Science & Technology


Birth of planets revealed in astonishing detail in ALMA's "best image ever"

© National Science Foundation, A. Khan
Artist's impression of a protoplanetary disk. Newly formed planets can be seen traveling around the central host star, sweeping their orbits clear of dust and gas. These same ring-link structures were observed recently by ALMA around the young star HL Tau.
Astronomers have captured the best image ever of planet formation around an infant star as part of the testing and verification process for the Atacama Large Millimeter/submillimeter Array's (ALMA) new high-resolution capabilities.

This revolutionary new image reveals in astonishing detail the planet-forming disk surrounding HL Tau, a Sun-like star located approximately 450 light-years from Earth in the constellation Taurus.

ALMA uncovered never-before-seen features in this system, including multiple concentric rings separated by clearly defined gaps. These structures suggest that planet formation is already well underway around this remarkably young star.

"These features are almost certainly the result of young planet-like bodies that are being formed in the disk. This is surprising since HL Tau is no more than a million years old and such young stars are not expected to have large planetary bodies capable of producing the structures we see in this image," said ALMA Deputy Director Stuartt Corder.

Direct brain interface between humans

© University of Washington
In this photo, UW students Darby Losey, left, and Jose Ceballos are positioned in two different buildings on campus as they would be during a brain-to-brain interface demonstration. The sender, left, thinks about firing a cannon at various points throughout a computer game. That signal is sent over the Web directly to the brain of the receiver, right, whose hand hits a touchpad to fire the cannon.Mary Levin, U of Wash.
Sometimes, words just complicate things. What if our brains could communicate directly with each other, bypassing the need for language?

University of Washington researchers have successfully replicated a direct brain-to-brain connection between pairs of people as part of a scientific study following the team's initial demonstration a year ago. In the newly published study, which involved six people, researchers were able to transmit the signals from one person's brain over the Internet and use these signals to control the hand motions of another person within a split second of sending that signal.

At the time of the first experiment in August 2013, the UW team was the first to demonstrate two human brains communicating in this way. The researchers then tested their brain-to-brain interface in a more comprehensive study, published Nov. 5 in the journal PLOS ONE.

"The new study brings our brain-to-brain interfacing paradigm from an initial demonstration to something that is closer to a deliverable technology," said co-author Andrea Stocco, a research assistant professor of psychology and a researcher at UW's Institute for Learning & Brain Sciences. "Now we have replicated our methods and know that they can work reliably with walk-in participants."

Watch a bowling ball and feather falling in a vacuum

You probably know that two objects dropped in a vacuum fall at the same rate, no matter the mass of each item. If you've never seen a demonstration of this, then you really should, because it's incredible to watch.

Here is perhaps the perfect example, brought to us by physicist Brian Cox. He checked out NASA's Space Simulation Chamber located at the Space Power Facility in Ohio. With a volume of 22,653 cubic meters, it's the largest vacuum chamber in the world.

In this hypnotizing clip from the BBC, Cox drops a bowling ball and a feather together, first in normal conditions, and then after virtually all the air has been sucked out of the chamber. We know what happens, but that doesn't stop it from being awesome, especially with the team's ecstatic faces.


Debris-strewn exoplanetary construction yards

© NASA, ESA, G. Schneider
This is a set of images from a NASA Hubble Space Telescope survey of the architecture of debris systems around young stars. Ten previously discovered circumstellar debris systems, plus MP Mus (a mature protoplanetary disk of age comparable to the youngest of the debris disks), were studied. Hubble's sharp view uncovers an unexpected diversity and complexity in the structures. The disk-like structures are vast, many times larger than the planetary distribution in our solar system. Some disks are tilted edge-on to our view, others nearly face-on. Asymmetries and warping in the disks might be caused by the host star's passage though interstellar space. Alternatively, the disks may be affected by the action of unseen planets. In particular, the asymmetry in HD 181327 looks like a spray of material that is very distant from its host star. It might be the aftermath of a collision between two small bodies, suggesting that the unseen planetary system may be chaotic. The stars surveyed may be as young as 10 million years old and as mature as more than 1 billion years old. The visible-light survey was done with the Space Telescope Imaging Spectrograph (STIS). The STIS coronagraph blocks out the light from the host star so that the very faint reflected light from the dust structures can be seen. The images have been artificially colored to enhance detail.
Astronomers using NASA's Hubble Space Telescope have completed the largest and most sensitive visible-light imaging survey of dusty debris disks around other stars. These dusty disks, likely created by collisions between leftover objects from planet formation, were imaged around stars as young as 10 million years old and as mature as more than 1 billion years old.

