrests someone for hiring them under the guise of hiring a prostitute, how is that different from entrapment? Because entrapment is illegal, I’m pretty sure. I just don’t get the difference.
|
Entrapment involves the officer inducing someone to commit a crime they wouldn't otherwise commit. However, in the examples you're citing, the officer isn't doing anything to induce the crime. If you walk up to a woman on the street and hire them for a sex act, you're not doing so because she forced you to do something you wouldn't otherwise do. You're doing something you'd normally do - and you just happened to pick the wrong woman. An example from the other end would be an undercover officer who befriends you and asks to buy drugs from you. You're not a drug dealer, so you say no. The officer persists and finally you consent to talk to a guy you know and pick up the drugs for him. Despite the fact that conveying the drugs from the dealer to the officer is illegal, this would normally be considered entrapment since you would have never engaged in the act if it weren't for the officer.
| 5 |
lpdh88
|
Physics
|
If gravity distorts time how did this affect time right after the Big Bang?
|
That's one of the interesting and unanswered questions of physics. If the universe was dense and all matter was together did time move at a slower rate? It's possible, and probable, But the next question is would it have mattered? Since the universe was all equally as dense, all of space time would have been affected by this effect so it would it have made any appreciable difference? The problem is we can't directly observe the universe at that early age because light didn't exist yet, so it's hard to predict what was going on.
| 1 |
flu0qa
|
Biology
|
How does a health practitioner know / feel the different levels of depth with an injection? (Intravenous, intramuscular, etc.)
|
Intravenous is practice and aim- you get that vein to pop up, you put a needle in it, you may well draw back a bit to see if there's good blood return. Intramuscular is just sort of taking a stab at it (pun only slightly intended). You know skin's thin, you can squeeze a bit to see how much fat they've got and you know about how much meat you're stabbing it into. God help you if you're dealing with the morbidly obese. Subcutaneous (just under the skin) is a bit trickier, but again, you generally know about how thick skin is, so you can practice. Intradermal...who knows. I presume a lot of practice again, because damned if people don't tend to screw those up and give it subcutaneous instead. Use a short needle, a shallow angle, and hope for the best. Then let's go to the fun things- Z-track injections (for stuff where you *do not* want what you stuck in to leak back out again, even a little, or intraosseous which requires essentially a spike to get through bone into the marrow.
| 2 |
hxftc4
|
Mathematics
|
Can anyone explain Bayes Theorem? I’m just interested in the math but have a hard time wrapping my head around.
|
Let's look at an example. Say we have a population of 10000 people, and there's some disease that affects 1% of them. There's a test that's 98% accurate. Assuming you test positive, how likely is it you actually have the disease? Well, if 1% have the disease, that means 100 people have it. 98 of them will test positive, and 2 negative. The other 9900 people don't. So 9702 will test negative, and 198 positive. That means in total 296 people test positive. And 98 of those have the disease. So if you tested positive, you have a 33% chance of actually having the disease. (And if you tested negative, it would be a 0.02% chance.) Bayes' Theorem captures all this casework in a formula: P(A | B) = P(B | A) \* P(A) / P(B). In this example, P(have disease | test positive) = P(test positive | have disease) \* P(have disease) / P(test positive) = 0.98 \* 0.01 / 0.0296 = 0.33.
| 1 |
6r84l7
|
Economics
|
How is the USA still the worlds biggest economy when pretty much everything I buy is made in Asia?
|
An economy is production + consumption + services provided. While a lot of production has moved to Asia, not all of it has. We still have very high consumption rates, and we have a service economy.
| 3 |
b5nu0y
|
Culture
|
This Quote: "Your preparation for the real world is not in the answers you’ve learned, but in the questions you’ve learned how to ask yourself."
|
My interpretation: > Memorizing facts isn't bad, but if you want to be successful in the real world, you need to know how to learn — especially about yourself. That's especially true in today's fast-moving society. If you know how to ask yourself the right questions ("Why is this important?", "How will this impact others?", or even "Why should I react the way I do?"), then you can keep growing and adapting to life. To put it another way, self-awareness is more important than regurgitating answers someone else came up with. It's not that being able to say, "2+2=4" is a bad thing! But it's more important to be strong enough to ask yourself, "Why do I struggle with math?" & #x200B;
| 10 |
9jtolz
|
Technology
|
What is the difference between C, C#, C-- and C++ other than the fact that they are different languages? I'm assuming for the most part that C#, C-- and C++ are based on C. But i have no idea how to code so I would like a detailed explanation on the difference between the four. As many people have stated, C-- is a language for compliers. It's a language, but it isn't used as often.
