question
stringlengths 19
300
| answer
stringlengths 31
1.02k
| negative_1
stringlengths 31
1.02k
|
|---|---|---|
What is a “defeat device”, and how does it work?
|
In this case, it's just a device that senses when an emission test is taking place. When it senses the test is taking place, it alters how the car runs to conform with emissions requirements. In practice, this usually makes the car accelerate less aggressively. So when it isn't sensing that a test is taking place, it runs in a way that does not conform with emissions standards or even its own test result. It's a way of gaming the emissions testing system.
|
They make at least 3 copies of your data, stored on different devices. If one device breaks, they replace it and make a new copy of your data from the surviving copies.
|
Did Capitalism initially emerge in Europe? If so how and why?
|
Check out Ferdinand Braudel's three-volume series (available on Amazon in English) on Civilization and Capitalism. The whole series is great and very readable. The books can be purchased as a three-part series now for a very reasonable price. But each of the books can also be purchased and read separately. Book 2, "The Wheels of Commerce," deals specifically with the rise of capitalism in Europe. Braudel was a French historian and leader of the Annales School.
|
Capitalism refers to an economic system that is free from government influence. It is comprised of privately owned industries that conduct business without regard to any formal law. The only true capitalist system is the black market, but certain countries, such as the U.S. or Germany, are said to be capitalist because their economies are relatively independent of the government compared to other countries. They do however have some government run industries, so they are not considered truly capitalist.
|
How do spiders know to avoid my finger?
|
[How spiders sense things. Pix.](_URL_0_) She has scent-sensitive hairs on her legs, so she's smelling you to see if you're food. Apparently you aren't, so she moves on.
|
Most spiders are ambush predators. They invest their energy into web-making and just wait. There's others like the jumping spiders that actively hunt, but most wait for prey to come to them. They're very good at waiting. On a wall or out in the open as opposed to in a web, I would suspect they're hoping to remain unseen by you (a potential predator). Not all animals can see as humans do. Some can detect movement much better than fine detail so maybe they're just playing the odds that you don't notice them by remaining still. Spiders themselves can't really see for shit despite having so many eyes, but they are very good at sensing their environment through vibration. Something your size (assuming you're human) will make A LOT of vibrations.
|
why actors and actresses in big movies get paid so much
|
Because the people who make movies know the big actors will make them more money than they cost.
|
The biggest expense in a Hollywood movie are people expenses. The stars get a big part of the price of the film, usually at least half the budget between top stars, co-stars and the rest of the cast. The screenwriter(s), director, and producers get a big chunk. Everyone who works on the set is paid a union-scale wage; the gaffers, cinematographers, makeup, riggers, etc. A big special-effects film will pay an army of people who do modeling, art, animation, motion capture, and building customized tools. Sit through the credits of one of these films and you'll see and endless list of people who do this work. These are pretty good paying jobs, and the work can last six months or more. Then there are rentals for equipment, payments to use exterior and interior locations, royalties for licenses, food service, travel and lodging, and overhead for lawyers, accountants, security, "personal assistants", etc.
|
How do we measure the height of mountains on planets with no sea level?
|
1. First you need to define a zero altitude. Height is a relative value instead of an absolute value. 2. If the planet has atomsphere, we can use the pressure deference between the mountain top and the defined zero altitude to find out the height of the mountain. You will also need to measure Temperature lapse rate, Standard temperature at zero altitude, Surface gravitational acceleration, Molar mass of dry air. 3. We can also send satellites to do the job, if there is no atmosphere. The cheapest way to do so is to send one satellite with laser distance measuring tool. The satellite sends a laser to two places I mentioned above and calculates the difference of the time of the laser traveled. The time times the speed of light(assume it’s vacuum), you get the height.
|
OK. Triangulation. Now, how big is impact of the form of the mountain? Usually, when climbing, there are many false tops - you keep climbing and climbing just to discover that what you assumed was a top, was actually just a bump. And what is height exactly? It's said above sea level, but it probably means accumulating lots of errors? The definition would be more clear if the Earth was an ideal spherical ocean, with mountain peaks sticking out of it, but even the ocean isn't spherical. Wouldn't that mean that heights would be different if we started going from different shores? What about tides? They probably mandate starting the measurement at a specific time, when the tide is low/high/middle?
|
Why standing up quickly sometimes causes me to black out for a few seconds, and standing up and stretching is even worse.
|
I had this problem a lot as a teenager, and had to see a neurologist and cardiologist about it. Here's the basic idea: When you're lying or sitting down, your heart is in a "rested" state. Your pulse slows down and your muscles relax, and your brain needs less blood to function as your nerves and body become calmer and calmer. When you suddenly stand up, your muscles and heart start to quickly "wake up" and work harder, and your brain all of a sudden needs a lot more blood to send messages throughout your nervous system. You black out briefly because your brain isn't getting enough blood from your heart in the short period of time in which it needs it. This is usually because the message isn't getting to your heart fast enough via your nervous system, and conversely, the blood isn't reaching your brain by the time you're on your feet. Eat more salt, drink more water, or Gatorade. Electrolytes help your nerves work more efficiently.
|
Standing in place is actually way harder for your body. The muscles in your lower back are always tense when you stand. Where as when walking, they get relaxed and then tense up again. Imagine doing 20 pushups in 5 minutes. Now imagine doing 1 pushup in 5 minutes (staying low)
|
What's wrong with Comic Sans?
|
There's nothing wrong with it as long that it's used appropriately. The problem is it became so overused, appropriately and inappropriately. Subjects that contain a serious matter or something that wants to come off as credible would lose all of its credibility and seriousness due to Comic Sans' whimsical/cartoonish look (Imagine seeing a missing child poster or a wanted poster set in Comic Sans). Another overused font, for example, is Helvetica. People hate on it too because it can be seen almost everywhere just like Comic Sans. The only thing about Helvetica is that it's flexible enough that you can apply it to pretty much any subject matter, unlike Comic Sans.
|
Because the html page uses [this](_URL_1_) css stylesheet and on line 443, it has the following a[href*="comic"], #siteTable_t3_wlser { /* put in id of comical threads */ font-family: "Comic Sans", "Comic Sans MS", cursive !important } This applies to all links which have the word comic in the link and makes them have the Comic Sans font. Edit: So in theory [this comical link](_URL_0_) should be in Comic Sans too.
|
How do sea monkeys work? It's like they're in suspended animation or something...I need answers!
|
The animals undergo [Crytobiosis](_URL_0_), it is when an animal, usually and invertebrate, can shut down all functions in order to survive a harsh environment and wait for better conditions. Usually occurs when there is no water, too cold or not enough air. In the case of the sea monkey, or brine shrimp, the egg is able to undergo this for up to 2 years because of a special coating on the egg that is naturally made by the female, which protects the egg. The eggs are then sold in the sea monkey packets and stay dormant until placed in briny water. Judging from your username, I would recommend that you don't put them in your teacher's coffee, along with other things...
|
Thank you for all your awesome explanations! Nobody who actually believes in evolution has ever explained it to me before, so I've only heard things like "monkeys magically turned into people", so evolution never made much sense to me. Now that I properly understand it, I'm going to do some more research :) Although I certainly won't be telling my friends or family about this, they aren't fans of evolution.
|
Why do planes fly at 30,000 feet?
|
There's multiple reasons * the air is thinner the higher you go up, meaning you need less power to travel through it. However, go too high up, and the air is too thin, to where you need more power just to keep going forward. A little over 30k ft is a sweet spot for this * most storms don't break 30k ft, so you can simply fly over a storm, instead of trying to plot a route around it. * There's little to no turbulance at higher altitudes, so the flight and go on without shaking a lot, something passangers seem to like * There's high altitude jet streams around 30k+ ft, which can allow for a flight to "hop" onboard, and use the jet steam, in addition for their engines, to arrive at their destination much faster than otherwise possible
|
difference in distance traveled is negligible, they fly about 7 miles high earth is about 7000miles in diameter. circumfrance of the earth is then 21980. add 14 miles to that diameter for the distance the plane flies is 22024. so a full lap around the entire earth would only be 44 miles farther than at ground level. Negligible. flying at height means much lower air pressure, which means less drag, far better speed and fuel efficiency which majorly offsets the slight distance, plus spends less fuel, and it makes less noise pollution for people on the ground.
|
Why do seeds grow even though they don't have access to sunlight?
|
Plants need sunlight to create sugars, which they use as an energy source. Seeds are plant embryos packaged with some of those sugars in a protective shell. When the embryo begins to grow, it can feed on the sugars that it was packed with for a while, until it breaks through the soil and can start making them independently.
|
For the same reason seeds can sprout through concrete I imagine. Plants seek light, they'll grow around whatever they need to to get to it easier.
|
In theory... If I dont sleep, but just keep my eyes closed for 8 hours, will it be the same as sleeping?
|
Not the same at all. The difference is your brain would never go through the sleep cycle your body needs
|
While we're on this topic, why do I permanently have bags under my eyes regardless of how much sleep I do/don't have?
|
When and how did capitalism first come into existence?
|
Looks likes a lot has been deleted, and this probably will too, you should just read the wiki pages on the history of capitalism. In the 16 and 17th century the beginning of capitalism started, but generally it's better viewed as mercantilism. By the 18th century, the practices you'd consider truly capitalistic began to take hold. Maybe it helps to tl:dr it. The idea of capitalism has been around for a very long time, our modern interpretation was established in the 17/18th century, and it revolves around larger national economic decisions
|
Short answer- yes, but the specification of the English social and economic system that led to capitalism was important too. Without the Magna Carta and the unique geography and resources of England, capitalism would likely not have evolved the way it did, if at all. (Ellen Wood's *Origin of Capitalism*)
|
Why do people get mad when being told to do what they were already going to do?