"It's like looking back in time to see the kinds of destructive events that once routinely happened in our solar system after the planets formed," said survey leader Glenn Schneider of the University of Arizona's Steward Observatory. The survey's results appeared in the Oct. 1, 2014, issue of The Astronomical Journal.

Once thought to be simply pancake-like structures, the unexpected diversity and complexity and varying distribution of dust among these debris systems strongly suggest these disks are gravitationally affected by unseen planets orbiting the star. Alternatively, these effects could result from the stars' passing through interstellar space.

The researchers discovered that no two "disks" of material surrounding stars look the same. "We find that the systems are not simply flat with uniform surfaces," Schneider said. "These are actually pretty complicated three-dimensional debris systems, often with embedded smaller structures. Some of the substructures could be signposts of unseen planets." The astronomers used Hubble's Space Telescope Imaging Spectrograph to study 10 previously discovered circumstellar debris systems, plus comparatively, MP Mus, a mature protoplanetary disk of age comparable to the youngest of the debris disks.

SpaceShipTwo's fatal crash not caused by rocket engine

crash SpaceShip2
Crash site of SpaceShipTwo, Mojave, CA
It wasn't SpaceShipTwo's hybrid rocket motor -- which was flying on Friday with a new type of fuel -- that caused the fatal crash, the head of the accident investigation agency said late Sunday. The ship's fuel tanks and its engine were recovered intact, indicating there was no explosion.

"They showed no signs of burn-through, no signs of being breached," Christopher Hart, acting chairman of the National Transportation and Safety Board, told reporters at the Mojave Air and Space Port in Mojave, Calif. Instead, data and video relayed from the ship show its hallmark safety feature -- a foldable tail section designed for easy re-entry into the atmosphere from space -- was deployed early.

"The engine burn was normal up until the extension of the feathers," said Hart. Normally, the feather system wouldn't be unlocked until the rocket-powered spaceship is moving about Mach 1.4, or 1.4 times faster than the speed of sound.

Instead, the co-pilot moved the lever from locked to unlock when the spaceship was traveling at about Mach 1, Hart said. "I'm not stating that this is the cause of the mishap," he added. "We have months and months of investigation to determine what the cause was."

In addition to the possibility of pilot error, Hart said the NTSB is looking a variety of other issues that may have caused or contributed to the accident, including training, spacecraft design and the safety culture at Virgin Galactic and Scaled Composites, which designed and manufactured the spaceship. "There is much more that we don't know and our investigation is far from over," Hart said.

Comment: Variable geometry rudders can be "feathered" (rotated up 90 degrees) to increase drag and control vehicle yaw (a twisting or oscillation of a moving ship or aircraft around a vertical axis). They also reduce heating from friction. At 70,000 feet the rudders are de-feathered into gliding configuration.

Deploying the feather system is in two steps: move the lever to unlock, then move the lever to deploy. The co-pilot did the first but not the second step which is why it is called an "uncommanded" deploy. While the unlock was performed early on, they are not saying it was a pilot error that caused the crash. It is more likely a system failure of the second step, a tragic flaw unknowable by the pilot. A more thorough investigation will determine the final word on this fatal tragedy. As a totally commercial venture, the National Transportation Safety Board is the one handling the investigation.


