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7 Things to Know About Spacewalks

On Wednesday, Oct. 28 and Friday, Nov. 6, Commander Scott Kelly and Flight Engineer Kjell Lindgren will perform spacewalks in support of space station assembly and maintenance. You can watch both of these events live on NASA Television. But, before you do, here are 7 things to know:

1. What’s the Point of a Spacewalk?

Spacewalks are important events where crew members repair, maintain and upgrade parts of the International Space Station. Spacewalks can also be referred to as an EVA – Extravehicular Activity. On Wednesday, Oct. 28, Commander Scott Kelly and Flight Engineer Kjell Lindgren will complete a spacewalk. During this time they will service the Canadarm2 robotic arm, route cables for a future docking port, and place a thermal cover over a dark matter detection experiment, which is a state-of-the-art particles physics detector that has been attached to the station since 2011.

2. What Do They Wear?

The Extravehicular Mobility Unit (EMU) spacewalking suit weighs around 350 pounds. It’s weightless in space, but mass is still very real. The EMU provides a crew member with life support and an enclosure that enables them to work outside the space station. The suit provides atmospheric containment, thermal insulation, cooling, solar radiation protection and micrometeoroid/orbital debris protection.

3. How Long Are Spacewalks?

Spacewalks typically last around 6 ½ hours, but can be extended to 7 or 8 hours, if necessary. The timeline is designed to accommodate as many tasks as possible, as spacewalks require an enormous amount of work to prepare.

4. What About Eating and Drinking?

Before a spacewalk astronauts eat light, usually something like a protein bar. The spacesuits also have a drink bag inside, and there is a bite valve that allows ready access to water.

5. What About Communication?

Spacewalkers wear a ‘comm’ cap that allows them to constantly communicate with astronauts inside the space station that are helping with the walk, and with mission control. Astronauts also wear a checklist on their left wrist called a “cuff checklist”. This list contains emergency procedures.

6. What About Light?

Something that most people don’t realize about spacewalks is that the crew will experience a sunrise/sunset every 45 minutes. Luckily, their spacesuits are equipped with lights that allow them to see in times of darkness.

7. How Do They Stay Safe?

When on a spacewalk, astronauts use safety tethers to stay close to their spacecraft. One end of the tether is hooked to the spacewalker, while the other end is connected to the vehicle. Another way astronauts stay safe is by wearing a SAFER, which is a Simplified Aid for EVA Rescue. This device is worn like a backpack and uses small jet thrusters to let an astronaut move around in space.

You can watch both of the upcoming spacewalks live on: NASA Television or the NASA App, or follow along on @Space_Station Twitter.

Wednesday, Oct. 28: Coverage begins at 6:30 a.m. EDT. Spacewalk begins at 8:10 a.m.

Friday, Nov. 6: Coverage begins at 5:45 a.m. EDT. Spacewalk begins at 7:15 a.m.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com 

Magnetic Wormhole Created in Lab

“Ripped from the pages of a sci-fi novel, physicists have crafted a wormhole that tunnels a magnetic field through space.

“This device can transmit the magnetic field from one point in space to another point, through a path that is magnetically invisible,” said study co-author Jordi Prat-Camps, a doctoral candidate in physics at the Autonomous University of Barcelona in Spain. “From a magnetic point of view, this device acts like a wormhole, as if the magnetic field was transferred through an extra special dimension.“ 

The idea of a wormhole comes from Albert Einstein’s theories. In 1935, Einstein and colleague Nathan Rosen realized that the general theory of relativity allowed for the existence of bridges that could link two different points in space-time. Theoretically these Einstein-Rosen bridges, or wormholes, could allow something to tunnel instantly between great distances (though the tunnels in this theory are extremely tiny, so ordinarily wouldn’t fit a space traveler). So far, no one has found evidence that space-time wormholes actually exist. 

The new wormhole isn’t a space-time wormhole per se, but is instead a realization of a futuristic “invisibility cloak” first proposed in 2007 in the journal Physical Review Letters. This type of wormhole would hide electromagnetic waves from view from the outside. The trouble was, to make the method work for light required materials that are extremely impractical and difficult to work with, Prat said.

But it turned out the materials to make a magnetic wormhole already exist and are much simpler to come by. In particular, superconductors, which can carry high levels of current, or charged particles, expel magnetic field lines from their interiors, essentially bending or distorting these lines. This essentially allows the magnetic field to do something different from its surrounding 3D environment, which is the first step in concealing the disturbance in a magnetic field.So the team designed a three-layer object, consisting of two concentric spheres with an interior spiral-cylinder. The interior layer essentially transmitted a magnetic field from one end to the other, while the other two layers acted to conceal the field’s existence.”

