3-D printing turns nanomachines into life-size workers

Nanomachines are tiny molecules – more than 10,000 lined up side by side would be narrower than the diameter of a human hair – that can move when they receive an external stimulus. They can already deliver medication within a body and serve as computer memories at the microscopic level. But as machines go, they haven’t been able to do much physical work – until now.

My lab has used nano-sized building blocks to design a smart material that can perform work at a macroscopic scale, visible to the eye. A 3-D-printed lattice cube made out of polymer can lift 15 times its own weight – the equivalent of a human being lifting a car.

Our polymer is able to lift an aluminum plate when chemical energy is added in the form of a solvent.

Nobel-winning roots are rotaxanes

The design of our new material is based on Nobel Prize-winning research that turned mechanically interlocked molecules into work-performing machines at nanoscale – things like molecular elevators and nanocars.

Rotaxanes are one of the most widely investigated of these molecules. These dumbbell-shaped molecules are capable of converting input energy – in the forms of light, heat or altered pH – into molecular movements. That’s how these kinds of molecular structures got the nickname “nanomachines.”

For example, in a molecule called [2]rotaxane, composed of one ring on an axle, the ring can move along the axle to perform shuttling motions.


Left, a [2]rotaxane. The ring can shuttle along the axle. Right, representation of billions of [2]rotaxanes in solution. The motions of nano-rings counteract macroscopically.
Chenfeng Ke, CC BY-ND

So far, harnessing the mechanical work of rotaxanes has been very challenging. When billions of these tiny machines are randomly oriented, the ring motions will cancel each other out, producing no useful work at a macroscale. In order to harness these molecular motions, scientists have to think about controlling their three-dimensional arrangement as well as synchronizing their motions.

Molecular beads on a string

Our design is based on a well-investigated family of molecules called polyrotaxanes. These have multiple rings on a molecular axle. In our new material, the ring is a cyclic sugar and the axle is a polymer.

If we provide an external stimulus – like adding water – these rings randomly shuttling back and forth can instead stick to each other and form a tubular array. When that happens, it changes the stiffness of the molecule. It’s like when beads are threaded onto a string; many beads slid together make the string much stronger, like a rod.


Cartoon presentation of a polyrotaxane. The rings are changed from the shuttling state, left, to the stationary state, right.
Chenfeng Ke, CC BY-ND

Our approach is to build a polymer system where billions of these molecules become stronger with added water. The strength of the whole architecture is increased and the structure can perform useful work.

In this way, we were able to get around the original problem of the random orientation of many nanomachines together. The addition of water locks them into a stationary state, therefore strengthening the whole 3-D architecture and allowing the united molecules to perform work together.

3-D printing the material

Our research is the first to add 3-D printability to mechanically interlocked molecules. It was integrating the 3-D printing technique that allowed us to transform the random shuttling motions of nano-sized rings into smart materials that perform work at macroscopic scale.

Getting the molecules all lined up in the right orientation is a way to amplify their motions. When we add water, the rings of the polyrotaxanes stick together via hydrogen bonds. The tubular arrays then stack together in a more ordered manner.

It’s much easier to get the molecules coordinated while they’re in this configuration as opposed to when the rings are all freely moving along the axle. We were able to successfully print lattice-like 3-D structures with the rings locked into position in this way. Now the molecules aren’t just randomly positioned within the material.

After 3-D-printing out the polymer, we used a photo-curing process – similar to the UV lamp that hardens nail polish at a salon – to cure it. We were left with a material that had good 3-D structural integrity and mechanical stability. Now it was ready to do some work.

Shape changing back and forth

The three-dimensional geometry of the polymer is crucial for its shape changing. A hollow structure is easier to deform than a solid one. So we designed a lattice cube structure to maximize its shape-deformation ability and, in turn, its ability to do work as it switched back and forth from one state to the other.

The next important step was being able to control the work our polymer could do.

It turns out the complex 3-D architecture of these structures can be reversibly deformed and reformed. We were able to use a solvent to switch the threaded ring structure between random shuttling and stationary states at the molecular level. Exchanging the solvent let us easily repeat this shape-changing and recovery behavior many times.


Squirting in solvent adds chemical energy to our polymer. As the solvent evaporated over time, the polyrotaxane returned to its original form.

This is how we converted chemical energy into mechanical work.

