'Star in a Jar' Fusion Reactor Works and Promises Infinite Energy
For several decades now, scientists from around the world have been pursuing a ridiculously ambitious goal: They hope to develop a nuclear fusion reactor that would generate energy in the same manner as the sun and other stars, but down here on Earth.
Incorporated into terrestrial power plants, this "star in a jar" technology would essentially provide Earth with limitless clean energy, forever. And according to new reports out of Europe this week, we just took another big step toward making it happen.
In a study published in the latest edition of the journal Nature Communications, researchers confirmed that Germany's Wendelstein 7-X (W7-X) fusion energy device is on track and working as planned. The space-age system, known as a stellerator, generated its first batch of hydrogen plasma when it was first fired up earlier this year. The new tests basically give scientists the green light to proceed to the next stage of the process.
It works like this: Unlike a traditional fission reactor, which splits atoms of heavy elements to generate energy, a fusion reactor works by fusing the nuclei of lighter atoms into heavier atoms. The process releases massive amounts of energy and produces no radioactive waste. The "fuel" used in a fusion reactor is simple hydrogen, which can be extracted from water.
However, to achieve fusion, scientists must generate enormously high temperatures to heat the hydrogen into a plasma state. The plasma is so hot, in fact, that it would instantly burn material used to contain it. That's where the stellerator design comes in. The W7-X device confines the plasma within magnetic fields generated by superconducting coils cooled down to near absolute zero. The plasma — at temperatures upwards of 80 million degrees Celsius — never comes into contact with the walls of the containment chamber. Neat trick, that.
The W7-X is the world's largest and most sophisticated stellerator and is currently operated by Max Planck Institute for Plasma Physics in Germany. But development of the W7-X has been an ongoing, international effort. The latest tests were conducted in collaboration with scientists from the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL).
David Gates, principal research physicist for the advanced projects division of PPPL, leads the agency's collaborative efforts in regard to the W7-X project. In an email exchange from his offices at Princeton, Gates said the latest tests verify that the W7-X magnetic "cage" is working as planned.
"This lays the groundwork for the exciting high-performance plasma operations expected in the near future," Gates said.
In terms of the big-picture goal, Gates said that nuclear fusion reactors, if properly developed and deployed, would provide the planet with safe, clean and virtually inexhaustible energy.
"The fuel source is found in seawater in quantities sufficient to last tens of thousands of years," he said. "The waste product is helium, an inert gas. A viable fusion reactor would provide a secure, plentiful and environmentally benign energy resource to all nations."
That last part is critical. Gates said he's encouraged by fact that the W7-X project, and nuclear fusion research in general, is the result of close collaboration among scientists from around the world.
'Fusion is a problem best solved by the peoples of all nations working together, since the entire world will benefit from it."
Ancient Space Dust Washes Up in Rooftop Gutters
Through dogged determination, Jon Larsen has become driven to find space particles, which date back to when our sun was a baby, in the urban sediment that collects in the guttering of building rooftops. And, after he convinced a British planetary scientist to study his findings, years of work have finally paid off.
In 2011, Larsen reached out to Matthew Genge, of Imperial College London, with his plan to find dust particles in this seemingly unlikely place. Though distinguishing space particles from the zoo of man-made dust particles in a city environment was considered too difficult, the hurdle didn't deter Larsen.
"It was an amateur scientist, a chap called Jon Larsen who's actually quite a well-known jazz musician in Norway, who got interested in this and started collecting all the debris that ends up in the gutter," Genge told Seeker. After going through the debris found in the roof guttering from buildings in Oslo, Paris and Berlin, Larsen would send photos of interesting particles he'd find to Genge and, despite his pessimism that Larsen would ever uncover this unlikely quarry, he eventually struck gold.
Now, with Genge's assistance, the pair have identified hundreds of particles that fell from space and have origins dating back to the birth of the solar system. Larsen documents his micrometeorite discoveries as part of Project Stardust.
"Imagine somebody who has been sending you pictures every other week of something, and every time you look at them, you're like 'no, no, no, that's not it' and then after 5 years they send you a picture and it actually is the thing that you're looking for... that was the moment I went 'oh, my God! I should pay more attention to this guy!'" Genge added.
"He's put in so much work. He went through 300 kilograms [660 lb] of sediment from gutters. That's pretty incredible."
As described in research published in the journal Geology, the duo identified 500 particles of dust that originate from asteroids and comets. But finding these cosmic artifacts in the dirt was just the beginning; their research has revealed some profound science about the space dust that is falling onto our heads right at this moment and could add another layer to our understanding about the building blocks of planets.
