Videos uploaded by user “BrainStuff - HowStuffWorks”
Why Do People In Old Movies Talk Weird?
It’s not quite British, and it’s not quite American – so what gives? Why do all those actors of yesteryear have such a distinct and strange accent? Learn more at HowStuffWorks.com: http://entertainment.howstuffworks.com/movies-film-channel.htm Share on Facebook: http://goo.gl/1j6yim Share on Twitter: http://goo.gl/4FoAQy Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com If you’ve ever heard old movies or newsreels from the thirties or forties, then you’ve probably heard that weird old-timey voice. It sounds a little like a blend between American English and a form of British English. So what is this cadence, exactly? This type of pronunciation is called the Transatlantic, or Mid-Atlantic, accent. And it isn’t like most other accents – instead of naturally evolving, the Transatlantic accent was acquired. This means that people in the United States were taught to speak in this voice. Historically Transatlantic speech was the hallmark of aristocratic America and theatre. In upper-class boarding schools across New England, students learned the Transatlantic accent as an international norm for communication, similar to the way posh British society used Received Pronunciation – essentially, the way the Queen and aristocrats are taught to speak. It has several quasi-British elements, such a lack of rhoticity. This means that Mid-Atlantic speakers dropped their “r’s” at the end of words like “winner” or “clear”. They’ll also use softer, British vowels – “dahnce” instead of “dance”, for instance. Another thing that stands out is the emphasis on clipped, sharp t’s. In American English we often pronounce the “t” in words like “writer” and “water” as d’s. Transatlantic speakers will hit that T like it stole something. “Writer.” “Water.” But, again, this speech pattern isn’t completely British, nor completely American. Instead, it’s a form of English that’s hard to place… and that’s part of why Hollywood loved it. There’s also a theory that technological constraints helped Mid-Atlantic’s popularity. According to Professor Jay O’Berski, this nasally, clipped pronunciation is a vestige from the early days of radio. Receivers had very little bass technology at the time, and it was very difficult – if not impossible – to hear bass tones on your home device. Now we live in an age where bass technology is booms from the trunks of cars across America. So what happened to this accent? Linguist William Labov notes that Mid-Atlantic speech fell out of favor after World War II, as fewer teachers continued teaching the pronunciation to their students. That’s one of the reasons this speech sounds so ‘old-timey’ to us today: when people learn it, they’re usually learning it for acting purposes, rather than for everyday use. However, we can still hear the effects of Mid-Atlantic speech in recordings of everyone from Katherine Hepburn to Franklin D. Roosevelt and, of course, countless films, newsreels and radio shows from the 30s and 40s. SOURCES: http://www.motherjones.com/kevin-drum/2011/08/oh-old-timey-movie-voice http://news.discovery.com/history/us-history/old-time-baseball-players-talk-130404.htm http://web.archive.org/web/20051118050043/http://www.ling.upenn.edu/phonoatlas/Atlas_chapters/Ch7/Ch7.html http://www.slate.com/articles/news_and_politics/explainer/2008/02/why_did_william_f_buckley_jr_talk_like_that.html
How Does The Common Cold Work?
We've all had a cold at one point or another; it entails an uncomfortable cocktail of symptoms like sneezing, coughing and a runny nose. But why do we get colds? How do they work? Find out in this episode of BrainStuff! Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
What The Heck Is GDP?
GDP, GNP – what does it all mean? Jonathan explains what economists mean when they bring up these common economic indicators. Learn more at HowStuffWorks.com: http://money.howstuffworks.com/gross-national-happiness.htm Share on Facebook: Share on Twitter: Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com OK, let’s say you’ve just gotten a job offer to work in the majestic country of Bumpsylvania. Awesome, right? You’ve always wanted to live amongst the scenic Bumpsylvanian swamplands and hear the local ghost toads sing their famous mating screech. But before you pony up the $549.95 for Rosetta Stone: Bumpsylvanian Edition, you want to do a little research on the economic health of this country. So you ask your friend the economics professor: How is the economy of Bumpsylvania doing these days? One number that will almost definitely figure into her reply is the country’s GDP. This stands for Gross Domestic Product. GDP is a common measure that’s used to roughly represent the size of a country’s economy. The way you calculate GDP is both simple as a general principle, and complicated in the details. The simple version is that GDP is the value of all the goods and services produced within a country in a given period of time, such as a financial quarter or a year. So if we look at Bumpsylvania, we can calculate its yearly GDP by adding up the dollar-value of all the stuff it creates: All the pork sandwiches, shoe shines, fashion magazines, bullets, massages, motorcycles, jiu-jitsu classes, ghost toad swamp tours, and, of course, traditional, Bumpsylvanian-style wooden hats. Every item, product or service brought to market by workers or other economic resources located inside the country in that year is part of the GDP. Coming up with this figure is not as easy as it sounds. GDP is actually a highly complex and abstract statistical instrument that takes some real work to calculate. Just one example of the many complications: Let’s say somebody cuts down some swamp trees and turns those trees into lumber, and then sells that lumber to a haberdasher who turns it into a traditional, Bumpsylvanian-style wooden hat. Do you count the sales of both the lumber _and_ the hat? Well, no, because GDP is a measure of the final value of goods and services. So if you counted the sale of the wood to the hat-maker and the sale of the hat, you’d be counting the same value twice. The value of the wood gets wrapped into the final value of that gorgeous, gorgeous headgear. GDP is probably the most important measure of the size and performance of an economy, but it’s not the only one. There’s also GNP, which is related, but slightly different. GNP stands for gross national product. The difference is that GNP is the value of all the products and services produced by a country’s residents, even if production takes place outside of the country. So if a Bumpsylvanian business has a factory making wooden hats in another country, the output of that factory would be included in Bumpsylvania’s GNP, but not its GDP. While GDP is a widely used indicator of economic strength, many critics point out that it’s not necessarily the best indicator of the “real” health of a nation. For example, a country with a large, growing GDP might look strong on paper, but what if that number is masking vast income inequality – a productive economy based on huge amounts of low-wage labor? Of course by comparing GDP with other pieces of data, you can do more with the figure. A simple example would be comparing GDP with population to come up with Per Capita GDP (which means economic value per person). So for example, according to the World Bank, in 2013, China’s GDP was a massive $9.2 trillion. Compare that to Luxembourg’s relatively small GDP of $60 billion. Yet in the same year, China’s GDP Per Capita was only about $6,800, while Luxembourg’s was more than 16 times that, at about $110,000. So while China’s economy is certainly much larger, it looks like each individual citizen, on average, is better off in Luxembourg. Financially speaking, that is. SOURCES: http://www.britannica.com/EBchecked/topic/246663/gross-national-product-GNP http://www.bea.gov/newsreleases/national/gdp/gdpnewsrelease.htm http://www.britannica.com/EBchecked/topic/246647/gross-domestic-product-GDP http://money.howstuffworks.com/gross-national-happiness.htm/printable http://www.nytimes.com/2013/10/05/world/asia/index-of-happiness-bhutans-new-leader-prefers-more-concrete-goals.html?_r=0 https://books.google.com/books?id=V5IpAgAAQBAJ&printsec=frontcover&dq=how+to+calculate+gnp&hl=en&sa=X&ei=QlVyVZH1CJKFyQTo-4D4CQ&ved=0CDYQ6AEwAg#v=onepage&q=how%20to%20calculate%20gnp&f=false http://data.worldbank.org/indicator/NY.GDP.MKTP.CD http://data.worldbank.org/indicator/NY.GDP.PCAP.CD http://www.factcheck.org/2008/02/gdp-vs-gnp/
How Does LASIK Work?
Jonathan Strickland explains the process and risks of LASIK surgery, from preoperative exams, to lasers in your eyes. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Subscribe Now! http://www.youtube.com/subscription_c... Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff For centuries we’ve relied on external lenses (like glasses or contacts) for correction. But with modern technology surgeons can actually alter the shape of the eye itself using lasers to change its focal point. The most popular technique is called LASIK, which stands for Laser-Assisted In-Situ Keratomileusis. It’s very effective at treating several visual problems, especially near-sightedness. Before any reputable eye doctor performs LASIK, they’re going to give you a thorough preoperative eye exam. They’ll measure your current prescription and manually check the surface of your cornea with a dye called Fluoracaine. Other tests map your cornea’s topography and measure the exact diameter of your pupil. To qualify for LASIK, you’ll need to meet a certain range of vision, corneal thickness and pupil size. It’s also risky if you’re pregnant, have severe heart problems, certain diseases, or take some types of drugs. Once you’ve passed pre-op assessment, you come back for the actual LASIK process, conducted by both the surgeon and a technician operating the laser machine. They’ll put a topical anesthetic in your eyes to numb any discomfort. That’s good, because the next step is to pry open your eyes with special tape and that good old Eyelid speculum. Then they’ll calibrate the laser and mark your cornea for alignment. Using a suction ring and an extremely precise surgical blade called a microkeratome, the surgeon cuts a flap in your cornea and folds it back. You’ll be asked to focus on a red light which isn’t the laser, but helps center your eye. Now it’s laser time! An Excimer laser mixing reactive gases like chlorine and fluorine with inert gases like argon, krypton and xenon, produces a tightly focused beam of ultraviolet light that vaporizes a microscopic portion of the cornea. This is a “cool laser” that doesn’t heat the surrounding air or surface. Instead it breaks down the molecular bonds of organic materials. The beam itself is microscopic, less than a nanometer wide. The surgeon reshapes the cornea by controlling the size, position and number of laser pulses applied. Surprisingly, this only takes a few seconds. When it’s finished, your corneal flap is replaced with a small antibiotic added. The cornea heals and rebonds immediately, naturally sealing itself again. Taking into account the time for both eyes, the entire procedure is usually done in only 15-30 minutes. After the operation they’ll give you these cool eye shields that prevent you from touching your eyes but let you see enough to get around. You’ll wear them the rest of the day and sleep in them that night. Of course, someone has to drive you home and once you get there you’ll need to apply rewetting drops, antibiotic drops and possibly a moisturizing gel inside your bottom eyelid. The opthamologist will follow up the next day and on a recurring basis for about a year. Now you’re probably asking, “But Jonathan, couldn’t there be side effects when a doctor shoots a laser into my eye?” Of course there could. Most commonly, eyes can be undercorrected, overcorrected or get a small wrinkle when the corneal flap is replaced that causes a blur. For the most part these are easily fixed with a second procedure. Sometimes a surgeon won’t even recommend further refining since many recipients of LASIK never achieve “normal vision,” but do reduce their corrective prescriptions significantly. Other, rarer side effects can include halos around lights, light sensitivity and double vision. I’d be lying if I said there wasn’t a chance of partial or complete blindness, but it is miniscule compared to the success rate. This is especially true if you’re seeing a reputable doctor. Keep in mind that there are so many unscrupulous practitioners out there that the FDA had to issue a stern warning about dodgy sales pitches underplaying the risks of LASIK. But twenty-five years after it was invented by Gholam Peyman, LASIK is safer than ever before. http://health.howstuffworks.com/medicine/surgeries-procedures/lasik.htm http://podcasts.howstuffworks.com/hsw/podcasts/techstuff/2011-10-24-techstuff-laser-eye-surgery.mp3 YOUR EYES. By: Sklar, Hallie Levine, Health (Time Inc.), 1059938X, Apr2013, Vol. 27, Issue 3 LASIK: Illustration. CRS - Adult Health Advisor, Jun2012
Why Do Limbs Fall Asleep?
Pressure on nerves can cause the nerves to stop sending impulses to the brain, causing limbs to fall asleep. Learn more about limbs falling asleep in this episode of BrainStuff. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
Is There A Noise Loud Enough To Kill You?
Loud noises suck. But are they deadly?​ Share on Facebook: http://goo.gl/QhNzk5 Share on Twitter: http://goo.gl/BKyh8z Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com CREDITS: "Large European Acoustic Facility" photo by Guus Schoonewille
How (And Why) Do Cats Purr?
Cats purr for all kinds of reasons, including communication and healing themselves. Cristen explains how purring works and which cats can't do it. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Download the New TestTube iOS app! http://testu.be/1ndmmMq Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
What Is White Noise?