Just like moving beads to strengthen or weaken a string, this shape-changing is critical because it allows the amplification of molecular motion into macroscopic motion.

A 3-D printed lattice cube made of this smart material lifted a small coin 1.6 millimeters. The numbers may sound small for our day-to-day world, but this is a big step forward in the effort to get nanomachines doing macro work.

We hope this advance will enable scientists to further develop smart materials and devices. For example, by adding contraction and twisting to the rising motion, molecular machines could be used as soft robots performing complicated tasks similar to what a human hand can do.

Chenfeng Ke, Assistant Professor of Chemistry, Dartmouth College

Photo Credit:  Chenfeng Ke, CC BY-ND

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NASA’s Swift Mission Maps a Star’s ‘Death Spiral’ into a Black Hole

Some 290 million years ago, a star much like the sun wandered too close to the central black hole of its galaxy. Intense tides tore the star apart, which produced an eruption of optical, ultraviolet and X-ray light that first reached Earth in 2014. Now, a team of scientists using observations from NASA’s Swift satellite have mapped out how and where these different wavelengths were produced in the event, named ASASSN-14li, as the shattered star’s debris circled the black hole.

“We discovered brightness changes in X-rays that occurred about a month after similar changes were observed in visible and UV light,” said Dheeraj Pasham, an astrophysicist at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts, and the lead researcher of the study. “We think this means the optical and UV emission arose far from the black hole, where elliptical streams of orbiting matter crashed into each other.”

This animation illustrates how debris from a tidally disrupted star collides with itself, creating shock waves that emit ultraviolet and optical light far from the black hole. According to Swift observations of ASASSN-14li, these clumps took about a month to fall back to the black hole, where they produced changes in the X-ray emission that correlated with the earlier UV and optical changes.
Credits: NASA’s Goddard Space Flight Center

Astronomers think ASASSN-14li was produced when a sun-like star wandered too close to a 3-million-solar-mass black hole similar to the one at the center of our own galaxy. For comparison, the event horizon of a black hole like this is about 13 times bigger than the sun, and the accretion disk formed by the disrupted star could extend to more than twice Earth’s distance from the sun.

When a star passes too close to a black hole with 10,000 or more times the sun’s mass, tidal forces outstrip the star’s own gravity, converting the star into a stream of debris. Astronomers call this a tidal disruption event. Matter falling toward a black hole collects into a spinning accretion disk, where it becomes compressed and heated before eventually spilling over the black hole’s event horizon, the point beyond which nothing can escape and astronomers cannot observe. Tidal disruption flares carry important information about how this debris initially settles into an accretion disk.

Astronomers know the X-ray emission in these flares arises very close to the black hole. But the location of optical and UV light was unclear, even puzzling. In some of the best-studied events, this emission seems to be located much farther than where the black hole’s tides could shatter the star. Additionally, the gas emitting the light seemed to remain at steady temperatures for much longer than expected.

ASASSN-14li was discovered Nov. 22, 2014, in images obtained by the All Sky Automated Survey for SuperNovae (ASASSN), which includes robotic telescopes in Hawaii and Chile. Follow-up observations with Swift’s X-ray and Ultraviolet/Optical telescopes began eight days later and continued every few days for the next nine months. The researchers supplemented later Swift observations with optical data from the Las Cumbres Observatory headquartered in Goleta, California.

In a paper describing the results published March 15 in The Astrophysical Journal Letters, Pasham, Cenko and their colleagues show how interactions among the infalling debris could create the observed optical and UV emission.

Tidal debris initially falls toward the black hole but overshoots, arcing back out along elliptical orbits and eventually colliding with the incoming stream.

“Returning clumps of debris strike the incoming stream, which results in shock waves that emit visible and ultraviolet light,” said Goddard’s Bradley Cenko, the acting Swift principal investigator and a member of the science team. “As these clumps fall down to the black hole, they also modulate the X-ray emission there.”

Future observations of other tidal disruption events will be needed to further clarify the origin of optical and ultraviolet light.

Goddard manages the Swift mission in collaboration with Pennsylvania State University in University Park, the Los Alamos National Laboratory in New Mexico and Orbital Sciences Corp. in Dulles, Virginia. Other partners include the University of Leicester and Mullard Space Science Laboratory in the United Kingdom, Brera Observatory and the Italian Space Agency in Italy, with additional collaborators in Germany and Japan.

