Month: August, 2018

Why You Really Can Smell Approaching Storms

The researchers captured the moment water droplets impact different surfaces using high speed cameras and saw that tiny clouds of aerosols were produced, as seen above, as the droplets flattened on the surface

Most people can detect the distinctive fresh, earthy aroma of an approaching rainstorm, but now scientists have worked out why.

Researchers using high-speed cameras have found that drops of water release clouds of tiny particles when they hit surfaces like soil and leaves.

Their study showed that a raindrop hitting an uneven surface, they trap bubbles of air that shoot upwards and burst from the top of the water droplet like fizz in a champagne glass.

These tiny bubbles carry minute amounts of aromatic particles of oil and dust from the surface that can then be blown for miles by gusts of wind ahead of rain storms.

This, the scientists say, explains why it is possible to smell a rainstorm long before it arrives, even when it has been dry for several days.

The effect, known as Petrichor, is often most pronounced during the summer, accompanying the first rain after a long dry smell when more dust and oils have accumulated on plants and on the ground.

The new research, which was conducted by scientists at the Massachusetts Institute of Technology, found that different types of rainfall could alter the smell.




The scientists found that light showers and moderate seemed to trigger more aerosols compared with heavy rain that might accompany thunderstorms.

They also found that the type of soil could also influence how many aerosols were released and was particularly pronounced on clay or sandy soil.

Dr Youngsoo Joung, one of the scientists at MIT’s department of engineering who conducted the research, said the findings could also help to explain how some soil-based bacteria can spread disease.

He said: “Until now, people didn’t know that aerosols could be generated from raindrops on soil.

“When moderate or light rain hits sandy or clay soils, you can observe lots of aerosols, because sandy clay has medium wetting properties.

“Heavy rain (which has a high) impact speed, means there’s not enough time to make bubbles inside the droplet.

“This finding should be a good reference for future work, illuminating microbes and chemicals existing inside soil and other natural materials, and how they can be delivered in the environment, and possibly to humans.

“To prevent transmission of microorganisms from nature to humans, we need to know the exact mechanism. In this work, we provide one possible way of transmission.”

Scientists in Australia were the first to coin the word ‘petrichor‘ for the smell of approaching rain and characterized it as the release of plant oils along with a compound called geosmin, which is produced by soil-dwelling bacteria.

However, the new research is the first to explain the mechanism that causes these compounds to become airborne.

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Pass it on: Popular Science

How To Become A Full-Fledged Astronaut

Becoming an astronaut doesn’t just happen overnight. It takes many years of education and experience to meet the basic qualifications.

Many people aren’t accepted on the first try, either, requiring them to learn more to be better prepared for the next try.

Even then, only a small percentage of applicants become astronaut candidates, making it a hard job to get.

The fact that I applied to become an astronaut 15 times has not been lost on my friends, followers, or fans,” wrote retired astronaut Clay Anderson in his biography, “The Ordinary Spaceman,” as quoted in Popular Mechanics.

Jokes and snide remarks have hinged upon the ugly truth that on 14 of those 15 attempts I was a complete and abysmal failure. As a matter of fact, there’s a NASA public service announcement highlighting how it took me 15 tries. I like to cling to the reality that I can always say ‘better late than never,’ but at this point it’s all academic.

This article focuses on the selection process for NASA, which applies to American citizens.

While many of the qualifications can be generalized to astronaut programs in other countries, it’s important to note that each space agency has its own selection process.

Non-U.S. citizens in the following geographical areas should consult one of these agencies for more information on becoming an astronaut:

  • European Space Agency
  • Japanese Aerospace Exploration Agency
  • Canadian Space Agency
  • Russian Federal Space Agency
  • China National Space Administration




The first step to being an astronaut is getting relevant experience in school. There are two main classes of astronaut applicants: military applicants and civilian applicants.

Military application procedures vary depending on the branch of the U.S. armed forces you are working for, since you apply through your respective branch. Civilians apply to NASA directly.

No matter the background, NASA wants its astronauts to have at least a bachelor’s degree in engineering, biological science, physical science or mathematics.

Many astronauts have a master’s degree or even a Ph.D. in their field. Some astronauts, such as Story Musgrave (now retired), have degrees even beyond that.

While education implies you’ll need some money to make astronaut selection possible, a Forbes article points out that several astronauts received assistance from the military or government programs to pick up qualifications.

It takes more than school to gain a foothold as an astronaut selection candidate, however.