Jonathan defines what white noise actually is and how it's used to mask other annoying sounds. Learn more at HowStuffWorks.com: http://science.howstuffworks.com/question47.htm Share on Facebook: http://goo.gl/n7YNrZ Share on Twitter: http://goo.gl/Fq9InS Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Cross over into BrainStuff now children. All are welcome! But… before we go into the light together, there seems to be some confusion among you about what “white noise” is. No, it isn’t when you have that snowy static on your TV and ghosts fly out of the screen and your daughter says, “They’re here!” White noise is something we’ve all heard, some of us without even knowing it. So let’s define what it is exactly, how it’s used to mask other sounds and what other “colors” exist on the spectrum of sound. The simplest definition is that white noise is the noise produced by combining all the different frequencies of sound together at once. Each of these frequencies is projected at an equal amount, from low to high. Because white noise has an equal energy distribution, sound technicians refer to its frequency spectrum as being completely flat. Some machines -- like fans for instance -- can create an approximation of white noise by hitting all these notes. That’s why they’re so good at creating background noise that masks other sounds. When there are sudden changes in noise, we’re often distracted by the jarring clash. Especially if we’re sleeping. White noise’s masking effect blocks out those changes, making it easier to sleep through the night. That’s one reason some people leave a fan, air purifier or a television on in the middle of the night. This sound masking is also used to block noise in places like offices, hotels and libraries, often broadcast over a PA system. If you’re trying to concentrate in a disturbing environment and there aren’t filters like these in place, you can always listen to white noise on your headphones to mediate the conflicting sounds around you. How do you think we write these BrainStuff episodes when we all live together in this tiny studio prison and are never allowed to leave? There is peace and serenity in the white noise. We call it “white” noise because it’s analogous to how white light works, being made up of all the different frequencies of light. But white noise isn’t the only “color” on the sound spectrum. Depending on the way signals are distributed over different frequencies they can be red, blue, violet or gray. Pink noise for example is very similar to white noise, but its higher frequencies have less intensity, making it louder and more powerful on the low end. This makes it useful for testing speakers and amplifiers. Like white noise, it’s also used to mask background sounds. And pink noise even occurs naturally in heartbeat rhythms, meteorological data and the radiation output of astronomical bodies. SOURCES: http://science.howstuffworks.com/question47.htm http://www.popsci.com/article/science/fyi-why-does-white-noise-help-people-sleep Spinney, L. (2008). The noise within. New Scientist, 198(2661), 42-45 Carroll, J. (2012). Can white noise ease tinnitus effects?. Plant Engineering, 66(8), 19. http://www.wired.co.uk/news/archive/2011-04/7/colours-of-noise http://www.livescience.com/38464-what-is-pink-noise.html
Why Shouldn't You Give Honey To Babies?
Botulism bacteria creates a type of poisoning and paralysis -- but how does it actually work? Check out this episode of BrainStuff to learn more about the effects and spread of botulism. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_c... Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff Hi. I’m Lauren, this is BrainStuff, and today’s question is “Why shouldn’t you give honey to babies?” It’s not because bees and babies have an ancient grudge match – probably. It’s because of botulism. Botulism is a condition – a poisoning by the neurotoxin botulinum. It’s named after these bacteria, Clostridium botulinum, that produce the toxin just as a byproduct of existing. In the human body, the toxin attaches to nerve endings that stimulate muscles and block them, preventing them from doing their jobs. This leads to a feeling of weakness, and in severe cases can cause immobilization and even death -- from respiratory paralysis. It’s a less cartoony version of the Joker’s laughing toxin. These bacteria are pretty common, but lucky for us, they’re killed by oxygen – and, as I’ve mentioned before, there’s a good amount of free-range oxygen in our air. Unfortunately, they’ve adapted to form spores around themselves that let them lie dormant until they find themselves back in an oxygen-free environment. When adults get botulism, it’s usually from improperly canned food. During the canning process, if the food is heated properly, it’ll destroy the spores. But if it’s heated improperly, the bacteria can activate once the can’s been sealed, creating that oxygen-free environment they grow in. And that’s why you shouldn’t eat food from bloated cans – the bloat comes from rapid bacterial growth that creates a lot of toxin in the food. Side note: Dented cans are fine. But, OK, we all know that babies are completely incompetent at operating can openers. The thing is, honey frequently contains a few spores of clostridia botulinum – bees accidentally pick them up while they’re collecting nectar. Adults with functioning immune systems and established intestinal flora – that’s the helpful gut bacteria -- can handle a couple spores. But babies can’t. So when the botulinum get into the oxygen-free intestines of the baby, they can activate and poison the baby. This is all scary. Botulinum is one of the most toxic compounds known to humankind. It can be deadly in the magnitude of nanograms. That’s a billionth of a gram. That’s really small. But it can also be used as a medical treatment. When it’s really diluted, doctors can inject it in patients who have overactive muscle conditions that affect their mobility or eyesight. And hey, you’ve heard of Botox? That’s carefully controlled botulism in your face. http://textbookofbacteriology.net/themicrobialworld/Botulism.html http://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/safe-food-handling/shelf-stable-food-safety/ct_index/!ut/p/a1/jVJtT4MwGPw19BtrGdOgSWMQXebUzWXRMb4spZSXhVFsy1B_vS2auE2nQkjbu3t42rvCCIYwqsi2yIgqeEVKs45OV2iGTp2zAI2nZ84Q3UyeZtPbIEDe_EQLlr8IJu4_6488PvqrfvyPBn1xH9xnMKqJyu2iSjkMM6ZsUsmWCQnDlPPEliRl6tVOCVW2zBlTmjCY3bE5qZKyqDKN5axMbalIXH5yH5UwpGpVVAl7gQsY7e8KOfq9mbjzwWg8cdF0cCj4wbYPwXFf9MGzksddRku_il1Pn1CwlAkmeo3QcK5UfW4hC7Vt28s4z0rWo3xjIc1eSIIVEFThNXjGgElBsQSSN4Iy3LIY0AT3ASUJFmsCGm0K9sCWJRgFV9ez4dq_BPov2LSwHNe3nP7QfKZTKgvZa2RCdM9tB9bSDDUXipRmZhRmVLwuaDfbTYAlDe2unyF2cjrU7SRlqO9ZdehXWj_5lHOpYLjvD6w3j-HbnT9CxcNm4Un_HaFCwfA!/#10 http://www.babycenter.com/408_when-can-my-baby-eat-honey_1368490.bc http://www.infantbotulism.org/general/faq.php http://money.howstuffworks.com/personal-finance/budgeting/safe-to-buy-dented-foods-from-grocery-store.htm/printable
What Happens When I Have A Hangover?
If you've ever had a few too many beers at a party, then you've probably encountered the symptoms of a hangover -- the pulsing headache, dry mouth, nausea and more. But what's actually happening to you? And what is it about alcohol that can turn a wonderful Saturday night into an agonizing Sunday morning? Learn more with Ben Bowlin. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. SOURCES Perry, Lacy. “How Hangovers Work.” http://science.howstuffworks.com/life/human-biology/hangover.htm/printable Stuff You Should Know: “What is a hangover, really?” http://www.stuffyoushouldknow.com/podcasts/what-is-a-hangover-really/ “Your Complete Guide to the Science of Hangovers” Stromberg, Joseph. http://www.smithsonianmag.com/science-nature/your-complete-guide-to-the-science-of-hangovers-180948074/?no-ist Download the New TestTube iOS app! http://testu.be/1ndmmMq Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
Are Stupid People More Confident?
We've all heard about the supposed relationship between confidence and knowledge - but is it true? Two researchers think they've found the answer. Learn more at HowStuffWorks.com: http://people.howstuffworks.com/decisions-groups-decisions-alone.htm Share on Facebook: http://goo.gl/SBM7wy Share on Twitter: http://goo.gl/tz0IoH Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Hey, BrainStuff, it’s me, Ben. If you’re like most people, you think you’re very good at some things, and are able to admit you’re less good at others. You probably think you’re superbly talented in one or two areas - and hey, you might be right. You try to be honest with yourself about your strong points and your weak ones. You likely shake your head in pity at people you see as, well, stupid. “Why do they keep dumbing everywhere?” you ask yourself, “Why don’t they understand that they’re bad at doing stuff? There is an answer, but you might not like it. And this answer doesn’t just apply to people you think of as “dumb”. It applies to everyone on Earth… including you and me. It’s not a matter of intelligence, necessarily– a difficult thing to measure– but it is related to “competence”, the ability to do something well. In 1999 a psychologist named David Dunning and his grad assistant Justin Kruger tested a group of students in several categories: “the ability to think logically, to write grammatically, and to spot funny jokes”. They also asked the students to rate their skills in these categories. That’s when they noticed something weird. The people scoring below average on these tests weren’t just incompetent in these categories – they also didn’t know they were incompetent. And here’s the kicker: the less competent they were, the MORE competent they ranked themselves. This is a phenomenon called “illusory superiority” (which sounds like the name of a Radiohead B-Side, but isn’t, as far as we know). Instead, this is a cognitive bias wherein people tend to rate their own abilities as above-average. You know, like how everyone’s thinks they’re a good driver or believes they have a great sense of humor. Multiple studies have proven this effect in everything from firearms to college debates and med students’ opinions of their interviewing skills. It doesn’t seem to matter what specific skill we’re talking about – the less a person knows about it, the more likely they are to overestimate their knowledge. While Dunning and Kruger popularized this effect in modern society, they weren’t the first people to notice the relationship between confidence, modesty and skill. Philosophers throughout the ages have contemplated this idea, like Bertrand Russell, who famously wrote “The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.” And here’s another weird thing. People with actual competency are likely to actually underestimate their abilities. Researchers believe this modesty comes because competent people are more aware of how much they don’t actually know, as well as their field in general. They also consistently overestimate the performance ability of others. It all goes back to one primary thing – metacognition. Metacognition is the ability to be aware of and understand your own thought process. In other words, the ability to think about how you think. People tend to evaluate themselves through what Dunning and Kruger call a “top-down” approach. Instead of objectively measuring their performance, people start with their preconceived notions of their skill and use that belief to evaluate their performance. SOURCES: http://psych.colorado.edu/~vanboven/teaching/p7536_heurbias/p7536_readings/kruger_dunning.pdf http://people.howstuffworks.com/human-intelligence-info.htm http://theness.com/neurologicablog/index.php/lessons-from-dunning-kruger/ http://psycnet.apa.org/?&fa=main.doiLanding&doi=10.1037/0022-3514.77.6.1121 http://petapixel.com/2014/10/13/dunning-kruger-peak-photography/ http://www.psych.nyu.edu/jost/Zuckerman%20&%20Jost%20(2001)%20What%20Makes%20You%20Think%20You're%20So%20Popular1.pdf
What Causes The Northern Lights?
There are many misconceptions about what causes the Aurora Borealis when it really requires solar winds, magnetic fields and excited atmospheric gases. Learn more at HowStuffWorks.com: http://science.howstuffworks.com/nature/climate-weather/atmospheric/question471.htm Share on Facebook: http://goo.gl/FMuiBa Share on Twitter: http://goo.gl/TR4YyU Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com The Northern Lights are beautiful and odd and have understandably inspired many myths. The Vikings thought they were a bridge between our world and Asgard where Thor and the other gods live. In another Norse myth, they are the light reflected of the armor of the Valkyries. And people in Finland thought it was the archangel Michael (John Travolta) battling Beelzebub (the devil). Wrong. Wrong. Wrong. All wrong. It was the famous early astronomer and recanter of science, Galileo Galilei, who gave the Northern lights the name Aurora Borealis, which means “dawn of the North” in Latin. But it wasn’t until Norwegian scientist Christian Birkeland figured it out in 1896 that the true origin of the auroras was understood. In the center of the Earth, the molten iron core generates magnetic fields that extend through the crust and into space around the planet, creating what’s called Earth’s magnetosphere. It’s a pretty great thing that Earth has it, because the magnetosphere protects us from all manner of charged particles spit out from the Sun. The Sun is so hot that it produces plasma (a fourth state of matter) where positively charged atoms (ions) and negatively charge electrons flow freely around one another. These highly charged particles have enough energy to escape the Sun’s gravity and fly out into space, barreling toward Earth at 1 million miles per hour like a shotgun blast of solar hate. This is called solar wind. When they encounter our magnetosphere, most of these ions and electrons bounce harmlessly off and Earth is saved. But some of these particles make it through the magnetosphere where it’s weakest (at the north and south poles), and when they do the light show begins. The electrons that make it into our atmosphere interact with some of the elements there, particularly oxygen and nitrogen. The electrons transfer energy to them, exciting them in the process. To calm down, the excited atoms must release some energy, which they do as tiny packets of light called photons -- beautiful, beautiful photons. Depending on where in the atmosphere the electrons interact with these other atoms, different colors are produced. Oxygen emits a yellow-green color up to about 150 miles in the atmosphere. After that, it turns red. Nitrogen emits a nice blue color about 60 miles up. And don’t forget these colors can blend, which can create glowing pinks, purples and whites. It’s like Miami Beach up there. This interplay is most vibrant during solar storms, which depend somewhat on the Sun’s solar cycle. And, although these lights can be produced at all hours, they aren’t visible during the day, since the sunlight outshines them. SOURCES: http://science.howstuffworks.com/nature/climate-weather/atmospheric/question471.htm http://www.physics.org/article-questions.asp?id=64
Why Do So Many Price Tags End In .99?
