Best products from r/explainlikeimfive

Animals are not the only ones which use tools, there has been documented tool use in many primates, bird species, invertebrates, and other mammals. Tools are not unique to humans. Just google tool use in animals, or watch videos of them using tools on youtube.

> Have an advantage over every other species ever?

Well, we still have a long way to go. We are not the longest lived species, or even the longest lived kind of species. For example, the bacteria have been around for billions of years, we hominins have only been around for ~7 million years. If you were to look at this from the perspective of an elephant or dolphin, there are plenty of things that they can do that we can't (like swim very well at all). So why have you determined that intelligence is the best and most superior trait to which we should compare all other species? That is a very human-centric point of view. From a dolphins perspective we look pretty dumb in the water.

What makes humans unique?

The short answer is not much, maybe aspects of three things: language, cognition and culture.

The long answer is this: Animal intelligence and intelligence in general is very very hard to define. Traditionally, we would test animals and define them based on what we thought humans could only do. One of our most defining characteristics was thought to be the use of tools - but that is so obviously not true, many animals from various orders use tools. And so we went down the list of things we thought were unique to humans and found that on some level or another animals could do the very same things we could - albeit under different contexts, usually pertaining specifically to the needs of the animal. I guess the easiest way to discuss this topic is to let you know about where animal behaviour science is.

Aspects of language: mainly in how complex we can make it, and our ability to change it so quickly. Animals also communicate in many different ways and we are still discovering new modes of communication. Some species display tendencies of recursiveness, syntax, regional dialects and other aspect of language that one might consider "human". This is a highly debated area.

(Human) language may require complex thought, but complex thought may not require language. It is hypothesized that "theory of mind must have preceded language use, based on evidence of use of the following characteristics: intentional communication, repairing failed communication, teaching, intentional persuasion, intentional deception, building shared plans and goals, intentional sharing of focus or topic, and pretending." - all of these precede language and we see many of them being expressed in animals, especially within the primate order. So first cognition then language. Why is this important? Because while animals may not be able to express themselves verbally in the same way we do, they may approximate us in many other aspects of cognition. This is important when we consider ethical treatment of animals. You wouldn't lock a 3 year old in a cage...yet that is exactly what we are doing with chimpanzees, dolphins, and elephants. You wouldn't preform tests on a 5 year old yet we do that with macaques and rats. We are beginning to understand that these species feel, react and think much like we do - yet we still consider them to be "others" which are less worthy. This isn't a PETA statement, I am just trying to get you to think about why we treat other animals the way we do and if it is justified.

We also need to consider that many animals communicate using other senses - smell, touch, they even use magnetic fields to sense their world. Testing them on their ability to use speech or writing is biased. How should we test them? or even begin to compare them to humans? We also need to consider that our 'voice boxes' are developed in such a way that enables us to talk the way we do. You can't roar like a lion or make ultra low frequencies like a elephant - so why should we judge them on their ability to talk exactly like us? I am trying to get you to think from the perspective of another animal, not from the perspective of a human.

Language and communication take many forms. It has been postulated that gestures played an important role in pre-language hominins (including early humans), in that they used gestures rather than words to communicate. The snag is that there is no way for this to be archeologically preserved like written language or oral traditions and gestures don't require specific physical adaptions (i.e. you don't need a "voice box").

Aspects of cognition: We know that animals are capable of cognitive reasoning, problem solving, they teach and learn, they feel many if not all the emotions we feel especially mammals, they are capable of deception, lying, cheating etc. They have a concept of the "self" and "others". They are knowing, being and living like us to top it all off... they also have morals.

However, humans do stand apart in some key areas of cognition. Some researchers surmise that cooperative breeding enhances the performance of social cognitive domains and it also motivates the individual to share mental states with others. Cooperative breeding is a social system where mothers require help from others to raise their offspring - all human cultures exhibit this trait and this developed because we are bipedal and have trouble giving birth. Combined, cooperative breeding and the motivation to share mental states leads to shared intentionality, which is the ability and desire to work collaboratively with others towards a shared goal, as well as understanding that others are aware of your intentions. Cooperative breeding in primates to date is observed only in callatrichids and humans, both of which exhibit shared intentionality. What sets apart humans from other cooperative breeders with shared intentionality is our ancestral ape-level cognitive system. The unique combination of social cognitive skills, ape-level cognitive skills and shared intentionality led to the development of our species-specific traits, including language and enhanced cultural transmission. Our ape-level cognitive skills stem from freed grasping hands, our tool use and ability to solve complex problems.

In theory, extant apes have all the necessary cognitive preconditions (i.e. simple understanding of others mental states) approximating humans but they lack the motivational components of cooperative breeding, and thus lack shared intentionality. However, groups of chimpanzees hunting involve the delegation of tasks (i.e herders, ambushers) where all participants must assess the others hunting position and effectiveness in order to successfully carry out a shared goal. What is contested is whether they understand that together they are dedicated to the shared goal, a key component of shared intentionality.

Although there are two major camps on this it is thought that modern human intelligence and behaviour developed about 60,000 years ago in what is known as behavioural modernity. Before this date humans could not use language in the way we do it now, and effectively were more like chimpanzees in terms of intelligence. Humans evolved about 200,000 years ago. Others think that our intelligence developed slowly, over time not from one single mutation or behavioural event.

Aspects of Culture Animals posses culture in much the same way we do. There are countless examples and I would be happy to provide them but this post is already long enough. Human culture is only different in one way - we build upon previous experience. Known as the ratchet effect we can take someone else's idea and change it slightly to build on it, the previous idea is never lost. Our knowledge is continuously building upon its self. Animals have a harder time accomplishing this, if a novel idea is presented it takes a long time for it to take hold.

Fire and Cooking

I think fire and learning to cook food definitely changed the way our brains work - only fire and cooking predate humans. Physical fire and cooking evidence dates back 400,000-700,000 years. Things like fire pits and charred remains. Morphological evidence dates back 1.2 million years with Homo erectus being the first hominin to show morphological changes due to a change in diet - the teeth change, the length of the intestine changes etc. If the hominin body underwent such drastic changes as a result of cooking food, then why not the brain as well? There is a chimpanzee named Kanzi, who learned without training how to build a fire and cook food. So it is not necessarily that our closest cousins can't do something we think is uniquely human - they lack the motivation to do so.

Summary

My favourite quote that revolves around this topic is this: "“Everybody is a genius. But, "if you judge a fish by its ability to climb a tree, it’ll spend its whole life believing that it is stupid." – Albert Einstein. We need to make sure we are testing animal's intelligence in their own right - not based off of our own preconceptions or misconceptions. Moreover, its not cars, or guns or any modern object that we have that makes us unique it is the underlying behaviours and traits (like enhanced cooperation and cumulative culture) which make us unique.

If you have any questions or specific examples you would like me to explain please let me know.

TL;DR The only things that make humans different from other animals is that we have complex language, cumulative culture and shared intentionality. This does not make us better, just different.

We have a very good understanding of their intelligence. They are probably some of the most well studied species in terms of behaviour and cognitive abilities on this planet. In ELI5/TLDR* most researchers would characterize their intelligence of being equivalent to a 2-3 year old human child. Just a short list of things that characterize these species:

• They form long-term social bonds and remember individuals
  
  
• They are able to recognize self from other
  
  
• They are able to lie
  
  
• They are able to understand fairness
  
  
• They are able to make, modify and use tools
  
  
• They have culture and tradition
  
  
• They are able to demonstrate empathy
  
  
• They feel the same or similar emotions to humans
  
  
• They have morals
  
  
• They mourn the dead
  
  
• They are able to solve multi-step problems
  
  ...
  
  I suppose another way of looking at this is what do we have that they lack. What makes humans unique?
  
  We know of some factors that contributed to our awareness and unique intelligence as compared to other living species. It is important to know that this is a very active area of study in many different disciplines (psychology, biology, animal behaviour, psychiatry, physiology, anthropology, neurology, linguistics, genetics, archeology...).
  
  
• Traits we inherited from our distant ancestors. Obviously all species are a cumulation of inherited traits. Who we are today is largely due to who "we" were in the distant past. We inherited a strong tendency to be a very social species from our mammalian ancestry. Mammals are social beings, humans included. We inherited opposable thumbs from our early primate ancestors. Humans are not the only species with opposable thumbs so it is not a trait that is unique to our species. However, the inheritance of thumbs enabled us and the other primates to develop fine motor skills like precision grip. This enables us to manipulate objects, and make/modify tools. Humans also inherited an upright bipedal posture from our early ancestors. Humans are not the only bipedal species (after all, all birds are bipedal!) but our upright posture has given us many advantages, namely that it frees our hands to do other tasks.
  