Related:

Scientists Identify a Black Hole Choking on Stardust (MIT)

ASASSN-14li: Destroyed Star Rains onto Black Hole, Winds Blow it Back

‘Cry’ of a Shredded Star Heralds a New Era for Testing Relativity

Researchers Detail How a Distant Black Hole Devoured a Star


Banner image:

This artist’s rendering shows the tidal disruption event named ASASSN-14li, where a star wandering too close to a 3-million-solar-mass black hole was torn apart. The debris gathered into an accretion disk around the black hole. New data from NASA’s Swift satellite show that the initial formation of the disk was shaped by interactions among incoming and outgoing streams of tidal debris.

Credit: NASA’s Goddard Space Flight Center

Editor: Karl Hille

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The latest bump in the road of Turkey’s quest to join the EU: European ultra-nationalism

The rift between Turkey and Europe is growing. From a Turkish perspective, Ankara’s long and winding quest to join the European Union, which began in 1987, has never been less likely than it is today.

President Recep Tayyip Erdoğan has invoked Nazism in his criticism of his European counterparts. And a recent dispute between the Turkish government and Dutch Prime Minister Mark Rutte over Turkish ministers campaigning in Rotterdam cast a shadow over the March 15 Netherlands election.

This is only the latest in a long history of self-defeating conflicts between Turkey and EU leaders. But this time around, the diplomatic crisis goes beyond European anti-AKP sentiments toward Turkey’s ruling party. It relates also to social and political transformations underway in the EU itself.

Turkey’s EU bid

After positive early signs, Turkey’s EU accession process stalled in 2006 when an additional protocol, related to the division of Cyprus, was implemented to the opening of Turkey’s ports and airports to trade with Cyprus.

Cyprus was partitioned in 1974, divided between the Greek Cypriots and the Turkish Cypriots. Greek Cypriots have been integrated into the EU since 2004 as the sole representatives of the whole island, while Turks there live under isolation in the Turkish Republic of Northern Cyprus, recognized only by Ankara.

In 2011, the EU Commission proposed a positive agenda for Turkey’s accession to the EU. But thanks to growing European fatigue over the enlargement of the bloc and the numerous economic and political crises it was then facing, the process again quickly ground to a halt.

By 2015 Turkey’s EU process had been revitalized while refugee migration to the EU was on the rise. However, in 2016 the EU Parliament proposed a temporary freeze on talks.

Loss of faith

Today’s EU is not as same as the one Turkey first sought to join. For Turkey, the European ideal has deteriorated as some European countries have increasingly embraced xenophobia, islamophobia, and anti-immigration sentiments.

All of these issues – which are in one way or another associated with Turkey – are discussed in the context of Turkish accession to the block. Europeans are also raising concerns about Turkey, especially after the state of emergency declared in the aftermath of the July 15 failed coup attempt.

The EU is of the view that some of the measures taken during the state of emergency pose problems for freedom of expression and rule of law in Turkey. Europe wonders whether the country is experiencing a democratic backlash.

Meanwhile, Europe’s weak response after the failed coup was disturbing for Turkish policy-makers and for President Erdoğan.

Many European leaders stayed silent during the event and in its immediate aftermath. EU officials’ later condemnation of the attempted coup was ambiguous, and they waited two months to visit Ankara.

Additionally, the failure of some EU countries to uphold European values in the context of the Arab Spring and the refugee crisis have exposed the limits of EU’s capacity to adapt itself to shifting domestic, regional and global conditions.

Turkish leaders have said several times that the refugee problem is a humanitarian crisis, warning that the EU perception of refugees as a security threat is not a solution.

Although it is true that the EU turned its eyes to the refugee crisis only when it started to be directly affected, some European countries, namely Germany, were the first to open their borders and integrate refugees. Therefore the main problem is not about a common European anti-refugee sentiment but rather the lack of a jointly undertaken, systematic European response to a crisis that’s banging up against the union’s door.

The image of a declining EU weakened by its institutions and threatened with post-Brexit disintegration seems to be growing in Turkey.

The “other” and ultra-nationalism in Europe

For Turks, this is further complicated by European foreign policy that has long perceived Turkey as the “other” in its backyard.

