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What Is Electric Charge?


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What Is Electric Charge?

Most electric charge is carried by the electrons and protons within an atom. Electrons are said to carry negative charge, while protons are said to carry positive charge, although these labels are completely arbitrary (more on that later). Protons and electrons attract each other, the archetype of the cliché “opposites attract,” according to the University of Georgia’s website, HyperPhysics. Conversely, two protons repel each other, as do two electrons.

The movement of protons and electrons creates an electric field, which exerts a force called the Coulomb force, which radiates outward in all directions. According to Serif Uran, a professor of physics at Pittsburg State University, the electric field radiates outward from a charged particle similarly to how light radiates outward from a light bulb. Just as with the brightness of the light, the strength of the electric field decreases as the square of the distance from the source (1/r2). If you move twice as far away, the strength of the field decreases to one-fourth, and if you move three times as far away, the field decreases to one-ninth.

Because protons are generally confined to the nuclei imbedded inside atoms, they are not nearly as free to move as are electrons. Therefore, when we talk about electric charge, we nearly always mean a surplus or deficit of electrons. When an imbalance of charges exists, and electrons are able to flow, an electric current is created.

A localized and persistent deficit or surplus of electrons in an object causes static electricity. Current can take the form a sudden discharge of static electricity such as a lightning bolt or the spark between your finger and a grounded light switch plate; the steady flow of direct current (DC) from a battery or solar cell; or an oscillating current such as that from an alternating-current (AC) generator, a radio transmitter, or an audio amplifier.

Electric universe

We are usually unaware of electric charge because most objects contain equal amounts of positive and negative charge that effectively neutralize each other, according to Michael Dubson, a professor of physics at the University of Colorado Boulder. It is generally believed that the net charge of the universe is neutral. If the ratio of positive to negative charge were off by a factor of only 10−40, the Coulomb force would be more powerful than gravity, which would make the universe quite different from the one we observe, Dubson told Live Science. Nevertheless, some researchers, such as Michael Düren of the Justus Liebig University Giessen in Germany, have speculated on the possibility of an electrically charged universe.

Early electric research

Positive and negative values of charge were originally assigned by the American statesman and inventor Benjamin Franklin, who started studying electricity in 1742. Until then, most people thought that electrical effects were the result of mixing of two different electrical fluids, one positive and one negative. However, Franklin became convinced that there was only one single electric fluid and that objects could have excess or deficiency of this fluid. Therefore, according to theUniversity of Arizona, he invented the terms positive and negative to designate an excess or deficiency, respectively.

The unit for measuring electric charge is the coulomb (C), named afterCharles-Augustin Coulomb, an 18th-century French physicist. Coulomb developed the law that says “like charges repel; unlike charges attract.” A coulomb is defined as the amount of charge transported by a current of one ampere for one second. While this sounds like a small amount, according to HyperPhysics, “Two charges of one coulomb each separated by a meter would repel each other with a force of about a million tons!” Electrical engineers often prefer to use a larger unit for charge, the ampere hour, which is equal to 3,600 C.

The Coulomb force is one of the two fundamental forces that is noticeable on a macroscopic scale, the other being gravity. However, the electrical force is much, much stronger than gravity. The repulsive Coulomb force between two protons due to their charge is 4.1 × 1042times stronger than the attractive gravitational force between them due to their mass. This is true at any distance, since the distance cancels out on both sides of the equation.

Just how big of a number is that? Comparing the magnitude of the two forces is like comparing the mass of the Earth to the mass of a single molecule of penicillin! However, gravity still dominates the universe on a large scale, because, unlike charge, it is possible to assemble large quantities of mass. Large accumulations of similarly charged particles are not possible due to their mutual repulsion and their affinity for unlike charges.

Other properties of charge

Electric charge is quantized, meaning that it occurs in discrete units. Protons and electrons carry charges of ±1.602 × 10−19 C. Every accumulation of charge is an even multiple of this number, and fractional charges cannot exist. Quantum chromodynamics (QCD) states that protons and neutrons are each composed of three quarks with charges of +2/3 or −1/3 of the unit proton charge, and two of one and one of the other combine to form particles with charges of zero or +1 unit charge.

However, these particles cannot exist separately. Whenever you try to split a proton or neutron into its constituent quarks, it takes so much energy to do so, the energy is converted into matter in accordance with Einstein’s famous equation E = mc2, and instead of a single quark, you end up with a neutrally charged quark–antiquark pair, called a meson. Electrons, though, are believed to be truly fundamental, meaning they cannot be split into smaller parts.