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I'm not sure how to explain the differences in coding languages in a simple way to someone who doesn't know how to code. The main difference is a concept called object oriented programming, as contrasted to procedural programming. Procedural programming is the most straight-forward way to think about programming. You have a list of things you want the computer to do, so you tell it to do those things, in order. Object-oriented programming doesn't focus on the tasks themselves, but on the elements of the tasks, and tries to section off pieces of the code into discrete chunks that are called "objects". An object has data (like numbers of words) and also methods (functions that do things with the data). Neither approach is universally better, but in some cases one is clearly better. C is the original language, and it's very basic. It was formed in the era of procedural programming. It has a kind of nascent support for objects, but it's not really fully there yet. C++ is the extension of C into object orientation. The extension is very natural and fits very well with the original syntax of C. The main differences are: the syntax to print statements to the screen is changed, the syntax to manage space in memory for storage is changed, and the standard library in C++ includes support for things like variable-length arrays called vector. Apart from that, the two are mostly compatible, and code written in C can usually be transferred to C++ without any edits. C# is similar to C++, but specific to Windows. I've never used it, so can't comment much on that one. I don't know what C-- is, but I guess it's an appropriate name for Objective-C, which is the Apple extension of C to object orientation. Objective-C is a hideous, horrible, frankenstein monster of a language, formed by almost literally duct-taping two completely different languages together and then never bothering to seam them up. Whereas C++ treats objects with the same syntax it uses for numbers and stuff, Objective-C has a completely different syntax for objects than the one it uses for numbers.
| 4 |
fxkuw4
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Psychology
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What's the psychology behind the appeal of effeminate K-pop male stars to girls, even in places without the Korean "male beauty" standards?
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As a female far outside of the age when K-Pop boys might be attractive, I would hazard that it's because they don't come off as threatening. I don't consider them particularly 'effeminate' myself, but they do seem to be shorter and slighter than a lot of Western men, and their music doesn't seem to have the aggressive sense of owning women that I've heard in a fair bit of modern music. They're nice to look at, they sound good, they dance very well, and they don't seem like they'd commit date rape. What's not to love?
| 2 |
5oq4yo
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Culture
|
Why is everyone suddenly obsessed with tax records?
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People are obsessed with tax records right now because Donald Trump has broken with a tradition of the President (and Presidential Candidates) to release their tax records, so that members of the public can see what things they own (property, stocks, etc.). Right now there are many people concerned about what ties Trump might have with Russia. Since he hasn't provided much information for public scrutiny people are guessing and assuming the worst.
| 3 |
67k3q3
|
Biology
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Why do some people function better in the morning and other function better at night?
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The circadian rhythm is endogenous. (yay Google search!) But... it can be affected by light and dark patterns. Otherwise, I have no idea. I've always had a preference for the night and was a night owl until I had a kid. Now I have trouble sleeping past 6am since 6am isn't my bed time anymore.
| 2 |
ob0kor
|
Earth Science
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How come every element on the periodic table (which we know doesn't have any holes) is found on earth (except higher unstable elements)?
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This Awesome Periodic Table Shows The Origins of Every Atom in Your Body [ URL_1 ]( URL_1 ) [ URL_0 ]( URL_0 )
| 14 |
6122cs
|
Other
|
Why is it that we can remember some childhood memories so vividly, and others not at all?
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It depends on the type of impression the memory caused on you (and how old you were). Many memories are forgotten because they weren't "important" enough, therefore you don't think about them often and they fade (i.e. the neurons that connect to preserve those memories lose those connections). Also, if memories weren't particularly pleasant and/or caused you to have some form of anxiety, your brain may unconsciously repress the memory causing you to forget it. This is an unconscious defense mechanism meant to "protect" yourself from the stress and anxiety brought on by such memories. That's just a very quick overview! :)
| 3 |
6yijl7
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Other
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How do people kayak or swim across oceans without...you know...dying.
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Generally, the kayaks used are specifically designed for the trip- they are large enough to move around in, and contain things like navagational equipment, food/water, and space to sleep.
| 2 |
75xiae
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Culture
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What does it mean for the US to leave UNESCO?