During the period of positive relations in the late 1990s and early 2000s, this stance was largely publicly disavowed. But more recently some EU leaders have used Turkey as a political instrument, building their strong rejection of its possible accession to the EU on this view.

The domestic and regional challeges Turkey faces – and more importantly the EU’s perception of them – have hampered the possibility of building a stable relationship with the EU and creating a new roadmap for Turkey to join the European bloc.

Another piece to this “otherness” puzzle is the rise of ultra-nationalist parties in Europe, from the National Front in France and Alternative for Germany to the Freedom Party in the Netherlands.

Opposing Turkish membership of the EU has become a useful posture for some European capitals in mustering domestic support in the age of right-wing populism. Take, for example, the dense debates on Turkey’s EU campaign during Brexit vote, and the Dutch and Austrian elections.

This anti-Turkey discourse is likely to reinforce European ultra-nationalist parties in terms of obtaining more votes from the euro-sceptical, anti-Turkey electorate. But catering to nationalist instincts also makes it harder for the EU to defend its democratic credentials and to cast judgment on Turkey’s democracy.

Finally, it is damaging the institutional and formal character of relations between a candidate country, Turkey, and an international organization, the EU. A political schism among member states prevents the EU from acting as a unified, coherent potential partner.

Countries that, like Turkey, are engaging in institutional relations with the EU, must now deal with many different leaders, all of whom represent not only the EU but also the various domestic shifts in their own countries.

A rational common ground

Derailing Turkey’s accession process is counterproductive. It distances Turkish society from European societies and cuts off existing societal, historical and cultural ties between the two sides. Today, what remains of the progressive relation between the EU and Turkey is a loose network of institutions.

This does not serve the interest of either party. It is in the direct interest of Turkey to put the progressive relations of the past back on track and draw a renewed framework based on the shared value of democracy within the EU bloc. Both parties should also boost mutual understanding by searching the possibilities of further inclusion, rather than by playing on xenophobia and exclusion.

In the short term, a renewed Turkey-EU cooperation could help Europe to manage better the consequences of the Syrian crisis.

For the EU, then, a stable, democratic and prosperous Turkey in its neighborhood acts as something of a guarantee to its members’ own economic development, security, and democracy.

And in the long term, perhaps more importantly, such rational cooperation would bring new life to the belief in internationalism in an era marked by the rise of nationalism and populism.

Emel Parlar Dal, Associate Professor of International Relations, Marmara University; Ali Murat Kurşun, Research Assistant, Marmara University, and Hakan Mehmetcik, Assistant researcher, Marmara University

Photo Credit: Middle East Monitor

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This article was originally published on The Conversation. Read the original article.

Can social media, loud and inclusive, fix world politics?

The Conversation Global’s new series, Politics in the Age of Social Media, examines how governments around the world rely on digital tools to exercise power.

Privacy is no longer a social norm, said Facebook founder Mark Zuckerberg in 2010, as social media took a leap to bring more private information into the public domain.

But what does it mean for governments, citizens and the exercise of democracy?
Donald Trump is clearly not the first leader to use his Twitter account as a way to both proclaim his policies and influence the political climate. Social media presents novel challenges to strategic policy and has become a managerial issues for many governments.

But it also offers a free platform for public participation in government affairs. Many argue that the rise of social media technologies can give citizens and observers a better opportunity to identify pitfalls of government and their politics.

As government embrace the role of social media and the influence of negative or positive feedback on the success of their project, they are also using this tool to their advantages by spreading fabricated news.

This much freedom of expression and opinion can be a double-edged sword.

A tool that triggers change

On the positive side, social media include social networking applications such as Facebook and Google+, microblogging services such as Twitter, blogs, video blogs (vlogs), wikis, and media-sharing sites such as YouTube and Flickr, among others.

Social media as a collaborative and participatory tool, connects users with each other and help shaping various communities. Playing a key role in delivering public service value to citizens it also helps people to engage in politics and policy-making, making processes easier to understand, through information and communication technologies (ICTs).

Today four out of five countries in the world have social media features on their national portals to promote interactive networking and communication with the citizen. Although we don’t have any information about the effectiveness of such tools or whether they are used to their full potential, 20% of these countries shows that they have “resulted in new policy decisions, regulation or service”.