Electric charge is a conserved quantity. That means it cannot be created or destroyed, and the net amount of electric charge in the universe is constant and unchanging. Positive and negative charges can neutralize each other, or neutral particles can split to form positively and negatively charged pairs of particles, but the net amount of charge always remains the same.

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Disney’s New Rolling Robot Climbs Walls Like a Gecko


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Disney’s New Rolling Robot Climbs Walls Like a Gecko

 http://gizmodo.com/disneys-new-rolling-robot-climbs-walls-like-a-gecko-1750083587

Disney's New Rolling Robot Climbs Walls Like a Gecko

Not even walls can stop Disney’s and ETH Zurich’s new four-wheeled robot called VertiGo that can quickly transition from rolling on the ground to climbing obstacles like a gecko—and without those sticky feet.

http://gizmodo.com/ajax/inset/iframe?id=youtube-video-e9P9_QM8cN8&start=0

So how does the VertiGo seemingly defy gravity? Atop the robot is a pair of steerable propellers that generate thrust, which pushes the vehicle against the wall. and keeps it from falling.

The propellers work similar to spoilers and other aerodynamic features on cars, which generate downward forces to help keep a race car pressed to the road to improve traction. But because the propellers on top of VertiGo can be steered, the robot can easily transition from horizontal to vertical surfaces, and back again. And neither surface has to be smooth for the robot to be able to ‘stick’ to it. As long as it has enough batteries to keep those props spinning, gravity doesn’t have a chance.

[Disney Research]

Here’s the Most Complete Ocean Floor Map Ever Made


Post 7321

Here’s the Most Complete Ocean Floor Map Ever Made

Here's the Most Complete Ocean Floor Map Ever Made

What lies beneath the deep blue sea? So much more than you might think.

The results that let this new, marvelously-detailed map of the seafloor fromNASA’s Earth Observatory be made were actually first published last year as part of a paper in Science from researchers at NOAA and Scripps Institution of Oceanography. They were also made available in a series of area maps and even as a Google Earth interactive. This latest incarnation, though, offers—in a single glance—perhaps the most complete unified view of the Earth’s seafloor to date, showing not just the mountains beneath the water, but also the crevices cracking the watery ground.

The detail of the map is particularly impressive. Not only does it show features that had previously not been seen, it’s also capable of catching any feature larger than 5 kilometers, which has been especially good for capturing some of the smaller ridge features.

It’s not just the map itself that’s interesting, though—it’s how they finally managed to make it.

Here's the Most Complete Ocean Floor Map Ever Made

So, how do you map what you can’t see?

Typically, finely-wrought ocean maps have been the result of extensive sonar. This is expensive and time-consuming, so sonar maps are mostly only made of places where ships spend the most time. The problem with that approach is that our oceans are vast and ships are small—meaning only a tiny percentage of the ocean floor (between 5 – 15 percent, NASA estimates) was mapped.

So, instead of depending on sonar, researchers looked to something else: Gravity. Using existing satellite data of the ocean, researchers searched for gravity anomalies as measured by sea surface heights. Where gravity was slightly stronger (those red/orange areas), they found mountains rising upwards, in the weaker areas (those blue patches) they were deep cracks.

This isn’t the first time researchers have made use of gravity as a measurement tool. A similar method has been used in the past to measure changes to ice cover in the Antarctic (yes, ice cover is changing so rapidly that you can even read the results in Earth’s gravitational field).

What’s exceptional about this effort is really the scale of it. Instead of just looking at changes to one area, the technique was used to chart the single largest unexplored area on our own planet. You often hear that Earth has already been extensively mapped, and certainly for inhabited areas that’s true. But for the remote regions, we’ve only begun to scratch the surface of our planet—and this map is a tantalizing clue to just what the future of earth exploration may look like.

Maps: Joshua Stevens / NASA Earth Observatory

The Coolest Images From National Geographic’s 2015 Photo Contest


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The Coolest Images From National Geographic’s 2015 Photo Contest

The Coolest Images From National Geographic's 2015 Photo Contest

This year, more than 13,000 photographs were submitted to National Geographic’s annual photo contest. These 13 are the very best.

Dirt

The Coolest Images From National Geographic's 2015 Photo Contest

This stunning image of an anti-cyclonic tornado was the grand prize winner. Captured by James Smart, the photo shows a monster of a tornado infused with brown dust as it sweeps through open farmland — just narrowly missing a home near Simla, Colorado. Here’s how he described the photo to National Geographic:

The tornado was slowly getting bigger as it picked up the dust and soil from the ground on the farmland. It wasn’t moving very fast, so we kept getting closer as it tracked next to the home as you can see in the image. Driving down a Colorado dirt road, we were lucky enough to be on the west of the tornado, so it was front lit. This really helped to get great detail out of the image and the perfect light for the sky and foreground.