Our solar system is filled with dust from collisions between asteroids and venting from comets. The most visible sign of this dust encountering Earth are the meteor showers that light up the upper atmosphere as Earth orbits though one of the many dusty trails left behind these interplanetary vagabonds. However, the tiny particles that rain through the atmosphere as "shooting stars" burn up completely, leaving only a bright flash in their wake. Their journey comes to an abrupt end as a blaze of super-heated glory.
"These particles [in gutter sediment] are almost definitely not coming from meteor showers as that dust comes in too fast — it comes in at maybe 30 kilometers per second [67,000 miles per hour] — and it completely evaporates in the Earth's atmosphere," said Genges.
The gutter particles are thought to enter the atmosphere at a speed of around 12 kilometers per second (27,000 miles per hour) where atmospheric heating does inevitably heat up the particles, but the dust survives the fall. Judging by their size of around 0.3 millimeters, these are likely the fastest dust particles to survive the hot atmospheric entry, noted Genges. Through analysis of the 500 specimens, the researchers found there to be a mix of particles that originate from asteroids and others that originate from comets.
"We have found dust particles that we think come from comets and they are subtly different from those that come from asteroids ... they are carbon rich. Whereas the ones from asteroids look similar to the material from meteorites, that are also from asteroids," he added.
Separating the cosmic particles from plain old gutter dirt is no easy task, but the researchers used an important trait found in these space particles to their advantage — they contain minerals that make them magnetic. So, by magnetically separating the dirt under the microscope, these particles could be found.
"These [particles] are very similar to the cosmic dust from deep sea sediments," said Genges. "The main difference is that these are very young. Because they've been largely collected from roofs on commercial buildings, those buildings have their gutters cleaned at least every 3-5 years, so we know these [particles] have landed on Earth at least in the last 5 years. Whereas the particles found on the seabed are up to 50,000 years old. These are a sample of what's landing on Earth, practically today."
As this dust has fallen to Earth within the last 5 years, the researchers could even deduce how the solar system dust falling on Earth has changed over the last million years. The dust found in city gutters contains fewer crystals than the dust that has been found in million-year-old ice Antarctica, for example, but the particles are remarkably similar to cosmic dust that fell onto Earth in medieval times.
According to an Imperial College London press release, the researchers think that the changes in dust particle structure could be down to very small orbital changes in the solar system's planets over millions of years. The slight gravitational disturbances likely change the trajectory of the interplanetary dust, causing it to hit the Earth's atmosphere at different speeds and angles. These slight changes can therefore influence how much heating is caused by atmospheric entry which, in turn, influences the size of the particles that make it to the ground and influence the shape of the crystals inside the microscopic grains.
In short, these tiny cosmic grains of dust hold an incredible amount of information about the state of the planets' orbits when they hit Earth, but they are also the very tiny fossilized remains of our solar system, emerging directly from the material in the nebula that went on to form our sun and the planets.
"The actual materials of comets and asteroids have a very long history; they date back to the birth of our solar system four and a half billion years ago," said Genges.
When Oscar Wilde composed his famous quote, "we are all in the gutter, but some of us are looking at the stars," little did he know that, one day, a Norwegian amateur scientist would be looking for star dust in the gutter.
Why Do We Fall for Fake News
This article was originally published at The Conversation. The publication contributed the article to Live Science's Expert Voices: Op-Ed & Insights.
In recent weeks, the amount of online fake news that circulated during the final months of the presidential race is coming to light, a disturbing revelation that threatens to undermine the country's democratic process. We're already seeing some real-world consequences. After fake news stories implicated a Washington, D.C. pizza shop as the site of a Clinton-coordinated child sex ring, a man wielding an AR-15 assault rifle entered the store on Dec. 4 to "investigate" and fired shots.
Much of the analysis, however, has focused on the people who create these false articles – whether it's teenagers in Macedonia or satirical news sites – and what Facebook and Google can do to prevent its dissemination.
But fake news wouldn't be a problem if people didn't fall for it and share it. Unless we understand the psychology of online news consumption, we won't be able to find a cure for what The New York Times calls a "digital virus."
Some have said that confirmation bias is the root of the problem – the idea that we selectively seek out information that confirms our beliefs, truth be damned. But this doesn't explain why we fall for fake news about nonpartisan issues.
A more plausible explanation is our relative inattention to the credibility of the news source. I've been studying the psychology of online news consumption for over two decades, and one striking finding across several experiments is that online news readers don't seem to really care about the importance of journalistic sourcing – what we in academia refer to as "professional gatekeeping." This laissez-faire attitude, together with the difficulty of discerning online news sources, is at the root of why so many believe fake news.