Social media can be an effective tool to trigger changes in government policies and services if well used. It can be used to prevent corruption, as it is a direct method of reaching citizens. In developing countries, corruption is often linked to governmental services that lack automated processes or transparency in payments.

Can new technologies increase government accountability? India was ranked 79th on 176 countries by Transparency International in 2016.
Nirzardp/Wikimedia, CC BY

The UK is taking the lead on this issue. Its anti-corruption innovation hub aims to connect several stakeholders – including civil society, law enforcement, and technologies experts – to engage their efforts toward a more transparent society.

With social media, governments can improve and change the way they communicate with their citizens – and even question government projects and policies. In Kazakhstan, for example, a migration-related legislative amendment entered into force early January 2017 and compelled property owners to register people residing in their homes immediately or else face a penalty charge starting in February 2017.

Citizens were unprepared for this requirement, and many responded with indignation on social media. At first, the government ignored this reaction. However, as the growing anger soared via social media, the government took action and introduced a new service to facilitate the registration of temporary citizens.

Shaping political discourse

Increasing digital services have engaged and encourage the public to become more socially responsible and politically involved. But many governments are wary of the power that technology, and most specifically smart media, exert over how citizens’ political involvement.

Popular social media platforms like Facebook, Twitter and WhatsApp are being censored by many governments. China, South Africa and others are passing laws to regulate the social media sphere.

Availability of Youtube.com as of May 2016. May be incomplete or incorrect due to lack of information.
SurrogateSlav/Wikimedia, CC BY-NC

The dominance of social media allows citizens to have quick access to government information – information whose legitimacy may not be validated. As this happens, the organic image formed in their minds will be affected and changed and an induced image, whether negative or positive, will be formulated.

For example, the top trending topics on social media right now are related to a tweet from Wikileaks claiming that CIA can get into smart electronics – like iPhones and Samsung TVs – to spy on individuals. This series of revelations led Wikileaks founder Julian Assange to see his internet access cut off, allegedly by the government of Ecuador, in October 2016.

Julian Assange in 2014.
David G Silvers- Cancillería del Ecuador/Flickr, CC BY-SA

For his supporters, this step jeopardizes what they perceive as the voice of truth. WikiLeaks usually spread a mass of sensitive and reliable information into the public domain about politics, society and the economy.

Others state that confidential information should not be published in social media because it might endanger life and could be misinterpreted.

In 2011, social media played a crucial role in the direction of the Arab spring in Egypt, Tunisia, and Libya, enabling protesters in those countries to share information and disclose the atrocities committed by their own governments. This ignited a “domino effect” that led to mass revolts.

Governments reacted by trying to impose draconian restrictions on social media, from censorship to promoting fake new and propaganda against them.

Social networks played a vital role in initiating Egypt’s 2011 uprising.
Essam Sharaf/Wikimedia, CC BY-ND

The dissemination of uncensored information through social media has precipitated a wave of public shows of dissatisfaction, characterized by a mix of demands for better public services, changes in the institutions and instating a socially-legitimated state. Citizens use social media to meet up and interact with different groups, and some of those encounters lead to concrete actions.

Where’s the long-term fix?

But the campaigns that result do not always evolve into positive change.

Egypt and Libya are still facing several major crises over the last years, along with political instability and domestic terrorism. The social media influence that triggered the Arab Spring did not permit these political systems to turn from autocracy to democracy.

Brazil exemplifies a government’s failure to react properly to a massive social media outburst. In June 2013 people took to the streets to protest the rising fares of public transportation. Citizens channeled their anger and outrage through social media to mobilize networks and generate support.

The Brazilian government didn’t understand that “the message is the people”.
Though the riots some called the “Tropical Spring” disappeared rather abruptly in the months to come, they had a major and devastating impact on Brazil’s political power, culminating in the impeachment of President Rousseff in late 2016 and the worst recession in Brazil’s history.

As in the Arab Spring countries, the use of social media in Brazil did not result in economic improvement. The country has tumbled down into depression, and unemployment has risen to 12.6%.

The movement #Blacklivesmatter has grown immensely on social media.
The All-Nite Images/Wikimedia, CC BY-SA

Extremism, fake news and hate speech

Social media is also used to propagate “fake news” in order to destabilize an organization or a country. The spread of disinformation through social media shows how governments can use the art of communication to channel specific facts to their own citizens – or to the world.