Smart won $10,000 for the photo, and a trip to National Geographic headquarters in Washington, D.C., to participate in the annual National Geographic Photography Seminar next month.

Orangutan in the Rain

The Coolest Images From National Geographic's 2015 Photo Contest

Honorable mention in the Nature category was awarded to Andrew Suryono for this glorious image of an orangutan in the rain.

I was taking photos of orangutans in Bali, Indonesia, when it started to rain. Just before I put my camera away, I saw this orangutan take a taro leaf and put it on top on his head to protect himself from the rain! I immediately used my DSLR and telephoto lens to preserve this spontaneous magic moment.

Acrobats of the Air

The Coolest Images From National Geographic's 2015 Photo Contest

Alessandra Meniconzi received honorable mention for this photo of Alpine Choughs. The image was taken at Appenzell, Canton d’Appenzell Rhoden-Interieur, Switzerland.

Changing Shifts

The Coolest Images From National Geographic's 2015 Photo Contest

Photographer Mohammed Yousef snapped this cool pic of cheetahs.

In Maasai Mara National Reserve in Kenya, the cubs of the famous cheetah Malaika learned to hunt. They moved from one hill to another, scanning the lands. Here, they seemed to change shifts as one cheetah left the hill while another took her place.

Colorful Chaos

The Coolest Images From National Geographic's 2015 Photo Contest

Bence Mate took this photo of white-fronted bee-eaters as they gathered on a branch before going to sleep in their burrows.

I was working on this theme for 18 days, as there were only five to ten minutes each day when the light conditions were appropriate. Ninety percent of my efforts to capture this image were not successful. I used flashlights to light the bee-eaters sitting on the branch, but not the others flying above. At this angle, the backlight generated rainbow coloring through the wings of the flying birds.

“Asteroid”

The Coolest Images From National Geographic's 2015 Photo Contest

Francisco Mingorance was awarded first place in the Places category for this otherwordly image.

While preparing a report on Spain’s Rio Tinto from the air, I decided to include the phosphogypsum ponds located in the marshes of red, whose radioactive discharges has destroyed part of the marsh. As an environmental photojournalist I had to report this story, but had to do it with an image that by itself attracts the viewer’s attention. On a low-flying training flight, this image caught my attention for its resemblance to the impact of an asteroid on its green waters.

Hill of Crosses

The Coolest Images From National Geographic's 2015 Photo Contest

An honorable mention award in the Places category went to Hideki Mizuta for this striking photo.

There are many hundreds of thousands of crosses on the Hill of Crosses near Šiauliai, Lithuania. It represents Lithuanian Catholicism’s peaceful resistance to oppression. Many spirits of the dead are thought to live here on this small hill. When I visited this place, a girl in a pink dress ran through as if she brought peace, hope, and love.

From Generation to Generation

The Coolest Images From National Geographic's 2015 Photo Contest

This photo, taken by Jackson Hung, was captured during Chinese New Year’s Eve of 2015 in Taiwan.

I noticed how the light was coming into the room as our family members passed incense sticks to each other, sending our prayers and paying respects to our ancestors. The photo is symbolic, as the passing of incense sticks represents the knowledge and wisdom passed down from generation to generation.

Surrealist Painting in Nature

The Coolest Images From National Geographic's 2015 Photo Contest

Tugo Cheng earned an honorable mention award in the Places category for this gorgeous image.

As the largest system of mountain ranges in Central Asia, Tian Shan—which translates to “sky-mountain” in Chinese—has one of the best collections of natural landscapes in the world and is considered a paradise for outdoor adventures. Thanks to the richness of the land’s sediments, compounded by the power of erosion caused by rivers flowing down the mountains, the north face of Tian Shan is carved into stunning plateaus and colorful canyons hundreds of meters deep, resulting in this surrealist painting in nature.

At the Playground

The Coolest Images From National Geographic's 2015 Photo Contest

First place in the People category went to Joel Nsadha.

Bwengye lives in a slum called Kamwokya in Kampala, Uganda’s capital city. He cherishes his bicycle more than anything and brings it to this playground in the slum every evening, where he watches kids playing soccer.

Overlooking Iraq From Iran

The Coolest Images From National Geographic's 2015 Photo Contest

An honorable mention in the People category went to Yanan Li for this dramatic image.