  
• Brain/body size ratio & exceptional brain gyrification is a somewhat useful indicator of how intelligence a species is. The correlation is decent among related mammal species, but it breaks down when applied to distantly related animals. It underestimates intelligence in heavy animals like horses and overestimates small animals like mice and birds. You also have to consider what the animal's brain has evolved for. Bird's typically have very large brains for their body but may not be exceptionally smart. A lot of that large bird brain is used for flight calculations and isn't available for higher level processing. Fruit flies have enormous brains compared to their mass, but that brain is simply too small to have any real thought processes. Humans are highly intelligent because they have an extremely large brain for their normal body mass and that brain has evolved specifically to perform complex thought. Size isn't the only factor, scientists also consider the degree of specialization, complexity of neural connections, and degree of brain gyrification. Humans score high on all these physical qualifiers associated with increased intelligence.
  
  
• Two cognitive traits thought to be unique to humans - shared intentionality and cumulative culture. Shared intentionality goes one step further than being able to solve problems as a group, it involves anticipating the needs of others and the situation in order to solve a common goal. This requires incredible foresight, flexibility, and problem solving skills. It requires an almost hyper-sociality group structure. We couldn't stick 100 chimpanzees on a plane and expect it to land in one piece...but you can stick 100 human strangers and all, for the most part, get along just fine. This level of cooperation is rarely seen among other animals (save for the Eusocial insects, naked mole rats, and perhaps Callitrichid monkeys)...my point is we have a shared intentionality that allows us to be hyper-social and cooperative. Cumulative culture goes beyond the cultures exhibited by other animals. Other animals have culture where [non-essential] traditions are passed on from one generation to the next and can be modified slowly over many generations. Humans also have traditions, but these are past on much more easily between individuals. Moreover, these traditions are quickly modified, almost unlimited times within a generation. We are able to rapidly build upon the ideas of others and modify these ideas to suit new problems. Moreover, our adults, as compared to the adults of other species, are much better at learning and retaining new skills or traditions. Generally speaking, the age old adage "you can't teach an old dog new tricks" applies well to the non-human animal kingdom.
  
  These two traits, shared intentionality and cumulative culture, led to the development of other aspects of our being which are unique (e.g language). Everything else that we can do is just a happy by-product of these two traits: being able to go to the moon, or build a super dam, or create art, or think in the abstract, maths, industrial agriculture...Those things are by-products of our level of cognition. Our uniqueness is derived from shared intentionality and cumulative culture plus a couple of random physical traits that we were lucky enough to inherit from our distant ancestors - a big brain, bipedalism, and opposable thumbs. We are not the only species with a large brain-to-body ratio, we are not the only bipedal species, and we are certainly not the only species with opposable thumbs - these are physical characteristics that we inherited from our distant primate ancestors. These traits built the foundation for what was to come.
  
  Whatever the pressure around 40,000-50,000 years ago we notice a significant shift in the archeological record. All of a sudden humans are making cave art, our hunting tools are changing rapidly, we began to engage in long distant trade, we made jewellery and we even had symbolic figures - perhaps the seeds of language. This is known as the period of behavioural modernity. Not only did these humans look like us, they acted like us too. Its hypothesized that an infant from this time could be raised in a modern context with little to no intellectual deficit...we wouldn't be able to pick them out of a crowd. Humans haven't gotten more intelligent over time. It is hypothesized that a human from 50,000 years ago is anatomically and behaviourally modern.
  
  So, if we aren't any smarter - why do we have cell phones and galaxy print jeggings and people didn't way back then? Increasing complexity - we know more than people in the past because we've built upon what they've learned. Humans have always been smart, and our great benefit is that we build on other people's discoveries. Someone figured out how to domesticate plants, someone figured out how to sew cloth, someone figured out how to weave materials, someone figured out synthetic materials and dyes, someone put it all together in those jeggings. We just build on what other people have found out. This is cumulative culture in action. Humans today are not more intelligent than humans living 50,000 years ago - we both have the same potential. The difference between us and them is we have a wealth of shared knowledge to draw upon, and they did not. Humans 5000 years from now could be asking the very same question..."Why didn't they invent warp travel, its so easy!"...well we don't have the wealth of another 5000 years of experience and scientific study to draw upon. We only have what our ancestors gave us. As more and more knowledge is accumulated we should in theory progress faster and faster.
  
  Some interesting books on the subject:
  
  Age of Empathy
  
  Our inner ape
  
  Moral lives of animals
  
  Affective neuroscience
  
  Mothers and others
  
  

The ability to feel, to have emotions, are not limited to human beings. Other animals also have and express emotions, from reptiles, to birds, to mammals. However, one could argue that mammals do it best. Our hallmark is that mammals, humans included, are very social beings...with sociality comes the ability to feel complex emotions.

Affective neuroscience is a very interesting area of study which examines "the study of the neural mechanisms of emotion. This interdisciplinary field combines neuroscience with the psychological study of personality, emotion, and mood." It also examines how our own neural mechanisms are mirrored in animals (and especially mammals) because of shared ancestry. The study of motion is definitely a very active area of science that permeates many different fields - evolutionary biology, animal behaviour, human behaviour, animal communication, human communication, origin of communication, psychology, psychiatry, neurobiology...each look at different questions concerning emotions.

In ELI5 words this means that animals are certainly capable of feeling emotions because the neural mechanisms that produce emotions are conserved through evolution, and are similar to the neural mechanisms that produce emotions in ourselves. All mammals, being related through common ancestry, have even more similar and conserved mechanisms - humans are of course mammals too!

But a few things to note:

1. The way animals express a particular emotion may differ from the way humans express that emotion. For example, humans often smile to exhibit happiness. But for the rest of the primate order smiling is either a signal of submissiveness or fear. This does not mean that other primates are incapable of feeling happiness, but that they very likely express it in different ways from ourselves. We also have to be very mindful that other animals, even cognitively complex ones, may be physically constrained and incapable of complex facial expressions. For example, we know dolphins are capable of a lot of complex cognitive tasks, they are able to identify themselves in the mirror and they may even have names for one another...but they don't have the facial musculature to make the expressions that are, well, as expressive as ours. Their emotions may not even be obvious for this reason, but that doesn't mean they don't exist.
   
   
2. Humans like to make emotions poetic, like love. But love is simply a kind of attachment emotion. Humans become attached to each other and objects, sometimes to the point of obsession. Animals also become attached to each other. Mothers and their infants, bonding pairs of adults...all forms of attachment exhibited in the animal kingdom. Again if you were interested in studying love, as a scientist you would actually study attachment. I recommend the book affective neuroscience: the foundations of human and animal emotions. It can be rather technical, but it is very good read. In any case, if we want to objectively study emotion and their origins, we sort of need to take the "humanity" out of emotions and look at them in a more universal way.
   
   As to why emotions would be beneficial there are a number of good reasons. First, it allows social beings to create meaningful attachments to each other, strengthening group bonds. This may allow a group to be better able to accomplish a task, which may benefit some or all of the group members. For example, defending a food resource from a neighbouring group. Emotions might also help an individual remember a negative experience. For example, becoming frustrated when being treated unfairly. This might help an individual remember who is helpful, and who is not. Even if the animal cannot recall a specific memory, they may form impressions of individuals, in the same way human babies form impressions of those around them. Thus for a social being, emotions may help an individual form positive or negative associations with other individuals.
   
   Edit: For something a little more directed towards the layman, the moral lives of animals is a very good read, as is age of empathy.

If I may, I'll throw in my somewhat-learned 2 cents. I have read a fair number of books on the subject and am currently studying music at the undergrad level--I'm by no means an expert.

If you're interested in the neurological understanding of music, I would recommend the book Music, the Brain, and Ecstasy. Pretty good read that goes into some detail without requiring an MD to understand. Basically, we respond to tension and resolution because of tendencies in our brain to seek out new and variant stimuli.

You mentioned major sounding happy and minor sounding sad. It would be interesting for you to know that this was not always the case. If you're playing in an orchestra or wind ensemble, chances are most of the music you're being exposed to in that setting is from the Classical and Romantic periods of the so-called Western Music Tradition: Beethoven, Brahms, Mozart, Haydn. Maybe some more modern music as well, but probably nothing too "out there". Also bear in mind, most of the music you hear on the radio, pretty much since the 1970s is very closely related harmonically to classical music from the Classical and Romantic periods.