NASA’s 2017 astronaut candidate class, with Robb Kulin in the center with the selfie stick.

NASA wants at least three years of “related, progressively responsible, professional experience” or (in a nod to military candidates) at least 1,000 hours of “pilot-in-command time in jet aircraft.”

Advanced degrees are considered equivalent to this experience, however, with a master’s equaling one year of experience and a doctorate three years of experience.

A notable exception to these requirements are teachers, who still must have a technical bachelor’s degree but can qualify through the act of teaching — even for elementary school children.

NASA astronaut candidates must also pass a demanding physical. Among the requirements:

  • 20/20 vision (either naturally or with corrective lenses)
  • blood pressure not more than 140/90 in a sitting position
  • a height of between 62 and 75 inches

In general, you must be in extremely good shape to be an astronaut as it’s expensive to make an emergency return to Earth in case of medical emergency in orbit.

There also are interviews during the selection process to figure out if a candidate is physically and psychologically able to work as an astronaut.

Flexibility, group work skills and a love of learning are some of the personality traits NASA looks for.

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Pass it on: Popular Science

Steve The Weird ‘Aurora’ Is Not What We Thought It Was

Well, well, well. Looks like the jig is up. The “new kind of aurora” discovered earlier this year, and subsequently named “STEVE” has been rumbled. It seems Steve isn’t an aurora after all.

But that doesn’t mean the game is over. Because Steve’s actual identity may be even more interesting. Physicists have concluded that the erstwhile aurora is in fact an entirely new celestial phenomenon.

Steve – which manifests as gorgeous glowing purple ribbons across the sky – has been around for a few decades now, known to photographers and aurora chasers, but was only brought to the attention of scientists in 2016.

It had been nicknamed Steve by the Alberta Aurora Chasers, which scientists upheld when they officially named it Strong Thermal Emission Velocity Enhancement (STEVE).

Earlier this year, researchers announced that the purple and white streamers, while very different from the shimmering green auroral curtains, were indeed a new kind of aurora.




But the light produced by Steve isn’t the same as the light produced by an aurora, so a new team of researchers worked on figuring out Steve’s mechanism by studying a Steve event from March 2008.

An aurora is generated by solar winds, which interact with charged particles in our magnetosphere, mainly protons and electrons.

These charged particles rain into the ionosphere and travel along the planet’s magnetic field lines to the poles, where they manifest as dancing lights in the sky, usually green, but sometimes red or blue, producing strong radio emissions.

This is not what is happening with Steve.

Such an event occurred on 28 March 2008, and data was obtained both by ground-based cameras that record auroras, and the NOAA’s Polar Orbiting Environmental Satellite 17, which was directly overhead at the time, and which carries an instrument that can measure charged particles raining into the ionosphere.

This instrument detected no such particles. This means the mechanism that produces Steve must be different from the mechanism that produces auroras.

For now, the researchers have named the new optical phenomenon “skyglow” (don’t worry, it’s also still Steve for now). And they have plans to learn more.

The next step in their mission to unmask the true Steve is to try and determine if streams of fast ions and hot electrons in the ionosphere are responsible for Steve, or if its source is occurring at a higher altitude.

The research has been published in the journal Geophysical Research Letters.

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Why The Theory that Computer Processors Will Double In Power Every Two Years May Be Becoming Obsolete

IBM PC (1981): IBM’s first proper effort at home computing was so successful it popularised the term ‘PC’. It could be connected to the user’s TV, process text and store more words than a large cookbook.

Almost exactly 50 years ago, the American electrical engineer Gordon E. Moore made a prediction which would come to have a profound impact on people’s expectations about technology.

Writing in Electronics magazine in April 1965, he suggested that as advances were made, the power of the average computer processor would double every year.

Moore went on to become a co-founder of Intel Corporation, now one of the world’s largest producers of microprocessors, which govern the speed of most laptops and PCs.

His prediction, which he updated in 1975 and now states that the doubling of processor power will occur every two years, came to be known as Moore’s Law.




Since then, this two-year cycle has provided the blueprint which has underpinned the continual advances in technology to which most of us are now accustomed – and has led to consumers taking ever faster computers, more realistic computer games and better iPhones for granted.

But according to Brian Krzanich, the current chief executive of Intel, the era of Moore’s Law may be coming to a natural end.