In October 2014 in Khuzestan, Iran, I came across a group of female Iranian students on the border between Iran and Iraq. Some of them climbed up the tanks left after the war between the two countries and took pictures of themselves. I pressed the shutter when I saw this girl stretch out her arms and turn to face the Iraqi border.

Nothing to Declare

The Coolest Images From National Geographic's 2015 Photo Contest

Lars Hübner received honorable mention in the Places category.

After a family member passes away in Taiwan’s countryside, their body is kept in the house or in a tent built specifically for this purpose. After a set period of time, the deceased is given a funeral procession before their burial.

The Game

The Coolest Images From National Geographic's 2015 Photo Contest

Simone Monte took this photo at a beach in Rio.

Beachgoers kick around soccer balls on Ipanema Beach in Rio de Janeiro, Brazil, the nation that is home to la joga bonita—the beautiful game.

[ National Geographic ]


Email the author at george@gizmodo.com and follow him at @dvorsky.

Magnesium and silicon carbide recipe results in lightweight metal with record strength


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Magnesium and silicon carbide recipe results in lightweight metal with record strength

http://www.gizmag.com/magnesium-silicon-carbide-nanoparticles-strong-metal/41079/

A deformed sample of pure metal on the left, compared to the strong new metal made ...

A deformed sample of pure metal on the left, compared to the strong new metal made of magnesium with silicon carbide nanoparticles on the right (Credit: UCLA Scifacturing Laboratory)

Magnesium has a number of potential advantages when it comes to engineering. It is considered the lightest of structural metals (those capable of bearing loads in buildings and cars) and it is the eighth most abundant element in the Earth’s crust. On the flipside, however, it is not as strong and durable as some of its counterparts. Scientists are now reporting to have overcome its main limitations by infusing it with silicon carbide nanoparticles to form a new type of super-strong composite material, which they claim may lead to lighter and more efficient airplanes, spacecraft and cars.

“It’s been proposed that nanoparticles could really enhance the strength of metals without damaging their plasticity, especially light metals like magnesium, but no groups have been able to disperse ceramic nanoparticles in molten metals until now,” says Xiaochun Li, Professor of Mechanical and Aerospace Engineering at the University of California, Los Anglese (UCLA) and leader of the research team.

Previous efforts to infuse metals with microscale ceramic particles has caused a loss in the material’s plasticity. Researchers have sought to overcome this by working with ceramic particles at the nanoscale, which make the metal stronger while maintaining, or sometimes even improving, its plasticity. But this brings on other problems, as the nanoscale particles are inclined to clump together in the metal, rather than dispersing evenly.

At the heart of the UCLA team’s breakthrough is a new manufacturing approach involving the use of silicon carbide, a super-hard ceramic commonly found in industrial cutting blades. Silicon carbide nanoparticles smaller than 100 nanometers were able to be dispersed into a molten magnesium zinc alloy in such a way that the kinetic energy in the particles’ movement prevented them from clumping.

The material was then compressed using high-pressure torsion, a metal processing technique where compressive force and torsional straining are applied to the sample simultaneously. This approach has grown in popularity over the last two decades as it helps achieve a high level of strength and grain refinement, often at the nanometer level.

The resulting metal composite is made up of around 14 percent silicon carbide nanoparticles and 86 percent magnesium. In testing, the team found that it demonstrated record levels of both specific strength (how much weight a material can withstand before breaking) and stiffness-to-weight ratio. Furthermore, it also showed superior stability at high temperatures.

“The results we obtained so far are just scratching the surface of the hidden treasure for a new class of metals with revolutionary properties and functionalities,” Li says.

The research was published in the journal Nature.

Source: UCLA

A California Gas Leak Is the Biggest Environmental Disaster Since the BP Oil Spill


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A California Gas Leak Is the Biggest Environmental Disaster Since the BP Oil Spill

 http://gizmodo.com/a-california-gas-leak-is-the-biggest-environmental-disa-1749958081

A California Gas Leak Is the Biggest Environmental Disaster Since the BP Oil Spill

The largest natural gas leak ever recorded is jeopardizing health and causing evacuations for thousands of Southern California residents. And two months into it, scientists and engineers still can’t figure out a way to contain the seeping gas.

It is easily the worst environmental disaster since BP’s Deepwater Horizon oil spill in 2010. Tellingly, some experts who stopped that leak are working to contain this one.

On October 23, the Southern California Gas Company discovered a leak in its natural gas storage facility in Porter Ranch, a neighborhood about 25 miles northwest from downtown Los Angeles. Engineers don’t know what caused it, but believe that a well casing failed deep below the surface. It will take at least several more months to find the source and repair the leak, which requires careful drilling far from the tank itself to avoid igniting the gas and causing an explosion.