It’s very common to see the number 9 at the right end of a price tag. Why is this? Lauren explains the psychology of prices and nines in this episode of BrainStuff. Learn more at HowStuffWorks.com. Share on Facebook: Share on Twitter: Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Hi there! I’m Lauren, and this is BrainStuff. The other day I was shopping at Bavmorda’s Trebuchet and Millinery Emporium and I started wondering -- why do so many prices end in the number 9? You might have wondered the same thing too, and if you have, it’s not just your imagination. Studies have shown that many retailers disproportionately use prices within 5 cents of the nearest dollar, 1 cent of the nearest 10 cents, $5 of the nearest $100 or $1000, and within $1 of the nearest 10-dollar amount. Prices like this are often known as “charm” prices, “odd” prices, “magic” prices, or “psychological pricing.” Pricetags ending in the number 9 are especially common. But why? These days, two main psychological theories of charm pricing have emerged. And yes, this is a field of study. For the purpose of this video, we’ll call them the “rounding off” theory and the “bargain signaling” theory. The rounding off theory argues that shoppers tend to pay a lot more attention to the first digits in a listed price. So, when you see a product labels $29.99, even though it's only 1 penny off from being 30 bucks, the theory goes that you mentally round down to think of it as a $20 price point based on that first digit. For example, a 2005 study found that prices ending in 99 cents caused shoppers to make math errors that even-dollar prices did not. It worked like this: Test shoppers were given an allowance of exactly 73 bucks, and they were then asked to estimate how many products they could buy with this allowance. It turned out that when 99-cent endings were in the picture, shoppers overestimated their spending power. In other words, they thought they could buy significantly more products at prices like $2.99 and $5.99 than they could at $3 and $6. This seems to suggest that we do tend to “round down” and ignore the final digits in prices, even though it makes no economic sense to do so. The bargain signaling theory suggests that odd prices work the same way “Sale” signs do, meaning they imply to shoppers that the price listed is especially good. Maybe the weird specificity of something priced $5.98 or $2.39 makes us think that the store is selling that bag of Gummy Bears at the lowest price point they can possibly afford. Or maybe we’ve all been conditioned by marketing to associate odd prices, especially the ones ending in 9, with sales and discounts. In 2003, researchers showed that in some cases, you could actually increase demand for an item by raising the price so that it ended in a ‘9,’ which would seem to contradict rational economics. One example they studied: A $34 dress in a clothing catalog. By raising the price from 34 bucks to 39 bucks, demand for the dress actually went up. When they raised the price to $44, however, the trend didn’t hold -- so it wasn’t just that buyers liked paying more for their clothes. Since 34 and 39 both start with the same digit, this would seem to favor the bargain signaling theory rather than the rounding off theory. Something about the 9 just seemed to make people think they were getting a good deal. So it looks like our penchant for buying at the 9s might be explained by a mixture of our tendency to round down to the leftmost digit AND our beliefs that 9s inherently indicate bargains. SOURCES: http://www.jstor.org/stable/10.1086/678484?seq=1#page_scan_tab_contents http://www.theatlantic.com/business/archive/2015/01/the-psychological-difference-between-1200-and-1167/384993/ http://timharford.com/2012/06/pound-for-pound-99p-is-worth-every-penny/ http://www.nytimes.com/2009/02/08/weekinreview/08arango.html?_r=0 http://dept.camden.rutgers.edu/business/files/Schindler-2006.pdf http://dept.camden.rutgers.edu/business/files/Bizer-Schindler-2005.pdf http://onlinelibrary.wiley.com/doi/10.1002/mar.20084/abstract https://hbr.org/2003/09/mind-your-pricing-cues http://classes.bus.oregonstate.edu/fall-05/ba499/elton/Articles/Mind%20Your%20Pricing%20Cues.pdf http://link.springer.com/article/10.1023%2FA%3A1023581927405 http://www.ozshy.50webs.com/21why99.pdf https://www_nelsonpricing_com_ar.1.com.ar/biblioteca_pricing/1997-02_why_are_so_many_goods_priced_to_end_in_nine_Basu_K.pdf http://marketing-bulletin.massey.ac.nz/V8/MB_V8_N1_Holdershaw.pdf
What Causes Chapped Lips?
For some people, winter means a daily battle against cracking, scaling or peeling lips. But what actually causes chapped lips? How can you prevent it? Learn more at HowStuffWorks.com: http://health.howstuffworks.com/skin-care/lip-care/tips/5-tips-for-battling-cracked-lips.htm Share on Facebook: https://goo.gl/R2ZwmK Share on Twitter: https://goo.gl/eyBIVF Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com I’m going to go out on a limb here and say you’ve probably had chapped lips at some point. Here’s what’s happening. Your lips are pretty delicate things – this one at the top is your Labium superius oris, and the one at the bottom is your Labium inferius oris. Collectively they form an enormously sensitive, incredibly flexible part of your body. However, they also have some vulnerabilities. For instance, the skin of your lips is different from the rest of your face – let’s take a closer look. Here we go – this is your skin! The outer layer is called the epidermis, and it has a protective covering called the stratum corneum. Underneath your epidermis is another layer of skin, the dermis. Like the rest of your skin, your lips have all three of these layers -- the difference is that the stratum corneum on your lips is way thinner than it is anywhere else on your body. In fact, it’s part of the reason people’s lips have that alluring red or pink pigment. It comes from underlying blood vessels -- red-colored, blood-filled capillaries close to the thin skin on your lips. Next, your lips also don't have the oil and sweat glands that protect other parts of your skin. Their only source of moisture is your saliva, and that's why they can easily become dry and chapped. And that’s usually the culprit here: hydration. We often experience chapped lips in cold weather – not because our lips are allergic to winter or anything, but instead because the outside air tends to be drier, and this also dries out the lips. And this drying out is the leading cause of chapped lips, also known as common cheilitis. Luckily, there are some pretty simple ways to prevent this. First, and no matter what the cause of your chapped lips might be… stop licking them! I know, I know it can be a difficult habit to break. But licking your lips can contribute significantly to dry, cracked skin. The saliva evaporates quickly, taking with it any moisture that was already on your lips and leaving them even drier, especially in winter air. And speaking of amazing segueways, let’s tackle weather-related chapping. If you have very dry air in your house, consider investing in a humidifier. If you’re outside, then protect your lips with a product that contains beeswax or petrolatum, which will help maintain your lips' hydration. If you plan to be out in the sun for awhile, help prevent dryness by using a sunscreen on your lips as well. A lip balm with SPF in it could help address both of these issues at once -- and, as always, drinking plenty of fluids is a great move for your entire body, not just your lips. And that’s it. Well, almost. We didn’t talk about the multiple other causes of chapped lips, or lip balm addiction, or whether some of the ingredients in those things actually cause chapped lips – an interesting little conspiracy theory. SOURCES: http://health.howstuffworks.com/skin-care/lip-care/health/lips-most-sensitive.htm http://health.howstuffworks.com/skin-care/lip-care/health/lips-different-skin.htm http://health.howstuffworks.com/skin-care/lip-care/health/dry-lips-health-problem.htm http://health.howstuffworks.com/skin-care/lip-care/health/cold-temperatures-damage-lips.htm http://www.today.com/id/22505976 http://www.healthline.com/symptom/chapped-lips http://www.medilexicon.com/medicaldictionary.php?t=47434 http://www.medilexicon.com/medicaldictionary.php?t=47448 http://www.webmd.com/beauty/lips-smile/end-chapped-lips http://drtrue.com/2014/02/cheilitis-inflammation-of-the-lips/ THE LIP BALM CONSPIRACY THING: http://lifehacker.com/5974745/know-which-ingredients-in-lip-balm-actually-cause-dry-lips http://www.today.com/style/got-chapped-lips-lip-balm-isnt-answer-I313924 http://www.mayoclinic.org/diseases-conditions/dry-skin/expert-answers/chapped-lips/faq-20057819 http://health.howstuffworks.com/skin-care/lip-care/tips/10-tips-for-battling-dry-lips.htm
How Does Silica Gel Work?
What is silica gel, and why do I find little packets of it in everything I buy? Lauren explains it all in this week's episode. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Download the New TestTube iOS app! http://testu.be/1ndmmMq Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
How Do One-Way Mirrors Work?
How can a single piece of glass look like a mirror from one side but a window from the other? It's not magic, it's materials technology. Learn more at HowStuffWorks.com: http://science.howstuffworks.com/question421.htm Share on Facebook: http://goo.gl/b6Tts3 Share on Twitter: http://goo.gl/mQM4qB Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Hi! I’m Jonathan, this is BrainStuff, and today we’re talking one-way mirrors, aka two-way mirrors, aka half-silvered mirrors, aka transparent mirrors, aka security mirrors, aka surveillance mirrors, aka observer-ator-trons. Y’know, those things you see in crime dramas when one cop’s interrogating a suspect, while another watches through a window that appears - from the suspect’s side - to be a mirror. It’s not magic. TV cops aren’t wizards. Except sometimes they are. But that’s fiction, and transparent mirrors are science. Specifically, materials science and optics. OK. A regular ol’ mirror – the kind hanging over your bathroom sink – is a sheet of glass holding up an extremely thin layer of reflective metal. The metal comes in the form of a metallic salt, which can be dissolved in liquid and sprayed onto the glass in a process called silvering. That’s because silver nitrate was the first stuff used for this process. These days, most mirrors are actually silvered with aluminum, which is cheaper and sturdier. But silvering doesn’t make perfect mirrors: They reflect most light, but a little is still transmitted through infinitesimal gaps in the reflective metal layer. So everyday mirrors receive an opaque backing, like dark paint. This stops cold any photons that slip through the metal layer (and protects it from scratches). Without the backing, you’d be able to faintly see the wall behind the mirror. But what if you purposefully make a mirror imperfect? Manufacturers of transparent mirrors spray an even thinner, less dense layer of silvering onto the glass. Meaning it reflects less light – for example, let’s say half the light of an ordinary mirror. The rest passes straight through the glass like it’s a window. Which it is. A transparent mirror, with its sparse silvering and lack of backing, is just a reflective window. And it’s a window from both sides! So: How come the suspect sees his reflection, but the cop sees the suspect? It’s a trick of the light. The observer room is kept dark, while the observee’s room is lit up like the Vegas strip. So on the cop’s side, more light is coming through the glass than being reflected from the room. And from the suspect’s side, more light is reflecting from the room than being transmitted through the glass. And hey, people ask about this a lot: If you ever want to test a mirror to see if it’s transparent, block the light around you and try to peer through. A bright flashlight can help illuminate anything that might be behind the mirror. CREDITS: "Bean" movie clip from MovieClips.com YouTube channel: https://www.youtube.com/watch?v=fkHlhiG0h70 SOURCES: http://science.howstuffworks.com/question421.htm/printable http://science.howstuffworks.com/innovation/everyday-innovations/mirror.htm/printable http://articles.adsabs.harvard.edu//full/1911PASP...23...13C/0000015.000.html http://www.google.com/patents/US2996406 http://www.photonics.com/EDU/Handbook.aspx?AID=25501
How Can There Be Seedless Grapes?
Seedless grapes are the most common kind on the market, but have you ever wondered how a grape can be seedless? How does it grow? Discover how seedless grapes accidentally came about -- and how they grow -- in this episode of BrainStuff. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
How Does A Gas Nozzle Know When To Shut Off?