All this is to say that if you look at Baroque music and earlier, or more modern Western music, as well as music from any other cultural tradition, you'll find very different understandings of harmony, melody, and rhythm. There are few universally enjoyable traits in music across various cultures and types of listener. /u/Bears_in_Blue_Houses has some good points: repetition is usually favored, and people usually like music they can understand and relate to. Beyond that, it really depends on 1. why you're listening to music and 2. what music you're used to. Some people desire intellectual stimulation, and find more complex harmonies, rhythms, structures, and sounds to be enjoyable; others look for simple beats to dance or relax to. Most people look for different things at different times.

> Rhythm comes built into your body. You have a heart beat and if you close your eyes in a quiet room you can feel and hear the blood pumping in your ears. Your body is designed to be rhythmic.

Complementary reading:

(WARNING: I'm not an expert on anything, this is me trying to push an idea that I like upon which I've done no serious research at all, approach with skepticism and caution!)

I remember reading in The Ego Tunnel by Thomas Metzinger (which I don't have anymore and can't go back to) how the synchronicity of our neurons firing played a major role into creating this layer of self-vs-the-world feeling essential in creating a sense of consciousness in the human brain, to the point that a slight delay could have been at the source of some sorts of schizophrenia like feeling totally disconnected with the world or at the opposite of the spectrum a feeling of being only one with our external stimulus. (I found this, but haven't read it yet to ensure of it's content: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4423156/ )

So it's not just the rhythm of our hearts, it's actually the brain connecting everything at the same time (the lights from that apple hitting your eye, the breeze of the wind, you arm moving, your sense of balance - bref, bringing all your senses into one self contained experience) and keeping this sensation as a regular and predictive "tempo" is also essential.

Music plays with and satisfy that sensation. "My arm will take that glass - yep, it did, I have control over it" and "The snare is gonna hit really soon - yep it did, I'm still in contr-- wait what's that sound? This is interesting I didn't predict that! I bet it will be there again... yep there it is!"

Please! Feel free to correct me or add to it, I find this is a fascinating subject.

COMPLEMENTARY READING: "This Is Your Brain on Music" by Daniel Levitin, https://www.amazon.ca/This-Your-Brain-Music-Obsession/dp/0452288525

You may find this book called your inner fish: a journey into the 3.5-Billion-Year History of the Human Body very interesting. It is a really fascinating and, quick read.

Tetrapods include amphibians, reptiles, birds, turtles and mammals. All tetrapods have a single common ancestor, that was as you describe "the first fish dude who jumped out of the water". Really, that is the best way I have heard it described and youre not wrong! We don't know which species is the first, but we do have several transitional fossils from water to land. These species are collectively known as tetrapodomorphs which basically means "kind of like a tetrapod - kind of like fish". This picture gives you a good idea of some of the different species alive around that time. Tiktaalik is one of my favourites, mostly because the name is fun to say. This species lived about ~375 million years ago, during the Denovian. Here is another example of the limbs of those transitional species from fin to limb!

Acanthostega (~365 million years ago) and Itchthyostega (~360 million years ago) are two species of tetrapods that lived after Tiktaalik, and they are better suited for life on land. They likely lived in swampy areas but were still tied to the water.

After the first tetrapods established themselves on land they evolved or radiated into many different groups. This is a good and simplified family tree of tetrapods. There are the amphibians, the turtles, the mammals and the reptiles. This is another family tree which depicts some extinct groups. Notice that the birds are placed firmly with the other dinosaurs and are now the only living representatives of that lineage. And that early mammal ancestors (therapsids) stem from a distant synapsid ancestor which evolved quite early on.

The reptiles are a bit of a funny group because they contain a lot of extinct species and this confuses people as to what actually is a reptile. Simply put reptiles include the living turtles, crocodilians, snakes, lizards, and tuatara and many other extinct species including the dinosaurs, the extinct flying reptiles like the pterosuars and the extinct aquatic reptiles like ichthyosaurs. Another cool fact is that crocodiles and birds are more closely related to each other than they are to the other reptiles (turtles, snakes, lizards and tuatara).

The whole subject is a bit too complicated and a bit too deep for a short ELI5, but I'll give a stab at the gist of it.

The reason why computers work (at least in the vein of your question) is very similar to the reason why we have language -- written, spoken, etc.

What you're reading right at this very moment is a complex system (language) simplified to symbols on the screen. The very fact that you can read these words and attain meaning from them means that each sentence, each word, and each letter represent a sort of code that you can understand.

If we take an apple for example, there are many other ways to say that in different languages. Manzana. Pomme. Apfel. And so on. Codes -- some symbol maps to some concept.

In the context of computers, well, they can only "understand" binary. Ones and zeros. On and off. Well, that's okay, because we can map those ones and zeros to codes that we (humans) care about. Like 101010111 could represent "apple" if we wanted it to.

So we build these physical circuits that either have power or don't (on and off) and we can abstract that to 1's (power flowing through that circuit) and 0's (no power flowing through it). This way, we can build physical chips that give us basic building blocks (basic instructions it can do) that we can leverage in order to ultimately make programs, display stuff, play sounds, etc. And the way we communicate that to the computer is via the language it can understand, binary.

In other words, in a basic sense, we can pass the processor binary, and it should be able to interpret that as a command. The length of the binary, and what it should contain can vary from chip to chip. But lets say our basic chip can do basic math. We might pass it a binary number: 0001001000110100 but it might be able to slice it up as 0001 | 0010 | 0011 | 0100 -- so the first four, 0001, might map to an "add" command. The next four, 0010, might map to a memory location that holds a number. The third group of four might be the number to add it to. The last group might be where to put it. Using variables, it might look like:

c = a + b. Where "c" is 0100, "a" is 0010, "b" is 0011, and the "+" (addition operator) is 0001.

From there, those basic instructions, we can layer abstractions. If I tell you to take out the trash, that's a pretty basic statement. If I were to detail all the steps needed to do that, it would get a lot longer -- take the lid off the can, pull the bag up, tie the bag, go to the big garbage can, open the lid, put the trash in. Right? Well, if I tell you to take out the trash, it rolls up all those sub actions needed to do the task into one simple command.

In programming, it's not all that different. We layer abstractions to a point where we can call immense functionality with relatively little code. Some of that code might control the video signal being sent to the screen. Some of that code might control the logic behind an app or a game. All of the code though, is getting turned into 1's and 0's and processed by your cpu in order to make the computer do what is asked.

If you want to learn more, I highly recommend Code by Charles Petzold for a much more in depth but still layman friendly explanation of all this.

For a more in-depth look at String Theory I recommend The Elegant Universe.

You undoubtedly already know the part of the theory that posits everything boils down to these fundamental "string" objects, and the way they vibrate (both in terms of the typical wave vibration, but also the way where the whole object moves back and forth) determines how it behaves in the universe. And that's influenced and constrained by the type of space in which the strings can move, etc.

But how might that help resolve QM and GR? Well, because strings have a little bit of length.

When we think about particles, we treat them as points with zero dimensions. That works all right in the framework of QM, but when you apply the equations of GR to those points, you end up with some fun, indeterminate divide by zero issues. Any nonzero length at all, like something on the scale of the Planck Length, can bridge the connection and produce a meaningful result.

Now, that's not to say that's all there is to it or everything has been solved (far from it), but that may shed some light on why it's an attractive theory to pursue. There are then many types of String Theory, which may just be different facets of one larger one, but finding connections between them is difficult. And experimental confirmation of strings is completely out of reach of our current technology. So, much remains to figure out.

I thought Colgate Total was different as it contained Triclosan. But i think other toothpastes have this too.

Big difference.. Sensodyne Repair and Protect has a bioglass compound called Novamin that actually bonds with the enamel and gives it an extra coating that fortifies teeth enamel. It is the only compound and toothpaste that actually repairs or fortified your enamel.

I know a new compound called Biomin has come out which is a superior version of Novamin, but it is only available in the UK for now.

Edit: correction: Bioglass is not the only compound that repairs your enamel. But it is the best or among the best there is. Also available over the counter so you don't need some expensive prescription toothpaste.

Novamin (a type of bioglass) was invented by a scientist and Sensodyne bought out his research, so to my knowledge Sensodyne Repair and Protect (non US version) is the only off the shelf toothpaste that has Novamin.