In a discussion with analysts on Wednesday night, he admitted that while his firm had “disproved the death of Moore’s Law many times over”, its next generation of microprocessors would take slightly longer to produce.

Gordon E. Moore

Apple iPhone 6: Apple’s latest smartphone in 2014 sold more than 100 million units by 1 March in 2015. Features include an 8MP camera, up to 128GB of storage and a 4.7in high-definition display

The electrical engineer was in his 30s when he made his famous prediction in the pages of a magazine that the number of transistors which could be fitted into computer chips would double approximately every year, meaning that computers would become increasingly more powerful.

In 1975 he extended the interval to two years. Now known as Moore’s Law, it has so far proved correct.

Three years after making his prediction, Moore co-founded NM Electronics alongside Robert Noyce.

The company later changed its name to Intel Corporation – a portmanteau of the words “integrated” and “electronics” – and currently employs more than 100,000 people. Now aged 86, Moore is estimated to be worth more than $6.1 billion.

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The Deadly Combination Of Heat And Humidity

The most deadly weather-related disasters aren’t necessarily caused by floods, droughts or hurricanes. They can be caused by heat waves, like the sweltering blanket that’s taken over 2,500 lives in India in recent weeks.

Temperatures broke 118 degrees in parts of the country. The death toll is still being tallied, and many heat-related deaths will be recognized only after the fact.

Yet it’s already the deadliest heat wave to hit India since at least 1998 and, by some accounts, the fourth- or fifth-deadliest worldwide since 1900.

These heat waves will only become more common as the planet continues to warm.

They don’t just affect tropical, developing countries; they’re a threat throughout the world. The July 1995 heat wave in the Midwest caused over 700 deaths in Chicago.

The August 2003 heat wave in western Europe led to about 45,000 deaths. The July-August 2010 heat wave in western Russia killed about 54,000 people.

But as anyone who’s spent a summer in the eastern United States knows, it’s not just the heat; it’s also the humidity. Together, they can be lethal, even if the heat doesn’t seem quite so extreme.




Scientists measure the combination using a metric known as wet-bulb temperature. It’s called that because it can be measured with a thermometer wrapped in a wet cloth, distinguishing it from the commonly reported dry-bulb temperature, measured in open air.

Wet-bulb temperature can also be calculated from relative humidity, surface pressure and air temperature.

But this fate is not yet locked in. Moderate reductions in emissions of heat-trapping gases sufficient to stop global emissions growth by 2040 and bring emissions down to half their current levels by the 2070s.

This can avoid those paralyzing extremes and limit the expected late-century experience of the average American to about 18 dangerously humid days a year.

And strong reductions — bringing global emissions to zero by the 2080s — can cap the growth of humidity extremes by the midcentury.

Climate change is increasing the risks to our health, our economy and our environment.

Communities need to prepare. But as world leaders get ready for the United Nations climate change conference in Paris this December, it’s also important to recognize that shifting to carbon-free energy will reduce the risks we will face from extreme heat and humidity.

As India’s tragic heat wave shows, these risks cannot be ignored.

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How The Media Gets AI Alarmingly Wrong

In June of last year, five researchers at Facebook’s Artificial Intelligence Research unit published an article showing how bots can simulate negotiation-like conversations.

While for the most part the bots were able to maintain coherent dialogue, the researchers found that the software agents would occasionally generate strange sentences like: “Balls have zero to me to me to me to me to me to me to me to.

On seeing these results, the team realized that they had failed to include a constraint that limited the bots to generating sentences within the parameters of spoken English, meaning that they developed a type of machine-English patois to communicate between themselves.

These findings were considered to be fairly interesting by other experts in the field, but not totally surprising or groundbreaking.

A month after this initial research was released, Fast Company published an article entitled AI Is Inventing Language Humans Can’t Understand. Should We Stop It?




The story focused almost entirely on how the bots occasionally diverged from standard English – which was not the main finding of the paper – and reported that after the researchers “realized their bots were chattering in a new language” they decided to pull the plug on the whole experiment, as if the bots were in some way out of control.

The ice of AI’s first winter only fully retreated at the beginning of this decade after a new generation of researchers started publishing papers about successful applications of a technique called “deep learning”.

While this was fundamentally a decades-old statistical technique similar to Rosenblatt’s perceptron, increases in computational power and availability of huge data sets meant that deep learning was becoming practical for tasks such as speech recognition, image recognition and language translation.