If you've ever put gas in a car, you've probably noticed how the gas pump shuts off when your tank is full. But how does it know to do that? Learn more about the clever mechanism that keeps your gas tank from overflowing in this episode of BrainStuff. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
How Do GPS Coordinates Work?
So you’ve seen those location-tagging numbers on maps and GPS devices before, but do you actually know what they mean? Brainstuff is here to fill you in. Learn more at HowStuffWorks.com: http://electronics.howstuffworks.com/gadgets/travel/gps.htm Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com SOURCES: https://www2.usgs.gov/faq/categories/9794/3022 http://maps.nationalgeographic.com/downloads/Map_Skills_Booklet.pdf https://www.britannica.com/place/Greenwich-meridian http://astro.unl.edu/naap/motion1/tc_units.html https://pubs.usgs.gov/fs/2001/0077/report.pdf https://www.fcc.gov/media/radio/dms-decimal
Do You Really Need To Wash Your Jeans?
You might have heard this odd advice from fashion gurus before – “don’t wash your jeans!” But why? Is it real advice, or just a prank pulled on unsuspecting, dim-witted denim rubes? Learn more at HowStuffWorks.com: http://lifestyle.howstuffworks.com/style/fashion/denim Share on Facebook: https://goo.gl/qpypzt Share on Twitter: https://goo.gl/OCVkI0 Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Here’s the thing: whether you’re wearing a pair of busted Levis or brand-new raw denim from some fancy boutique, your pants are part of a debate that designers and customers alike have been having for decades: When should you wash your jeans? Do you need to wash them at all? Let’s look at the basics. Denim is a kind of cotton with a twill textile weave. Check out this photo: in a twill weave, the thread called the weft – the crosswise yarn - passes under at least two warp threads – those are the lengthwise yarns. In most jeans, only these warp threads are dyed, meaning that these other threads, the weft threads, remain white. That’s why blue jeans are white inside. That blue shade on the warp threads comes from a dye called indigo. Unlike some other dyes, indigo doesn’t penetrate the cotton. Instead, it sits atop the yarn, on the surface of each thread. Over time, molecules of indigo chip away, causing the fabric to fade. This fade makes each pair unique, so much so that the FBI analyzes denim patterns when tracking criminals. The more you wear a pair, the more broken in they become. You’ll see the appearance of fade patterns. Whiskers on the front, honeycomb patterns behind the knees and so on. And here’s where it gets – oh, wait. Wrong show. Not all jeans are created equally. Let’s divide them into two rough categories – washed and raw. Washed denim is just that – washed after dyeing, to make the fabric softer and reduce shrinkage. Sometimes washed denim is artificially distressed to give it a broken-in or worn look. The fading of raw denim, on the other hand, happens naturally over time depending on the daily activities of the person wearing the jeans. The longer you go without washing these jeans, the more pronounced fading patterns will become, personalizing the pants. Once you have a pair of jeans, you’ll hear numerous pieces of advice about caring for them. Most of this doesn’t apply across the board. For example, companies like Hiut denim will ask you to wait at least 6 months before washing your jeans, because if you wash them early the indigo will wear off uniformly, robbing you of those unique fade patterns. And this is the heart of the whole “to wash or not to wash” question. The longer you go without washing a pair of jeans, the more pronounced the wearing pattern becomes. You’ll also preserve the indigo, as well as the stiff texture of the fiber. But what happens if you don’t wash them? Won’t bacteria pile up, turning your lower hemisphere into a plague-ridden cesspool of filth? Not necessarily. In 2011 a microbiology student at the University of Alberta went, get this, 15 months without washing his jeans. He tested their bacterial content, along with the bacterial content of another pair that had been washed about two weeks beforehand. He found almost no difference. So if you can’t wash them, what do you do to keep your blue jeans clean? You’ll hear some crazy stuff. Levi’s famously recommended freezing your jeans to kill bacteria and stave off any funky odors, but microbe expert Stephen Craig Cary says that’s a myth. Most bacteria in our pants comes from our skin, and a lot of these organisms are preadapted to low temperatures. Cary recommends using high temperatures – think 121 degrees Celsius for ten minutes – to rid the denim of bacteria. Or, he adds, just wash them. So, depending on how often you wear your jeans, their age, the denim type and what you do while you’re wearing them, you really don’t have to wash them as often as, say, your underwear. If you want to get that uber-cool unique fading pattern, your best bet really is to avoid washing them for awhile, even if you have to soak them first to shrink them. SOURCES: http://www.bbc.com/news/magazine-17101768 http://www.wsj.com/articles/SB10001424052702303365804576429730284498872 http://hiutdenim.co.uk/pages/washing-instructions http://www.heddels.com/2011/08/understanding-raw-denim-warp-weft-and-twill/ http://www.heddels.com/dictionary/sanforization/ http://www.heddels.com/2014/04/unsanforized-denim-worth/ http://www.tellason.com/the-journal/sanforized-vs-unsanforized-denim/ http://www.theguardian.com/fashion/2014/oct/24/why-you-should-never-ever-wash-your-jeans-unless-you-really-really-have-to http://www.wired.com/1998/04/fbi-tracks-the-denim-trail/ http://www.smithsonianmag.com/science-nature/the-myth-of-the-frozen-jeans-129092730/?no-ist=
How quickly does hair grow?
On average, human hair grows a small amount each day. Watch as Jonathan and Lauren explain hair growth in this episode of BrainStuff. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
Do Figs Really Have Dead Wasps In Them?
Some figs need fig wasps to pollinate their fruit. But are we eating dead wasps every time we bite into a fig? Learn more at HowStuffWorks.com: http://animals.howstuffworks.com/insects/fig-wasp.htm Share on Facebook: http://goo.gl/0FrBlz Share on Twitter: http://goo.gl/HxEVIx Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Imagine for a minute that you’re a pregnant woman. Still with me, guys? Now, the only way you can give birth is if you crawl into a small, cramped cave made out of chocolate. And the tunnel to this cave is so cramped that the only way you can get through is by cutting your own arms off “127 Hours” style. Once you’re in this cave you give birth! Then you eventually die from either exhaustion or starvation. Sounds pretty grim, right? As if giving birth wasn’t difficult enough, what I just described to you is the life cycle of the fig wasp. Their role in the pollination of figs is crucial, both to the propagation of their species and the survival of fig trees. This arrangement between wasp and plant is called “mutualism,” and it’s evolved over millions of years. Without the wasps you wouldn’t have figs. And vice versa. And yes, most of the figs we eat contain at least one dead wasp. But more on that later. First, let’s talk pollination. A fig is technically just a flower with its petals folded inside. There are male figs – which are inedible, and called caprifigs – and female figs, which we eat. But in order to create seeds (and tasty fruit), the female figs need to receive some pollen from the male figs. Since the figs’ reproductive bits are tucked away, wind and bees can’t help as they do with lots of plants. Enter the fig wasp. So okay… let’s get away from the whole pregnant lady/chocolate metaphor thing and break down how this wasp/fig mutualism process works. For a dude fig plant to share its pollen with a lady fig plant, a female fig wasp needs to enter a male fig. She crawls through a narrow passage in the fig called an ostiole. It’s so cramped that her wings and antenna break off along the way. But the messed up thing is that these lady fig wasps don’t know is whether they’re entering a male caprifig or a female fig. If it’s a caprifig, she’ll find its male flower parts perfectly shaped for her to lay eggs into. The eggs hatch into larvae and grow within the fig’s petals. The male wasps hatch first and are born blind and flightless. They mate with their female counterparts (yes… I guess they’re technically brothers and sisters) and start eating an exit tunnel through the fig. The wasp dudes can’t escape, though, so they die inside. But the females collect the fig’s pollen, crawl out of the tunnel and fly away in search of a new fig plant to lay their eggs in. These wasps are only a few millimeters long, but they can fly up to 20 kilometers (12.4 miles) to find the right species of fig plant. When they arrive, they deposit their natal fig’s pollen, lay their eggs, and the whole process starts over again. But if a female wasp enters a female fig, she won’t be able to lay her eggs because of a long part of the flower called a stylus. She’ll probably die, but at least she’s delivered the pollen. An enzyme inside the fig called ficin breaks down her corpse into protein, ingesting the dead wasp and making it part of the ripened fruit.* Just so we’re clear, those crunchy bits you’re chewing in figs aren’t bits of dead wasp or larvae; they’re the fig’s seeds. And anyway, you should get used to the idea of occasionally eating an insect by accident. The FDA considers certain amounts of insect content in various foods “natural” and “unavoidable” – and it’s really not hazardous, just gross. SOURCES: http://animals.howstuffworks.com/insects/fig-wasp.htm Nature's Little Magician The Fig Wasp. By: Andersen, Christie B., Cricket, 00906034, Sep2005, Vol. 33, Issue 1 Fig-Wasp Upset. By: Milius, Susan, Science News, 00368423, 4/26/2003, Vol. 163, Issue 17 Nature's recourse. By: Milius, Susan, Science News, 00368423, 7/31/2010, Vol. 178, Issue 3 Big on figs. By: Kinnaird, Margaret, International Wildlife, 00209112, Jan/Feb2000, Vol. 30, Issue 1
Why Are Your Eyes That Color?
What makes eyes brown, blue, green, and so on? Share on Facebook: http://goo.gl/Pfb2NK Share on Twitter: http://goo.gl/3GGFbq Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com
How Does Sleepwalking Work?
Have you ever walked in your sleep? Somnambulism isn't as rare as you might think. Join Cristen as she explores the facts and fiction about sleepwalking, from its many possible causes to whether you can safely wake up a somnambulist mid-stroll.
Are Pop Rocks Dangerous?
Did Pop Rocks really blow the door off of a delivery van? Has anyone ever died from eating these popping bits of sugar? The answers might surprise you. Join Josh as he looks into the truth behind the rumors surrounding the uniquely (and surprisingly loud) candy called Pop Rocks. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Download the New TestTube iOS app! http://testu.be/1ndmmMq Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
Are Plants Conscious?
Scientists have found evidence that plants have senses, memories, and can even communicate with each other. But does this mean they're conscious? Learn more at HowStuffWorks.com: http://science.howstuffworks.com/life/botany/plants-feel-pain.htm Share on Facebook: https://goo.gl/JEor1U Share on Twitter: https://goo.gl/xM6eZ7 Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com SOURCES: http://science.howstuffworks.com/life/botany/plants-feel-pain.htm http://www.scientificamerican.com/article/do-plants-think-daniel-chamovitz/ https://www.youtube.com/watch?v=fGLABm7jJ-Y http://www.npr.org/blogs/krulwich/2014/04/29/307981803/plants-talk-plants-listen-here-s-how http://gizmodo.com/nice-try-vegans-plants-can-actually-hear-themselves-b-1599749162 Roots of consciousness. By: Ananthaswamy, Anil, New Scientist, 02624079, 12/6/2014, Vol. 224, Issue 2998 Do Plants Have Brains? By: DeSalle, Rob, Tattersall, Ian, Natural History, 00280712, May2012, Vol. 120, Issue 5 http://www.newyorker.com/magazine/2013/12/23/the-intelligent-plant
Why Does Hydrogen Peroxide Foam When Put On A Cut?
Hydrogen peroxide's foaming action is due to the catalase in blood and cells. Check out this episode of BrainStuff to learn how hydrogen peroxide interacts with catalase. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
Why Can't People Remember Being Born?