For some reason, the version in the US does not have Novamin. If you want to buy the Novamin version in the US, buy it from Amazon here: https://www.amazon.com/Sensodyne-Repair-Protect-Whitening-Toothpaste/dp/B008VPSTOA

It takes a few weeks to ship from the UK. But the price is reasonable: $6.60 and free shipping.

This is due to the [overtone series](http://en.wikipedia.org/wiki/Harmonic_series_(music). Basically there are resonant frequencies when you play a pitch. You'll notice in the examples on the Wikipedia page that the first couple overtones are the octave, the fifth, and the fourth. So those intervals tend to share overtones, making them sound better together to our ears.

For example, the first couple of overtones where C4 is our fundamental are C5, G5, and then C6. For G4, the overtones would be G5, D5, and G6. That's an interval of a fifth.

A lot of this is related to the Western tuning system. Most Western music is equally tempered. Basically, when a piano is tuned, you're making a bunch of compromises so that everything sounds good together, even if it's not perfectly in tune. You could tune certain intervals perfectly, but then others would sound really bad, so we compromise.

Another thing about Western music is that we're all about building tension and then relieving it ^justlikesex and you can see this in a lot of common chord progressions. Take your standard cadence, G7 to C, for example. G7 is a fairly unstable chord and it's built so that the third and seventh, B and F, collapse really naturally into C and E, giving us a nice, stable C triad.

Music also operates similarly to comedy in that it's all about delaying and overturning expectations. Like three men walk into a bar. You've heard that before and have some idea of what will follow. But then someone says "the third one ducks" and that's a new one and that's funny, so you laugh. Music works the same one. Let's say we set up the classic I-V-vi-IV chord progression but instead of IV we do something else. That's new, that's interesting, and we like it.

Disclaimer: I'm really sorry if I screwed up some of the overtone series stuff, I have only a vague idea of how it works.

You can read an entire book on why we like the music we do -- check out This Is Your Brain on Music by Daniel Levitin -- it's a great read!

There are too many reasons to post here. I recommend reading the book Guns, Germs, and Steel by Jared Diamond (or at least the miniseries--available on Netflix last I checked).

Some of the main reasons include:

• No domesticable pack animals in the Americas to do work. Eurasia has things like cows, horses, etc. that could be tamed and trained to do hard labor like plowing fields and hauling carts. The closest such animal in the Americas is the llama/alpaca, native to northern South America. This made food production in the Americas more human labor intensive which took away time from other endeavors.
  
  
• The Americas are "taller" than they are "wide." That is, they cover a greater range of latitudes than longitudes. The opposite is true of Eurasia. As it turns out, crops, technology, and people diffuse less efficiently north/south than they do east/west. This is primarily due to climates being more even along latitudes than longitudes. This retardation in trade would slow the exchange of ideas, and therefore technological development.
  
  
• The Americas have fewer cereal crops (rice, wheat, barley, corn, sorghum, etc.) native to them compared to Eurasia. These are the crops that are responsible for the establishment of agriculture and, as a result, sedentary societies. A sedentary society (i.e., one that is not picking up and moving itself every few months to follow food supplies) is one that can allow for specialization. Some people will become really good farmers and can produce enough food such that others can pursue different fields. With fewer available crops there were fewer opportunities in the Americas to establish such societies.
  
  Again, there are reasons beyond these and everything I just listed is conjecture. Human development was an incredibly complex process and for every example supporting one argument there is another example that refutes it.

As stated Guns, Germs, and Steel by Jared Diamond. The region played a factor. Focusing on Europe, Europe had easy access of travel due to the Mediterranean sea. In broader view they had the silk road. There is a book called Why Nations Fail. A very interesting read. Out of dozens of examples the book shares, I will point out two that help shape Europe; the first being the story of Hercules and second the Black Death. The story of Hercule enabled a change in thought over the centuries as greek men went to the Olympics trying two win fame and glory for themseleves. The individual. The Black death on the other hand destroyed the working class and enabled a change in the current western system.

I'll try at ELI5 level.

Paper is a good analogy, but expand it to 3 dimensions. To see what flat means, you need to know what "not flat" means. Imagine a really large piece of paper covering the Earth. You mark an arrow on the ground then walk off in that direction, keeping in a straight line. Eventually you circle the globe and end up back at your arrow on the ground, approaching it from the tail of the arrow. You then pick a random direction and draw another arrow and do the same thing. No matter which direction you go, you always end up coming back to the same spot.

In this case, the paper is not flat; it is curved. Specifically, it is closed, meaning it loops back onto itself. However, locally it might look flat from any point you are standing. Imagine it on a bigger planet like Jupiter, or around the sun, or even larger. Locally you would measure it as being very flat, within a tiny fraction of a percent. So something that looks flat could actually be curved but with a very large radius of curvature.

But this analogy is only in 2 dimensions, covering the surface of a sphere of really large size. The curvature is in the third dimension in the direction of the center of the sphere (perpendicular to the local surface of the paper).

Imagine it now in 3 dimensions. You are floating in space at leave a real arrow pointed in some direction. You fly off in your rocket in that direction and eventually find yourself approaching the arrow from the tail end. It doesn't matter which direction you point the arrow, that always happens. That is a closed universe in 3D, meaning it is curved in a fourth dimension.

A flat universe would be one where the radius of curvature is infinite, meaning you'd never end up back at your arrow from the tail end.

I think this description is important because there is some disagreement on this. The measurement of the universe being flat within 0.4% does not mean that it is flat; it means the radius of curvature could be infinite (flat) but could just be very large. In fact, if you watch theoretical cosmologist Lawrence Krauss' talks on "A Universe from Nothing" or read the book, if you pay close attention you'll note a contradiction. At one point he jokes about how theorists "knew" that the universe must be flat because that makes it mathematically "beautiful", but then later describes how theorists "knew" the total energy of the universe must add up to zero as that is the only type of universe that can come from nothing, and yet also says that only a closed universe can have a total energy that adds up to zero. Hence is it closed or flat?

I attended one of these talks in person where this was asked and he confirmed that he thinks the evidence is strong that it is actually closed, but really, really large and hence looks flat to a high degree, and that the inflationary universe model explains why it would be so large and flat looking while being closed and zero net energy (and hence could come from nothing).

After going through all of what I know of the topic, including many other sources, I tend to agree with him that it makes the most sense that it is likely just very close to flat but is really slightly curved back onto itself at a very large radius of curvature. That also means our observable universe is only a very tiny percentage of the universe that exists.

What would be considered safe for retirement plans? There aren't any other investments available that can be liquidated on the spot at the decision of the retirees that also provide the amount of growth necessary to have a retirement plan worth anything.

I don't really see how this law would destroy Comcast, at all. It would radically harm working class people with retirement plans, but the wealthy people in control of Comcast would develop complex legal arrangements via contracts and insurance to ensure that their business would continue otherwise.

For example: suppose such a law passes and all shareholders are held directly liable in proportion to their ownership. This effectively destroys limited liability capitalism. Share prices of every company would drop as every charity, retirement fund, investment bank, and regular person sells as fast as they can. The economy suffers another Great Depression due to the sell-off. Smaller firms die. The larger ones, like Comcast, will have the capital to buy back their shares and "go private." The individuals owning those shares could then put the shares into a trust - they would be the grantors and trustees, but the beneficiary (the individual with legal title to the property) would be a well-paid fall guy. That fall guy would likely never have the money necessary to cover any of a company's legal obligations; the company would become judgment proof.

Destroying limited liability capitalism in this way would not kill Comcast. But it would essentially halt all economic growth and cement wealth even more firmly into the upper classes. Before limited liability, economic growth was essentially zero. Limited liability capitalism (read: the distribution of risk and reward behind an artificial legal entity) is the engine that enabled the global economy to grow so rapidly since the 1500s. This is what enables the vast majority of humans to have the wealth necessary to be something besides subsistence farmers. Check out Sapiens for an explanation.

You should really read an economics book because your response is illogical. This book is very good. Technological innovation creates wealth and increases purchasing power, not the other way around. The time from the industrial revolution to the baby boomer generation involved massive leaps in automation, and yet the middle class became much better off. The period to which OP refers comes after massive automation. Your timeline is wrong. The wealth created from automation is specifically what gave individual men the purchasing power necessary to support a family.