Imprisoned Molecules ‘Quantum Rattle’ in Their Cages

ScienceDaily (Aug. 20, 2012) — Scientists have discovered that a space inside a special type of carbon molecule can be used to imprison other smaller molecules such as hydrogen or water…. (read more)

Hubble Finds That the Nearest Quasar Is Powered by a Double Black Hole

The finding suggests that quasars—the brilliant cores of active galaxies – may commonly host two central supermassive black holes, which fall into orbit about one another as a result of the merger between two galaxies. Like a pair of whirling skaters, the black-hole duo generates tremendous amounts of energy that makes the core of the host galaxy outshine the glow of its population of billions of stars, which scientists then identify as quasars.

Scientists looked at Hubble archival observations of ultraviolet radiation emitted from the center of Mrk 231 to discover what they describe as “extreme and surprising properties.”

If only one black hole were present in the center of the quasar, the whole accretion disk made of surrounding hot gas would glow in ultraviolet rays. Instead, the ultraviolet glow of the dusty disk abruptly drops off toward the center. This provides observational evidence that the disk has a big donut hole encircling the central black hole. The best explanation for the donut hole in the disk, based on dynamical models, is that the center of the disk is carved out by the action of two black holes orbiting each other. The second, smaller black hole orbits in the inner edge of the accretion disk, and has its own mini-disk with an ultraviolet glow.

Read more ~ NASA.gov

Image: This artistic illustration is of a binary black hole found in the center of the nearest quasar to Earth, Markarian 231.    Credits: NASA, ESA, and G. Bacon (STScI)

Physicists Set a New Speed Record for Light-Emitting Quantum Dots

Photonic computing is closer than ever.

Researchers at Duke University have developed a light-emitting device that can be switched on and off up to 90 billion times per second. This 90 GHz is roughly twice the speed of the fastest laser diodes in existence, potentially offering a whole new level of optoelectronic computing. Central to the technology are the infinitesimal crystal beads known as quantum dots.

The computing devices we’re used to are based on shuttling electrons around via wires and switches. This has worked out pretty well through the history of computing, but electronics have limits, both in speed and in scale. Optoelectronics swap out electrons for pure light: photons. A computer based on information carried via photon is just by definition optimal, offering the literal fastest thing in the universe. Other advantages over electronic systems: less heat, less power, less noise, less information loss, less wear.

Continue Reading.

Associated Press

GENEVA — Physicists on the team that measured particles traveling faster than light said Friday they were as surprised as their skeptics about the results, which appear to violate the laws of nature as we know them.

Hundreds of scientists packed an auditorium at one of the world’s foremost laboratories on the Swiss-French border to hear how a subatomic particle, the neutrino, was found to have outrun light and confounded the theories of Albert Einstein.

“To our great surprise we found an anomaly,” said Antonio Ereditato, who participated in the experiment and speaks on behalf of the team.

An anomaly is a mild way of putting it.

Going faster than light is something that is just not supposed to happen, according to Einstein’s 1905 special theory of relativity. The speed of light — 186,282 miles per second (299,792 kilometers per second) — has long been considered a cosmic speed limit.

The team — a collaboration between France’s National Institute for Nuclear and Particle Physics Research and Italy’s Gran Sasso National Laboratory — fired a neutrino beam 454 miles (730 kilometers) underground from Geneva to Italy.

They found it traveled 60 nanoseconds faster than light. That’s sixty billionth of a second, a time no human brain could register.

“You could say it’s peanuts, but it’s not. It’s something that we can measure rather accurately with a small uncertainty,” Ereditato told The Associated Press.

If the experiment is independently repeated — most likely by teams in the United States or Japan — then it would require a fundamental rethink of modern physics.

“Everybody knows that the speed limit is c, the speed of light. And if you find some matter particle such as the neutrino going faster than light, this is something which immediately shocks everybody, including us,” said Ereditato, a researcher at the University of Bern, Switzerland.

Physicists not involved in the experiment have been understandably skeptical.

Alvaro De Rujula, a theoretical physicist at CERN, the European Organization for Nuclear Research outside Geneva from where the neutron beam was fired, said he blamed the readings on a so-far undetected human error.

If not, and it’s a big if, the door would be opened to some wild possibilities.

The average person, said De Rujula, “could, in principle, travel to the past and kill their mother before they were born.”

But Ereditato and his team are wary of letting such science fiction story lines keep them up at night.

“We will continue our studies and we will wait patiently for the confirmation,” he told the AP. “Everybody is free to do what they want: to think, to claim, to dream.”

He added: “I’m not going to tell you my dreams.”