In 2014, Russia spread conspiracy theories and fake stories, both during the Crimea crisis and the downing of Malaysia Airlines Flight 17 , to hide its military involvement in Ukraine. More recently, the Kremlin (or its agents) manipulated social media to spread “fake news” and pro-Trump messages during the American presidential election. The objective of this digital disinformation campaign was to shake the American political system, rather than to change the results of the election.

Social media also provide a powerful platform for extremism and hate speech, citizen activities that should compel government action.

Social media may have been used for extreme purposes, to topple presidents, spread calumny, and meddle in internal affairs of foreign countries. But it remains a potent technological tool that governments can use to capture and understand the needs and preferences of their citizens, and to engage them, on their own terms from the very beginning of the process as agencies develop public services.

Government typically asks “how can we adapt social media to the way in which we do e-services, and then try to shape their policies accordingly. They would be wiser to ask, “how can social media enable us to do things differently in a way they’ve never been done before?” – that is, policy-making in collaboration with people.

Rania Fakhoury, Chercheur associé à LaRIFA, Université Libanaise

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This article was originally published on The Conversation. Read the original article.

Hubble Discovery of Runaway Star Yields Clues to Breakup of Multiple-Star System

As British royal families fought the War of the Roses in the 1400s for control of England’s throne, a grouping of stars was waging its own contentious skirmish — a star war far away in the Orion Nebula.

The stars were battling each other in a gravitational tussle, which ended with the system breaking apart and at least three stars being ejected in different directions. The speedy, wayward stars went unnoticed for hundreds of years until, over the past few decades, two of them were spotted in infrared and radio observations, which could penetrate the thick dust in the Orion Nebula.

Three-panel hubble image shows star motion

This three-frame illustration shows how a grouping of stars can break apart, flinging the members into space. Panel 1: members of a multiple-star system orbiting each other. Panel 2: two of the stars move closer together in their orbits. Panel 3: the closely orbiting stars eventually either merge or form a tight binary. This event releases enough gravitational energy to propel all of the stars in the system outward, as shown in the third panel.

Credits: NASA, ESA, and Z. Levy (STScI)

Now NASA’s Hubble Space Telescope has helped astronomers find the final piece of the puzzle by nabbing a third runaway star. The astronomers followed the path of the newly found star back to the same location where the two previously known stars were located 540 years ago. The trio reside in a small region of young stars called the Kleinmann-Low Nebula, near the center of the vast Orion Nebula complex, located 1,300 light-years away.

“The new Hubble observations provide very strong evidence that the three stars were ejected from a multiple-star system,” said lead researcher Kevin Luhman of Penn State University in University Park, Pennsylvania. “Astronomers had previously found a few other examples of fast-moving stars that trace back to multiple-star systems, and therefore were likely ejected. But these three stars are the youngest examples of such ejected stars. They’re probably only a few hundred thousand years old. In fact, based on infrared images, the stars are still young enough to have disks of material leftover from their formation.”

All three stars are moving extremely fast on their way out of the Kleinmann-Low Nebula, up to almost 30 times the speed of most of the nebula’s stellar inhabitants. Based on computer simulations, astronomers predicted that these gravitational tugs-of-war should occur in young clusters, where newborn stars are crowded together. “But we haven’t observed many examples, especially in very young clusters,” Luhman said. “The Orion Nebula could be surrounded by additional fledging stars that were ejected from it in the past and are now streaming away into space.”

The team’s results will appear in the March 20, 2017 issue of The Astrophysical Journal Letters.

Luhman stumbled across the third speedy star, called “source x,” while he was hunting for free-floating planets in the Orion Nebula as a member of an international team led by Massimo Robberto of the Space Telescope Science Institute in Baltimore, Maryland. The team used the near-infrared vision of Hubble’s Wide Field Camera 3 to conduct the survey. During the analysis, Luhman was comparing the new infrared images taken in 2015 with infrared observations taken in 1998 by the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). He noticed that source x had changed its position considerably, relative to nearby stars over the 17 years between Hubble images, indicating the star was moving fast, about 130,000 miles per hour.

hubble nebula image with annotations and insets

The image by NASA’s Hubble Space Telescope shows a grouping of young stars, called the Trapezium Cluster (center). The box just above the Trapezium Cluster outlines the location of the three stars. A close-up of the stars is top right. The birthplace of the multi-star system is marked “initial position.” Two of the stars — labeled BN, and “I,” for source I — were discovered decades ago. Source I is embedded in thick dust and cannot be seen. The third star, “x,” for source x, was recently discovered to have moved noticeably between 1998 and 2015, as shown in the inset image at bottom right.