|
Because people in general do not like being told what to do. When you are going to do something, and then someone *tells* you to do it, it robs you of the autonomy of the action.
|
Because people are angry, hurt and frightened so they get mean and selfish about it.
|
What happens to a lost ant when it's dropped off to another ant colony?
|
Ant nests near to each other are actually often related. The queens split off from nests and go and start new colonies close by, so they have close relationships with others. If the ant you dropped into the other ants was related, it's pheromones are likely close enough that it will be adopted into the new colony. If it is driven away, it will find a spot and start walking in a growing spiral until it finds an acceptable pheromone trail.
|
Due to gravity, the ant would fall. Depending on a couple of other weather factors, it would land more or less in front of or in the vicinity of the Empire State Building.
|
How can scientists be confident that GMOs won't have multigenerational impact?
|
In a typical GMO, it is well understood what genes have been changed, so their impact is predictable. Nothing about having future generations changes this point. By analogy: how do you know painting your house won't make it catch fire? Because that's not what paint does.
|
That's sort of like asking if potatoes are unhealthy. There are kinds that are awesome, and kinds that are poisonous. People worry about GMOs mainly because they give the corporations that create them so much freedom. Cross-breeding can produce some pretty out-there traits, but on human time scales it's pretty limited. Genetic tweaking can produce a Hell of a lot more bizarre things a Hell of a lot quicker. (e.g. who would ever expect that maize would start secreting a mildly carcinogenic pesticide? But Bt corn does just that.). So most folks who are ticked off or worried about GMOs are actually worried about the motives and/or honesty of the big corporations that create them (e.g. Monsanto, whose ethical track record reads like Anakin Skywalker's later days...)
|
will the US ever convert to metric, and what will it take to make it happen?
|
_URL_0_ > It declared the Metric system "the preferred system of weights and measures for United States trade and commerce", but permitted the use of United States customary units in non-business activities. Basically, the United States is legally converted to the metric system for official purposes, but nobody else is required to use it.
|
This question is technically in breach of the the 20 year rule, as the last two countries to metricate did so in 1998 (Jamaica) and 2005 (St. Lucia). However, pinning down a date is difficult for many countries as many have very long transition period (e.g the USA, where the metric system has been legal since the 1800's) or old units remain co-official in some circumstances (e.g the UK). As the process is still very much ongoing in many countries I won't comment further, only to direct you to /r/ask_politics, /r/asksocialscience or /r/neutralpolitics
|
What is the difference between a Function Call and a Function Definition?
|
Function Definition: You define what the function will do when you call it. Function Call: You call the function to do what you defined previously. 🙂
|
Procedures and functions are pretty much interchangeable terms. The proper C++ terminology is "function", and the term "procedure" isn't used (a function which has a void return type is still a function). Other languages (like Pascal) differentiate between procedure and function, just like you asked.
|
What would happen to a rope hanging from outer space to earth?
|
This is probably of interest to you: [Several simulations of what would happen if the cable on a space elevator snapped.](_URL_0_)
|
A rope that long would not be able to support its own weight and would snap. We don't have any materials strong enough to build such a rope. It's hoped that carbon nanotubes will one day be an option.
|
Does foaming make soap more effective?
|
First of all, soap foams/lathers due to **foaming agents** in the soap. These are chemicals present in the soap that interact a certain way to cause the soap to foam (that's another story). These chemicals also work as **surfactants**. A surfactant reduces the surface tension of water and helps to break up oil and dirt on the skin, thereby increasing the effectiveness of the soap. Ref: _URL_0_
|
do you mean how the soap foams, or how the foaming pump turns it to foam? either way, it uses a [foaming agent](_URL_0_), commonly [sodium laureth sulfate](_URL_1_). this chemical weakens the surface tension of water, allowing it to better adhere to and wash away dirt.
|
how electron microscopes work?
|
Let's start with light microscopes. You shine light on your sample, and the light bounces through a couple of lenses and hits your eye. The concept is exactly the same for electron microscopes, but the difference is that you're using electrons instead of light. Due to wave-particle duality (which you can read about in this [other ELI5](_URL_0_)), electrons have qualities like a wave and like a particle. It's these wave-like properties that we're using in electron microscopes. Past that, it's exactly the same. You have an electron source, the electrons hit your sample, pass through lenses, and then hit a detector. Since you can't see electrons, you need a special detector that takes the signals and converts it to an image which you can see on the computer screen.
|
Not sure about electron microscopes, but atomic force microscopes (AFMs) can fit on a tabletop and aren't much bigger than a light microscope. Unfortunately they cost thousands of dollars.
|
Why is it that when we drink too much milk too fast we will bloated and our stomach hurts?
|
Your body produces an enzyme called lactase in your stomach. This is needed to process the lactose in the milk. If you drink more milk than your body can supply lactase to process it, you'll feel bad.
|
There is acid in your stomach already. So the milk will curdle up anyway.
|
When scientists are filming using light during deep ocean dives does it hurt the animal's eyes?
|
It strictly depends on what wavelength of light is being used. [Widder *et al.* \(2005\)](_URL_2_) looked at how different wavelengths of light can elicit behavioral change in deep-sea sablefish. For the most part, this is why many scientists use red lights for photography/videography for underwater work; the spectrum of wavelengths for "red" light are less intrusive than traditional "white" light. This is because many, if not most, [deep sea critters lack the ability to perceive light with relatively shorter wavelengths, such as red \(~710-850 nm\)] (_URL_0_). While [some research suggests that deep sea critters are super sensitive to light and are susceptible to photoreceptor damage](_URL_1_), it's hard to say since it is difficult to perform controlled experiments on deep sea animals who are likely already very stressed from either 1) being brought up from depth and/or 2) a ROV/camera system that is generating noise and particle motion, which many animals will be able to detect.
|
It depends, on the water. Water in a swimming pool is purified, so there are "anti-life" chemicals in it that can irritate your eyes. Most swimmers get used to it, because the benefits of seeing outweigh the sting, or they wear goggles. The ocean is full of salt, so the sting there tells you something different. There is more salt in the ocean that your body prefers. Polluted water can have very serious consequences for your eyes.
|
how we turn electricity into the cold in refrigerators
|
When you squeeze something really really hard (much harder than you can do with your hands) it gets hot. And then when you let go it gets colder again. The refrigerator uses the electricity to turn a pump that squeezes some gas in pipes on the back of the fridge, and lets that hot gas cool down. Then it lets it expand so it gets even colder. It uses this (now very cold) gas inside the fridge to cool it down. Then it pulls the gas out and starts squeezing it all over again.
|
There are devices called cryocoolers, without getting into details, they're really good refrigerators. If you only want to cool down an atom or molecule we can use lasers, since heat is expressed on the atomic scale as motion, we can use lasers to push the atom/molecule in the direction opposite to the direction it's currently going. by doing this to a high precision, we can get down to tiny fractions of a kelvin.
|
Why do black tattoos turn blue eventually?
|
Cheap ink and Sun Exposure. Not all black inks fade to blue. My grandfather's 35yr old tattoo is still black, mind you it's blurry due to 30 years of aging.
|
It's just black ink that has faded. Some inks will fade and turn blue more than others, while some stay quite black. It all depends on the ink manufacturer. It also depends on how the person takes care of their ink. Exposure to the sun will fade tattoos and give black ink that dull blue appearance.
|
How do civil engineers determine if a building is structurally sound after an earthquake?
|
They would assess the structural components for signs of failure or serviceability issues. If they were looking at steel they could check and see if members or connections had yielded or worse. This might be evident through several different methods such as bolt holes being larger than they should be or members having localized sections with a reduced cross-sectional area and elongation. If they were looking at concrete they could check for unusual cracks, spalling, exposed rebar, or again a multitude of other things. They could also check member deflection. Typical floor members are generally limited to a serviceability deflection of L/240 under dead + live load. For example, if a floor beam was 20 feet long (240 inches) that beam would be limited to 1" of deflection over the span length under this condition. If the beam is sagging 6 inches something is probably off.
|
Get into the frame of a door, keep low, and cover your head. But earthquakes happen really fast. You might not even have time for that. I got caught in an earthquake once. Very mild. I thought it was just really big truck passing by. Edit: Apparently, this thing about the doorway is old advice. It only applies to old homes. Nowadays it says to go under a sturdy piece of furniture, like a desk, and cover up. Source: _URL_0_
|
How does the tax evasion loophole work?
|
A loophole = > tax avoidance Tax evasion == a crime, you go to jail. These are completely different. The Congress adds loopholes on purpose, to encourage people to do things that Congress wants done but don't have the money for, like building businesses or funding charities. Rich people follow the law and take advantage of opportunities offered them, because they would otherwise pay a lot more tax. The bottom 50% of taxpayers in the US pay 3% of the personal income taxes while the top 1% pay 37.3% of the taxes (even with the current loopholes).
|
Generally speaking, tax avoidance is legal whilst tax evasion isn't. Tax avoidance is cleverly exploiting loopholes in tax law to pay less tax. This might include things like setting up trusts or changing your tax residency. Tax evasion is doing something that actually contravenes tax law and therefore not paying as much tax as you are legally obliged to. It can be difficult to determine what constitutes tax evasion, however, because the tax laws of countries are often extremely complicated.
|
Do gas station brands really make any dfference in anything?