A California Gas Leak Is the Biggest Environmental Disaster Since the BP Oil Spill

A relief well is being connected to the leaking well in the hopes that all the gas can be diverted there while engineers try to seal the leak. (Dean Musgrove/Los Angeles Daily News via AP, Pool)

For two months the leak has been spewing natural gas into the atmosphere at up to 110,000 pounds per hour. Why is it such a big deal? Although natural gas is a better energy source than coal when it comes to emissions, in its raw form this is the same climate-destroying gas that 195 countries have been trying so hard to keep out of the atmosphere, according to a report by the Environmental Defense Fund, which is tracking the amount of gas leaked in real time:

Methane—the main component of natural gas—is a powerful short-term climate forcer, with over 80 times the warming power of carbon dioxide in the first 20 years after it is released. Methane is estimated to be leaking out of the Aliso Canyon site at a rate of about 62 million standard cubic feet, per day. That’s the same short-term greenhouse gas impact as the emissions from 7 million cars.

That’s not just bad news for local residents, who are suffering from headaches and trouble breathing (two schools have been relocated for the 2016 semester), it’s potentially devastating on a planetary scale. A spokesperson for California’s Air Resources Board told Mashable the leak is dumping the equivalent of “eight or nine coal plants” worth of methane into our already fragile climate.

http://gizmodo.com/ajax/inset/iframe?id=youtube-video-exfJ8VPQDTY&start=0

The leak itself is invisible but new infrared video shows a jet of gas pluming into the foothills, which hopefully will bring some awareness to the issue. I admit, even as a Southern California resident I didn’t understand the gravity of the situation. Let’s hope that not only the leak can be repaired soon but that the state takes swift action to ensure the safe storage and transportation of natural gas in the future. Or better yet, switch the state to entirely renewable energy sources, quick.

[Motherboard, Mashable]

New sampling device promises to make blood tests needle-free


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New sampling device promises to make blood tests needle-free

http://www.gizmag.com/hemolink-blood-tests-needle-free/37114/?li_source=LI&li_medium=default-widget

The HemoLink device can draw enough blood for certain routine tests without the need for needles ...

The HemoLink device can draw enough blood for certain routine tests without the need for needles (Photo: David Tenenbaum)

Image Gallery (2 images)

Though the pain they cause is minor and fleeting, a lot of people still find something pretty unsettling about needles. When it comes to conducting a routine blood test, US-based company Tasso Inc. believes that these unpleasant pricks can be removed from the equation completely. Its ping pong ball-sized HemoLink blood sampler can be operated by the patient at home, and needs only to be placed against the skin of the arm or abdomen for two minutes to do its job.

The roots of HemoLink can be traced back to the Tasso founders’ research in microfluids at the University of Wisconsin-Madison. It was here that observations of circulating tumor cells, immune cells and visions of a medical device startup spawned the beginnings of Tasso Inc., which has just received US$3 million in funding from the Defense Advanced Research Projects Agency (DARPA).

HemoLink is designed as a low-cost, disposable device made from as few as six injection-molded plastic parts. Inside is a vacuum, which enables a small sample of blood to be drawn from tiny open channels into a small tube through a process known as capillary action. This process is made possible by forces that dictate the flow of tiny fluid streams, even against gravity.

“At these scales, surface tension dominates over gravity, and that keeps the blood in the channel no matter how you hold the device,” says Tasso Inc.’s vice president and co-founder Ben Casavant.

The device can draw around 0.15 cubic centimeters of blood, which is enough to test for things like cholesterol, infections, cancer cells and blood sugar, before being mailed off to a lab for analysis. The company says that its target market will be people who need blood samples to be taken regularly, but not constantly, with the device being so simple to use that patients can take their own blood samples.

“We see our specialty as people who need to test semi-frequently, or infrequently, to monitor cancer or chronic infectious diseases, for example,” says Casavant.

The money from DARPA will go toward advancing the preservation of the blood. The agency hopes to get to the point where they can stabilize the blood so it can survive for one week at 140° F (60° C). This would remove the need for expensive cold-chain transportation.

Tasso Inc. plans on applying to the US Food and Drug Administration for approval at the end of this year, with hopes of bringing HemoLink to market in 2015. If this eventuates, its benefits could be two-fold: easing the pain for needle-phobic patients and making healthcare cheaper and more accessible by eliminating countless trips to the doctor.

Source: Tasso Inc.