No, the answer has to do with inflation - specifically the switch to free-floating fiat currency in Nixon's economic reforms - which led to a massive transfer of wealth to the top, which continues to this day. Inflation devalues a currency, which wipes out the effect of minimum wage laws, and folks at the top are the closest to the printing press so they benefit while those furthest from the printing press are disproportionately harmed.

Both concepts are discussed in the book I linked. You would do well to read it.

> So, when we look at Andromeda through an ultra-mega-super powerful telescope - we are seeing something that is 3.5 billion years "old"?

Well, 2 million years old. That's how far away it is.

But the galaxy itself (not it's light) will collide with the milky way in 3.5 billion years. Sorry for combining those two facts in a confusing way.

But there are PLENTY of galaxies we can see today that are many billions of light years away. Which means what we see of them is how they were many billions of years ago, which is crazy.

I'm not really sure what I could recommend. I've been poking around and reading about space for a while just reading stuff I come across. If you aren't watching it I'd recommend the TV series Cosmos running right now with Neil Degrasse Tyson. I also really liked a couple books by Brian Greene (here's a link to one, and another.). The first one I really liked and it helped me to get a grasp on some things that always confused me.

Also, as a mod of ELI5 I'm not afraid to say ELI5 is an awesome source, and most any topic you can think about has been covered in depth here. Just type keywords into the search box and go to town. If there's something you can't find a great explanation for, post and ask and you'll get some great responses. /r/askscience is also great, although they are more sticklers for citation and aren't always as focused on layman explanations as ELI5.

A young person has spent his entire life having his needs provided for by his parents. So the only model he really knows is one where a benevolent authority figure takes care of people in need. Naturally he supports a strong welfare state.

As he grows older and becomes responsible for himself, he begins to understand that making good choices and working hard helps him do better in life, and helps him best provide for his family. So when the authorities take more and more of his earnings and give it to other people who he thinks are making bad choices and working less hard, he gets resentful. He wants the government to get stop interfering in his life. [Here I'm using a more classical understanding of conservatism, not the currently popular xenophobic, warfare-oriented understanding of conservatism.]

Also, in rare cases, as he gets older he'll learn enough economics to understand why welfare programs do more harm than good, and will advocate against them.

http://www.amazon.com/Merkur-Model-180-Handled-Safety/dp/B000NL0T1G/ref=sr_1_1?ie=UTF8&qid=1375443911&sr=8-1&keywords=razor

Razor is expensive but this is what they use in the old days and it's what I use. It's pretty good after using this you will wonder what in the heck was the point in all the extra blades on those other razors.

When you need more razors you just buy them for like 3.50 for 10 blades. You can easily change them monthly and keep the razor, well razor sharp.

The actual question has been answered well by others, but I'd like to take this opportunity to recommend a book: Charles Petzold's Code. It's pretty much an eli5 of everything about computers. It starts with an explanation of "binary codes" that consists of "you and a friend sending messages across the street by turning flashlights on and off," and from there brings the reader (gently, and without much math!) to an understanding of how all the parts of the computer work together.

You're going to have a hard time finding someone to explain the biology of it in laymen's terms. There's a good book called "Music, the Brain, and Ecstasy" that spends the first third explaining the biology of it.

Sound waves are produced by vibrations (guitar string, vocal chords, etc.) These vibrations start at a fundamental frequency (what you called "pitch") but they also vibrate at higher frequencies relative to the fundamental--these are called overtones. These higher frequencies aren't perceived as readily as the fundamental but they will color the tone of sound (timbre).

http://en.wikipedia.org/wiki/Overtone

http://www.amazon.com/Music-The-Brain-And-Ecstasy/dp/038078209X

EDIT: I guess, in an overly simplistic way, you could say that the overtones do excite the nerves in the ear dedicated to those frequencies and the brain decodes them in pretty much the same way it does the fundamental. So, since the two sound sources emit different overtones the brain can tell them apart.

For anyone interested in this kind of stuff, I highly recommend The Elegant Universe by Brian Greene (http://www.amazon.com/The-Elegant-Universe-Superstrings-Dimensions/dp/039333810X). I thought it was a great read and relatively easy to understand for someone not in the physics field.

I'd like to take this opportunity to recommend a great book: The Elegant Universe. The answer to many questions here and more! :)

If you want to have a better shave and also save a lot of money, buy a safety razor. You can get the handle for around thirty dollars, for example this one, and the razors are dirt cheap, for example, this pack of 100 blades costs $11.

So there you go, a safety razor and 100 blades for $50. That is a whole lot of shaves right there, and if you ever need more blades, you can get 100 more for $11. It is also way easier to shave with a safety razor, because it is so heavy.

When you hear an instrument play a note -- e.g., Middle C, which plays at approximately 262 Hz --, the instrument is actually playing more than just that frequency. Even so, as far as your brain is concerned, the resultant frequencies produced are equivalent to just the frequency you hear being played.

For the sake of an example (I'm making the following numbers up), Middle C played on a piano might generate a 262 Hz sound, along with a 362 Hz sound, a 462 Hz sound, a 562 Hz sound, etc. Even so, your brain combines all these signals and hears them exactly as it would if only a 262 Hz sound had been generated.

How those extra frequencies are generated (that is, what the increments between all the generated sounds are) partially help your brain interpret an instrument's tonality, a musical term for the distinctive sound of the instrument.

Source: This Is Your Brain on Music: The Science of a Human Obsession (This is a really fun book, by the way.)

I would this in a top level comment but it’s against the rules of the sub to do so, but OP can check out this book, called “Code” is a great, truly ELI5 intro to computers. If someone is interested they can check it out.

For people who enjoyed this explanation I highly recommend The Elegant Universe it gives a great ELI5 overview of modern physics from Newton to string theory.

Further to the excellent comments already left, if you want to investigate things later on in your own time, you might enjoy this book Code: The Hidden Language of Computer Hardware and Software. It explains programming and computer hardware fundamentals using excellent (and real - based on history) examples. I think even a 10 yr old would get a lot out of it, I would go so far as to recommend it to tech inclined parents for themselves and their children.

If you are truly interested in how the computer performs these functions, this is a GREAT book. I found it easy to understand, and I think it will answer the question you have.

A wake-up light is nice, too. It's pretty delightful to wake up to "sunrise" instead of an alarm and I find it easier to get out of bed when it's bright.

Something like that! There's a lot more to be said on the topic, if you're interested. Jared Diamond's Guns, Germs, and Steel talks about a lot of what I mentioned above in greater detail (there's also a pretty good PBS Documentary based on the book).

okay mister echo chamber :) . Have you then also read one of the many books that claim otherwise, like this: http://www.amazon.com/Delusions-Gender-Society-Neurosexism-Difference/dp/0393340244

I'd also recommend you read the top amazon review on your link. Check for dissenting opinions before agreeing with someone in the future.

If you like TIYBOM, Robert Jourdain's Music, the Brain, and Ecstasy: How Music Captures Our Imagination is right up there. Awkward title to explain in public but a fantastic read. I liked it a lot more than TIYBOM but in fairness read TIYBOM second.

You're assuming that we don't have evidence, though. That was more of less true even as recently as the 1980s, but there's been a ton of work done on cosmology since then.

I suggest A Universe from Nothing: Why There Is Something Rather than Nothing as a decent starting point. There are other good books on the subject out there as well, but I like Krauss' writing style. Echo of the Big Bang is good as well, even if it's getting a bit dated.

Anyway, I get it. Cosmology (and a lot of physics in general) is unintuitive. Which is why relying on intuitive experience is a Bad Idea™.

There's a book I've been wanting to read but haven't yet: This Is Your Brain on Music: The Science of a Human Obsession

If you've got more free time than me go for it, but I'm extremely interested in studies on the subject. I think music is something bigger than we understand so far and I want to find the answer.

Along with Kngjon's comment I would suggest reading the book ("Code")[http://www.amazon.com/gp/aw/d/0735611319?pc_redir=1411971211&robot_redir=1]. It's a very easy read and super fun also. You'll learn everything you ever need to know about computers. (Mostly)

Code is a great book that starts with this analogy & works its way up to advanced computer science and information technology concepts. Highly recommended if your'e interested in this!

You want to read Code by Charles Petzold. It is a modern classic and takes you from a flash light to a modern CPU. One of the best books computer books I have ever read. It is so good it never leaves my desk as I love to read it randomly. Pic!

Try buying one of these.

I got it a few years ago to clean out my PC and it works amazing. Much better than buying cans.