|
Different companies add different additives to the gasoline. The EPA require a minimum amount of additives that must be added. Which additives and how much determine the differences When I fill up at a Shell gas station and use the "V Power,'' which is about 40 cents more expensive, i get about 3-4 mpg more. I feel that my engine runs smoother with Exxon gasoline. This is in comparison to a little Arco gas station that i always go to because it is a block away from my house Here is a link that goes more in depth. _URL_0_
|
Gas is a commodity with very high price sensitivity. Customers will drive stupid distances to save a few cents per gallon. This means that profits are razor thin and competition is cutthroat with very little brand loyalty. Anything that affects production, processing or transport must *immediately* be reflected in the price so as not to lose those margins altogether to a competitor for being too high or to suppliers for being too low. Also, politics and speculation can also play into it. When summer vacations approach, governments and large buyers such as airlines can play with supply and reserves to influence prices downward so that people travel and spend money and drive the economy.
|
Why are rubber ducks such a staple in our culture?
|
While the origin of the iconic rubber ducky is not entirely [clear](_URL_0_), I would say that in the United States, at least, they gained popularity since 1970 because of Sesame Street and Ernie's [Rubber Ducky Song](_URL_1_). The song became extremely popular and rose in the Billboard charts.
|
Followup: What about rubber chickens? I don't think the younger generations might be aware of it, but rubber chickens were a staple in American comedy (and possibly other countries?) for decades. There's nothing particularly funny about them that stands out from any other prop yet they were the go-to comedy prop in stand up routines, cartoons, television shows, and movies up until fairly recently.
|
Why is gasoline rainbow on pavement?
|
The thickness of the gasoline is close to the wavelengths of visible light. Light reflects off of the surface of the gas/air border as well as the gas/water border. The two reflections can mix in two ways. At a given thickness, some colors are attenuated due to destructive interference, while others are enhanced by constructive interference.
|
When a bit of oil or gasoline gets in a puddle of water it will create a very thin and even coating on top of the surface. This thin coat of oil will be enough for the light that passes through it to refract, bend, in different angles than it would have had the oil not been there. These variations in how the light bends and reflects registers in our eyes as different colours. "But if the coating is even, why isn't the entire puddle the same colour?" you might ask. That is because you aren't looking at the entire oil spill from straight on and the differences in angle and distance from the far side to the near side of the spill is what makes you see a rainbow of colours in oil spills.
|
When non-identical, conjoined twins are born, does the immune system of one try to attack the other?
|
I don't think there exists non-identical conjoined twins. All conjoined twins originated from the same fertilized egg.
|
Certainly. Perhaps the best-known example is the cheetah, which are all so genetically similar that [they accept tissue transplants without rejection](_URL_0_), suggesting their immune genes are all identical.
|
Why is Light white, but if you the same number of colors, mix them together, they would usually turn black?
|
If you mix many colored lights together you get white. If you mix many colored *pigments* together you get black or gray because each color's reflectivity is cancelled out by another color in the mix.
|
This is asked all the time here (did you search first?). The short answer is that when you combine lights, you get more light. White light is made up of different colours of light, so if you combine them, you get back to white light. Paint, however, absorb some of the colours of white light and reflects the colour that the paint is. For example, red paint reflects the red part of white light but absorbs the other visible colours, and green paint reflects the green part of white light but absorbs the other visible colours. So if you mix red and green paint, you get paint that absorbs *all* colours and so, in theory at least, looks black. In practice, the mixed paint still reflects a bit of red and a bit of green, and so looks dark yellow, which is a colour we call "brown".
|
Book recommendation needed: The British Empire since the 19th century?
|
"The Cambridge Illustrated History of the British Empire" by P J Marshall will meet your requirements quite nicely.
|
Hi there, I would particularly recommend Jon Wilson's *India Conquered: Britain's Raj and the Chaos of Empire*, which takes a consistently critical view of the British Empire in India. You might also be interested in the [South East Asia section](_URL_0_) of our booklist which contains many works on the British Empire in Asia.
|
Does a double pendulum show quantum effects on a macroscopic scale?
|
I believe you are referring to the chaotic nature of the double pendulum. This really has nothing to do with quantum effects, the behavior arises in an ideal, classical double pendulum with no friction. It is more a consequence of the mathematics. Although the system is deterministic, the behavior of the system cannon be predicted because any perturbations in the system or errors in measurement will cause the paths of the real and predicted systems to diverge exponentially. Even in a classical universe you really can't expect measurements to be perfect or for a system to be completely isolated, so you really don't need the heisenberg uncertainty principle or anything fancy like that to see these types of effects.
|
[Here's a java demo of a double mass-spring system](_URL_3_). The motion of these types of systems can often be described as a sum of [normal modes](_URL_4_). In the geometry you described, a common normal mode is for the masses to sort of [pass the oscillation back and forth](_URL_0_). There are plenty of other sorts of [coupled oscillators](_URL_2_) such as [two pendulums connected by a spring](_URL_5_) (sorry about the obnoxious music, it's the only video I could find right now). Now things get really crazy when you have a [double pendulum](_URL_1_). The equations of motion are nonlinear, so there are no normal modes. The motion is chaotic.
|
why it's better to rent a car for a trip in lieu of taking your own.
|
The first thing you need to do is check the rates and do the math. If things are slow and the rental company has a good deal, it can be cheaper. Also, bear in mind the rental company is going to have people on staff to do maintenance, so it is cheaper for them than for you. And often your vehicle isn't suitable for a long trip. It might be too small, have poor fuel economy, not be reliable enough, or not do well at highways speeds. Your '98 Corolla might be fine for you daily commute, but you wouldn't want to drive across a desert in it. Sometimes people like to rent a vehicle they are considering buying in the future to try it out. In the end, it is kind of like buying insurance. It will probably cost you a little more, but if you do have a breakdown, you won't be out hundreds, if not thousands of dollar on top of spoiling your vacation.
|
One tip: Living on your own is way more expensive than you think.
|
how does the blood brain barrier work?
|
While "blood-brain barrier" sounds like some sort of membrane surrounding the brain, it actually refers to the specialized structure of the capillaries in the brain. [Here's](_URL_0_) an image that gives you an idea of what the BBB really looks like (caveat: this image suggests that astrocytes are responsible for the BBB, which is what I learned back in neuroanatomy, but apparently current thinking is the "barrier" is mostly the structure of the capillary wall. TIL!). To answer your followup question, the brain still gets oxygen in spite of the BBB because oxygen can diffuse through it. The BBB really only blocks polar (charged) molecules. For example, dopamine won't cross the BBB (it has a big ole amine group hanging off one end) which is why in dopamine-replacement therapies (e.g., for Parkinsons) they administer the (non-polar) dopamine precursor L-DOPA.
|
The brain lets blood in, in great quantities (20% or more of your cardiac output goes straight to your brain). You have misunderstood the blood-brain barrier. It is a cellular barrier that prevents many substances from leaking out of the blood vessels into the brain tissue. But not every substance. Nutrients are quite welcome to cross, for the most part.
|
Why do Indians bob their heads forward and backward when they talk? [FIXED]
|
The culture is different in india. A left to right wobble means "I agree". If they sort of bobble their head in a circular motion it means they are listening. If slow its friendly if fast its more like "I really understand".
|
Their eyes don't correct for motion very well so they compensate for this by keeping their heads still for as long as they can, moving their heads forward and *then* their bodies so their eyesight is more stable.
|
Why is an air bubble in the blood bad?
|
That assumes the air bubble can move through the next obstruction. Blood itself has surface tension, meaning that there is a minimum size of air bubble to travel through it. That size is smaller than our veins and arteries. If a bubble is unable to squeeze through a smaller or obstructed vein, it just stops dead and ceases bloodflow.
|
Air bubbles are dangerous when they manage to get into your blood vessels. This is known as an air embolism. Your blood is liquid so any air in them can form a blockage. This is especially deadly if the blockage happens to blood flowing to or from the heart, brain, or lungs. And yes, this is why nurses are extra careful with getting air out especially for IV drips since they are going directly to your veins. However, if the injection of air does not reach your vessels, it is not as dangerous but still painful as you are separating parts of your tissues for air to fill it. Your body will eventually absorb the air over time.
|
Why are the blue lights of police cars so visible?
|
What do you mean? Those lights are incredibly bright, and are built within reflective lenses designed to be as visible as possible. They are bright because they are built that way. Plus, they are flashing, or moving, and the eye tends to lock onto moving objects.
|
More light outside, less light in the car. The tinted windows make it harder to see inside, but not out. This is also why it is sometimes hard to see at night out of the car with tinted windows if it is basically pitch black outside and some light inside.
|
Are people with darker skin better suited to living in sunny conditions?
|
In fact they are. Darker skin pigmentation helps protect against harmful UV radiation from the sun. Less UV light penetrating the cells means that there is a much smaller risk of skin cancer and African albinos can typically have skin cancer by the age of thirty. At the same time, less UV light makes it harder for darker pigmented humans to synthesize vitamin D. So in hot equatorial regions people with darker skin have a lower incidence of skin cancer, but in more extreme latitudes people with lighter skin can more easily meet their nutritional needs.
|
For skin tone, its all about Melanin, cancer and Vitamin D. Melanin is the chemical that gives skin its pigment. More Melanin = darker skin tone. Now, melanin does a great job of blocking potentially harmful rays from the sun. People who live in very sunny climates, like Africa, tend to have darker skin tones to protect them from those rays. Now, not all of those rays from the sun are harmful. Our bodies use some of them in the production of Vitamin D. In very sunny climates, enough of those rays managed to bypass the melanin to provide sufficient Vitamin D production. As humans moved to less sunny climates, darker skin tones became less beneficial; there were fewer UV rays to cause cancer and fewer rays getting past the melanin to allow for sufficient Vitamin D production. Those people developed light skin tones in response.