As reports of deep learning’s “unreasonable effectiveness” circulated among researchers, enrollments at universities in machine-learning classes surged, corporations started to invest billions of dollars to find talent familiar with the newest techniques, and countless startups attempting to apply AI to transport or medicine or finance were founded.

As this resurgence got under way, AI hype in the media resumed after a long hiatus.

In 2013, John Markoff wrote a feature in the New York Times about deep learning and neural networks with the headline Brainlike Computers, Learning From Experience.

Not only did the title recall the media hype of 60 years earlier, so did some of the article’s assertions about what was being made possible by the new technology.

Since then, far more melodramatic and overblown articles about “AI apocalypse”, “artificial brains”, “artificial superintelligence” and “creepy Facebook bot AIs” have filled the news feed daily.

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Power Of The web: Methods Of How Spiders Catch Their Prey

spider web

Spun from silk, with the strength of steel but with extraordinary elasticity, a spider’s web has long been regarded as one of Mother Nature’s most amazing feats.

Now scientists at Oxford University have revealed another unique quality – webs actively spring towards prey thanks to electrically conductive glue spread across their surface.

Researchers discovered that the electrical properties of a glue that coats spider webs causes them to reach out to grab all charged particles, from pollen and pollutants to flying insects.




The study, published in Naturwissenschaften journal, shows how a quirk of physics causes webs to move towards all airborne objects, regardless of whether they are positively or negatively charged.

This explains why webs are able to spring towards prey and how they collect small airborne particles so efficiently. Spider webs could, according to researchers, be used for environmental monitoring as they actively filter airborne pollutants with the same accuracy as expensive industrial sensors.

spider web

“Electrical attraction drags airborne pollutants including aerosols and pesticides to the webs, so you could harvest and test webs to monitor pollution levels – for example, to check for pesticides that might be harming bee populations,” said Professor Fritz Vollrath of Oxford University’s department of zoology, who led the study.

“What’s fascinating is that you can detect some airborne chemicals just by looking at the shape of the webs. Many spiders clear particles from their webs by eating them, including chemicals that are electrically drawn to the web.”

In tests spiders are known to create different qualities of web depending on their drug consumption, Professor Vollrath said.

spider web

The researchers showed that the webs also cause local distortions in the Earth’s electric field since they behave like conducting discs.

Many insects are able to detect small electrical disturbances, including bees, that can sense the electric fields of different flowers and other bees.

Electrical disturbances caused by spider webs are extremely short-ranged, so it is not yet clear whether insects would be able to sense them before the web snaps out to grab them.

spider web

Professor Vollrath added that spider webs make use of the static charge developed by moving insects to “actively catch prey”.

The latest revelation will add to the fascination with spiders’ webs, the structures of which are already under investigation for potential applications in industry, including in bullet-proof vests and even in artificial tendons.

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Pass it on: New Scientist

Just Another Day on Aerosol Earth

Take a deep breath. Even if the air looks clear, it is nearly certain that you will inhale millions of solid particles and liquid droplets.

These ubiquitous specks of matter are known as aerosols, and they can be found in the air over oceans, deserts, mountains, forests, ice, and every ecosystem in between.

If you have ever watched smoke billowing from a wildfire, ash erupting from a volcano, or dust blowing in the wind, you have seen aerosols.

Satellites like Terra, Aqua, Aura, and Suomi NPP “see” them as well, though they offer a completely different perspective from hundreds of kilometers above Earth’s surface.

A version of a NASA model called the Goddard Earth Observing System Forward Processing (GEOS FP) offers a similarly expansive view of the mishmash of particles that dance and swirl through the atmosphere.

The visualization above highlights GEOS FP model output for aerosols on August 23, 2018.




On that day, huge plumes of smoke drifted over North America and Africa, three different tropical cyclones churned in the Pacific Ocean, and large clouds of dust blew over deserts in Africa and Asia.

The storms are visible within giant swirls of sea salt aerosol (blue), which winds loft into the air as part of sea spray.

Black carbon particles (red) are among the particles emitted by fires; vehicle and factory emissions are another common source.

Particles the model classified as dust are shown in purple. The visualization includes a layer of night light data collected by the day-night band of the Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP that shows the locations of towns and cities.

Note: the aerosol in the visualization is not a direct representation of satellite data.

The GEOS FP model, like all weather and climate models, used mathematical equations that represent physical processes to calculate what was happening in the atmosphere on August 23.