Do people even consider news editors credible?
Since the earliest days of the internet, fake news has circulated online. In the 1980s there were online discussion communities called Usenet newsgroups where hoaxes would be shared among cliques of conspiracy theorists and sensation-mongers.
Sometimes these conspiracies would spill out into the mainstream. For example, 20 years ago, Pierre Salinger, President Kennedy's former press secretary, went on TV to claim that TWA Flight 800 was shot down by a U.S. Navy missile based on a document he had been emailed. But these slip-ups were rare due to the presence of TV and newspaper gatekeepers. When they did happen, they were quickly retracted if the facts didn't check out.
Today, in the age of social media, we receive news not only via email, but also on a variety of other online platforms. Traditional gatekeepers have been cast aside; politicians and celebrities have direct access to millions of followers. If they fall for fake news, any hoax can go viral, spreading via social media to millions without proper vetting and fact-checking.
Back in the 1990s, as part of my dissertation, I conducted the first-ever experiment on online news sources. I mocked up a news site and showed four groups of participants the same articles, but attributed them to different sources: news editors, a computer, other users of the online news site and the participants themselves (through a pseudo-selection task, where they thought they had chosen the news stories from a larger set).
When we asked the participants to rate the stories on attributes tied to credibility – believability, accuracy, fairness and objectivity — we were surprised to discover that all the participants made similar evaluations, regardless of the source.
They did disagree on other attributes, but none favored journalistic sourcing. For example, when a story was attributed to other users, participants actually liked reading it more. And when news editors had selected a story, participants thought the quality was worse than when other users had selected ostensibly the same story. Even the computer as the gatekeeper scored better on story quality than news editors.
The problem of layered sources
When it comes to internet news, it seems that the standing of professional news agencies – the original gatekeepers — has taken a hit. One reason could be the amount of sources behind any given news item.
Imagine checking your Facebook news feed and seeing something your friend has shared: a politician's tweet of a newspaper story. Here, there's actually a chain of five sources (newspaper, politician, Twitter, friend and Facebook). All of them played a role in transmitting the message, obscuring the identity of the original source. This kind of "source layering" is a common feature of our online news experience.
Which of these sources is most likely to resonate with readers as the "main source?"
My students and I approached this issue by analyzing news aggregator sites of varying credibility, such as Yahoo News (high credibility) and Drudge Report (low). These sites will often republish or link to articles that have originated somewhere else, so we wanted to know how often readers paid attention to original sources in the stories appearing on these websites.
We found readers will usually pay attention to the chain of sourcing only if the topic of the story is really important to them. Otherwise, they'll be swayed by the source or website that republished or posted the story – in other words, the vehicle that directly delivered them the story. It's not surprising, then, to hear people say they got their news from "sources" that don't create and edit news articles: Verizon, Comcast, Facebook and, by proxy, their friends.
When friends — and the self — become the source
When reading online news, the closest source is often one of our friends. Because we tend to trust our friends, our cognitive filters weaken, making a social media feed fertile ground for fake news to sneak into our consciousness.
The persuasive appeal of peers over experts is compounded by the fact that we tend to let our guard down even more when we encounter news in our personal space. Increasingly, most of our online destinations — whether they're portal sites (such as Yahoo News and Google News), social media sites, retail sites or search engines – have tools that allow us to customize the site, tailoring it to our own interests and identity (for example, choosing a profile photo or a news feed about one's favorite sports team).
Our research shows that internet users are less skeptical of information that appears in these customized environments. In an experiment published in the current issue of the journal Media Psychology, a former student, Hyunjin Kang, and I found that study participants who customized their own online news portal tended to agree with statements like "I think the interface is a true representation of who I am" and "I feel the website represents my core personal values."
We wanted to see if this enhanced identity changed how they processed information. So we introduced fake health news stories – about the negative effects of applying sunscreen and drinking pasteurized milk — into their portal.
We discovered that participants who had customized their news portal were less likely to scrutinize the fake news and more likely to believe it. What's more, they showed a higher tendency to act on the advice offered in the stories ("I intend to stop using sunscreen") and recommend that their friends do the same.
These findings explain why fake news thrives on Facebook and Twitter, social media sites where we're connected with our friends and have curated our own pages to reflect ourselves. Lulled into a false sense of security, we become less likely to scrutinize the information in front of us.
We can't distinguish between real news and fake news because we don't even question the credibility of the source of news when we are online.
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