|
How we know there are nine dimensions and what is it like in each one?
|
We dont know there are 9. It was just thought up by inexplicably following a pattern of the first 3 dimensions by folding a dimension on itself. Edit: Also /u/pucklermuskau's answer adds more to what dimensions are used for in mathematics. If you want to define a system you can use extra dimensions to define values other than 3d coordinates. Such as height above sea level, pressure, temperature, colour. There are all different at every position. This means you could have a 7 dimensional matrix defining the value of each of these: X, Y, Z, sea level, pressure, temperature, colour.
|
In math there's no absolute 1st, 2nd or 3rd dimensions. All dimensions are the same, we only say "2d" or "3d" to reference the number of dimensions at play. There's nothing that's actually different about a 4th dimension as compared to a 3rd or 2nd, it's just how we ordered them. A dimension is just an axis along which something can move on or be situated in. Any two dimensions make a plane something can move about on or be situated in. Any three make an 3d plane, any 4 make a 4d plane, etc. Just because we can't really imagine what a 4d plane looks like in the real world doesn't make it special in math or anything, it just makes it a limitation of humans that math isn't concerned with. We can still do the math with 4d lines or curves just the same as we can with 2d objects.
|
Why do we use rats to test products?
|
Rats are used for some products, rabbits for others (usually eye products), pigs for skin products. They all (as Somewhat__Useful said) grow and reproduce quickly. They also have very well known responses, and have reactions similar to people. Because they have been inbred for so long, there is almost no genetic diversity between two animals of the same type. Rats are also very docile, easy to handle, and unlikely to bite (mice bite. I do not like mice).
|
Yes, specific types of rats are used in research. In fact there are different types of rat bred especially for different areas of research. In general the reason for this is that when conducting an experiment, you want to limit the number of variables as much as possible. While the rats of living beings, with all the unpredictability that brings, rats of a specific type that all come from a specific vendor tend to have similar sizes, behaviors, genetics etc. You can also order specific rat types that are bred to be useful in certain fields of experimentation. For example our lab uses immuno-compromised rats (they have essentially no immune system) that allows us to implant human tumors in them. This allows us to work with human tumors grown in a natural but carefully monitored and controlled environment. [Here](_URL_0_) is a good page on wikipedia which covers some of the basic strains of lab rat.
|
What is the highest altitude fish?
|
Since fish need a body of water you can probably bet that the highest altitude fish will be found in a volcano basin. Since these form perfect high altitude lakes. So if we go though the list ticking off the ones that are poisoned. You get to something like [Lake Titicaca](_URL_1_) It used to have a species of fish unique to the area called [Titicaca Orestias](_URL_0_) (Though now extinct) So now it would probably be trout.
|
238 900 miles or 384 400 kilometers is the highest altitude we have ever found living organisms at. Its the distance to the Moon... Yes, I'm taking about humans. All jokes aside, it depends on what exactly you want to know. Highest altitude non-human organism to be *spotted in nature* is the GRIFFON VULTURE who reached 37 000 feet or 11.3 kilometers - an altitude of a commercial airliner. However, organisms can *survive* at higher altitudes if we decide to put them there. TARDIGRADES are the only non-human creatures capable of surviving in vacuum of space. Unlimited altitude.
|
I am a young men of the Equestrian class in Rome around 200BC and want to become an officer in the Army. How do I join? How am I trained? How quick can I reasonably expect to rise up the ranks? What are these ranks?
|
What, precisely, do you mean by "officer?" It seems like a pedantic question, but it's really not. The army contained ranks like the centurions, who might be considered something like junior officers, but the "commanders," so to speak, of the army were not career soldiers but magistrates. Prior to the Principate very few *equites* would be considered for centurions and other such ranks, but would instead hold the military tribunate. But I'm not sure if that's what you're really asking about, as the military tribunate was really a political magistracy and not a career position
|
This is a question with a few different answers, depending on which country you're asking about. Special military academies did exist, broadly speaking. Napoleon himself attended the Ecole Militaire and graduated at the age of 16, at which point he gained a lieutenancy. Less than ten years later he was a brigadier general with command over the French revolutionary army's artillery in Italy. French, Prussians, Russians, Spaniards, Brits, Dutch, Italians, and Ottomans all did things slightly differently. Can you specify a nation you're interested in?
|
Why does the government permit lethal habits like alcoholism and sometimes drug addiction?
|
The government has no power to prevent alcoholism or drug addiction. They can make these things illegal, but anti-alcohol/drug laws have been shown to be ineffective. Prohibition didn't work and created a great deal of violent well-funded gangs and corruption. Today lots of drugs are illegal, but people still use illegal drugs if they choose to.
|
Because there is or there is perceived to be a social harm that stems from drugs.
|
Why some things that aren't a real evolutionary threat (i.e. spiders) such common phobias?
|
I think spider phobias are partially due to other people having spider phobias. As a child being told that something is scary (or seeing that other people are bothered by something) can be enough to cause us to develop the same fears. Another theory, many phobias have a trigger that helped create them. Basically, something unpleasant happened to us as a child and we associate it with spiders causing a fear/dislike. This might be something as insignificant as walking into a spider web and disliking it. Finally, the idea of something small that could be anywhere and could deliver a poisonous bite is quite scary on its own.
|
There is actually research suggesting that spiders are feared all around the world across cultural boundaries, and this points to them being a danger to the survival of humans early on in their development. Basically spiders used to be so dangerous to survival that being afraid of them was a beneficial evolutionary trait. [Here](_URL_0_) is a more detailed answer
|
Why do artist still release singles? Especially now that with streaming services, you can buy/listen to individual songs.
|
Publicity mainly. Big singles generate buzz for artists in the run up to an album release and can pump up sales.
|
Because most people only listen to the radio for short periods of time (e.g., their daily commute). To maximize the possibility of the listeners hearing the promoted songs, the stations play the songs a lot.
|
could someone please explain to me the differences between right political parties and left political parties (ex. Fascism and Communism) ?
|
The left usually is for high taxes to redistribute wealth, expensive social welfare programs, and big government spending The right is usually for lower taxes, less social welfare programs, and more moderate government spending
|
- Fascism is always nationalistic, whereas communism is "international" (edit: the practical forms of communism of course didn't give too many fucks about this) - communism demands a planned economy, whereas practical Fascism worked closely with the capitalistic elite - unlike traditional reactionary (extremely conservative) ideologies fascism in Germany and Italy did use some inherently socialistic ideas, like government controlled unions, public healthcare, public welfare - while both ideologies are inherently militaristic, the ideological motivations for this are different: Fascists seek to conquer, while communists seek to spread their ideology.
|
I've never seen people taking cats out for a walk on a leash, whereas people take out dogs all the time. why is that so? does it have to do something with the way cats have evolved?
|
Cats are contary, dogs love you. There are exceptions to the rule on cats like Bengal cats, or the odd domestic shorthair that LIKE walks but most cats if you were to put them in a harness (collar is a very bad idea for walking cats) will freeze up and probably flop on their side almost immedately. They are independed animals and most take high offense at being put in a harness. Or crate. Or locked in a big room with all the things they need.
|
Dogs and cats evolved to walk without things on their feet, so when you put boots on them, they feel like something is abnormal. In the animal kingdom, animals without functioning feet don't survive, so they've learned to not let things get into or on their feet. Some dogs and cats don't care, but most do, and most will learn to walk normally after a little practice.
|
Why is NASA using the Delta IV Heavy instead of building more Saturn V's?
|
Its costs. We don't need the power of a Saturn V for most launches. Most of the fuel burned in a launch is used to lift fuel. A Saturn V that holds a significantly more fuel than a Delta IV (6,540,000 lbs vs 1,616,000 lb most of which is fuel). If the payload doesn't require that much thrust to lift off why spend the money to lift the fuel you didn't need?
|
Fuel tank sizes can be deceptive. The Delta IV uses liquid hydrogen, which is much less dense than Falcon’s kerosene. Fully fueled, Falcon Heavy is nearly twice the mass of Delta IV Heavy (1,421 metric tons to 733 metric tons).
|
How does online money work? What's stopping a bank (or some other entity?) from just using computers to make money from nothing?
|
Laws and regulations. Let's say I'm a bank and I just decide to virtually print my own money from nothing. That's fraud. If and when it is uncovered through audits and reporting the result will be that the people who did it will go to prison, so people don't do it.
|
Instead of higher interest rates, it offers services like in person tellers, physical branches, linked checking accounts, notary services, certified checking and networks of no-fee atms. Enough people value those extra benefits that those banks don't feel the need to offer higher interest rates to compete with online no frills banks.
|
How do watches work, and how did someone figure out all the gears, crystals, springs, etc needed to make a watch without a battery?
|
Note that mechanical watches predate watches with batteries, and check this old timey video out. _URL_0_ My understanding of the evolution was that it began with big ass church or town clocks and worked its way down to clocks, pocket watches, and then wrist watches. It took a while.
|
Quartz crystals oscillate when a voltage is applied to them, and they oscillate at a very regular, stable frequency. By cutting the crystal to a particular shape, you can get a desired oscillation frequency (typically, for convenience, the frequency chosen is 32768 cycles per second, i.e., 2^(15) cycles per second). These oscillations cause the crystal to emit electrical impulses (quartz is a [piezoelectric](_URL_0_) material), which are then used by the rest of the watch to keep track of the time. [This description](_URL_3_) is quite good, except it refers to the quartz responding to electric charge rather than to voltage; [this page from the Smithsonian](_URL_1_technology/quartz.html) is also useful, as are the rest of the pages from their [quartz watch exhibition](_URL_1_). Edit: Typo fixed ('chose' -- > 'chosen').