Credits: NASA, ESA, K. Luhman (Penn State University), and M. Robberto (STScI)

BN was discovered in infrared images in 1967, but its rapid motion wasn’t detected until 1995, when radio observations measured the star’s speed at 60,000 miles per hour. Source I is traveling roughly 22,000 miles per hour. The star had only been detected in radio observations; because it is so heavily enshrouded in dust, its visible and infrared light is largely blocked.

The three stars were most likely kicked out of their home when they engaged in a game of gravitational billiards, Luhman said. What often happens when a multiple system falls apart is that two of the member stars move close enough to each other that they merge or form a very tight binary. In either case, the event releases enough gravitational energy to propel all of the stars in the system outward. The energetic episode also produces a massive outflow of material, which is seen in the NICMOS images as fingers of matter streaming away from the location of the embedded source I star.

Future telescopes, such as the James Webb Space Telescope, will be able to observe a large swath of the Orion Nebula. By comparing images of the nebula taken by the Webb telescope with those made by Hubble years earlier, astronomers hope to identify more runaway stars from other multiple-star systems that broke apart.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

By The Space Telescope Science Institute (STScI) in Baltimore, Md.

Editor: Karl Hille

Photo Credit: NASA


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What’s behind phantom cellphone buzzes?

Have you ever experienced a phantom phone call or text? You’re convinced that you felt your phone vibrate in your pocket, or that you heard your ring tone. But when you check your phone, no one actually tried to get in touch with you.

You then might plausibly wonder: “Is my phone acting up, or is it me?”

Well, it’s probably you, and it could be a sign of just how attached you’ve become to your phone.

At least you’re not alone. Over 80 percent of college students we surveyed have experienced it. However, if it’s happening a lot – more than once a day – it could be a sign that you’re psychologically dependent on your cellphone.

There’s no question that cellphones are part of the social fabric in many parts of the world, and some people spend hours each day on their phones. Our research team recently found that most people will fill their downtime by fiddling with their phones. Others even do so in the middle of a conversation. And most people will check their phones within 10 seconds of getting in line for coffee or arriving at a destination.

Clinicians and researchers still debate whether excessive use of cellphones or other technology can constitute an addiction. It wasn’t included in the latest update to the DSM-5, the American Psychiatric Association’s definitive guide for classifying and diagnosing mental disorders.

But given the ongoing debate, we decided to see if phantom buzzes and rings could shed some light on the issue.

A virtual drug?

Addictions are pathological conditions in which people compulsively seek rewarding stimuli, despite the negative consequences. We often hear reports about how cellphone use can be problematic for relationships and for developing effective social skills.

One of the features of addictions is that people become hypersensitive to cues related to the rewards they are craving. Whatever it is, they start to see it everywhere. (I had a college roommate who once thought that he saw a bee’s nest made out of cigarette butts hanging from the ceiling.)

So might people who crave the messages and notifications from their virtual social worlds do the same? Would they mistakenly interpret something they hear as a ring tone, their phone rubbing in their pocket as a vibrating alert or even think they see a notification on their phone screen – when, in reality, nothing is there?

A human malfunction

We decided to find out. From a tested survey measure of problematic cellphone use, we pulled out items assessing psychological cellphone dependency. We also created questions about the frequency of experiencing phantom ringing, vibrations and notifications. We then administered an online survey to over 750 undergraduate students.

Those who scored higher on cellphone dependency – they more often used their phones to make themselves feel better, became irritable when they couldn’t use their phones and thought about using their phone when they weren’t on it – had more frequent phantom phone experiences.

Cellphone manufacturers and phone service providers have assured us that phantom phone experiences are not a problem with the technology. As HAL 9000 might say, they are a product of “human error.”

So where, exactly, have we erred? We are in a brave new world of virtual socialization, and the psychological and social sciences can barely keep up with advances in the technology.

Phantom phone experiences may seem like a relatively small concern in our electronically connected age. But they raise the specter of how reliant we are on our phones – and how much influence phones have in our social lives.

