Category: science

teded:

Happy First Day of Spring, Tumblr! 

What better way to celebrate than to **ACHOO!!**….wait, what were we saying?

image

Ah, spring! Grass growing, flowers blooming, trees growing new leaves, but if you get allergies, this explosion of new life probably inspires more dread than joy.  

image

Step outside, and within minutes, you’re sneezing and congested. Your nose is running, your eyes are swollen and watery, your throat is itchy. For you and millions of others, it’s seasonal allergy time. So what’s behind this onslaught of mucus?

image

The answer lies within you. It’s your immune system. Seasonal allergies, also called hay fever, or allergic rhinitis, are a hypersensitive immune response to something that’s not actually harmful. Pollen from trees and grass, and mold spores from tiny fungi find their way into your mucous membranes and your body attacks these innocuous travelers the same way it would infectious bacteria. 

image

The immune system has a memory. When a foreign substance gets tagged as threatening, white blood cells produce customized antibodies that will recognize the offender the next time around. They then promptly recruit the body’s defense team. But sometimes, the immune system accidentally discriminates against harmless substances, like pollen. When it wafts in again, antibodies on the surface of white blood cells recognize it and latch on.

image

This triggers the cell to release inflammatory chemicals, like histamine, which stimulate nerve cells, and cause blood vessels in the mucous membranes to swell and leak fluid. In other words, itchiness, sneezing, congestion, and a runny nose. 

image

Allergies usually, but not always, show up for the first time during childhood. But why do some people get allergies and others don’t? Allergies tend to run in families, so genetics may be one culprit. In fact, errors in a gene that helps regulate the immune system are associated with higher rates of allergies. The environment you grow up in matters, too. Being exposed to an allergen as a baby makes you less likely to actually develop an allergy to it. People who grow up on farms, in big families, and in the developing world also tend to have fewer allergies, although there are plenty of exceptions, partly thanks to genetics. One theory is that as children, they encounter more of the microbes and parasites that co-evolved with traditional hunter-gatherer societies.

image

Called the hygiene hypothesis, the idea is that when the immune system isn’t exposed to the familiar cast of microbes, it’ll keep itself busy mounting defenses against harmless substances, like pollen. Another theory is that an immune system toughened up by a barrage of pathogens is less likely to overreact to allergens. Pollen is a common offender, just because we encounter so much of it, but there’s a long list of substances: dust, animal dander, insect venom, medications, certain foods, that can send your immune system into overdrive. Some of these reactions can be scary. An allergy can develop into full-blown anaphylaxis, which typically brings on severe swelling, shortness of breath, and very low blood pressure. It can be deadly.

image

But as we who suffer from seasonal allergies know, even non-life threatening allergy symptoms can make you miserable. So what can you do about it? Medications can help reduce the symptoms. The most common ones keep histamines from binding to your cells. These antihistamines stop the inflammation response. Steroids can help dial down the immune system. Another more permanent option is immunotherapy. Deliberate, controlled exposure to gradually increasing amounts of an allergen can teach the immune system that it isn’t dangerous after all. 

image

Of course, you can always just wait your seasonal allergies out. The spring pollen onslaught dwindles by mid-summer…just in time for ragweed season!

From the TED-Ed Lesson Why do people have seasonal allergies? – Eleanor Nelsen 

Animation by TED-Ed

For all you allergy sufferers of the world, Happy Spring?

teded:

Happy First Day of Spring, Tumblr! 

What better way to celebrate than to **ACHOO!!**….wait, what were we saying?

image

Ah, spring! Grass growing, flowers blooming, trees growing new leaves, but if you get allergies, this explosion of new life probably inspires more dread than joy.  

image

Step outside, and within minutes, you’re sneezing and congested. Your nose is running, your eyes are swollen and watery, your throat is itchy. For you and millions of others, it’s seasonal allergy time. So what’s behind this onslaught of mucus?

image

The answer lies within you. It’s your immune system. Seasonal allergies, also called hay fever, or allergic rhinitis, are a hypersensitive immune response to something that’s not actually harmful. Pollen from trees and grass, and mold spores from tiny fungi find their way into your mucous membranes and your body attacks these innocuous travelers the same way it would infectious bacteria. 