|
How much water does it take to offset the dehydrating effects of an alcoholic drink (0.6 fluid oz)?
|
There is no simple answer to this, because the dehydrating(diuretic) effects of alcohol are a function of your BAC, not the ABV of the drink. There is a relationship between ABV and BAC but it includes other factors such as body weight, amout of drinks consumed, when the drinks were consumed, personal tolerance to diuretics effects, how full your stomach was when you started drinking, whether you are male or female, age, and other things. Without accounting for these factors it is very hard to simply correlate ABV and dehydration. P.S. This is why you should treat your pharmacist with respect. It's not an easy job they do.
|
It doesn't. You are likely just not taking into account (or measuring) the different alcohol amounts in the different beverages.
|
If I'm in a noisy room, when I open the window will sound escape and make the room quieter?
|
Yes, if reverberation is making it louder in the room in the first place. If you were in a mostly anechoic room, opening the window to a street would make it louder inside the room. So really depends on the room in question.
|
The air moving into your car doesn't have an exit, so it pressurizes the existing air in the car, which then pushes it back out, over and over again. This creates alternating high and low pressure zones, aka, the "WUBWUBWUBWUB". Sounds are basically just alternating high and low pressure zones, so your ears are hypersensitive to it. If you open the front window as well, the air will have a path to flow along, so it will be a bit quieter
|
Why do food companies say a food package is two servings, when it's clearly designed to be one?
|
It's basically an accounting trick, to get more favorable nutrition stats. The numbers listed for calories/fat/sugar...etc are all measured per "serving". So, if they make 1 "serving" smaller, then they get to claim fewer calories/fat/sugar...etc on the label.
|
Because neither you nor they are certain how much you are going to order. Many people change their minds during the meal, and they don't want to keep getting out their wallet every time they add something.
|
Is each blade of grass a single organism?
|
Multiple blades can be part of the same organism (i.e. at some point they join and share the same roots). On the right of the link below, you can see multiple blades that are all part of the same root system: _URL_0_
|
A patch of grass can be a collection of individuals or, since grass is rhizomatous, a single individual can grow shoots from its root and become its own bunch. These are known as bunch grasses. So the answer to your question is sort of, "it's both!"
|
How ADHD medications (Adderall, Ritalin, Strattera) work?
|
when i was on ritalin he explained that my brain was understimulated in some areas and it stimulated those areas so they acted more equally with the rest of my brain. kinda like a weak brake pedal on an indy car. with the ritalin the indy car now has stimulated brakes and functions better as a whole. coulda just been something to shut me up though. source dr hughes psychatrist.
|
In a typical person's mind, the part that says [Stay on Target](_URL_1_) is stronger than the part that says [Squirrel!](_URL_0_). I'd an ADHD mind, the "Squirrel!" part is stronger and makes it difficult to ignore new distractions. Stimulants help because they help stimulate the "Stay on Target" part.
|
Why does the top post on the front page seem to appear out of nowhere when all the other posts on the front page stay in roughly the same position?
|
Due to the time aspect of the algorithm, a post reaches 1, then slowly will move down (if it follows a similar ratio of up/down votes (likely), as opposed to dropping out of sight if there was a backlash of downvotes on it) But a new post would be upvoted at its own ratio which will often be higher than other posts on the front page, and therefore quickly reach the top position since it is newer and has higher upvote ratio than everything else currently on the front page (due to previous high upvote ratio posts are likely ranked lower due to age by this time)
|
Margin of upvotes over downvotes, volume of upvotes and downvotes, *speed* of acquiring new ups and downs, and possibly presence of comments. When something "rockets to the front page," it's because the item received a significant number of upvotes over downvotes (+500? guesstimating...) in a very short period of time ( < 30 minutes).
|
Why is there a limit to how high certain birds can fly?
|
The same thing that limits human beings: lack of oxygen. You have to be able to breathe in order to fly. The air is probably thick enough at higher altitudes for wings to still work, but not thick enough to give birds the oxygen they need to metabolize.
|
Animals are limited biologically by temperature and oxygen levels at higher altitudes. Different species of animals can fly at different altitudes depending on their biology. Bees, for instance, have been found on Mt. Everest, and in a laboratory setting were shown to be able to fly up to 30,000 feet. _URL_0_ Birds have been recorded flying at 37,000 feet. _URL_1_ The mechanisms by which birds fly at differing heights depends greatly on their particular physiology. Different body chemistry, flight mechanics and morphological traits will determine the heights different birds can reach. _URL_2_ It is a case where biology determines how high an organism can physically go.
|
When was the bow and arrow last effectively used in large scale battle?
|
At the Battle of the Little Bighorn (1876), the Lakota and Cheyenne were armed with bows as one of their primary weapons, in addition to various types of firearms and other traditional weaponry. This would likely be the last "successful" (victorious on the battlefield) use of bows in North America, at least.
|
hi! not discouraging further discussion here, but fyi, there's a large section in the FAQ on this topic * [Origins and dispersal of bow & arrow technology](_URL_0_)
|
When voyager 1 escapes our sun's gravity and exits the solar system, will it continue to orbit the centre of the galaxy at the same speed?
|
Gravitational force has [infinite range](_URL_0_). Voyager 1 will never *really* escape the gravitational force of the Sun, but it might get to a point where the gravitational force of some other body becomes more dominant.
|
This is such an excellent question! Yes, the sun moves! It, alongside the entire solar system, orbits around the centre of the milky way galaxy. Our solar system's velocity averages around 828,000 km/h (514,495 mph), which means that it would take our solar system around 230 million years to complete one full orbit around the galaxy.
|
Will any repeated chain of permutations on a rubik's cube always return the cube to its initial state?
|
Yes, you are absolutely right. And this can be related to a more general fact in group theory. The set of all possible possible permutations of the rubik's cube is a **group**. Basically, it means that if you perform one permutation, and then another one, you can consider the "product" of these two permutations as a new permutation. And the properties of this "product" are nice. This group has only a finite number of element, because it can be included in the set of all possible coloring of the cube. In such a finite group, *any element is of finite order* : this means exactly that if you repeat the same permutation enough time, then at some point, you will get back to where you started. Here, a permutation could be any particular sequence of elementary moves like "F-R"
|
What you are doing is considering all the permutation on the cubes of your Rubik's cube (with the constraint that a corner must go to a corner and so on ...). And you want to know if you can come back to the initial position using only legal moves You can use group theory to do that. What you are exactly doing is looking at the quotient of the permutation group of the cubes by the action of the subgroup generated by the legal moves. With this vocabulary, you are asking the probability that a random permutation is in the equivalence class (or the subgroup) containing the initial position. The cardinal of this quotient is 12 (I cannot find a good source for that, but the [wiki page](_URL_0_) should point in the right direction). By group theory, all equivalence classes have the same number of element which means that **if you do a permutation at random, you have 1/12 chance that it will be solvable.**
|
How can an odor be contained?
|
An odor is a series of particles dispersed in the air that land in your nose and dissolve on your epithelium in your nose, which then signals the brain about what just dissolved on it, which is what we perceive as smells. So, anything that can contain particles dispersed in air can contain an odor. It would have to be an airtight, imoermwable container.
|
Odor is carried by molecules. When you smell lemon, for example, little molecules from the lemon are making their way through the air to your nose. Now think about what happens when you smell shit...
|
Why in the present does life seem obnoxiously long, yet looking even a week in the past I can feel just how short it is?
|
When you think of the past, you only remember the highlights and forget about the times where nothing happened. Therefore, life seems really short when you reminisce because the highlights (your birthdays, wedding, graduation, promotion, etc) make up a very tiny portion of your life.
|
Time goes faster as you age compared to how long you've been around. Your first day on earth would seem to take forever because that's 100% of your life. After a week, a day isn't so long. It's 1/7th of your life. After a year, a week isn't so long. It's 1/52nd of your life. After 20 years, a year isn't so long. It's 1/20th of your life. And on and on. That's why it feels like Christmas comes earlier and earlier every year, because comparatively, it feels that way. Combine that with the fact that adults are WAAY better at occupying themselves with things that interest them, time flies even faster. Time is moving so fast, we're all basically already dead.
|
Is it ever 'not raining anywhere'?
|
There's no reason it has to be raining at some point on Earth at any given time so it might happen/have happened. It could happen all the time, or it could be so rare as to never have happened yet. I don't know enough about global rain frequencies to tell you. Only that there isnt really a reason it CANT happen. On a distantly related note, according to the [hairy ball theorem] (_URL_0_) there will always be a point on earth (and any planet) where there is 0 wind at any given time.
|
Clouds are so large that generally one cloud covers the immediate vicinity around you. So it appears that rain starts and stops simultaneously in all directions from the perspective of a person on the ground. But if you look at a rainstorm from an airplane, you can often see pockets of rain and non-rain across a fairly small area. It just isn't apparent from ground level. [This picture] (_URL_0_) is a good example. A person in the center of this storm won't notice significant differences in their immediate surroundings but from an external vantage point the rate of rain varies considerably.
|
Did Julius Caesar really defeated 200 000 Gauls with his 40 000 in the battle of Alesia or did he exaggerate?
|
As far as I'm aware the only source for that number is Caesar himself. I'd say you're right to assume that too high a number for an army of that period, particularly in such a politically decentralized area.