You probably remember your 18th birthday, but not your first – or your zeroth. Why is that? Learn more at HowStuffWorks.com: http://science.howstuffworks.com/life/inside-the-mind/human-brain/remember-birth.htm Share on Facebook: https://goo.gl/hiKxeT Share on Twitter: https://goo.gl/E3UcM0 Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com A lot of things are easy to remember: My high school graduation. My first summer job. That time I got arrested for emptying a bunch of Jello packets into Bryan Cranston’s gas tank – long story. It doesn’t take a scientist to notice that adults don’t generally remember things that happened before the age of about 3 or 4. Why is that? Why can’t we remember the earliest events in our lives, up to and including birth? OK, here’s an experiment: Try to remember what happened the last time you ate a burrito. Where were you? Who was with you? Was the burrito full of spiders? These kinds of memories – being able to recall details of a particular event in the past – are called episodic memories. A person at age 60 will usually have some episodic memories from age 30 – she might not get all the details right, but she will be able to recall some events and explain what happened. But if you take that same person at age 30 and ask her to describe something that happened during her first year of life, you’ll typically get nothing at all. Sigmund Freud referred to this hole in our memory as “childhood amnesia,” or “infantile amnesia.” Freud, being Freud, explained it by saying we needed to repress memories from infancy because of their inappropriate or traumatic sexual content. But sometimes a blank is just a blank, and contemporary scientists don’t tend to throw in with Freud on this one. Another hypothesis that used to be popular says that babies can’t form episodic memories until they develop certain cognitive capacities, like language. But there’s a major problem with the language-based hypothesis: Experiments have shown that animals like mice also display both long-term memory and infantile amnesia. Since childhood amnesia crosses species lines, it’s probably something to do with brain biology rather than language. One possible answer would be to say that baby brains simply can’t make memories. It’s true that memory encoding isn’t as efficient in infant brains as it is in the brains of older children or adults – possibly because the prefrontal cortex of a baby’s brain hasn’t reached maturity yet. But recent studies have shown that very young children can form some memories, leading scientists to think it’s not that we don’t make memories early in life, but that after a certain point, we can’t access them. The memories are made, but something happens to them: They get erased, or put behind some kind of memory blockade. Patricia Bauer and Marina Larkina of Emory University have led research on this hypothesis: For example, in one study, researchers recorded children at age 3 describing a recent event, like a trip to a theme park. Years later, the researchers followed up with those same children to see how much they remembered. At ages 5, 6 and 7, the children could recall more than 60 percent of the earlier events, but by ages 8 and 9, their recall was less than 40 percent. More research of this kind is needed, but this looks like watching the onset of childhood amnesia as it happens. Another recent study has considered the role of neurogenesis in the hippocampus. The hippocampus is a part of the brain that’s crucial for creating and storing episodic memories. If you didn’t have either of your hippocampi, you could end up like the guy in “Memento” – unable to make new episodic memories. Neuroscientists Sheena Josselyn and Paul Frankland have proposed a theory that childhood amnesia happens because of rapid formation of new cells in the hippocampus when children are young. This is known as hippocampal neurogenesis. Basically, while your brain is manufacturing lots of the cells you will use to make memories for the rest of your life, it wipes away or obscures the memories you already created as a young child. SOURCES: http://www.tandfonline.com/doi/full/10.1080/09658211.2013.854806 http://learnmem.cshlp.org/content/19/9/423.short http://science.howstuffworks.com/life/inside-the-mind/human-brain/remember-birth.htm/printable http://www.livescience.com/32963-why-dont-we-remember-being-babies.html http://www.nimh.nih.gov/about/director/2013/infantile-amnesia.shtml http://www.npr.org/blogs/health/2014/04/08/299189442/the-forgotten-childhood-why-early-memories-fade https://www.sciencenews.org/article/birth-new-brain-cells-might-erase-babies%E2%80%99-memories http://www.scientificamerican.com/article/why-can-t-you-remember-being-a-baby/ http://www.apa.org/science/about/psa/2004/12/bauer.aspx
Can Absinthe Make You Hallucinate?
Absinthe has a dangerous reputation. But will you really meet The Green Fairy if you drink it? Share on Facebook: http://goo.gl/MxJWVf Share on Twitter: http://goo.gl/wIatnN Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com CREDITS: Anti-Absinthe posters: http://web.cortland.edu/flteach/wksp/French_alcool/ SOURCES: Sayre, C. (2007). Absinthe Is Back. Time International (Atlantic Edition), 170(23), 36. THE LAST WORD. (2013). New Scientist, 219(2928), 149. Padosch, S. A., Lachenmeier, D. W., & Kröner, L. U. (2006). Absinthism: a fictitious 19th century syndrome with present impact. Substance Abuse Treatment, Prevention & Policy, 114. doi:10.1186/1747-597X-1-14 It Makes The Heart Grow Fonder. By: Arnold, Eric, Forbes, 00156914, 9/21/2009, Vol. 184, Issue 5 The Search for Real Absinthe. By: Sullum, Jacob, Reason, 00486906, Aug/Sep2005, Vol. 37, Issue 4 http://science.howstuffworks.com/innovation/edible-innovations/absinthe.htm
Why Can't We Breathe Underwater?
Water is made up of hydrogen and oxygen, so why aren't we able to breathe underwater? Find out in this episode of BrainStuff. Source: http://science.howstuffworks.com/question386.htm
How Do Accents Work?
Have you ever wondered how accents work? Tune in to this episode of BrainStuff to find out about the ever-evolving accent. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
Can Water Go Bad?
Many people store water for emergencies -- but is it true that water sitting for too long will go bad? Listen in as BrainStuff explains it for you. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
How Do TV Ratings Work?
The future of your favorite TV shows hinges on their ratings – but what is a rating, and where does it come from? Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Learn more at HowStuffWorks.com: http://electronics.howstuffworks.com/question433.htm Share on Facebook: http://goo.gl/BMQidC Share on Twitter: http://goo.gl/Rd0RDA Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com SOURCES: http://electronics.howstuffworks.com/question433.htm http://people.howstuffworks.com/culture-traditions/tv-and-culture/dvr-viewings-tv-ratings1.htm http://splitsider.com/2011/01/why-nielsen-ratings-are-inaccurate-and-why-theyll-stay-that-way/ http://www.nytimes.com/2011/01/03/business/media/03ratings.html?_r=0 http://sites.nielsen.com/90years/ http://www.nielsen.com/content/corporate/us/en/about-us.html CREDITS: Arthur Nielsen photo: http://www.quotessays.com/bio/arthur-c-nielsen.html
What Determines Your Hair Color?
There's a lot of natural variation in the color of human hair. What's the physical explanation for the difference? Learn more at HowStuffWorks.com: http://science.howstuffworks.com/innovation/everyday-innovations/hair-coloring.htm Share on Facebook: http://goo.gl/CbE4Ks Share on Twitter: http://goo.gl/Gs2h7P Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Sometimes, you’re right in the middle of cleaning out the drain in the shower and you start pondering questions like, “Why is my hair a different color from my mom’s hair, or my neighbor’s hair, or my roommate’s disgusting, soggy, three-foot-long, wolf-tail drain-wad? What’s the real difference between blonde hair, black hair, red hair, and everything in between?” The main structural ingredient in human hair is a protein called keratin. It’s what your hair and fingernails are made of, but also what’s behind the silky sheen of wool, bear claws and horse hooves. Mmm, don’t you just want to run your fingers through those hooves? But keratin on its own is not very colorful. And if all humans had in our hair was keratin, we’d look like 18th-century French aristocrats in powdered wigs, because we’d all have the same sort of white, colorless hair. But, keratin is not the only ingredient in human hair. To create natural color, you need to add pigment. This is done by cells in the skin called melanocytes. These melanocytes create the natural pigment known as melanin and deliver it to the cells that create the keratin for your hair. This melanin comes in two varieties: eumelanin and pheomelanin. Eumelanin is a dark pigment that gives hair a brown or black color. Pheomelanin is a lighter pigment that gives hair a red, orange or yellow-ish color. Both of these are present in varying degrees – a person might have a little of each, or a lot of one and almost none of the other. So someone with black or dark brown hair probably has a lot of eumelanin. A redhead has a lot of pheomelanin, and blondes don’t have very much of either one. So what happens when we get older and start to “go gray”? You can probably guess: over time, melanocytes start to die off, and any new hair that grows has less pigment, so it looks gray or white. But! you might be asking: “What determines the eumelanin to pheomelanin mixture to begin with? Who writes that recipe?” Primarily, it’s your genes. For example: the melanocortin 1 receptor, or MC1R, gene. When the protein associated with this gene is active in melanocytes, it stimulates them to make eumelanin – the pigment that colors black or brown hair. When MC1R is not active in the melanocyte cells, they make mostly pheomelanin instead, and Hello Weasleys. But! The MC1R gene is not the only genetic factor that controls hair color – like most of your traits, hair color is actually affected by more than one genetic variable. SOURCES: http://www.scientificamerican.com/article/fact-or-fiction-stress-causes-gray-hair/ http://www.thenakedscientists.com/HTML/questions/question/1000018/ http://www.britannica.com/EBchecked/topic/315321/keratin http://www.scientificamerican.com/article/why-does-hair-turn-gray/ http://ghr.nlm.nih.gov/gene/MC1R http://news.sciencemag.org/biology/2014/06/genetics-blond-hair http://news.nationalgeographic.com/news/2014/06/140601-blond-hair-color-gene-mutation-science/ http://www.nature.com/ng/journal/v46/n7/pdf/ng.2991.pdf http://www.britannica.com/EBchecked/topic/647753/wool
How Do Antiperspirants Work?
Every day, millions of people safeguard themselves against excessive sweat with a quick roll of antiperspirant. But what does this stuff do, exactly? Join HowStuffWorks as we answer engaging, everyday science questions, demystifying the amazing world around you. Learn more at HowStuffWorks.com: http://health.howstuffworks.com/skin-care/underarm-care/problems/question627.htm Share on Facebook: http://goo.gl/JOSgRf Share on Twitter: http://goo.gl/pm4puA Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com SOURCES: http://health.howstuffworks.com/skin-care/underarm-care/tips/deodorant-antiperspirant.htm/printable “Are clinical strength antiperspirants really any stronger?” http://health.howstuffworks.com/skin-care/underarm-care/tips/clinical-strength-antiperspirant.htm/printable “Do you need a prescription antiperspirant?” http://health.howstuffworks.com/skin-care/underarm-care/problems/prescription-antiperspirant.htm/printable “What is in an antiperspirant that stops sweat?” http://health.howstuffworks.com/skin-care/underarm-care/problems/question627.htm Is antiperspirant toxic? http://health.howstuffworks.com/skin-care/underarm-care/tips/is-antiperspirant-toxic.htm/printable
Why Does Hot Sauce Make Me Feel So Good?
Hot peppers (and the sauce we make from them) can increase​ our natural tolerance for pain. But how? Learn more at HowStuffWorks.com: http://home.howstuffworks.com/chili-peppers.htm Share on Facebook: http://goo.gl/gcGiRP Share on Twitter: http://goo.gl/XR5hAJ Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Since ancient Mayan and Aztec civilizations, human beings have known there’s more to hot peppers than just their spicy kick. From medicine men to modern doctors, we recognized that hot peppers -- and the sauces we make from them -- can actually relieve pain. It may hurt at first, but spicy peppers eventually have an analgesic effect. So if you’re a lover of hot sauce, is it because you like the taste? Or because you’re a pepper junkie hooked on a feeling? Are you high on believing? Well believe this: there’s a two-part process that spicy foods like hot sauce use to make us feel like we’re high on fire. First is a potent chemical called capsaicin and its partner dihydrocapsaicin. They have no color, odor or actual flavor. However, both trick our nervous system into thinking that our tongues have touched something scorching hot, as though a burning coal fell in your mouth. These capsaicinoids trigger a protein in our mouths called “TRPV1.” This protein signals our brain by releasing a neuropeptide called “Substance P” and tells it our mouth is burning. To give you a comparison, it usually isn’t activated by anything in our mouths over 109 degrees Fahrenheit (43 degrees Celsius). That’s how hot something has to be to stimulate the same response as hot sauce. But when it’s triggered, “Substance P” tells our brains to pump endorphins to the site. These endorphins are what cause the “natural high” reported by fans of intense hot sauce. Similar to morphine, they make our nerves more tolerant to pain. It’s a pleasant sensation, kind of like the “runner’s high” reported by marathon racers. Endorphins like these also help pregnant women with the pain of childbirth, even increasing their soothing levels in amniotic fluid so the child itself is protected from birthing pains. So… in a way, eating hot sauce reminds us of being born into this big, bright world. So if it can make us feel that good, why aren’t we all hot sauce addicts, jonesing for our next fix? Well, it turns out you can actually build up a tolerance to it. If you’re consistently exposed to capsaicin, it can potentially kill fibers in the receptors that alert your brain. Also, it is possible to use up your nerve’s supply of “Substance P” and continued exposure to capsaicin can prevent it from replenishing. It’s only after the exposure stops that your nerves can produce it again. Despite this, scientists are looking into ways to use capsaicin to manage pain for everything from shingles to arthritis. SOURCES: http://www.npr.org/blogs/thesalt/2014/02/24/281978831/sriracha-chemistry-how-hot-sauces-perk-up-your-food-and-your-mood https://www.youtube.com/watch?v=U2DJN0gnuI8 http://www.bonappetit.com/trends/article/foods-that-make-you-hallucinate What Happens When You Inhale Sriracha Fumes. By: Sifferlin, Alexandra, Time.com, 5/16/2014 Ask Men's Health. By: Dailey, Kate, Men's Health, 10544836, Dec2005, Vol. 20, Issue 10 WHAT'S SO HOT ABOUT PEPPERS? By: Biebuyck, Valerie, Odyssey, 01630946, Mar2003, Vol. 12, Issue 3 Using the Brain to Conquer Pain. By: Myslinski, Norbert R., World & I, 08879346, Feb2003, Vol. 18, Issue 2
How Does A Duel Work?