image

The immune system has a memory. When a foreign substance gets tagged as threatening, white blood cells produce customized antibodies that will recognize the offender the next time around. They then promptly recruit the body’s defense team. But sometimes, the immune system accidentally discriminates against harmless substances, like pollen. When it wafts in again, antibodies on the surface of white blood cells recognize it and latch on.

image

This triggers the cell to release inflammatory chemicals, like histamine, which stimulate nerve cells, and cause blood vessels in the mucous membranes to swell and leak fluid. In other words, itchiness, sneezing, congestion, and a runny nose. 

image

Allergies usually, but not always, show up for the first time during childhood. But why do some people get allergies and others don’t? Allergies tend to run in families, so genetics may be one culprit. In fact, errors in a gene that helps regulate the immune system are associated with higher rates of allergies. The environment you grow up in matters, too. Being exposed to an allergen as a baby makes you less likely to actually develop an allergy to it. People who grow up on farms, in big families, and in the developing world also tend to have fewer allergies, although there are plenty of exceptions, partly thanks to genetics. One theory is that as children, they encounter more of the microbes and parasites that co-evolved with traditional hunter-gatherer societies.

image

Called the hygiene hypothesis, the idea is that when the immune system isn’t exposed to the familiar cast of microbes, it’ll keep itself busy mounting defenses against harmless substances, like pollen. Another theory is that an immune system toughened up by a barrage of pathogens is less likely to overreact to allergens. Pollen is a common offender, just because we encounter so much of it, but there’s a long list of substances: dust, animal dander, insect venom, medications, certain foods, that can send your immune system into overdrive. Some of these reactions can be scary. An allergy can develop into full-blown anaphylaxis, which typically brings on severe swelling, shortness of breath, and very low blood pressure. It can be deadly.

image

But as we who suffer from seasonal allergies know, even non-life threatening allergy symptoms can make you miserable. So what can you do about it? Medications can help reduce the symptoms. The most common ones keep histamines from binding to your cells. These antihistamines stop the inflammation response. Steroids can help dial down the immune system. Another more permanent option is immunotherapy. Deliberate, controlled exposure to gradually increasing amounts of an allergen can teach the immune system that it isn’t dangerous after all. 

image

Of course, you can always just wait your seasonal allergies out. The spring pollen onslaught dwindles by mid-summer…just in time for ragweed season!

From the TED-Ed Lesson Why do people have seasonal allergies? – Eleanor Nelsen 

Animation by TED-Ed

For all you allergy sufferers of the world, Happy Spring?

teded:

teded:

In order to celebrate Pi Day, we TED-Ed nerds are bringing you 3 fun facts about our favorite irrational number!

image

1. Pi is infinite! To write it out, you’d begin with 3.14159 and continue on….forever! That’s why, instead of trying to write out an infinite number of digits every time, we just refer to it using the Greek letter, Pi. 


image

2. Pi is an irrational number, or a number that can never be expressed as a ratio of 2 whole numbers.


image

3. Scientists have used Pi to calculate the density of our entire universe, which has infinitely less stuff in it than the total number of digits in Pi. 

From the TED-Ed Lesson The infinite life of pi – Reynaldo Lopes

Animation by Igor Coric

Happy Pi Day, Tumblr!

teded:

teded:

In order to celebrate Pi Day, we TED-Ed nerds are bringing you 3 fun facts about our favorite irrational number!

image

1. Pi is infinite! To write it out, you’d begin with 3.14159 and continue on….forever! That’s why, instead of trying to write out an infinite number of digits every time, we just refer to it using the Greek letter, Pi. 


image

2. Pi is an irrational number, or a number that can never be expressed as a ratio of 2 whole numbers.


image

3. Scientists have used Pi to calculate the density of our entire universe, which has infinitely less stuff in it than the total number of digits in Pi. 

From the TED-Ed Lesson The infinite life of pi – Reynaldo Lopes

Animation by Igor Coric

Happy Pi Day, Tumblr!

teded:

image

1. Cookies are for everyone. But everyone has cookie preferences. When you slide that cookie tray into the oven, you’re setting off a series of chemical reactions that transform one substance – dough – into another – cookies! The better you understand ‘Cookie Chemistry’, the better equipped you will be to create the cookies you crave.

image

2. Lots goes on in that oven, but one of science’s tastiest reactions occurs at 310º. Maillard reactions result when proteins and sugars breakdown and rearrange themselves into ring like structures which reflect light in a way that gives foods their distinctive, rich brown color. As this reaction occurs, it produces a range of flavor and aroma compounds, which also react with each other forming even more complex tastes and smells.