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[In the '90s, two pieces of legislation were signed into law]( URL_0 ) that prohibited funding to UN and its related entities, if membership were to be granted to an organization or group that was not officially recognized as state (aka country). In 2011, UNESCO admitted Palestine in as a member state, which effectively stopped the US from contributing its annual contributions, which made up approximately 22% of the organizations budget at $80 million a year. The US then became a non-voting member, but was offered a space on the Executive Board. It was a pretty big concession on part of UNESCO This ultimately reflects the current administration - reduction in soft power and diplomacy across the globe - withdrawing from global treaties, like the Paris Accords, and a pull away from UN-related bodies in general - a move away from multilateralism There was really no reason to pull away. There are basically no countries not as a member of UNESCO. UNESCO is an international organization dedicated to advancing educational opportunities, scientific advancement and cultural heritage through its many programs and initiatives. The most well-known is UNESCO World Heritage Sites, which seeks to protect and preserve the unique architectural, environmental and cultural sites all over the world. I don't work there, I just really believe in the work that they do. I don't think this inherently does anything (and I could be wrong), but I think it continues to set the tone for this administration's approach to international relations. Edit: Changed date on when UNESCO admitted Palestine as a member state. Also added a source.
| 1 |
jt3aoe
|
Biology
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what happens when my joints pop back into place?
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It is similar to cracking your knuckles, and any joint in your body is able to do the same thing. Every fluid in your body--including the slippery fluid lubricating your joints--has a certain amount of dissolved gasses in it. Nitrogen, oxygen, and carbon dioxide mostly. When you stretch your joints a certain way, you expand their internal volume which lowers the pressure, like opening your mouth to drink through a straw. This drop in pressure can cause a bubble of gas to come out of solution with an audible pop, like opening a can of soda. This bubble increases the volume of the fluid inside your joint, so now you can expand the space farther, so you gain a tiny bit of extra mobility. This also explains why you can't do it again right away: you have to wait for the gas to redissolve before you can repeat it, and that takes some amount of time.
| 1 |
j1gtn8
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Biology
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What happens to the sweat you don't sweat from your armpits because of "anti-sweat" deodorants?
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There is actually compensatory sweating that occurs when your pits are unable to sweat normally, and you might notice more sweat on your back or face.
| 14 |
7wtrub
|
Biology
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Why do some soft tissue muscle injuries take several months to heal
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My guess is that you're thinking about strains and sprains, which aren't muscle damage at all but actually damage to the tendons (bind muscle to bone) and ligaments (bind bone to bone). A piece of tissue's ability to heal itself directly corresponds to the amount of vascularization–i.e. blood–it has. Tendons and ligaments are *very* poorly vascularized, so the chemicals and cells needed to repair them aren't able to travel to them very easily. Skin, muscle, and body cavity tissues, on the other hand, are vascularized out the wazoo and heal relatively quickly.
| 1 |
krmyyi
|
Technology
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how do archaeology digging not damage artefacts or fossils?
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There are many techniques that can be loosely categorized as invasive (using an excavator), minimally invasive (manually troweling) and noninvasive (ground penetrating radar). The selection of excavation technique depends on the initial information gathered about the site locality and what is feasible for the project in terms of money and time. Different archaeologists in different areas of the world have different excavation preferences based on their research topic and geographical area. Mistakes unfortunately do happen, but when the research is important to society, it is unusual that the artifacts are not handled with care.
| 4 |
8g2i58
|
Chemistry
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How does steam remove the peanut protein when doing an allergen changeover? Did a plant tour and they said that for allergens they use steam along with other chemicals to remove the peanut protein before running a non-allergen. How does the steam work to remove the peanut allergen?
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It denatures (cooks and deforms) the allergen protein so it won’t be recognized by the antibodies. (In theory) However it’s not foolproof hence the “made in a factory where peanuts are processed” warning label.
| 1 |
dfjqb7
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Other
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Why are we not turning salt water into fresh water and mass producing it?
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It takes an extreme amount of energy to process salt water into fresh water and the facilities to do so are extremely expensive to build and maintain. So we quite literally do not yet have the technology to do this on a large scale.
| 2 |
6hg85c
|
Economics
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What are single payer healthcare and public option and how are they different?
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Single payer means that instead of having dozens of private, for-profit companies like Aetna, Cigna, BlueCross BlueShield, etc. charging for health insurance coverage, having different rules and coverage, etc. depending on whether you're on a company plan or an individual plan there would be a single governmental insurance -- sort of like what seniors have today on Medicare. All doctors, hospitals, other medical providers would submit claims to a single source and be paid by a single source. Instead of paying insurance premiums to the various companies, there would be some sort of tax to cover the insurance. Doctors, hospitals, and so on would continue to operate as they do today, just with streamlined billing operations because they're not having to deal with countless different plans/policies. Public option would be where the government nationalizes healthcare, and directly owns hospitals/medical offices, employs the doctors, nurses, physical therapists, technicians and runs the healthcare industry as a governmental agency. This is how the Veterans Administration runs its healthcare today.