Investigating a triple star system in formation

© ESO/L. Calçada
Artist's impression showing the gas and dust surrounding the triple star system GG Tau.
An international team of astronomers, including researchers at the LAB (CNRS/Université de Bordeaux), IPAG (CNRS/Université Joseph Fourier Grenoble 1) and IRAM (CNRS/MPG/IGN), has carried out the most accurate study so far of the cocoon of gas and dust surrounding the GG Tau A system. By combining complementary observations at submillimeter (ALMA and IRAM) wavelengths with those at infrared (VLTI/ESO) wavelengths, the researchers were able to identify the complex dynamics at work in GG Tau. For the first time, they detected motion of matter showing that exoplanets can form not only around one of the members of this trio of young stars, but also much further out in the disc surrounding the three stars. These observational findings, published in the October 30 issue of the journal Nature, reveal a more complex story than originally thought.

Although recent observational discoveries have shown the existence of many planets orbiting double stars, their formation ran up against the problem of the gravitational instabilities caused by the binary nature of such stars.. Observations of young binary stars are still too scarce to provide a detailed picture of these processes. Until very recently, GG Tau A, located 450 light years from Earth in the constellation Taurus, was thought to be a binary system of two stars, Aa and Ab. However, recent infrared measurements carried out with the VLT and VLTI (ESO) instruments have shown that GG Tau A is in fact a triple star system: GG Tau Ab is itself a binary star. The central star Aa is far enough away from the Ab pair for it to be surrounded by a circumstellar disc, first observed in 2011 with the IRAM interferometer.

Around this triple star system the researchers have already identified a rotating disc of gas and dust, whose center is cleared by gravitational tidal effects. As the three stars orbit around one another, they create an unstable gravitational region called a cavity, through which matter can only travel before falling onto the central stars. Further away, where the outer ring of matter is located, the gravitational field is no longer disturbed, and the rotating matter can form a stable structure. The existence of a central cavity around GG Tau A, known since the 1990s thanks to observations with the IRAM interferometer, partially confirmed these theoretical predictions. In the 2000s, the presence of gas in the cavity was detected, but the precise dynamics of this gas, which is the key to understanding the accretion mechanisms giving rise to planets, remained largely unknown.
Fireball 5

Newly discovered asteroid 2014 UR116 may threaten Earth

Asteroid 2014 UR116
© Reuters/NASA
Moscow University's robotic telescope has discovered a massive asteroid that could potentially hit Earth in the future. If such a collision happens, the explosion would be 1,000 more powerful the Chelyabinsk meteorite explosion in 2013.

An automatic telescope installed in Russia's Caucasus Mountains, near the city of Kislovodsk, first spotted the newly discovered space rock, dubbed 2014 UR116. The asteroid is estimated to be 370 meters in diameter, which is bigger than the size of the notorious Apophis asteroid.

Once Russian astronomers saw the new space object, they passed the data to colleagues at the Minor Planet Center of the Smithsonian Astrophysical Observatory. That means many observatories around the world closely scrutinized 2014 UR116, which helped to calculate the object's preliminary orbit.

2014 UR116's orbit is fluctuating because it also passes close to Venus and Mars, and the gravitational pull of these planets can also influence the asteroid's trajectory.

When a meteorite exploded in the skies above the Russian city of Chelyabinsk in February 2013, the energy of the explosion was estimated to be equivalent to 300-500 kilotons of TNT. But the Chelyabinsk meteorite was relatively small, about 17 meters in diameter and it disintegrated with a blast at an altitude of over 20 kilometers.
Cell Phone

How hackers use radio waves and cell phones to steal protected data

radio waves
Computers housing the world's most sensitive data are usually "air-gapped" or isolated from the internet. They're also not connected to other systems that are internet-connected, and their Bluetooth feature is disabled, too. Sometimes, workers are not even allowed to bring mobile phones within range of the computers. All of this is done to keep important data out of the hands of remote hackers.