3. The final reaction to take place inside your cookie is caramelization and it occurs at 356º. Caramelization is what happens when sugar molecules breakdown under high heat, forming the sweet, nutty and slightly bitter flavor compounds that define…caramel! So if your recipe calls for a 350º oven – caramelization will never happen. 

So, if your ideal cookie is barely browned – 310º will do. But if you want a tanned, caramelized cookie, crank up the heat! Caramelization continues up to 390º degrees.

image

4. No need to check that oven like a fiend. You don’t even really need a kitchen timer – when you smell the nutty, toasty aromas of the Maillard reaction and caramelization, your cookies are ready! 

image

5. Baking is chemistry, friends! That’s right – PURE. SCIENCE. Check carefully before altering those recipes – chances are some of those ingredients and quantities are there for a reason.

Curious what else happens in that oven? Check out the TED-Ed Lesson  The chemistry of cookies – Stephanie Warren

Animation by Augenblick Studios

For the winningest of cookies, #askscience.

teded:

To celebrate George Seurat’s birthday today, we thought we’d do a deep dive behind the scenes of one of our animated lessons, How do schools of fish swim in harmony?, which is about the concept of ‘emergence’ and whose animated style just so happens to have been largely influenced by the paintings of George Seurat and his contemporaries.

image

Emergence refers to the spontaneous creation of sophisticated behaviors and functions from large groups of simple elements, and can be used to explain the movements of ants, fish, and birds, as well as how the tiny cells in your brain give rise to the complex thoughts, memories, and consciousness that are you.

image

A Sunday Afternoon on the Island of La Grande Jatte, George Seurat (1884–86)

It’s kind of like a pointillist painting. When you zoom in real close, it’s just a collection of chaotic brush strokes. But take a few steps back, and you’ll see that all of those brush strokes are working together to illustrate a complex and detailed scene.

image

Pointillism stems from Impressionism, and depending on the artist’s technique, the size of the brush strokes vary, but are always visible. For example, Vincent van Gogh’s The Starry Night uses larger brush strokes in the night sky. Both the above and below concept designs show the animator of this lesson testing out how different brushstrokes interact to create depth within a scene. She decided that the swirling waters would make sense as large brushstrokes, which also offered contrast to allow the small fish to stand out.

image

George Seurat also employed a technique called ‘divisionism’, sometimes known as ‘chromoluminarism’, in which colors were separated into individual dots or patches which interacted optically. So, rather than relying on mixing colors, painters like Seurat and Paul Signac juxtaposed contrasting colors to allow for optical mixing – which in theory would produce more vibrant and pure colors than the traditional process of mixing pigments.

image

Circus Sideshow (Parade de Cirque), George Seurat (1887–88)

While designing this TED-Ed lesson, George Seurat and Paul Signac’s paintings provided inspiration not just for the brushstroke technique, but also for the color palette.

image

This GIF of the brain and it’s neural connections draws many of its colors from Seurat’s circus series palette, while the brighter colors – such as the ones used in the title GIF above – are drawn from the more vibrant colors commonly used by Paul Signac, like in the painting below.

image

Notre-Dame-de-la-Garde (La Bonne-Mère), Marseilles, Paul Signac (1905-06)

image

Animating this lesson was an opportunity to renew a sense of wonder in our ever complex universe, whether studying it up close or from afar. We hope that watching it might do the same for you!

From the TED-Ed Lesson How do schools of fish swim in harmony? – Nathan S. Jacobs

Animation by TED-Ed // Lisa LaBracio

Happy Birthday to George Seurat!

teded:

In 2008, something incredible happened: a man was cured of HIV. In over 70 million HIV cases, that was a first and, so far, a last. Worldwide, scientists are working to make these odds a bit better. One research approach involves using a drug to activate all cells harboring the HIV genetic information. This would both destroy those cells and flush the virus out into the open, where our current drugs are effective. Another is looking to use genetic tools to cut the HIV DNA out of cells genomes altogether. And while one cure out of 70 million cases may seem like terrible odds, one is immeasurably better than zero. We now know that a cure is possible, and that may give us what we need to beat HIV for good.