Has someone impeached your honor? Achieve satisfaction through dueling by following these easy steps! Learn more at HowStuffWorks.com: http://people.howstuffworks.com/duel.htm Share on Facebook: https://goo.gl/ZiQWrO Share on Twitter: https://goo.gl/tKsIay Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Hi. I’m Jonathan Strickland. This is BrainStuff. Today’s question: How do duels work? The English word “duel” seems to come from cramming together the Latin words “duo-“, meaning “two”, and “bellum”, meaning war. “Duellum,” or eventually, just “duel.” So a duel is combat between two people. The duel of honor was a specific cultural practice taking place mostly in Europe and the Americas, starting around the Renaissance and fizzling out in the early 20th century. There’s no one list of universal rules, but there were some especially popular guides -- for example, the Irish Code Duello of 1777. Let’s see how a duel according to the Code Duello might go down. First off – who would duel? There were some notable exceptions, but most duels of honor took place between men of the aristocracy. And what could cause a duel? Any insult to someone’s honor. Honor is a difficult concept to define succinctly, but it meant something like “a man’s reputation for respectability and aristocratic virtues.” But whether someone had an affair with your wife or simply made harsh jest of your new powdered wig, honor was on the line. And according to the 1824 “British Code of Duel,” honorable men were not only expected to accept duels when challenged; they were expected to demand them when offended. So: The offended party issues a formal challenge. Depending on the offense, the duel might be averted by an apology. If so, the two parties have to apologize for their offenses in the order they were committed. But according to the Code Duello, some offenses to honor couldn’t be fixed by apology alone. So a personal insult, maybe. But a punch to the nose was a point of no return: You pretty much had to duel to repair your honor. Duels could involve any number of weapons, usually chosen by the person being challenged. In France in 1843 two men reportedly dueled to the death with billiard balls – and yes, one of them was killed by a billiard ball straight to the face. But the two most common dueling weapons were, first, swords, and later, pistols. The two dueling parties usually appointed “seconds.” These were like lieutenants. The seconds had the job of trying to resolve the conflict before it came to violence, and they were also responsible for preparing the duelists’ weapons. You’d think from this arrangement that the seconds would tend to keep cool heads, but according to Rule 25 of the Code Duello, “Where seconds disagree, and resolve to exchange shots themselves, it must be at the same time and at right angles with their principals.” "Principals" meaning duelists - not their own personal philosophies. And honestly, it ends up with a whole lot of people shooting at each other. Many duels didn’t end in death. In fact, in England, between 1760 and 1820, there were 172 known duels (though probably plenty more that were off the books), but only 69 known fatalities from duels. Often, duels using swords could be called off once at least one swordsman had been bloodied. And those who used pistols often intentionally fired wide of the target – though the Code Duello strictly prohibits “dumb shooting or firing in the air,” referring to such practices as “children’s play.” But despite this command, many duelists simply didn’t aim to kill. Crazy duel fact from the 21st century: In 2002, an Iraqi official suggested that Saddam Hussein and George W. Bush could avoid an all-out war if they settled their differences through a one-on-one duel on neutral territory. The White House declined the challenge. SOURCES: http://people.howstuffworks.com/duel.htm/printable http://www.pbs.org/wgbh/amex/duel/sfeature/dueling.html http://www.smithsonianmag.com/history/duel-104161025/?all http://www.newyorker.com/magazine/2007/03/12/en-garde https://www.gwu.edu/~magazine/archive/2005_law_fall/docs/feat_duel.html http://www.pbs.org/wgbh/amex/duel/sfeature/rulesofdueling.html http://www.telegraph.co.uk/news/obituaries/11512352/Lieutenant-Colonel-John-Dymoke-Queens-Champion-obituary.html http://news.bbc.co.uk/2/hi/americas/2297371.stm https://books.google.com/books?id=3UpHXmlYHBcC&pg=PT204&lpg=PT204&dq=Lenfant+and+Melfant&source=bl&ots=iqHwSfrZ0s&sig=9FI0wnYiS5OG3zWRHu31DXSZeRQ&hl=en&sa=X&ved=0ahUKEwiJuLepq4fMAhUX7mMKHUW0CGQQ6AEISDAJ#v=onepage&q=Lenfant%20and%20Melfant&f=false
Why Do Movie Theaters Sell Popcorn?
For millions of moviegoers, the idea of visiting the local theater automatically conjures memories of popcorn. But this wasn’t always the case – so why, out of all snacks, did popcorn become the #1 snack for film? Learn more at HowStuffWorks.com: http://recipes.howstuffworks.com/question255.htm Share on Facebook: https://goo.gl/Xgrh2I Share on Twitter: https://goo.gl/IVhGKh Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com How, of all the snacks on earth, did popcorn become the mainstay of movie theaters? It starts with a bit of history. See, popcorn has been around for ages, and it was a popular snack at 19th century fairs and carnivals, especially after the invention of the first steam-powered popcorn-popper back in 1885. People loved the crunchy, salty, inexpensive snack. And movie theaters hated it. During the era of silent film, these companies followed many of the same rules as traditional theatres – and they didn’t want to be associated with a loud food that could distract from the show. Additionally, there was a little bit of a class consideration here. Since audiences had to read the dialogue on screen, they had to be literate. AKA a “better” sort of people, with superior education. Allowing popcorn inside was, in the opinion of these theater owners, kind of like throwing sawdust on the floor and saying “Yeah, sure, spit wherever.” Talkies, or films with spoken dialogue, emerged in 1927, and this brought movie theaters to the common folk. Suddenly anyone could cough up some change, grab a seat and understand what was going on. This was also the time of the Great Depression, when Americans from coast to coast pined for cheap, escapist entertainment. So the average Americans finally found the cinema, and they brought their snack culture along. And the Depression affected theaters, as well – theaters with the best chances of surviving were the ones that gave customers what they wanted. At first, independent vendors sold popcorn outside the theater, profiting from the casual passersby as well as from future movie patrons. Since corn kernels were dirt cheap, popcorn became even more - wait for it - popular. Anyway. Things, as the internet likes to say, escalated quickly. Movie theaters allowed vendors to sell their wares in the lobby for a small fee. Eventually, they cut out the vendors entirely, acquiring their own poppers. During World War II, popcorn sales saw another bump. Sugar was rationed, which made many conventional sweet snacks and drinks, like soda, more expensive. (At least, that is, when they were available at all.) Popcorn, on the other hand, only required salt and popcorn kernels, neither of which were hard to come by. By then the association between movies and popcorn was firmly established in the mind of the American public. This association continues today, but there’s another wrinkle to the story. “Ben,” you might be saying, “sure, popcorn was cheap in the Depression or whatever, but what happened? When did it become so expensive?” That’s a great question. The price hike really kicked in, not just on popcorn, but on all concessions, back in the 1970s. Contrary to popular belief, your local movie theater doesn’t actually make much bank off the films it screens. Instead, theaters use concessions to stay in business. According to the Stanford Business School, concessions comprise only about 20% of a theatre’s gross revenue, but 40% of its profits. This makes sense when we consider how theaters have to split ticket revenue with movie distributors, but can pocket 100% of whatever they manage to sell at the snack counter. The bulk cost of the ingredients is laughably small, and the profit margin is huge. And let's not forget that this stuff is addictively delicious. Thanks for watching. What’s a snack you think more movie theaters should sell? Is there anything that could replace popcorn? Everyone who said whiskey, let’s hang out later. In the meantime, stay tuned for more BrainStuff. SOURCES: http://www.smithsonianmag.com/arts-culture/why-do-we-eat-popcorn-at-the-movies-475063/?no-ist http://filmmakeriq.com/lessons/the-science-and-history-of-popcorn-the-snack-that-saved-the-movies/ http://filmmakeriq.com/lessons/the-science-and-history-of-popcorn-the-snack-that-saved-the-movies/ http://www.fastcodesign.com/3020051/how-popcorn-took-over-movie-theaters http://www.nytimes.com/2013/10/06/magazine/who-made-movie-popcorn.html http://www.tested.com/art/movies/458433-history-popcorn-and-movies/ https://consumerist.com/2013/10/03/why-is-popcorn-such-a-popular-snack-at-the-movies/ http://www.slate.com/articles/news_and_politics/summer_movies/2007/06/make_it_a_large_for_a_quarter_more.html
Does The Human Body Really Replace Itself Every 7 Years?
The short answer is “no.” Tune in to learn how long it really takes, plus how nuclear weapons led scientists to the solution. Learn more at HowStuffWorks.com: http://science.howstuffworks.com/life/cellular-microscopic/does-body-really-replace-seven-years.htm Share on Facebook: http://goo.gl/55pmys Share on Twitter: http://goo.gl/v2s366 Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Today’s question: Does your body really replace itself every 7 years? The short answer is “no,” but don’t worry: This isn’t a case of chicanerous researchers pulling the wool of shoddy science over your eyes. Your body mostly replaces itself every 7 to 15 years. Some bits are never replaced. Others, like the lining of your stomach and intestines, are renewed much faster. Due to constant wear and tear from the process of digestion, these cells have an average lifespan of just 5 days! Yes, the organs that work the hardest have the fastest changeover. You get a whole new skin every 2 to 4 weeks. Your red blood cells last less than half a year – not bad, considering that their route through your circulatory system is about a thousand miles. And your liver renews itself at least once every couple of years. As the human body’s detoxifier, it goes through a lot. Other tissues take longer to completely replenish themselves. Like your bones. Skeletal cells die and new ones grow constantly, but the complete process takes about 10 years. (And the process slows down as we get older, which is why our bones tend to get weaker as we age.) And, like I said, some parts of your body stay with you for life. The cells on the inner lens of your eye formed when you were just an embryo. Your tooth enamel wears down with use, never to return. And evidence indicates that you can’t regrow the neurons of your cerebral cortex. Its loss can lead to diseases like dementia. Luckily, other parts of your brain do regenerate. Like the hippocampus, which helps us create memories, and the olfactory bulb, which helps us smell. So how do we know all this? Turns out, it’s thanks to our old pal nuclear weapons testing. Yeah! High-fives for radioactive stuff being released into the atmosphere! No, really: Aboveground nuclear detonations during World War II and the Cold War spiked Earth’s air supply with extra carbon-14. It’s been declining back toward the norm at a predictable rate since the 1960s. Which means that you can use the amount of it present in any given tissue sample to determine when those cells were born. More carbon-14 means older cells. SOURCES: http://science.howstuffworks.com/life/cellular-microscopic/does-body-really-replace-seven-years.htm/printable http://www.nytimes.com/2005/08/02/science/02cell.html?pagewanted=all&_r=0 http://www.sciencedirect.com/science/article/pii/S0092867413005333 http://ac.els-cdn.com/S0092867405004083/1-s2.0-S0092867405004083-main.pdf?_tid=b128d0a8-9b4e-11e4-8103-00000aacb362&acdnat=1421172481_5286828a6b59ff28fb8e5b9fb5a7d3a3 http://www.state.gov/t/isn/4797.htm http://science.howstuffworks.com/life/inside-the-mind/human-brain/brain8.htm/printable
Why Do We Put Diamonds On Engagement Rings?