|
Out of curiosity, who, between 127 and 27 BCE besides Caesar, are you thinking about? C. Gracchus, I suppose, although that was technically a suicide. We don't know who killed M. Drusus or why; the most popular guess is Etruscans unhappy with his proposed citizenship laws. P. Clodius? I don't know if a street fight is the same as an assassination. Sertorius was killed by his officers. Who else?
|
Is there a limit to how much you can sleep in one "sitting"?
|
There is no hard biological limit to how much you can sleep at one time. Essentially, your body "knows" how much sleep you need on a nightly basis. As you get older, the need for sleep tends to decrease somewhat. If you haven't been getting enough sleep on a regular basis, your body will tend to try to "make it up" by having you sleep longer. (In my last week of Infantry Training, we had a week-long exercise, and I slept a total of about 6 hours over five days. When I got in bed Friday night, I slept until early Sunday morning.) Also, when you're ill, you tend to sleep more, so your body can reserve its strength to fight infection. In general, humans need about 8 hours of sleep per night, on average.
|
[this askscience post should answer your question more than adequately. TL;DR: For very short term sleep deprivations (a few days), the recovery of sleep debt is rapid. For chronic sleep restriction on the timescale of weeks to months, the recovery of sleep debt is much slower. On timescales of months to years or longer, we don't know whether chronic sleep restriction can be repaid or whether it causes more permanent damage that cannot be easily reversed.](_URL_0_)
|
If a person is convicted of a crime and gets imprisoned, and then escapes, but then it's proven that they never committed the original crime, can they still get in trouble for escaping?
|
Yes and no. Escaping from a prison facility is a felony. And any additional crimes committed during the escape are also still punishable. But if the escape didn't hurt anyone or property and you were found to be innocent while you were on the run it is unlikely that a prosecutor would file charges as long as you were cooperative. It is also likely the facility would insist that you divulge the details of your escape so that they can prevent further attempts. It would likely also require that you don't file a civil case against the state.
|
Most likely they would. If they had been found not guilty and were aware, why would they try to escape prison? The sentence would probably be reduced to a class B misdemeanor.
|
What do historians think about the assasination of John F. Kennedy?
|
[There is no credible professional historian who believes anything other than that Oswald did it, alone.](_URL_0_) If you'd like to read a book on the subject, I was assigned Gerald Posner's *Case Closed* as an undergrad, and found it quite thorough.
|
Not so well. In Robert Caro's last LBJ volume he talks about the relationship in detail. LBJ saw JFK as a lightweight in the Senate. But JFK saw the value in having Johnson on the ticket because oil-rich Texas was a crucial fundraising state for Democrats. Once in the Whitehouse JFK basically ignored Johnson and essentially treated Bobby Kennedy as his Vice President. Caro writes that during the run up to the Cuban missile crisis JFK solicited Johnson's opinion and was horrified by what he considered Johnson's irresponsible hawkishness. Their relationship got so bad that many believed Johnson was going to be removed from the ticket in 1964 in favor of then Texas governor John Connally.
|
How does HD Radio work, and what makes it clearer than non-HD FM radio?
|
HD radio uses the same type of radio waves as normal radio but the information is digital instead of analog. Analog audio can get warped and distorted as it travels over the air due to interference. Digital audio doesn't have the same problems. A digital receiver only has to tell if the signal is a 1 or a 0 at any moment. Even if there is some radio noise it's still easy for the receiver to tell the difference between a 1 or a 0. With analog, some radio noise can make it hard for the receiver to re-create the audio signal.
|
It's mostly dynamic range (how loud or soft something can get). We measure changes in volume in dB. Our ears have a dynamic range of about 120-130 dB, so we can hear the difference between loud and soft pretty well. Commercial CDs have a dynamic range of 96dB, which is close enough to the human hearing to be comfortable. Now FM radio (I assumer you're talking about FM) has a very limited dynamic range, about 50dB. That's a big jump. So, radio stations have to do what is called compression, which basically shrinks the dynamic range of a song, so it's harder to hear the difference between a "soft" signal and "loud" signal. Thus, you get a different sound from a CD to radio. Source: I'm an audio engineering student Edit: After some research, I also found out that FM radio can only transmit up to about 15kHz. All this means is that the high end of is a little muffled. Most people can hear up to 18-20kHz, so it's really only the tinny-high stuff that gets taken out.
|
What happens to water in space?
|
Here's a [phase diagram for water](_URL_0_). The y-axis (vertical axis) represents pressure, the x-axis represents temperature. So, to find out what phase water will be in at some particular conditions, find that temperature and pressure, and see what phase the point lies in. Three phases are represented on the diagram, solid ice (S), liquid (L), or vapor (v). In space, the pressure will be near 0 atm. The temperature can vary greatly, so water will be either ice (at low temperatures) or gas (at higher temperatures). Going from solid to gas without passing through the liquid phase is a phase transition called sublimation.
|
If I understand correctly, water, albeit frozen water, is surprisingly common throughout the universe.
|
What keeps water on Earth? What prevents the oceans from evaporating on a hot day?
|
Water does evaporate! That's what becomes rain... but the atmosphere can only hold so much water, so it rains and replenishes the ocean before any noticeable dip in ocean levels.
|
Water *boils* at 100ºC, but it *evaporates* at a lower temperature. The oceans don't boil and still they provide the water for rain.
|
What do you call the small broken up islands that surround northern land masses like Greenland?
|
I believe the word you are looking for is "archipelago".
|
An interesting question! I suppose it comes down to the way tectonic processes work. The processes that form continental crust mostly occur at convergent plate boundaries, which means they don't occur in random little spots throughout the oceans to create islands (hot spots do that! But we're talking about continents here). That means that we tend to add continental crust onto existing continental crust, which favors large continent chunks rather than lots of small pieces. Furthermore, lots of stuff moves towards subduction zones, which are often (although not always) found on the edges of continents. As islands move towards these zones, they're sometimes sort of scraped off the descending plate and added to the continent, again favoring adding pieces to already-big pieces of land.
|
Since humans have been reproducing for thousands of years, why isn't everyone physically attractive. Why are there this physically unattractive people?
|
Since agriculture began, people haven't always chosen their mates. In many cases families would arrange marriages years before the participants were fully grown. In other cases marriages between adults were done for political reasons. In these cases attractiveness would play only a minor role. Also, I believe there is evidence that people "find their level" of attractiveness in finding a mate. Therefore people of lower attractiveness will often mate with others who are "in their league" and are thus likely to have babies who are about as attractive as they are. Finally: attractiveness isn't entirely physical. A pretty but vapid person might be far less attractive than a less beautiful but more intelligent one. Especially when thinking about having a family.
|
Because it's still astetically pleasing to see any attractive person. And unattractive people are distracting because you focus on their negatives.
|
When you have sore muscles, is it better to move in a manner that avoids the feeling of soreness, or in a manner that "explores" it?
|
[This article](_URL_0_) says the following: > Cryotherapy, stretching, homeopathy, ultrasound and electrical current modalities have demonstrated no effect on the alleviation of muscle soreness or other DOMS symptoms. **Exercise is the most effective means of alleviating pain during DOMS, however the analgesic effect is also temporary**. Athletes who must train on a daily basis should be encouraged to **reduce the intensity and duration of exercise for 1–2 days following intense DOMS-inducing exercise**. Alternatively, exercises targeting less affected body parts should be encouraged in order to allow the most affected muscle groups to recover. (emphasis added) DOMS = delayed onset muscle soreness
|
'Sore muscles after physical activity, known as delayed onset muscle soreness (DOMS), can occur when you start a new exercise programme, change your exercise routine, or increase the duration or intensity of your regular workout. When muscles are required to work harder than they're used to or in a different way, it's believed to cause microscopic damage to the muscle fibres, resulting in muscle soreness or stiffness. DOMS is often mistakenly believed to be caused by a build up of lactic acid, but lactic acid isn't involved in this process'
|
Why can't we feel the g-force of the world spinning so quickly through space?
|
You actually *do* feel it. Because of your angular momentum, there is a slight centrifugal force acting in you, pulling you away from the center of mass of the planet. This effect, however, is small and is matched by the centrifugal forces experienced by everything around you — which all have the same or nearly the same angular momentum. You're not *aware* of this force vector because there is never an appreciable and swift change in the acceleration it provides — there is no *jerk* of it. Since gravity provides acceleration towards the centre of mass of the planet, our brains are used to constant acceleration and think of that as "steady" and "normal". We perceive not the acceleration itself but the *change* of acceleration — termed the *jerk*. So, in short, you're not aware of it because they're not jerks about it.
|
Dumb question, but I don't get why this works in space? I understand why a rotating object would have a pulling effect on earth (Like the carnival rides that force you against the wall), but why would this have the same effect in space where this is no gravity to begin with?
|
When scientific articles mention that they have "adjusted for" various factors, how is it done and how accurate are the results?
|
You can adjust for certain things by choosing the right things to measure and by trying to diversify your sample. For example, a common question is "Do men and women make the same amount of money?" You could look at total amount of money for a year, but then you are ignoring the amount of time worked. So to adjust for that you look at money per hour worked. That is better, but that ignores that there might be differences in experience in your sample. So you take a look at money per hour per year worked. In the case of the article you mention, they could do something like split the people in the sample into two groups, one wealthy and one poor. Then they split those groups into the fruit/veggy eating and non fruit/veggy eating. Now you can compare wealthy people to wealthy people and poor people to poor people. That way it should highlight the differences because of eating rather than just being wealthy.
|
/r/askscience may be able to better answer your question.
|
Why do people dance?