How can we navigate the use of cellphones to maximize the benefits and minimize the hazards, whether it’s improving our own mental health or honing our live social skills? What other new technologies will change how we interact with others?

Our minds will continue to buzz with anticipation.

Daniel J. Kruger, Research Assistant Professor, University of Michigan

Photo Credit: ‘Brain’ via http://www.shutterstock.com

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This article was originally published on The Conversation. Read the original article.

Relativistic Electrons Uncovered with NASA’s Van Allen Probes

Earth’s radiation belts, two doughnut-shaped regions of charged particles encircling our planet, were discovered more than 50 years ago, but their behavior is still not completely understood. Now, new observations from NASA’s Van Allen Probes mission show that the fastest, most energetic electrons in the inner radiation belt are not present as much of the time as previously thought. The results are presented in a paper in the Journal of Geophysical Research and show that there typically isn’t as much radiation in the inner belt as previously assumed — good news for spacecraft flying in the region.

Since their discovery at the dawn of the Space Age, Earth’s radiation belts continue to reveal new complex structures and behaviors. This visualization shows how the radiation belts change in response to the injection of electrons from a storm in late June 2015. Red colors indicate higher numbers of electrons.
Credits: NASA’s Goddard Space Flight Center/Tom Bridgman

Past space missions have not been able to distinguish electrons from high-energy protons in the inner radiation belt. But by using a special instrument, the Magnetic Electron and Ion Spectrometer — MagEIS — on the Van Allen Probes, the scientists could look at the particles separately for the first time. What they found was surprising —there are usually none of these super-fast electrons, known as relativistic electrons, in the inner belt, contrary to what scientists expected.

“We’ve known for a long time that there are these really energetic protons in there, which can contaminate the measurements, but we’ve never had a good way to remove them from the measurements until now,” said Seth Claudepierre, lead author and Van Allen Probes scientist at the Aerospace Corporation in El Segundo, California.

Of the two radiation belts, scientists have long understood the outer belt to be the rowdy one. During intense geomagnetic storms, when charged particles from the sun hurtle across the solar system, the outer radiation belt pulsates dramatically, growing and shrinking in response to the pressure of the solar particles and magnetic field.  Meanwhile, the inner belt maintains a steady position above Earth’s surface. The new results, however, show the composition of the inner belt isn’t as constant as scientists had assumed.

Ordinarily, the inner belt is composed of high-energy protons and low-energy electrons. However, after a very strong geomagnetic storm in June 2015, relativistic electrons were pushed deep into the inner belt.

The findings were visible because of the way MagEIS was designed. The instrument creates its own internal magnetic field, which allows it to sort particles based on their charge and energy. By separating the electrons from the protons, the scientists could understand which particles were contributing to the population of particles in the inner belt.

“When we carefully process the data and remove the contamination, we can see things that we’ve never been able to see before,” said Claudepierre. “These results are totally changing the way we think about the radiation belt at these energies.”

triptych of Van Allen Belt depictions, pre-, during and post-solar storm
During a strong geomagnetic storm, electrons at relativistic energies, which are usually only found in the outer radiation belt, are pushed in close to Earth and populate the inner belt. While the electrons in the slot region quickly decay, the inner belt electrons can remain for many months.
Credits: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith

Given the rarity of the storms, which can inject relativistic electrons into the inner belt, the scientists now understand there to typically be lower levels of radiation there — a result that has implications for spacecraft flying in the region. Knowing exactly how much radiation is present may enable scientists and engineers to design lighter and cheaper satellites tailored to withstand the less intense radiation levels they’ll encounter.

In addition to providing a new outlook on spacecraft design, the findings open a new realm for scientists to study next.

“This opens up the possibility of doing science that previously was not possible,” said Shri Kanekal, Van Allen Probes deputy mission scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, not involved with the study. “For example, we can now investigate under what circumstances these electrons penetrate the inner region and see if more intense geomagnetic storms give electrons that are more intense or more energetic.”

The Van Allen Probes is the second mission in NASA’s Living with a Star Program and one of many NASA heliophysics missions studying our near-Earth environment. The spacecraft plunge through the radiation belts five to six times a day on a highly elliptical orbit, in order to understand the physical processes that add and remove electrons from the region.

Related

Editor: Rob Garner

 

Photo Credit: NASA

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