| 3 |
6b3op5
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Biology
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How do bones and other organs "know" the correct shape they should be? This may be more like an ELI15, but how do bones and other organs "know" the correct shape they should be? I know the easy answer is "Because DNA", and the likely answer an actual 5-year old would get is "God made it that way" (or "evolution" depending on the parents; the two are not incompatible in my head and this is not the thread for that debate) but how do the various bits know when to stop growing and what shape they should be? There obviously must be a way, because when it quits working we get cancer - but why do everybody's femurs look more or less like femurs and not ribs or baseball bats or something? When I write code, I can set limits (while x < 1.5 and y < 5, increment x and y) and if I'm designing a 3D print job I can measure out a 3"x5"x2" block and the computer/printer can work that out to "move so far while laying down medium" , but as far as I'm aware DNA doesn't have little tiny calipers. So how does it know it's done growing, or especially regrowing? And how does the healing process know when to stop healing?
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So the answer is fairly complicated and ELI15 since each cell type differentiates differently. Yes, DNA is involved. To understand this we can first ask: how do cells that have all the same genetic package exhibit different characteristics ("phenotypes")? It's not like the DNA of your kidneys has different base pairs than the DNA of your skin. The answer is transcription factors and chromatin remodeling. Each cell presents only certain specific parts of its DNA for transcription into RNA and then protein- the rest is all rolled up into very efficiently packed clusters called histones. The proteins expressed determine the function of the cell, from secretion of mucous to recruitment of calcium for bone formation. With certain types of cellular signaling your cells may undergo an orchastrated reprogramming event where chromatin sort of unrolls or packs away your DNA, altering the part of the DNA exposed for copying. This is sometimes called "differentiation." Additional alterations can be made to the cellular products in the forms of factors that have affinity for particular segments of your DNA- they land there and can up regulate, down regulate, or completely alter the types of proteins expressed. Transcription factors account for the incredible diversity of cellular function. Let us take the immune system for example. You start with stem cells in your bone marrow that all look and act the same and they are in maintenence mode, waiting for a signal. Upon reception of the signal, an energetic threshold is met within the cell and its exhibited characteristics progress down a set path- the cell unrolls parts of its DNA that code for antigen receptors and gene rearrangements. In the case of immune cells, a differentiated cell will never go back to being a stem cell again. However, it will continue to differentiate further through the energetic follow through of its own function- these cells must produce successful protein chains as evidence of their differentiation to be allowed by other cells to leave the bone marrow and continue maturation. At stages of success, to select for success, the cells divide certain exact numbers of times. Most organ development is very similar to the immune system where you begin with stem cells, they recieve a signal, and then they recruit parts for their needs. With no stem cells, no signal, defective genes, or no / limited parts (think diet) you won't get normal growth. So now that we've described the system, you can perhaps imagine cellular signaling at the level of a developing child, where growth hormones provide the child's cells with the signal through the blood to up regulate hair growth for men, recruitment of fat to breasts for women, etc. To form each perfect nail bed on your five perfect fingers your fetal cells recieved an exact signal to grow for an exact amount of time and in an exact way, but to disapoint a computer scientist... there does not exist a processor capable of handling the sheer complexity of information and energy exchange. We can't model this yet.
| 2 |
6565h2
|
Culture
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What is going on with the whole U.S. vs N.K thing and how worried should we be?
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You should probably not be worried. NK has very little leverage in the international community, since it's essentially a "buffer zone" between China and capitalism in SK. As a result, they have gradually become increasingly brazen in their rhetoric. This was no big deal under "no drama Obama", because the US mostly ignored them. The current President has a very different personality. The government of NK is in no way interested in war with the US, regardless of what they might say on TV. They might not care about civilian casualties, but in a war with the US there would be leadership casualties. The US isn't interested in NK at all, and the recent actions are emphasizing the "China's Problem" approach to NK.
| 4 |
i9494e
|
Biology
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Why are ants able to do so much with brains so small?
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Team work. In relation to this, I just finished reading in some book that people with lower IQ’s that work as a team tend to be more productive at accomplishing tasks than really smart people trying to work together.
| 4 |
jatywf
|
Physics
|
Why is Sydney to Lisbon so much further than Sydney to Reykjavik (Iceland)? Sydney to Lisbon: 18,166km Sydney to Reykjavik: 16,605km By looking at a globe or map, this makes absolutely no sense...
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The fastest way from Sydney to Reyjavik is fly [straight up through Japan, through the north pole, and down to Iceland]( URL_0 ). On a globe, that's easier to see. It's hard to tell that that's the fastest route on a rectangular map that stretches out the north pole from a point to an entire side of the map and distorts the size of Europe and Russia. That route is shorter than the Lisbon route that goes across the Indian Ocean, Middle East, and Mediterranean.
| 2 |
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