But these security measures may be futile in the face of a new technique researchers in Israel have developed for stealthily extracting sensitive data from isolated machines - using radio frequency signals and a mobile phone.

The attack recalls a method the NSA has been secretly using for at least six years to siphon data in a similar manner. An NSA catalogue of spy tools leaked online last year describes systems that use radio frequency signals to remotely siphon data from air-gapped machines using transceivers - a combination receiver and transmitter - attached to or embedded in the computer instead of a mobile phone. The spy agency has reportedly used the method in China, Russia and even Iran. But the exact technique for doing this has never been revealed.

The researchers in Israel make no claims that theirs is the method used by the NSA, but Dudu Mimran, chief technology officer at the Israeli lab behind the research, acknowledges that if student researchers have discovered a method for using radio signals to extract data from hard-to-reach systems, professionals with more experience and resources likely have discovered it, too.

Comment: It appears as if nothing is safe anymore.


The 'plasmoelectric effect': New mechanism discovered to convert light into electricity

plasmoelectric effect
© Credits: Amolf/Tremani
Artist's impression of the plasmoelectric effect. An ultrasensitive needle measures the voltage that arises if a laser illuminates a metal nanocircuit consisting of a square matrix of miniscule holes in a thin gold film.
Researchers from FOM Institute AMOLF and the California Institute of Technology have discovered a new method for the generation of electrical potentials using light. With the help of minutely sculpted metal nanocircuits they could effectively capture light and convert it into an electrical potential of 100 millivolt. The research results are published on 30 October in the journal Science.

The AMOLF-Caltech team, which has worked together for many years, calls the newly discovered effect the 'plasmoelectric effect'. Albert Polman, leader of the AMOLF part of the team: "This is an entirely new way of converting light into electricity. We have now demonstrated that an electrical voltage can be generated; the next step is to see whether we can also collect electrical current and generate electrical power."

Small particles of precious metals such as copper, silver and gold are known to emit colourful spectrums if they are illuminated. A well-known example is stained-glass windows in old churches in which the colours are formed by small metal nanoparticles that have been enclosed in the glass. The light that shines on these particles is converted into plasmons: oscillations of the free electrons in the metal. That results in strong absorption and diffraction of certain colours of light.
Evil Rays

Ultracold disappearing act: 'Matter waves' move through one another but never share space

© Credit: Jeff Fitlow/Rice University
Physicists (from left) De Luo, Jason Nguyen and Randy Hulet observed a strange disappearing act during collisions between forms of Bose Einstein condensates called solitons. In some cases, the colliding clumps of matter appear to keep their distance even as they pass through each other.
A disappearing act was the last thing Rice University physicist Randy Hulet expected to see in his ultracold atomic experiments, but that is what he and his students produced by colliding pairs of Bose Einstein condensates (BECs) that were prepared in special states called solitons.

Hulet's team documented the strange phenomenon in a new study published online this week in the journal Nature Physics.

BECs are clumps of a few hundred thousand lithium atoms that are cooled to within one-millionth of a degree above absolute zero, a temperature so cold that the atoms march in lockstep and act as a single "matter wave." Solitons are waves that do not diminish, flatten out or change shape as they move through space. To form solitons, Hulet's team coaxed the BECs into a configuration where the attractive forces between lithium atoms perfectly balance the quantum pressure that tends to spread them out..

The researchers expected to observe the property that a pair of colliding solitons would pass though one another without slowing down or changing shape. However, they found that in certain collisions, the solitons approached one another, maintained a minimum gap between themselves, and then appeared to bounce away from the collision.

"You never see them together," said Hulet, Rice's Fayez Sarofim Professor of Physics and Astronomy. "There is always a hole, a gap that they must jump over. They pass through one another, but they never occupy the same space while they're doing that.

"It happens because of 'wave packet' interference," he said. "Think of them as waves that can have a positive or negative amplitude. One of the solitons is positive and the other is negative, so they cancel one another. The probability of them being in the spot where they meet is zero. They pass through that spot, but you never see them there."