Charles Petzold's Code: The Hidden Language of Computer Hardware and Software is a great book with several chapters about this topic and topics that are closely related to it, such as Morse code, Boolean algebra, the telegraph system, electromechanical telephone relays, etc. Those chapters explain really well how everything we do with computers is ultimately handled by tiny electrically controlled switches that are connected together in special ways.

• Microsoft Press Store: https://www.microsoftpressstore.com/store/code-the-hidden-language-of-computer-hardware-and-software-9780735611313
  
• Amazon.com: https://www.amazon.com/Code-Language-Computer-Hardware-Software/dp/0735611319

That's a pretty interesting course. I've read the book and done exercises up until you actually have to start building the CPU.

However, I would strongly recommend reading Charles Petzold's CODE first. It's a little less technical, but explains the general concepts much better than nand2tetris.

If you want to know more I would recommend checking out Code: The Hidden Language of Computer Hardware and Software by
Charles Petzold. It's not even really a coding book (well it is but it isn't). He goes form the bare basic of the telegraph and works all the way up to computers. It explains everything in a way that makes so much sense.

I'm not a programmer. I only really know how to make code spit out Hello World. I love this book as it was so freaking interesting.

https://www.amazon.com/gp/product/0735611319/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I'm literally on the other end of that... I haven't needed an alarm for a long time, since I'm almost always awake before it would go off, usually still with too little sleep. It's extremely rare that I get 8 hours of sleep. And yeah I would definitely trade with you.

Anyway, maybe you should try one of those light alarms, one like this, they simulate sunrise and make you wake up slowly and naturally over the span of a half hour or so. People I've talked to that have it said it's awesome.

https://www.amazon.com/gp/product/B001J4ZOAW
 
for the price of ten or fewer cans of air you get something that basically lasts forever and does a much better job. one of my best investments in a house full of computers.

also ..
http://www.amazon.com/Sailing-Ships-War-1400-1860/dp/0831776560/ref=sr_1_1?ie=UTF8&qid=1405749703&sr=8-1&keywords=sailing+ships+of+war+1400-1860

http://www.amazon.com/Harbors-High-Seas-Edition-Aubrey-Maturin/dp/0805066144/ref=sr_1_2?ie=UTF8&qid=1405749730&sr=8-2&keywords=patrick+o%27brian+reference

http://www.amazon.com/Under-Black-Flag-Romance-Reality/dp/081297722X/ref=sr_1_1?ie=UTF8&qid=1405749757&sr=8-1&keywords=under+the+black+flag

all three good places to start. The second one is fantastic to have open and waiting while reading the O'Brian Books

I installed it in my master bedroom. I have this one Luxe Bidet Neo 120 - Self Cleaning Nozzle - Fresh Water Non-Electric Mechanical Bidet Toilet Attachment (blue and white) https://www.amazon.com/dp/B00A0RHSJO/ref=cm_sw_r_cp_api_UhiLzbQHS5ZDG

I can't say enough positive things about it. I don't know how I lived without it so long. The kids might play with it but that seems easily correctable and worth the headache

Great question and a good answer. It's called the Cognitive Revolution and is described in more detail here

I have to order my Sensodyne from the UK for this very reason. I have weak enamel and regular Sensodyne wasn't doing anything. Someone in another reddit post mentioned you can order it from Amazon UK so I did.

It's like $6 a tube, but worth it.

EDIT: Here's the link. It's not Amazon.UK but it ships from the UK for $6.60 free shipping.

This is the one we got:

https://www.amazon.com/Luxe-Bidet-Neo-120-Non-Electric/dp/B00A0RHSJO

You can install yourself - super quick and easy

If this sounds interesting to anyone, I highly recommend the book Sapiens: A Brief History of Humankind.

It covers a lot of early evolutionary characteristics around and after the Cognitive Revolution (when we arguably "became human"). Some of my favorite parts are in depth discussions around how evolutionary prepositions like a belief in the supernatural/religion may have increased odds of survival (although may or may not have improved individual life quality).

If you're interested, this is an amazing read.

http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW
Is this what you are talking about? It's obnoxious but works great.

Edit: I have never had a problem with the standard one that I have used on multiple computers but here is the link for the anti-static version. https://www.metrovacworld.com/DataVac_ESD_Safe_Electric_Duster_ED_500ESD/overview

I use this one at work all the time: http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW

Other people have posted it here, and like I've mentioned, not cheap, but it's very effective, and very reliable.

It was a combination of multiple factors. In short, humans have reached North America and the American continent in general much later than humans reached Europe. By the time Native Americans managed to develop crops and livestock, Europeans were way ahead of them with much better food, weapons and with diseases that the Native Americans were not used to.

If you are interested in this topic, I would recommend this book,
Guns, Germs, and Steel: The Fates of Human Societies.

I really like Lawrence Krauss' explanation - universes with certain characteristics, which our seems to possess, can have zero total energy. As it turns out, empty space acts, as if it didn't want to be empty - in a state of high vaccum, space suddenly starts to boil with virtual particles - particles and antiparticles, that spring into existence and annihilate each other instantly. If that happens in empty space, then it is reasonable to suggest, that in absence of space, such virtual spaces might spring into existence, and if certain conditions are met, rather than instantly collapse, they might expand and be filled with matter, gravity and dark energy, while having zero total energy at the same time.

You might learn more from his lecture, or his book on the subject.

I highly recommend read this book about this topic : Sapiens by Yuval Noah Harari. This book is very easy to reed and explain a lot about Religion and gods.

Each CPU has a specific set of things it can do, called instructions. There are applications that turn human readable code into a bunch of instructions for the CPU. Most modern languages have several layers of applications that the code has to go through before it reaches the CPU. If you want a very awesome ELI5 book on how CPUs are made and how they process these instructions, see CODE here: https://www.amazon.com/Code-Language-Computer-Hardware-Software/dp/0735611319

There's a really good book that answers this question and a whole lot more

Jared Diamond - Guns Germs and Steel

AMAZON to the rescue:
http://www.amazon.com/Sensodyne-Repair-Protect-Whitening-Toothpaste/dp/B008VPSTOA

One way to do it:

• spray,
  
• go,
  
• spray,
  
• wipe,
  
• flush
  .. the first spray help ease in cleaning up after you go. Most bidet types will not agitate the bowl while spraying.
  
  I have this type:
  http://www.amazon.com/Luxe-Bidet-Neo-120-Non-Electric/dp/B00A0RHSJO/ref=sr_1_5?ie=UTF8&qid=1420674033&sr=8-5&keywords=bidet
  
  

OMG, only $35, though I recommend the $48 upgrade if you're a lady.
The hype is all true, IT WILL CHANGE YOUR LIFE

I got my beautiful adjustable merkur for $32 shipped on Amazon.

http://www.amazon.com/gp/product/B000NL0T1G/ref=oh_details_o01_s01_i00?ie=UTF8&psc=1

When you shave against the grain the razor tugs at the hair in addition to slicing through it, pulling it a bit farther out of the follicle. This makes it much easier to get ingrown hairs and irritation on the skin.

Edit to elaborate on everyone else's experiences by adding my own: Using Mach 3s and all that newer stuff I always broke out on my neck. Switching to a safety razor(a big part of this is also finding the right blade brand for you skin, Feather was way too sharp for me and caused razor burn, I ended up going with Derby), using a badger hair brush and shaving soap and making my own lather, shaving while showering and your hair is moist and skin is warm from the steam, and rinsing with ice cold water after the shave are what I found work the best. Hard to nail down exactly what helped the most cause I switched to doing all that at the same time.

Safety Razor

Blades

Soap

Fogless Shower Mirror

Mug to make lather in

Brush

After Shave

Cold Water ;P (I honestly think rinsing with cold water for at least 15 seconds before putting on after shave is the most important part in avoiding irritation and ingrown hairs.)

It doesn't "know." Any logical operation (especially basic math calculations) can be broken down into binary digits, and a single binary digit (bit) can be represented as the presence or absence of electricity.

It's almost how if you were to build a sequence of pipes and valves, and pour water into the opening, the water would end up flowing through the same way each time. The pipes don't "know" where the water goes, it just happens.

A computer does the same thing but on a tiny scale with tiny electric pulses travelling through sequences of thousands of gates all connected to each other. Imagine that the buttons you hit on a calculator slightly change how the valves open and close. (or which opening to dump the water into) You hit enter, the water is poured, and the result shows on screen.

fair warning: I am not a hardware guy so this explanation is probably not 100% accurate.
If you have more interest in the subject I HIGHLY recommend reading this book: http://www.amazon.com/Code-Language-Computer-Hardware-Software/dp/0735611319

I just bought this one a month ago. So far it's been great. Our apartment is on a lower floor by a corridor, and the bedroom doesn't get any light whatsoever in the morning.