The tradition of diamond engagement rings is actually less than 100 years old. How did it become so popular in such a short time? Learn more at HowStuffWorks.com: http://science.howstuffworks.com/environmental/earth/geology/diamond5.htm Share on Facebook: http://goo.gl/o0KmJ6 Share on Twitter: http://goo.gl/eGnFyy Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Today’s question: Why do most engagement rings feature diamonds? Why not emeralds, or pyrite, or beef jerky nuggets? Turns out, you can trace this precious tradition back to ... an ad campaign. Before the 1940s, opals, rubies, sapphires, and turquoise were way more popular than diamonds as engagement stones. In 1939, only some 10 percent of U.S. engagement rings bore diamonds. And the jewels being used were smaller and of poorer quality than the stones common today. But by the end of the 20th century, about 80 percent of U.S. engagement rings featured diamonds. Enter an ad campaign. In the 1930s, the world’s leading diamond mining and trading company, De Beers, found itself in a tight spot. De Beers has been in the business, in one form or another, since just after the discovery in 1870 of huge deposits of diamonds in South Africa. Before then, diamonds were truly scarce; they had to be panned from rivers. With this new supply, De Beers flourished. Well, it was really the supply plus careful corporate consolidation and market control. But yes, they flourished. That is, until the Great War, the ensuing Great Depression, and the looming promise of a second world war sent the demand for diamonds into freefall. So in 1938, De Beers hired ad agency N. W. Ayer to research the market and produce a comprehensive U.S. ad campaign: print, radio, and celebrity publicity. Print ads compared diamonds to paintings by Picasso and Dali – unique and precious. They commissioned portraits of famous couples who’d recently gotten engaged – all sporting diamonds. In 1947, they launched the slogan “A Diamond Is Forever”. By that time, the number of diamonds being purchased for engagement rings in the U.S. had already tripled. It was – and is – a brilliant campaign. Pun intended, for once. It set up diamonds as a near-indispensable part of engagement traditions. And as heirlooms to be cherished and kept – not to be resold back into the market. Meaning more diamonds would be bought, and almost all of them new. In the 1960s, De Beers and N. W. Ayers began educating the public about the quality of diamonds, encouraging the purchase of more expensive jewels. And their product placement continues to this day as they loan out extravagant pieces to Hollywood stars for films and the red carpet alike. CREDITS: Vintage De Beers ads from Vintage Ads: http://vintage-ads.dreamwidth.org/2228174.html N.W. Ayer Ad from MagazineArt.org: http://www.magazineart.org/main.php/v/ads/banksinsurancebrokers/advertisingagencies/N_+W_+Ayer+and+Son+-1920A.jpg.html Ad of man holding diamond ring from Art of Manliness: http://www.artofmanliness.com/2014/06/11/5-alternatives-to-the-diamond-engagement-ring/ SOURCES: http://www.theatlantic.com/magazine/archive/1982/02/have-you-ever-tried-to-sell-a-diamond/304575/?single_page=true http://science.howstuffworks.com/environmental/earth/geology/diamond.htm/printable http://www.bain.com/Images/PR_BAIN_REPORT_The_global_diamond_industry.pdf http://www.nytimes.com/2013/05/05/fashion/weddings/how-americans-learned-to-love-diamonds.html?pagewanted=all&_r=0 http://www.washingtonpost.com/opinions/why-a-diamond-is-forever-has-lasted-so-long/2014/02/07/f6adf3f4-8eae-11e3-84e1-27626c5ef5fb_story.html
Why do feet stink?
What causes stinky, smelly feet? Sweat and bacteria. Find out exactly how bacteria turn sweat into malodorous feet in this episode. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
Why Do I Hate The Sound Of My Own Voice?
The recorded sound of your voice usually makes you cringe because of two ways vibrations reach your ear. Share on Facebook: http://goo.gl/RM7uL9 Share on Twitter: http://goo.gl/Lp4CxM Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Have you ever heard a recording of yourself played back and thought, "Ugh. Why do I sound like that?!" It’s weird right? Usually our voices sound deeper but when played back the way everyone else hears them they are higher and tinnier. Why does it sound so different? And why do we hate it so much? The sound of your voice reaches your inner ear in two different ways. The vocal folds in your throat vibrate, creating sound waves that travel through the air. But those sound vibrations also conduct through your body, particularly through your skull and bones. Our skulls lower the frequency of these later vibrations as they bounce around inside our throat, mouth and neck before reaching the ear's cochlea through the fleshy tissue in our heads. The surrounding bones spread out the vibrations, lower their pitch and enhance the lower-frequency vibrations so your voice sounds fuller and deeper. When we hear our voice played back on a recording, we don't get it filtered through flesh and bone. What we're hearing then is only the air-conducted sound of our voice as waves of pressure. These vibrations are caught by our outer ears, and then transmitted through our eardrums, where they vibrate three bony ossicles before reaching the cochlea. In both cases, the cochlea converts these vibrations into impulses that are sent to the brain. But with the elimination of the bone-conducted sound we end up hearing our voice the way everyone else hears it. Most of us have had this experience and hate it. We're used to the combination of the air-conducted and bone conducted sounds of our voice. It’s what we've lived with all our lives. So of course it's unsettling to hear something so different than we're used to. But remember, this is how your friends have been hearing you your whole life. To them, it’s normal. So relax and rest easy knowing that everyone cringes at the sound of their own voice. SOURCES: https://www.youtube.com/watch?v=L2wThQljxcY http://mentalfloss.com/article/12796/why-do-our-voices-sound-different-us-other-people http://www.scientificamerican.com/article/why-does-my-voice-sound-different/ http://www.bbc.com/future/story/20130913-why-we-hate-hearing-our-own-voice http://www.popsci.com/scitech/article/2009-06/why-your-voice-sounds-different-recordings http://bodyodd.nbcnews.com/_news/2013/04/02/17557410-why-you-hate-the-sound-of-your-own-voice
What Is Synesthesia?
It’s true – some people hear colors, or taste words. But what produces synesthesia? Learn more at HowStuffWorks.com: http://science.howstuffworks.com/life/inside-the-mind/emotions/synesthesia.htm Share on Facebook: https://goo.gl/jowIii Share on Twitter: https://goo.gl/is4WqA Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Have you ever heard a color or smelled a sound? If so, don’t worry: you’re not alone. Instead, you’re part of a group I consider superpowered- you have synesthesia. Or you’ve done some crazy drugs. Maybe that’s a different episode? Anyway, when people with synesthesia experience input from one sense, it results in the experience of another sense. So, if you’re a synesthete like author Vladimir Nabokov, you would associate letters with colors – grapheme-color synesthesia. And there are different types of synesthesia. Nabokov called his “color hearing”. This grapheme-color stuff is the most common type, but synesthesia can occur between just about any combination of senses or cognitive pathways. And not everyone will experience the same type of synesthesia the same way. So while the soft “ah” sound always seems fire-engine red to one synesthete, it may be cobalt blue for others. Some people with this condition see music – which sounds kind of beautiful, when you think about it. There are less common types, such as lexical-gustatory. People with this condition taste certain flavors, dishes or entire meals based on a picture, word or sound. Smells could have colors and shapes, too. The list goes on. So, this is all fascinating, but how do people get it? Researchers are still working on that one, but they believe the condition tends to be somewhat inherited or genetic, as about 40% of synesthetes have a close relative with synesthesia. Most synesthetes recall having the condition for as long as they can remember. It might sound like people have just made mnemonic connections with sounds, colors or so on, but research shows it is a genuine sensory phenomenon, rather than a memory exercise. For example, if we drew the number five all over a piece of paper – scattered with a few twos, forming a triangle – most people would have a hard time seeing it. They’d have to look closely to search for the twos, and then slowly construct the shape. But a grapheme-color synesthete can see this triangle almost instantly. Researchers think that synesthesia is a kind of cross-wiring in the brain. In grapheme-color synesthetes, seeing a number stimulates your grapheme region and the area of your visual cortex that responds to color stimuli. One theory is that there are increased neural connections in the brain of synesthetes that could've been the result of less "neural pruning" while in utero. Even cooler is that there might be actual anatomical differences in the brains of synesthetes, like increased white and gray matter in the brain. One bit of sad news for all the non-synesthetes. Although one study did find that some exposure to color-letters built up their association, the effect didn't last. So people can’t just “catch” synesthesia. But, hey, it’s not like all synesthetes have a great time. It can be uncomfortable to see a number in the "wrong" color. And one lexical-gustatory synesthete also said that if a certain name doesn't taste “right” to him, he has a hard time liking the person it's attached to. Kevin. And it’s time to talk about drugs. Don’t act like you didn’t know this was coming. Hallucinogens might be one way that synesthesia can be "manufactured." Several drugs can produce vivid synesthesia in non-synesthetes, which might be a key to understanding the condition. One researcher has posited that in non-synesthetes, information in a multisensory area travels back easily to its single-sense area, but in synesthetes it gets a bit mixed up along the way. Hallucinogens may temporarily alter the user’s neurochemistry, confusing those existing connections. I mean, let’s face it, going to a concert might be pretty amazing for people with visually-associated synesthesia. SOURCES: http://science.howstuffworks.com/life/inside-the-mind/emotions/synesthesia.htm/printable http://videos.howstuffworks.com/science-channel/33372-talking-synesthesia-how-it-works-video.htm http://videos.howstuffworks.com/discovery/30572-one-step-beyond-synesthesia-video.htm http://videos.howstuffworks.com/science-channel/33870-when-senses-collide-synesthesia-origins-video.htm http://www.stuffyoushouldknow.com/blog/tag/synesthesia/ http://www.livescience.com/169-rare-real-people-feel-taste-hear-color.html
Why Are You Farting?
Sure, flatulence is embarrassing. But why do we do it? Share on Facebook: http://goo.gl/C2gzAz Share on Twitter: http://goo.gl/fqnyaO Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com
Why Don't Humans Have Tails?
Whether they’re swatting away horseflies or helping a monkey swing through the forest, tails are a pretty amazing adaptation. So why don’t humans have them? Learn more at HowStuffWorks.com: http://science.howstuffworks.com/life/evolution/atavism.htm Share on Facebook: http://goo.gl/oZcki8 Share on Twitter: http://goo.gl/T2RbKf Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Heads… or tails? As far as appendages go, tails are pretty much amazing. Over time, different animals have evolved various, highly-specialized tails. A horse uses its tail to swat flies, for instance, while a bird uses its tail to steer during flight. Which leads us to today’s question: If these specialized limbs are so useful… why don’t humans have them? There are two answers. First: we don’t really need them. In many quadrupedal, or 4-legged, creatures – like a cat, for example – a tail helps with balance. Fish and marine mammals, on the other hand, use their tails for steering or locomotion. Some lizards and primates use their prehensile tails to grip things, while crocodile store fat in their tails, kind of similar to the way camel store fat reserves in their humps. But let’s look at humans: we’re bipedal, meaning we walk on two legs. Our center of gravity passes vertically down our spine, so we don’t need a tail to counterbalance the weight of our heads. And, unlike some other primates, we don’t need a tail to help us hold onto stuff while we swing through trees, because as a species we don’t regularly Tarzan our way around the forest anymore. And why have a tail if you don’t use it? It’s just another thing that takes energy from the rest of the body. But here’s the second answer. Our ancestors did have tails, and, at some point, you had a tail, too. You can find evidence of our 5-limbed past in the skeleton of every human being. Each of us has a coccyx, or tailbone, made of fused vertebrate. In other primates, this coccyx leads to the tail, but, again, we don’t really need it. It’s a vestigial organ. Now, I know what you’re saying: “C’mon, Cristen! I may not be a doctor, but I’m pretty sure I don’t have a tail.” Well, maybe not now – but you did while you were in the womb. All mammals have a tail at some point in development. When you were about 30 days old in the womb, you had a tail-like structure sprouting out of your body. If you’re like most people, you reabsorbed this structure as you developed. It’s extremely rare, but a few modern people have been born with actual tails. This is what’s called an ‘atavism’, a trait of distant ancestors that reappears in the modern day. Usually these tails are a just a few centimeters long, and often removed shortly after birth. SOURCES: http://science.howstuffworks.com/life/evolution/atavism1.htm http://health.howstuffworks.com/human-body/parts/vestigial-organ1.htm http://www.sciencefocus.com/qa/why-dont-we-have-tails http://www.washingtonpost.com/lifestyle/kidspost/ever-wonder-why-animals-have-tails/2012/10/12/23c17198-b3d9-11e1-98e9-bbf4aa4074bb_story.html http://www.evolutionnews.org/2014/05/do_human_tails_085451.html https://www.youtube.com/watch?v=XfwMjTcaz64
Why Are There So Many Different Kinds Of Milk?