Measurements of physical properties, like temperature, moisture, aerosols, and winds, are routinely folded into the model to better simulate real-world conditions.

Some of the events that appear in the visualization were causing pretty serious problems on the ground.

Last August 23, Hawaiians braced for torrential rains and potentially serious floods and mudslides as Hurricane Lane approached.

Meanwhile, twin tropical cyclones—Soulik and Cimaron—were on the verge of lashing South Korea and Japan.

The smoke plume over central Africa is a seasonal occurrence and mainly the product of farmers lighting numerous small fires to maintain crop and grazing lands.

Most of the smoke over North America came from large wildfires burning in Canada and the United States.

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Scientists Discover A New Type Of Brain Cell In Humans

An international team of 34 scientists has identified a new type of brain cell in humans not found in other well-studied species.

The discovery of “Rosehip” neurons, published today in the journal Nature Neuroscience, raises a number of questions: How does it influence human behavior and experience?

How does it differentiate us from other species? Can it be found in primates and other cognitively advanced species?

But there is one issue this discovery highlights immediately: there’s a neuron in human brains that is missing from the brains of mice and other animals used to model human brains in experiments.

Does this mean current animal models yield distorted results? “If we want to understand how the human brain works, we need to study humans or closely related species,” says Trygve Bakken, co-author of the paper and a neuroscientist at the Allen Institute for Brain Science.




The flow of info

Rosehip neurons are inhibitory neurons that form synapses with pyramidal neurons, the primary excitatory neurons in the prefrontal cortex.

We all have inhibitory neurons and excitatory neurons,” says Bakken, “but this particular type of inhibitory neuron is what’s new in this study. It’s special based on its shape and its connections and also the genes that it expresses.

When a traffic signal turns red it helps controls the flow of traffic. Similarly, inhibitory neurons help control the flow of electrochemical information.

The type of information rosehip neurons control, and why they appear particular to humans, is yet to be discovered. “It has these really discrete connections with [pyramidal] neurons,” says Bakken.

It has the potential to sort of manipulate the circuit in a really targeted way, but how that influences behavior will have to come in later work.”

Found in the neocortex of human brains

The researchers identified rosehip neurons by looking at brain samples from two males who died in their 50’s and donated their bodies to science.

The brain slabs were tissue from the neocortex, a most recent evolutionary development inside our skulls responsible for higher-order thinking.

The neocortex, the outermost layer of cells, is greatly expanded in humans–about a thousandfold compared to mice,” says Bakken.

From neurological studies, if you have a stroke in your neocortex for example, it really impacts your ability to do these sorts of high-order cognitive processing.

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We Decode The Secret Language Of Birds

When we talk about birdsong, we cannot simply refer to a single “voice”. It is a great chorus of complex sounds, it is a real language in itself.

The dry “teak” of a sparrow, the plaintive “gheck gheck gheck” of a woodpecker, the shrill “chirrip” of a lark – each sound has its own purpose and is used in very specific circumstances.

For birdwatchers, learning how to ‘decode’ the secret language of birds is a great way to identify different species and to better understand their behaviour.

The language of birds

Just as vowels and consonants provide the foundation for our words and sentences, birds produce a series of calls, songs and melodies in a ‘language’ so nuanced it could rival our very own alphabet!

This is all thanks to a special vocal organ called the syrinx – the size of a pea, it sits at the junction of the trachea and the bronchi in the lungs.

Its structure – which varies with each species – makes such different songs and sounds possible.

Each sound has a different purpose and this, in turn, makes it possible for birds to communicate with each other in different circumstances.




The warning calls

These involve sharp and penetrating sounds – warning signals used by birds whenever they feel threatened and want to warn companions of danger.

They are usually short sounds strong enough to be heard at great distances. The same sound is often used by predatory birds as part of their attack.

The cries for help

Mom Mom Mom!” Just as children call for their mother with arms outstretched, small birds emit little moans and chirps to attract their mother’s attention, often flapping their wings for good measure.

The call intensity is low, but it can still be clearly perceived in the vicinity of a nest. Small birds frequently continue to use these calls after leaving the nest too – because mom is always mom!

The contact calls

Hey, are you all right?” Contact calls for birds are more or less the equivalent of us making sure a friend is ok.

They use contact calls when they travel in flocks, want to call each other or even just share news about a good food source.

These calls are characterised by moderately strong chirps, similar to a “hum” but not as penetrating as the warning calls.

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Pass it on: Popular Science