|
* a form of expression; an art form * socializing * it's a physical activity which releases endorphins, which then in turn would translate to "fun", because it makes you feel good I admit I am a terrible dancer and move like an epileptic robot, but that doesn't stop me from swaying and twitching my limbs for the reasons stated above.
|
Because you're making eye contact with them and you're both looking at each other's eyes to see where the other is going. When you feel that starting to happen, break eye contact and focus on the path you want to walk. As if by magic, you and the other person will cease doing "the dance" and continue on your way.
|
Why do videos get darker the higher the FPS?
|
The faster the camera is grabbing frames the less time the camera has to capture each frame. Less time means less light for the film or digital sensor. So just like setting the shutter speed faster on your point-and-shoot camera will result in darker shots, frames on a high-speed camera will likewise be dark.
|
Theres a difference between the fps of our eye and the fps on a screen _URL_0_ Read this it should help out with your understanding on fps :D
|
How do you check if your tap water is decently clean?
|
I can't think of any way that your landlord could have "switched" the water supply unless he's dug his own well out back and re-plumbed the building (which seems a bit crazy). There are definitely ways to go about testing for all kinds of possible contaminants. If you're in ON, Canada, [here](_URL_0_)'s a site with some info and contacts for accredited labs. Sending a tap water sample to a public health lab is free (in Canada).
|
The water that flows from your tap is treated, purified and in some cases minerals added. That costs money and also uses energy (fuel). In the country where I live we have no fresh water but we are surrounded by sea water. Fresh water is made from sea water using reverse osmosis - a process that produces good quality water but uses huge amounts of electricity. For us, letting a tap run for no reason is considered 'blasphemy'.
|
If the Earth is accelerating, and time is relative to velocity, then do we need to factor relativity into carbon dating?
|
Firstly, carbon dating is only available on samples that are less than 60,000 years old. Secondly, your sample is going to be in the same reference frame as the Earth. It's not going to be moving relative to the Earth. I haven't done the calculations, but at the speeds involved, the difference isn't going to matter all that much.
|
Wow, that was a scary search. i'm not sure if you'll be able to convince your co-worker, often people with young Earth beliefs are pretty sure of themselves already, but [here's](_URL_0_) one article, and [another](_URL_1_). Also, [this](_URL_2_) has a nice discussion of carbon dating and its accuracy.
|
How do lakes not dry up?
|
If it didn't rain for a really long time then they would. Lakes hold a LOT of water so it would take a long time to dry up. A little rainfall has more impact than you would think because a lot of rain that lands on the ground will eventually trickle down into the lake after a while
|
Lakes are very low energy environments. So while the hole in the topography they filled will have been irregular, over the long periods (thousands, perhaps even up to millions of years) that the lake is present, fine sediment gets settled out relatively evenly across the basin. The builds up a flat bottom. Once the water is evaporated, you're then left with a salt flat.
|
Why do the stars appear fixed?
|
The stars appear fixed because humans don't live very long and distances involved are mindbogglingly huge. When traveling along the highway, the median speeds by, the telephone poles move more slowly and the distant mountains hardly move at all—now consider the stars lightyears away. Those stars are indeed going about their own motion, here are two examples: _URL_1_ _URL_0_
|
There are more stars more densely packed in the center. We can't see them individually because they are so far away.
|
Is Gravity Weaker in the Center of a Stellar Body?
|
Within a star, compared to its surface value, gravity is much stronger towards the center, but becomes zero right at the center. This is because the density of the gas increases as you get deeper. Based on what we know about the sun, the gravitational maximum occurs 83% toward the center (17% towards the surface), where the gravity is 8.6 times its surface value.
|
Gravity isn't what is strong in a celestial body's core. Theoretically, the force of gravity in the dead center of a celestial body would be zero as you would be pulled the same amount in all directions. Instead, think of a planet as a collection of atoms, each of which is pulling on all other atoms of the planet. The result is the atoms form into a sphere, as a sphere has the lowest potential energy as atoms move and shift about. Denser elements such as iron will be pulled into the center during this process, eventually resulting in a dense, metallic core.
|
What evidence do we have that Hannibal crossed the Alps?
|
hi! you may be interested in a few earlier posts * [Have any elephant bones ever turned up in the Alps, where Hannibal lost a few trying to cross into Italy?](_URL_2_) * [Did anyone ever find remnants of Hannibal Barca's elephants that died during his crossing of the Alps?](_URL_0_) * [Have any remains of the war elephants that died in Hannibal's crossing of the Alps during the Second Punic War been found?](_URL_1_)
|
50 BC is a different story, but in the Second Punic War, the Romans sent their army to Marseille on ships in an attempt to cut Hannibal off from Italy (they were late). The Northern reaches of Italy, Liguria or Cisalpine Gaul, took the Romans a long time to conquer. At least one commander destined for Spain was killed on his way through Liguria in the second century (Livy 37.57). However, those regions were completely integrated after the Social War. This meant that the march through the Alps was much safer than it had been in the time of Hannibal.
|
Could you please explain a cavalry charge? Did charging cavalry physically crash at galloping speed with a mass of infantry?
|
Hi, you may be interested in a few earlier responses on cavalry charges * [How is it that such an unwieldy animal such as a horse was so effective in combat, especially when used to charge heavy infantry formations.](_URL_4_) - /u/britainopplsnerf discusses the effectiveness of horses; /u/Rittermeister and /u/Second_Mate talk charge tactics * [How do Cavalry charges actually work?](_URL_4_) - /u/DonaldFDraper and others discuss 17th/18th c; /u/MI13 looks at earlier eras * [Cavalry charges, in real life wouldn't the people in the back of the unit smash into the people in the front of the unit?](_URL_5_) - /u/Georgy_K_Zhukov, /u/Rittermeister and others describe charges, and include a few video illustrations * [Why was cavalry so deadly?](_URL_5_) /u/Aethelric , /u/TheGreenReaper discusses the value and effectiveness of cavalry
|
Cavalry charges were powerful against broken infantry lines and were often used to break a formation. The cavalry needed to be disciplined, in formation, highly skilled, and outfitted with the best arms and armor for a charge to be effective. If an infantry line did not rout after a charge and the cavalry became entangled with their enemy the cavalries effectiveness decreased dramatically and the infantry attained the advantage. The smart move for cavalry after a failed charge would be to disengage and prepare for another attack. Also steel armor wasn't particularly heavy and a knight could easily get up after falling from his horse, so long as there weren't enemies around him keeping him down.
|
Why is it that when a hologram is cut in half both halves retain the whole image?
|
Each half retains the whole image, but only half of the possible viewpoints. Think of it as though each point in the hologram contains the information for what all views through that point look like. If you lose half of the, you can still see the whole image, but you can't see what it looked like through the missing points.
|
My mind has been blown. I didn't know about this before reading your question, so I decided to research a bit and maybe make the science a little more ELI5-ish but, damn, there's exactly zero information out there about this. It's all so very vague like: > The image at upper right is the view through the larger part of the hologram, while that at lower right is through a small corner cut off the hologram. While the view through the small corner is from a particular point of view, it contains the whole object. I'll be here waiting for an answer with you.
|
What is the difference between Stand Your Ground Law and Self Defense Law in the United States?
|
Self defense is for if you're under immediate threat and you had no choice but to harm/kill to save your own life. In some states though, law says if you can run away, you should do that opposed to trying to fight. So if someone breaks into your home, and you run up and shoot them while after they stepped inside, that's not self defense under some laws. Stand your ground means that you don't have to run. Pretty much as long as you feel your life is threatened, you can do whatever you feel is necessary to defend it. There's still some stipulations. You can't shoot someone in the back, like if they tried to run away. They have to be within a certain proximity to you. You can't shoot someone 50 yards away.
|
Many states in the US have a *duty-to-retreat* law. This means that if you can safely do so, you must leave the area in which you are in danger. You can only use deadly force if you are unable to leave the area. Stand Your Ground laws differ in that it allows you to use deadly force if you feel your well-being is in danger with no requirement to retreat.
|
If the Budha promoted a life detached of all things (especially materials things) how come budhism (Tibetan, Indian, etc...) have such a rich decorum and apparat ?
|
People don't necessarily get attached to buddhist art. It is taught in buddhism that making stupas and art of buddhas gives you good karma and merits, so there is that. Tibetan buddhism was heavily inspired by bon religion, so that is where the art comes from. There is also the fact that religion inspires people heavily(probably the reason it persists) and therefore art is going to be made about religion.
|
That is the central point of Buddhism actually. Life is essentially unsatisfactory. You don't get what you want, you get what you don't want. When you get what you want, it isn't all that you had hoped, doesn't last as long as you want, would be even better if you just had that other thing too. I think it all arises from the very nature of consciousness and the mistaken belief that we are supposed to be happy.
|
Why nearly a quarter of Nobel Prize winners are Jewish
|
The Jewish people have had a culture which stresses education and intellectualism for centuries. This is mostly because of their depressingly long history of persecution and minority status. In order to keep their heads above the water and succeed in societies which looked down on and oppressed them they adopted an outlook that praised knowledge, wisdom, and intellect as means to get ahead in a world that was against them from the start. They also have a strong scholarly tradition dating back to BCE. Obviously, any culture that prides education for millennia will create a huge amount more innovators and geniuses than others that don't - or at least, not to the same extent. Similarly, because Jewish homes, land, and valuables where often forcably taken from them, they learned to keeep their wealth mobile and honed their financial skills who save as much of their wealth as possible, just in case. This lead them to often end up working in banks, and that's the origin of the Jewish banker stereotypes as well...
|
One factor is that jews have accumulated a large number of cultural practices/rules that can make it difficult to assimilate into other cultures.