Josh explains the difference between common types of milk, looking at calories, fat and the rest of their composition.
How many balloons would it take to lift you off the ground?
Balloons are often filled with helium, which has a lifting force of one gram per meter. It's possible to assemble enough balloons to lift yourself from the ground -- but how many balloons does it take? Tune into this episode to learn more. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff
Why Do Some People Faint At The Sight Of Blood?
Josh explains the science of why people faint at the sight of blood. Learn more at HowStuffWorks.com: http://health.howstuffworks.com/human-body/systems/circulatory/blood.htm Share on Facebook: https://goo.gl/RHuxR7 Share on Twitter: https://goo.gl/YZQDqY Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com Fainting at the sight of blood, which is a condition called either neurocardiovascular syncope or vasovagal syncope, is actually related in some cases to what's classified as a blood injury phobia. Something like 3-4% of people have a blood injury phobia. But what's really interesting is that 15% of people faint at the sight of blood. Which means there's a lot of people out there who really have no issue with cutting themselves, but still faint dead away anyway when they see themselves bleeding. That's kind of weird. When you faint from anxiety, which is what researchers think is going on when you faint from the sight of your own blood, your blood pressure suddenly spikes. But then, just as quickly, it decreases. And that decrease in blood pressure drains blood away from your brain, causing you to lose consciousness. When you're anxious or when you feel like you're in danger, it's normal for your blood pressure to rise. It's part of the sympathetic nervous system's "fight or flight" response. What's unusual in this case, is the sudden decrease in blood pressure that causes you to lose consciousness. At the center of all this oddness is the vagus nerve. It's a major nerve that connects your brain to various regions of your body that are involved in involuntary movement. Like your heart beating, your throat swallowing, that kind of stuff. And at the other end, your vagus nerve is connected to a region of your brain called the nucleus of the solitary tract, or the NST. The NST is kind of like a toggle switch that goes back and forth between the sympathetic response (your fight or flight response) or the parasympathetic response, which is what calms you down after danger has passed. What researchers think is going on is that the NST gets some sort of confused signal from the vagus nerve that causes it to decrease blood pressure as part of the parasympathetic response, without deactivating the increase in your heart rate. Which causes a lot of blood to suddenly be pumped away from your brain, hence making you pass out. Another explanation is that your NST simply toggles too quickly between the sympathetic and parasympathetic responses. Like it's working its joystick, like, "What's going on?" And then you're out on the floor. Then there's another parallel hypothesis, that because your NST is also in charge of mediating your disgust response, that there's some sort of mixture of fright and disgust that causes you to faint, because, again, the NST is confused. However you slice it, it seems that you can lay the fainting at the sight of blood thing at the feet of the NST. Evolutionarily speaking, passing out at the sight of your own blood doesn't make much sense. And researchers have bent over backwards to try to explain it. What they've come up with is that, possibly, when you faint at the sight of your own blood, say, after being mauled by a bear, the bear will take you as being dead and will lose interest. Pretty lame. Another more reasonable (in my humble opinion) explanation is that this sudden decrease in blood pressure prevents us from bleeding out of some sort of wound, and that the fainting is just an unfortunate byproduct of the whole thing. Either way, at any rate, whatever the case, once you're on the floor, which is usually what happens when you faint, the blood flow to your brain can be restored fairly quickly, because it's a lot easier for your heart to pump blood horizontally than upwards against gravity. SOURCES: https://www.researchgate.net/profile/Andrew_Page/publication/223277854_Blood-injury_phobia/links/54e340d20cf2d618e1962db5.pdf http://www.webmd.com/mental-health/features/swoon-at-the-sight-of-blood http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2854945/ https://www.mc.vanderbilt.edu/root/vumc.php?site=adc&doc=4789 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2726440/ http://www.mayoclinic.org/diseases-conditions/vasovagal-syncope/home/ovc-20184773
Why Do People Go Bald?
For most men, losing your hair is an inevitable side effect of aging. Jonathan describes the growth cycle of hair, types of baldness that affect men and women, and how most ladies feel about bald dudes.
How Does Hair Dye Work?
Some hair dyes are basically fine-grained paint. But dyes that stick with you for more than a couple weeks physically and chemically change each hair. Learn how with HowStuffWorks. Learn more at HowStuffWorks.com: Share on Facebook: Share on Twitter: Subscribe: http://goo.gl/ZYI7Gt Visit our site: http://www.brainstuffshow.com This is not my natural hair color. There are three basic chemical formulations of hair dye: temporary, semi-permanent, and permanent. Before we look at what each of them do, let’s look at the physical structure of hair. Hair is dead stuff. Three layers of slightly different dead stuff. The core, called the medulla, is not pertinent to our interests today. But it’s surrounded by a thick layer of cells called the cortex – no relation to your brain’s cortex. It’s where you find the pigmented melanin proteins that give hair its color. Protecting the cortex is hair’s outermost layer: the cuticle. As hair’s armor, it’s made up of overlapping scales. Temporary dye just sticks to the cuticle – it’s more like paint, really, and it’ll usually all circle the drain with your next shampoo. Semi-permanent dye contains molecules of pigment so tiny that they can slip between the scales of the cuticle and stick to the cortex. But it’s still more paintlike – it doesn’t chemically react with anything in the hair. The wee pigment particles will wash back out through the cuticle’s scales with soapy water, so a semi-permanent dye lasts about 12 shampoos max. Permanent dye, as the name suggests, is designed to stay with your hair until the hair grows or falls out. In general, permanent dye consists of two solutions. First, an alkaline chemical plus two types of particles that will come together to form the new color: dye precursors and dye couplers. Second, the developer: an oxidizer, usually a weak solution of hydrogen peroxide. You (or your salon professional) mix ‘em together right before applying them to your hair. The alkaline chemical (either ammonia or a gentler substitute) goes to work opening up the cuticle. For dye to be most effective, it needs access to hair’s cortex. The alkaline stuff temporarily softens and relaxes the cuticle’s scales. The next hurdle in achieving a new hair color is getting rid of some of the existing melanin in the hair’s cortex. Enter the developer. It oxidizes the melanin molecules, breaking melanin’s double carbon-carbon electron bonds and giving up one of its own oxygen atoms to fill in the space. The result: the melanin turns colorless and releases sulfur atoms. That’s right: part of permanent dye’s characteristic stink isn’t actually the dye at all, but an element of your hair passing into the air. But that’s not the developer’s only job: It also kicks off the reaction that brings together the new color molecules by oxidizing the dye precursors. These are usually colorless chemicals that develop color when oxidized. The resulting pigmented particles (called intermediates in industry lingo) are monomers that, left to their own devices, would slip through the cuticle’s scales like semi-permanent dye. But the dye couplers react with the intermediates to form polymers of pigment that’re too big to just slip back out. That’s how permanent color resists fading through multiple washes: It’s trapped beneath the cuticle. SOURCES: http://science.howstuffworks.com/innovation/everyday-innovations/hair-coloring.htm/printable http://chemistscorner.com/chemical-reactions-in-cosmetic-science/ http://pubs.acs.org/cen/whatstuff/stuff/7811scit4.html http://www.cancer.gov/cancertopics/causes-prevention/risk/myths/hair-dyes-fact-sheet Tro, Nivaldo. “Chemistry in Focus: A Molecular View of Our World”. Cengage Learning. Jan 1, 2015. p. 369. https://books.google.com/books?id=OYXCBAAAQBAJ&pg=PA369&lpg=PA369&dq=hydrogen+peroxide+hair+double+bonds&source=bl&ots=2_ZvbzOJL3&sig=ssaKMhzc-t-W_SCh7bHVBqyY2IA&hl=en&sa=X&ei=HcBHVfm4F8r1oAT-k4HYCg&ved=0CD8Q6AEwBQ#v=onepage&q=hydrogen%20peroxide%20hair%20double%20bonds&f=false http://www.thechemicalblog.co.uk/why-is-hydrogen-peroxide-used-to-bleach-hair/ http://www.madehow.com/Volume-3/Hair-Dye.html http://health.howstuffworks.com/skin-care/hair-care/straightening-treatments/a-case-of-good-chemistry-info1.htm/printable http://www.thechemicalblog.co.uk/why-is-hydrogen-peroxide-used-to-bleach-hair/ http://pgbeautyscience.com/dye-precursors.php

Bitcoin price forecast
International stocks are somewhat more cyclical and a whole lot more inflation sensitive. Stocks that seem like a bargain today can have their values halved in a brief time period. Along with unit bias, in addition, it makes it more challenging to see the method by which the price of a single Bitcoin could possibly go up more. The industry price per DCN is forecast to exceed the true bitcoin value as time passes. If you would like to preserve value, you can put money into gold bullion by heading to First Fidelity Reserve. Anything less and your return is going to be diminished by commission expenses. Such returns are also rather plausible.
In the event the economy cannot manage the rise in rates, and the Fed is made to reverse their decision, the cost of Bitcoin and other cryptocurrencies will probably respond positively. The last, dizzying increase of the exchange rate might have been predicted. A rise in value will actually lead to less volume of bitcoins necessary for the transaction. Just a few cents will receive a bitcoin transaction confirmed, and sent to any country in the whole world. In any event, an individual can forecast a bullish dollar during the next several months ahead. By way of example, say if you`ve sent money abroad, you`ve used aSWIFT support. In virtually all economies around the Earth, the money is merely printed without even statistics and economics model.
Investors typically begin searching for some nation or business to carry out well, but for the very first time in 20 decades, there are reduced correlations between different markets act in relation to one another. It`s still too uncertain for the majority of the investors to have a call. A lot of the investors are only holding their holdings patiently in order to learn whether the cryptocurrencies resume their uptrend or not. The reality is that currently, lots of the investors are concerned about putting new money into Bitcoins. Considering that it`s still so relatively affordable, that makes it even more attractive to investors who might be intimidated bybitcoin`s huge price tag. While the investors shall not have the ability to expect exceptional growth in the event of the bull market, they have a tendency to attain stable returns and make wealth in the future with least risk in the equity industry. In addition, the valuations are somewhat more appealing.
If you`re in search for virtual currencies with good return Smart is an excellent option. Through web portals you can readily find out all info required. Although the variety of Bitcoins composed of a block reward is all about to be split into half, Bitcoin value has more than doubled in the last few decades. There are a lot of theories to explain the sudden price boost in 2017 and a number of them have valid merit. Thus individuals that are searching for trading in the share market must make sure they are mindful of the conditions and the mechanism of the share market till they invest their money.
Human Design is a process, which we`ve used for bitcoin price astrological forecast, and it`ll also be on the platform. The creation and performance of futures markets, for example, is anticipated to tilt the price either manner. Business development is never as simple as technologists think. If you obey the strategy as outlined you`ll be able to buy a stock at a discount to the present market price and if not still earn a return that`s above average expectations. Stepping into the investing business you have to be experienced. There can not be any doubt many companies benefit from reduced energy expenses, but a lot of others in the oil company will pay a dear price. What`s more, the providers and manufacturers of the ATM machine are distinct benefits in support difficulties and not as efficient ATMs that is also anticipated to hinder the business.

How to become bitcoin trader? Exactly like Bitcoin, multiple digital currencies exist in the marketplace. So if you prefer to buy a few other currencies which aren`t available on Indian Exchange than you can utilize Bittrex. All you have to do is locate an exchange that you favor. Cryptocurrency exchanges have a massive potential to modify peoples minds and opinions concerning cryptocurrencies generally speaking and their application in actual life. So even in the event the exchange is attacked, its still true that you have your money. Furthermore, the exchanges prepare each and every industry for Bitcoin expansion. Existing stock exchanges will also compete to be able to fulfill the users configuration requirements. Sooner or later later on, the prices will grow more equal, meeting somewhere in the middleyour profit is equivalent to the quantity of convergence. No matter how far it is from Kijun, it is likely to return and test that level at some point. The amount of bitcoin is perpetually changing. In the US, it is 1000 USD. Whats even better, seek the services of a seasoned lawyer or at least ask for an in depth consultation. So youve read the newspaper about the meteoric growth of crypto currencies including Bitcoin or Ripple. Then coming up with 1000s of exchange rates simply to go out and get groceries is nearly impossible. Many cities around the world provide a bitcoin ATM where you are able to trade cash for bitcoin. The cryptocurrency world isn`t efficient.