When we first moved in I had the hardest time getting up, whereas our last place had a big window right next to the bed that let the sunrise in and I always woke up before the alarm and felt ready to go, even on the weekends. At the new place, I was hitting the snooze three or four times before waking up and feeling groggy for awhile once I was up.

I started setting the clock's alarm to follow the actual sunrise (my mornings are pretty flexible) and it'll start lighting up about half an hour beforehand. I use the sound during the week, and no sounds on the weekend. For me, it was completely worth the money.

Code is what helped me wrap my head around this.

You might have to read it a couple times to understand it, but it's really good.

The single best resource I've found for this is the book Code by Charles Petzold

http://www.amazon.com/Code-Language-Computer-Hardware-Software/dp/0735611319

He walks you through how computers work from the formation of Telegraphs, to logic circuits, to small memory, math, and near the end a small computer with a custom assembly language.

There's an easy solution to that.

Bro ya'll need to upgrade:

http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW/ref=sr_1_1?ie=UTF8&qid=1425938357&sr=8-1&keywords=electronic+air+duster

Best 60 bucks I spent when it comes to this kinda stuff.

This is the best $40 you will ever spend.

http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW

I work for a major manufacturer of things as a field tech. they pulled all the canned air out of our vehicles and issued us one of these. 10-20x more powerful, never runs out. comes with attachments. 11/10.

http://www.amazon.com/Sapiens-A-Brief-History-Humankind/dp/0062316095

Great book.

Excellent post. If any of you are still having trouble with the idea, then for a lengthier version of this explanation complete with diagrams, I highly suggest picking up The Elegant Universe by Brian Greene:
http://www.amazon.com/The-Elegant-Universe-Superstrings-Dimensions/dp/039333810X/ref=sr_1_1?ie=UTF8&qid=1397185322&sr=8-1&keywords=the+elegant+universe

read, "This Is Your Brain On Music"

http://www.amazon.ca/This-Your-Brain-Music-Obsession/dp/0452288525

an interesting read for sure

as others have stated, not every razor refill is expensive, mostly just the Gillette/P&G ones. they just put a lot of money into marketing and capture enough market share that they can get away with their rampant price increases.

here's what you need to do.
buy one of these: Merkur Long Handled Chrome Safety Razor

and a package of these: Derby Extra Double Edge Razor Blades - 200 Ct

even if you use a new blade every time you shave, that's less than $0.07 a shave

here's the one I bought (or at least, Amazon says so). $9 with free shipping.

For anyone interested: http://www.amazon.com/Sensodyne-Repair-Protect-Whitening-Toothpaste/dp/B008VPSTOA/ref=cm_cr_pr_product_top?ie=UTF8

I've always asked myself the "enamel rebuilding" question. I would see sensodyne ads on TV for enamel rebuilding toothpaste, but I can never find it in the store. I always assumed it just fell under their "pronamel" line. Now this makes so much sense.

Do you have any literature on the effectiveness of Novamin? I am strongly considering switching toothpastes now.

Here in the Netherlands they are available in supermarkets. They have advertisments on TV promoting it (so it's not seen as a medical product at all, for which it's illegal to advertise here).

I don't know if they are particularly popular, but they are somewhat well known. I've heard two people say it helped and nobody that it didn't, but that's more anecdotal evidence (after all, it's a sample of 2 and there are people who think homeopathics work so you can't even trust those 2).

Edit: this toothpaste with Novamin can be bought in the US on Amazon (just make sure to pick a seller that ships from the EU).

All of these answers answer your question on a general level, but I would really recommend reading Code: The Hidden Language of Computer Hardware and Software by Charles Petzold for a deeper understanding. He talks about how the first computers were built and how they were programmed, and he does it in a way that's understandable even to a person that doesn't know a thing about computers.

I have one of those wake-up lights http://www.amazon.com/Philips-HF3520-Wake-Up-Colored-Simulation/dp/B0093162RM/ref=dp_ob_title_hpc, they're fantastic.

You might be interested in Jered Diamond's book Guns, Germs, and Steel. He does a pretty thorough discussion of the subject. If boils down to white people coming in quantity from a content that's wider (East-West) than it is tall (North-South). This means temperate bands are longer, providing more opportunities to fight over crops and resources. This builds up the capability to fight, and when the advent of long-distance sailing comes into the picture, these fight-prone groups sail around the work, find less fight-prone people, and vanquish them.

Short answer: spontaneous quantum fluctuations, but i recommend you read
http://www.amazon.com/Universe-Nothing-There-Something-Rather/dp/1451624468" this

Read this book if you want easy to digest details.

https://www.amazon.com/Code-Language-Computer-Hardware-Software/dp/0735611319/ref=sr_1_2?ie=UTF8&qid=1482508891&sr=8-2&keywords=code

Related, this is a very good book about computing that happens to cover the history of the braille system in some detail. If you click on the "look inside" preview bit, and go to Chapter 3, most of the information relevant to your question is covered in these preview pages.

PLEASE read this book:

http://www.amazon.com/Economics-One-Lesson-Shortest-Understand/dp/0517548232

It seems that your comment contains 1 or more links that are hard to tap for mobile users.
I will extend those so they're easier for our sausage fingers to click!


Here is link number 1 - Previous text "$35"

Here is link number 2 - Previous text "$48"



----
^Please ^PM ^/u/eganwall ^with ^issues ^or ^feedback! ^| ^Delete

Yes, quantum fluctuations - where stuff can pop into existence out of empty space - is proven fact.

It's as exciting as it is disturbing when you think about it. But then the laws of physics don't really care much about our feelings.

Reading up further I would suggest Wikipedia
http://en.wikipedia.org/wiki/Introduction_to_quantum_mechanics

And a good book on the wider subject is A Universe From Nothing by Lawrence Krauss
http://www.amazon.com/Universe-Nothing-There-Something-Rather/dp/1451624468

You need to absolutely read this book (used copies are just a couple of bucks);

Code: The Hidden Language of Computer Hardware and Software

The book is very very accessible and written brilliantly. The only thing it doesn't cover, is the Physics behind the implementation of Electronics but the basics of that, you have probably studied in high-school and undergraduate classes. What you are looking for is the logical abstraction behind the application of Electronics.

The above book will clarify that like no other book i have read.

Thanks.

[For the lazy]
(http://www.amazon.com/The-Elegant-Universe-Superstrings-Dimensions/dp/039333810X)

I got a Datavac ED500 electric duster--it's stronger than any compressed can I've ever used, and though it's $60, I'll also never have to buy a can again.

I don't know. There is a book called "this is your brain on music", which is great for this exact topic. I don't really know too much about the brain beyond the basics. I have the book, but I'm in the middle of a few other books so I haven't read it yet

For further reading
http://www.amazon.com/Code-Language-Computer-Hardware-Software/dp/0735611319

It started from the beginning with binary, Morse code, and light switches, etc, gradually building up to motherboards and operating systems. It starts to make me feel like I could build a computer from scratch.

Just buy one of the bidets that attaches to your toilet like: https://www.amazon.com/Luxe-Bidet-Neo-120-Non-Electric/dp/B00A0RHSJO/ref=sr_1_2?ie=UTF8&qid=1502899352&sr=8-2&keywords=astor+bidet

http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW

This thing is badass, so glad I gave up the air cans.

Are you talking about one of these:

http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW

If it really works well, I wouldn't mind paying $60 for one to use with my PC

Get yourself a bidet. Solves the I've-used-so-much-paper-I'm-bleeding thing.

Searching for "novamin toothpaste" on Amazon brought up a few results.

http://www.amazon.com/Sensodyne-Repair-Protect-Whitening-Toothpaste/dp/B008VPSTOA/ref=sr_1_1?ie=UTF8&qid=1451925513&sr=8-1

http://www.amazon.com/Sensodyne-Protezione-Completa-Toothpaste-NovaMin/dp/B00I98E9SE/ref=sr_1_6?ie=UTF8&qid=1451925513&sr=8-6

If you have a chance, read "Guns, Germs and Steel", it goes into detail exactly how we got to the industrial revolution and what factors caused it.