|
How accurate are human beings at comparing frequencies(as in tuning a guitar)?
|
Humans can detect about a 0.6% change in frequency (within audible range). Read this: _URL_0_ Of course, there's a wide variation between people. [Try testing yourself!](_URL_1_) I scored 1.8 hz, which is (I think) a frequency change of about 0.4%
|
Hi there -- while there's always more to be said on these topics, [we had a previous thread here](_URL_1_) about guitar tuning that may be of interest.
|
Why do illegal immigrants who are already in France - a safe, prosperous developed nation - want to get into the UK so badly?
|
Because the United Kingdom has no form of identification act where as France does, so they're safer in the UK.
|
Economics. Firstly, you have an improved mobility of labour which reduces frictional unemployment. In theory therefore, a worker can lose his job on the border between France and Belgium. Now, without the EU he would only be able to look for work inside of France, but with the EU he can work across the unpatrolled border without the hassle of obtaining a visa or anything like that. Furthermore, trade. The EU have no tariffs within its borders. Therefore, businesses started in the UK can very easily become exporters without the large costs of tariffs. Consumers benefit as they have greater choice and cheaper prices, and producers benefit as they have lower average costs (also, large external tariffs reduce the impact of multinational corperations on local business). Then on a social level, if I so choose I can go and live in France and then go to Spain or Germany for the day and I won't need a visa or even a passport. This is just a few of many by the way.
|
Why is it taboo to wear white after labor day?
|
Because white is a color associated with summer fashion, and Labor Day is widely considered the last day of simmer. But this idea itself has fallen out of fashion over the years.
|
It isn't that way everywhere. Some countries have white as their mourning color. As for why it is in many western cultures, I'm curious too.
|
Can somebody else listen to what I'm listening to if I'm using a bluetooth headset?
|
Ideally, no. In theory, yes. In practice... probably not. Note: the system is only as strong as its weakest link. If an attacker can break _any_ of the following, they're in. Ideally, the Bluetooth encryption algorithm would be foolproof. In theory, E0 (the encryption algorithm) [can be cracked](_URL_1_). Since it requires approximately 41.8 MiB of frame headers (the first 0.87% of each frame) and approximately 256 gibicomputations, this is probably not going to happen in practice. I'm just going to skip to the biggest issue, editing some more in if I have time. Bluetooth systems such as headphones usually use a 4 digit pin. This gives a truly vast 10000 possibilities. Most fleshy meat brains can count that high. It's trivial to try all of these, identify which is which, then listen in. In practice, though, most people wouldn't even go that far. EDIT: Oh look, [somebody did](_URL_0_). `English("most people wouldn't") * len(Earth.population_of("humans"))` is greater than one.
|
Bluetooth does support an adhoc network of up to 7 devices, with one acting as a hub for the others, in it's low level protocols. However, since Bluetooth was designed to replace cables, most of the 'profiles' i.e. the virtual cables that are implemented on top of the protocol are designed to simulate 1 to 1 connections only, the two most used profiles being the virtual serial port and the virtual headphone jack. This is a problem for things like stereo wireless headphones that are not themselves connected to each other with a cable, as the data must be relayed from phone to earpiece 1 and then on from earpiece 1 to earpiece 2, causing additional latency. This is why the audio might get out of sync with video you're watching on a phone or laptop using wireless earbuds. There are new audio profiles that support 1 to many, I'm pretty sure the Apple AirPods use it, but most bluetooth headphones and speakers don't support them yet.
|
How did 19th century socialists and communists feel about colonialism?
|
Colonization was a dividing issue in the second international. The more liberal, or reform minded socialists tended to support colonization, the centrists turned a blind eye to it and it was only the radical left, the forerunners of the third international who really turned their interests to the people in the colonies. Marx however wrote extensively against British colonialism, so these liberal socialists really had no intellectual backing for their position.
|
Please note: Even though OP is phrasing the question such that it sounds like a current events question, it is still a valid question regarding the historical context and attitudes toward communism any time before 1995. As usual, single word answers or bare Wikipedia links will be removed. Please be sure you're commenting within the guidelines outlined in the subreddit rules. OP: If you could add a little more detail to your description that might help.
|
Why don't College Football programs use a Pro Style offense if that's what is deemed as necessary to succeed in the NFL?
|
Because College coaches aren't getting paid to create NFL quarterbacks, they're getting paid to make the boosters happy, which means winning college games, which doesn't necessarily mean running a pro style offense.
|
Because defensive players in the Nfl are bigger, faster, smarter, and more agile.
|
Why do certain tv channels come in when I'm close to the antenna?
|
It's because the signal is already right on the cusp of being strong enough. Your body interacts electrically with the antenna and the radio waves and distorts the antenna radiation pattern. An antenna is sort of a lens and by smooshing it on one side you can actually make it focus a bit more in one direction. Smoosh it just right and the signal is suddenly just strong enough to receive.
|
Im not 100% sure, but my best guess would be the delay occurs as the TV's in your room are receiving a signal from a single antenna (source) located elsewhere and then forwarded on to your TV. So the delay is the sending the request to the central hub and then it giving it back. Also from my experience a lot of Hotels have older, and/ or generic branded TV sets which are also slower to go about this process.
|
If games can render near photo-realistic graphics in real-time, why does 3D animation software (e.g Blender) take hours or even days to render simple animations?
|
Games use a lot of tricks to fake the photorealism at less cost than doing it for real (compressing textures, popins, etc.). The most important one is the lighting. You may notice that shadows don't always look right in games. You know how when you hold something colored under a light, it starts to glow that color? Games don't do this because they don't simulate the light for real, they change the textures to make shadows and light. Real animation software takes no shortcuts and renders things with full textures and full detail. This software often calculates the path of each ray of light bouncing around the area until it runs out of steam. This calculation is what takes all the time because there are millions and millions of light rays to trace. Fun sidenote: a few weeks back, Nvidia managed to make real-time Ray tracing possible using some new technology they're developing, but so far it still take colossal amounts of power to run.
|
Games use a completely different technique than programs such as Blender to create 3D graphics. Games have to run significantly faster to provide fluid motion and so use many tricks to essentially "fake" many effects that make a scene seem realistic. They do this through rasterization, the process of transforming triangles into screen coordinates and using "shaders" to calculate the colour of each pixel. As you only see one triangle at a time, things such as lighting have to be manually simulated. Blender (and other 3D modelling software) instead prioritise complete accuracy and so as a trade-off take significantly longer for the small increase in realism. They use ray tracing, where for each pixel a ray of light is sent out from the virtual camera. Each time it intersects the geometry the final colour is updated. Since this is a much more realistic model of how vision works in the real world, things like shadows and reflections are an automatic by-product.
|
why can humans get sick from eating raw flesh but animals do not?
|
1) Animals do get sick. We as humans just do not pay attention to it. 2) Animals in general eat fresh kills. The various pathogens in the meat have not had a chance to replicate to dangerous quantities yet. Humans do not eat fresh kills. The meat that we get has been sitting for days if not for weeks. Additionally if we have ground up the meat we have greatly increased its surface area and the amount of bacteria that can grow in it.
|
Muscles on animals are rarely infected. Any bacteria comes from outside contaminants like knives or though the air. So unless there is some extraordinary cases you can just cook the outside of the meat as the inside is perfectly fine to eat raw. There is still risk of infections if the animal had been sick. Most of the cases when the meat looks fine but are infected comes from parasites. There is a few parasites for cattle, sheep and pigs but not that is harmful for humans. With the exception of mad cow disease which is not present in the meat but in the spinal cord and brains of cows. However poultry can contain salmonella which can affect humans. This can be present in meat and eggs. For fish there is also some parasites which can affect humans but they can be handled by freezing the fish to very low temperatures which kills the parasites. This is why you can eat properly sources sushi.
|
Why is cannibalism so likely to cause disease in humans, but eating meat from other animals poses no apparent threat?
|
It's not eating another person's body that causes prion disease, it's specifically eating a person's brain and other nervous system tissue, if that person is himself suffering from prion disease (Creutzfeldt-Jakob disease). Similarly, eating nervous system tissue from cows that have bovine spongiform encephalopathy (mad cow disease) is problematic. So it's not eating people that's the problem, it's eating people's brains. If you stick to eating a nice leg, or some breast meat, cannibalism is totally fine (at least as far as prion disease goes).
|
Eating human meat is not really much different than eating pig meat, with some important caveats. Eating human brain and spinal cord tissue can lead to transmissible prion diseases, which are equivalent to *Mad cow Disease* that afflicts cattle. This was an issue in some tribal cultures in Papua New Guinea that ritualistically consumed the brain matter of deceased relatives leading to the disease known as *Kuru* _URL_0_
|
How do cassette to CD/mp3 adapters work?
|
An old school cassette player worked by passing a magnetic tape past the [cassette head](_URL_0_) (the shiny thing on the left) which converts the magnetic changes in to an electric signal. But the adapter has a [head](_URL_1_) that does the reverse (electric signals to magnetic) which the cassette head in your deck can make sense of. So instead of going through recording and playing back later, electric signal - > magnetic changes on tape, tape later played back through cassette head, it skips a stage and goes electric signal - > magnetic changes (but not stored on tape) and then back to electric through cassette head again. Not an optimal solution but it works.
|
A standard cassette tape has 4 different stripes (tracks) of audio recorded on it. The heads only read two of the outside ones when playing normally. Flipping the tape gives you the two on the other side. [Looking something like this](_URL_0_). A tape with auto-reverse either has 4 heads & chooses the right one **or** it has a mechanical device that flips the heads around.
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.