Today is World AIDS Day. World AIDS Day is held on the 1st December each year and is an opportunity for people worldwide to unite in the fight against HIV, show their support for people living with HIV and to commemorate people who have died. 

Globally, an estimated 34 million people have HIV. World AIDS Day is important because it reminds the public and Government that HIV has not gone away – there is still a vital need to raise money, increase awareness, fight prejudice and improve education.

For more ideas on how to get involved, visit www.worldaidsday.org.

From the TED-Ed Lesson Why it’s so hard to cure HIV/AIDS – Janet Iwasa

Animation by Javier Saldeña

teded:

It begins with a bit of discomfort and soon becomes a pressing sensation that’s impossible to ignore. Finally, it’s all you can think about, and out of sheer desperation, you go on a hunt for a bathroom until “ahh.” Humans should urinate at least four to six times a day, but occasionally, the pressures of modern life forces us to clench and hold it in. How bad is this habit, and how long can our bodies withstand it? 

image

The answers lie in the workings of the bladder, an oval pouch that sits inside the pelvis. The bladder can stretch – to a limit – so you can keep on keepin’ on, but how do you sense your bladder’s fullness so you know when to pee? As your bladder fills, millions of stretch receptors get triggered, and they send signals along your nerves to the sacral region in your spinal cord. A reflex signal travels back to your bladder, making the muscles of the bladder wall contract slightly and increasing the bladder’s pressure so you’re aware that it’s filling up. 

image

With about 150 to 200 milliliters of urine inside of it, the bladder’s muscular wall is stretched enough for you to sense that there’s urine within. At about 400 to 500 milliliters, the pressure becomes uncomfortable. The bladder can go on stretching, but only to a point. Above 1,000 milliliters, it may burst. Most people would lose bladder control before this happens, but in very rare cases, such as when as a person can’t sense the need to urinate, the pouch can rupture. Eep!

image

But under normal circumstances, your decision to urinate stops the brain’s signal to the external urethral sphincter, causing it to relax and the bladder to empty. The external urethral sphincter is one of the muscles of the pelvic floor, and it provides support to the urethra and bladder neck. It’s lucky we have these pelvic floor muscles because placing pressure on the system by coughing, sneezing, laughing, or jumping could cause bladder leakage. Instead, the pelvic floor muscles keep the region sealed until you’re ready to go. But holding it in for too long, forcing out your urine too fast, or urinating without proper physical support may over time weaken or overwork that muscular sling. That can lead to an overactive pelvic floor, bladder pain, urgency, or urinary incontinence. So in the interest of long-term health, it’s not a great habit to hold your pee. But in the short term, at least, your body and brain have got you covered, so you can conveniently choose your moment of sweet release.

From the TED-Ed Lesson Is it bad to hold your pee? – Heba Shaheed

Animation by Artrake Studio

What’s your smartphone made of?

As of 2018, there are around 2.5 billion smartphone users in the world. If we broke open all their newest phones, which are just a fraction of the total that’ve been built, and split them into their component parts, that would produce around 85,000 kilograms of gold, 875,000 of silver, and 40 million kilograms of copper. 

Gold, silver, and copper are actually just a few of the 70 or so chemical elements that make up the average smartphone. These can be divided into different groups, two of the most critical being rare earth elements and precious metals. Rare earths are a selection of 17 elements that are actually common in Earth’s crust and are found in many areas across the world in low concentrations. These elements have a huge range of magnetic, phosphorescent, and conductive propertie that make them crucial to modern technologies. In fact, of the 17 types of rare earth metals, phones and other electronics may contain up to 16.

In smartphones, these create the screen and color display, aid conductivity, and produce the signature vibrations, amongst other things. And yet, crucial as they are, extracting these elements from the earth is linked to some disturbing environmental impacts. Rare earth elements can often be found, but in many areas, it’s not economically feasible to extract them due to low concentrations. Much of the time, extracting them requires a method called open pit mining that exposes vast areas of land. This form of mining destroys huge swaths of natural habitats, and causes air and water pollution, threatening the health of nearby communities. Another group of ingredients in smartphones comes with similar environmental risks: these are metals such as copper, silver, palladium, aluminum, platinum, tungsten, tin, lead, and gold. We also mine magnesium, lithium, silica, and potassium to make phones, and all of it is associated with vast habitat destruction, as well as air and water pollution. 