Get an air blower. Datavac is one I got because a can of air wouldn't last me long with the amount of electronics/computers I have. One time purchase of $60~ a few years ago from amazon and I won't go back.
http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW

You can order Sensodyne with Novamin on Amazon.
http://smile.amazon.com/gp/product/B008VPSTOA
It ships from the UK.

Try the uk amazon

http://www.amazon.com/Sensodyne-Repair-Protect-Whitening-Toothpaste/dp/B008VPSTOA

Thish should have it

If you would like a very detailed explanation of this, might I recommend the book Guns, Germs, and Steel, but what it boils down to is similar to what person132 said in another comment.

High population density, and larger populations as a whole, combined with city living and poorer diets, means that more Europeans got sick in general. To infect the surviving Europeans, diseases needed to adapt to be stronger, and more resistant to their immune systems. When these diseases came with them to the colonies, they were no match for the Native American's less/differently developed immune systems.

Your Inner Fish by Neil Shubin

Closing the glottis to prevent water from entering the lungs while breathing with gills in amphibious development. Gill breathing can be blocked by carbon dioxide, just like holding your breath to convert air to CO2 usually dissipates the hiccup gill response.

Jared Diamond's masterpiece, Guns, Germs, and Steel had a chapter on this.

Zebras get nasty as they get older and don't stay tamed.

Lawrence Krauss wrote a book about it, A Universe from Nothing.

It doesn't actually answer the question since no one has yet found an answer. But if the question is really bugging you it is an interesting read.

You might want to look at this book

or this webpage

May I suggest: Guns, Germs, and Steel: The Fates of Human Societies by Jared M. Diamond

"Fascinating.... Lays a foundation for understanding human history."―Bill Gates

In this "artful, informative, and delightful" (William H. McNeill, New York Review of Books) book, Jared Diamond convincingly argues that geographical and environmental factors shaped the modern world. Societies that had had a head start in food production advanced beyond the hunter-gatherer stage, and then developed religion --as well as nasty germs and potent weapons of war --and adventured on sea and land to conquer and decimate preliterate cultures. A major advance in our understanding of human societies, Guns, Germs, and Steel chronicles the way that the modern world came to be and stunningly dismantles racially based theories of human history.

Correct:

Music, The Brain, And Ecstasy: How Music Captures Our Imagination

Most animals cant be domesticated. In history i think only 14 animals have been fully domesticated. In the book Guns Germs & Steel you can find more info on this

maybe check out these books: http://www.amazon.com/This-Your-Brain-Music-Obsession/dp/0452288525 http://www.amazon.com/gp/product/1400033535/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=1944579862&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=0452288525&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1M279DEH4CSSGMJ08BVZ

Take a look at this book: Code The book starts off with a switch and builds a whole computer from there.

http://www.amazon.com/gp/aw/d/0735611319?pc_redir=1411971211&robot_redir=1

Link

I use one of these. They're kinda loud and a little pricey, but at $8 a can, canned air is expensive.

http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW

You find yourself using all the time when you are not paying by the can.

> Is it possible to get cans without this shit?

Is normal air acceptable?

Or spend a bit more, and never buy a can again.

http://www.amazon.com/Metro-Vacuum-ED500-500-Watt-Electric/dp/B001J4ZOAW

I wouldn't say that there's nothing to replace it, it just has a higher up front cost.

What about this one, that says it's shipped from the UK and has the GSK NOVAMIN markings on the back ?

http://www.amazon.com/Sensodyne-Repair-Protect-Whitening-Toothpaste/dp/B008VPSTOA

The version available in the US doesn't have Novamin, so you have to buy it from the UK.

\>A loss result for tax purposes does not necessarily mean the company is losing money.

This line of thinking occurs often, because people do not look at both sides of situation.

If I buy $100,000 worth of computers with a loan, you think it's not a "real loss" because I make profit in the future.

But what if I don't make a profit? The money was still taken from someone else (investor/bank) and they will never get it back. So IT IS a real loss.

I recommend reading Economics in one lesson

Go check out "This Is Your Brain On Music" by musician and neuroscientist Daniel Levitin check it out here. Amazing book. Anyway I'll try to summarize some of the ideas behind human preference for the 4/4 meter. So you know tally marks right? Try writing out tally marks more than four in a row. It starts to get confusing to count! Most people can't really count more than 4 straight lines next to each other in a row at a glance (although some really crazy people can count 8 or more that way!) so we adopted the cross tally for the 5th mark. Birds, for example, get confused after seeing groups of 2 or 3 (can't remember which... maybe 3). So birds can tell if the difference between a predator that's alone and one that's with partner, but perceive more than 3 as basically also 3.

At the end of the day it's a limitation of our wiring. We like 4/4 because anything beyond that becomes very difficult to perceive and "feel" for most people. I imagine alien species with more advanced brains go to nightclubs for some 9/7 music. Weird.

EDIT: added amazon link. Damn good book!

Or for the same price as that 12 pack buy an electronic duster for $40-$60 and never have to worry about running low on canned air, pressure drops or holding cans that are freezing cold.

This is the one I've seen the most. Works pretty well, can get hot after a couple minutes but other than that no complaints about it.

What an absolutely idiotic response.

Whites weren't successful because they were white. They were successful because, their harsh environment and access to resources caused them to look toward innovation to overcome nature. After that mindset was established, they further advanced through structured warfare, and after that, colonization.

If you want to dumb it down and say, "cuz white ppl", then by all means...

Guns, Germs, and Steel can give you an absolutely masterful understanding of why white European peoples came to preeminence.

Historian here, ACTUAL truth, because of the warm all year climate and abundance of food with small tribal populations divided by geography (for the majority of the time) there was no development to the advanced civilization the rest of the world did, and the ones that did, didnt last long (great Zimbabwe, Nubia, ect). The middle east had vast deserts, Europe and to a lesser extent Asia had winters, so food cultivation and thus tool making never really materialized in vast amounts of sub-Sahara Africa because they didnt have to overcome their environment as far as climate goes. (i am assuming thats what you are talking about as north africa is a different story, they arent poor).

Africa actually has vast amounts of resources, rare earths for example, but their governments corruption keeps any of the wealth out of anyone's hands but the government and military war lords.

The idea that things were just fucking dandy until colonial powers came to the shores is laughable and only a fool with no education would believe such non-sense. The few iron age civilizations that did developed were gone long before the Europeans arrived. And it was the Arabs who arrived first and began slavery and "exploitation" of Africa, not Europe. And for every augment for colonialism raping Africa, there is another Rhodesia to Zimbabwe story to counter it.

tl;dr-Its not always Whitey's fault, despite it always being blamed on him


http://www.amazon.com/Guns-Germs-Steel-Fates-Societies/dp/0393317552

^gives you a basic idea in layman's terms

That's a monster of a question. Hell, development economics is an entire academic field, you might as well ask 'ELI5: Physics'. Anyone who seriously thinks they can give you an answer here is lying to you, and probably to themselves as well.

That being said, for my money there are three books that are really required reading on the topic of how countries end up poor, plus two books that are required reading on why it's so hard to fix. I'd call them the bare minimum to call yourself literate on the subject.

1. Guns, Germs, and Steel: The Fates of Human Societies, Jared Diamond. Essential reading on the big (i.e. several millennia) question of how the world ended up broadly split between rich and poor. I think they made it into a documentary, that's probably worth checking out.
   
   
2. Why Nations Fail: The Origins of Power, Prosperity, and Poverty, Daron Acemoglu and James A. Robinson. If you only read one of these, make it this one. Perfect blend of big picture history and modern policy analysis.
   
   
3. Poor Economics: A Radical Rethinking of the Way to Fight Global Poverty, Abhijit V. Banerjee and Esther Duflo. Much more micro-focused, this one is about poor people more than it's about poor countries. I mainly include it because Esther is a beast, and this is one of my favourite books of all time. Definitely worth the read.
   
   Two that you should read on why it's so hard to fix global poverty (Poor Economics sits at the intersection).
   
   
4. The End of Poverty: Economic Possibilities for our Time, Jeffrey Sachs. Jeff Sachs is one of those names that everyone in the world should know. Read this book, end of story.
   
   
5. The White Man's Burden: Why the West's Efforts to Aid the Rest Have Done So Much Ill and So Little Good, William Easterly. Easterly is another name everyone should know. To be honest, I don't agree with him on a whole lot of things. But pretending the other side of the debate doesn't exist is utterly moronic, and you can always learn a lot from people you disagree with.