Despite this, the number of smartphones is on a steady increase; by 2019 it’s predicted that there’ll be close to 3 billion in use. This means that reclaiming the bounty within our phones is swiftly becoming a necessity. So, if you have an old phone, you might want to consider your options before throwing it away. To minimize waste, you could donate it to a charity for reuse, take it to an e-waste recycling facility, or look for a company that refurbishes old models. However, even recycling companies need our scrutiny. Just as the production of smartphones comes with social and environmental problems, dismantling them does too. E-waste is sometimes intentionally exported to countries where labor is cheap but working conditions are poor. Vast workforces, often made up of women and children, may be underpaid, lack the training to safely disassemble phones, and be exposed to elements like lead and mercury, which can permanently damage their nervous systems. Phone waste can also end up in huge dump sites, leaching toxic chemicals into the soil and water, mirroring the problems of the mines where the elements originated. 

A phone is much more than it appears to be on the surface. It’s an assemblage of elements from multiple countries, linked to impacts that are unfolding on a global scale. So, until someone invents a completely sustainable smartphone, we’ll need to come to terms with how this technology affects widespread places and people.

From the TED-Ed Lesson What’s a smartphone made of? – Kim Preshoff

Animation by Compote Collective

teded:

image

Growing up in Warsaw in Russian-occupied Poland, the young Marie Curie, originally named Maria Sklodowska, was a brilliant student, but she faced some challenging barriers. As a woman, she was barred from pursuing higher education, so in an act of defiance, Marie enrolled in the Floating University, a secret institution that provided clandestine education to Polish youth. By saving money and working as a governess and tutor, she eventually was able to move to Paris to study at the reputed Sorbonne. here, Marie earned both a physics and mathematics degree surviving largely on bread and tea, and sometimes fainting from near starvation. 

image

In 1896, Henri Becquerel discovered that uranium spontaneously emitted a mysterious X-ray-like radiation that could interact with photographic film. Curie soon found that the element thorium emitted similar radiation. Most importantly, the strength of the radiation depended solely on the element’s quantity, and was not affected by physical or chemical changes. This led her to conclude that radiation was coming from something fundamental within the atoms of each element. The idea was radical and helped to disprove the long-standing model of atoms as indivisible objects. Next, by focusing on a super radioactive ore called pitchblende, the Curies realized that uranium alone couldn’t be creating all the radiation. So, were there other radioactive elements that might be responsible?

image

In 1898, they reported two new elements, polonium, named for Marie’s native Poland, and radium, the Latin word for ray. They also coined the term radioactivity along the way. By 1902, the Curies had extracted a tenth of a gram of pure radium chloride salt from several tons of pitchblende, an incredible feat at the time. Later that year, Pierre Curie and Henri Becquerel were nominated for the Nobel Prize in physics, but Marie was overlooked. Pierre took a stand in support of his wife’s well-earned recognition. And so both of the Curies and Becquerel shared the 1903 Nobel Prize, making Marie Curie the first female Nobel Laureate.

image

In 1911, she won yet another Nobel, this time in chemistry for her earlier discovery of radium and polonium, and her extraction and analysis of pure radium and its compounds. This made her the first, and to this date, only person to win Nobel Prizes in two different sciences. Professor Curie put her discoveries to work, changing the landscape of medical research and treatments. She opened mobile radiology units during World War I, and investigated radiation’s effects on tumors.

image

However, these benefits to humanity may have come at a high personal cost. Curie died in 1934 of a bone marrow disease, which many today think was caused by her radiation exposure. Marie Curie’s revolutionary research laid the groundwork for our understanding of physics and chemistry, blazing trails in oncology, technology, medicine, and nuclear physics, to name a few. For good or ill, her discoveries in radiation launched a new era, unearthing some of science’s greatest secrets.

From the TED-Ed Lesson The genius of Marie Curie – Shohini Ghose

Animation by Anna Nowakowska

Happy Birthday to Marie Curie!