Physicists Measure Force that Makes Antimatter Stick Together

Peering at the debris from particle collisions that recreate the conditions of the very early universe, scientists have for the first time measured the force of interaction between pairs of antiprotons. Like the force that holds ordinary protons together within the nuclei of atoms, the force between antiprotons is attractive and strong.

The experiments were conducted at theRelativistic Heavy Ion Collider (RHIC), a U.S. Department of Energy Office of Science User Facility for nuclear physics research at DOE’s Brookhaven National Laboratory. The findings, published in the journal Nature, could offer insight into larger chunks of antimatter,including antimatter nuclei previously detected at RHIC, and may also help scientists explore one of science’s biggest questions: why the universe today consists mainly of ordinary matter with virtually no antimatter to be found.

“The Big Bang—the beginning of the universe—produced matter and antimatter in equal amounts. But that’s not the world we see today. Antimatter is extremely rare. It’s a huge mystery!” said Aihong Tang, a Brookhaven physicist involved in the analysis, which used data collected by RHIC’s STAR detector. “Although this puzzle has been known for decades and little clues have emerged, it remains one of the big challenges of science. Anything we learn about the nature of antimatter can potentially contribute to solving this puzzle.”

RHIC is the perfect place to study antimatter because it’s one of the few places on Earth that is able to create the elusive stuff in abundant quantities.

RHIC is the perfect place to study antimatter because it’s one of the few places on Earth that is able to create the elusive stuff in abundant quantities. It does this by slamming the nuclei of heavy atoms such as gold into one another at nearly the speed of light. These collisions produce conditions very similar to those that filled the universe microseconds after the Big Bang—with temperatures 250,000 times hotter than the center of the sun in a speck the size of a single atomic nucleus. All that energy packed into such a tiny space creates a plasma of matter’s fundamental building blocks, quarks and gluons, and thousands of new particles—matter and antimatter in equal amounts.

“We are taking advantage of the ability to produce ample amounts of antimatter so we can conduct this study,” said Tang.

The STAR collaboration has previous experience detecting and studying rare forms of antimatter—including anti-alpha particles, the largest antimatter nuclei ever created in a laboratory, each made of two antiprotons and two antineutrons. Those experiments gave them some insight into how the antiprotons interact within these larger composite objects. But in that case, “the force between the antiprotons is a convolution of the interactions with all the other particles,” Tang said. “We wanted to study the simple interaction of unbound antiprotons to get a ‘cleaner’ view of this force.”

To do that, they searched the STAR data from gold-gold collisions for pairs of antiprotons that were close enough to interact as they emerged from the fireball of the original collision.

“We see lots of protons, the basic building blocks of conventional atoms, coming out, and we see almost equal numbers of antiprotons,” said Zhengqiao Zhang, a graduate student in Professor Yu-Gang Ma’s group from the Shanghai Institute of Applied Physics of the Chinese Academy of Sciences, who works under the guidance of Tang when at Brookhaven. “The antiprotons look just like familiar protons, but because they are antimatter, they have a negative charge instead of positive, so they curve the opposite way in the magnetic field of the detector.”

“By looking at those that strike near one another on the detector, we can measure correlations in certain properties that give us insight into the force between pairs of antiprotons, including its strength and the range over which it acts,” he added.

The scientists found that the force between antiproton pairs is attractive, just like the strong nuclear force that holds ordinary atoms together. Considering they’d already discovered bound states of antiprotons and antineutrons—those antimatter nuclei—this wasn’t all that surprising. When the antiprotons are close together, the strong force interaction overcomes the tendency of the like (negatively) charged particles to repel one another in the same way it allows positively charged protons to bind to one another within the nuclei of ordinary atoms.

In fact, the measurements show no difference between matter and antimatter in the way the strong force behaves. That is, within the accuracy of these measurements, matter and antimatter appear to be perfectly symmetric. That means, at least with the precision the scientists were able to achieve, there doesn’t appear to be some asymmetric quirk of the strong force that can account for the continuing existence of matter in the universe and the scarcity of antimatter today.

But the scientists point out that we wouldn’t know that if they hadn’t done these experiments.

“There are many ways to test for matter/antimatter asymmetry, and there are more precise tests, but in addition to precision, it’s important to test it in qualitatively different ways. This experiment was a qualitatively new test,” said Richard Lednický, a STAR scientist from the Joint Institute for Nuclear Research, Dubna, and the Institute of Physics, Czech Academy of Sciences, Prague.

“The successful implementation of the technique used in this analysis opens an exciting possibility for exploring details of the strong interaction between other abundantly produced particle species,” he said, noting that RHIC and the Large Hadron Collider (LHC) are ideally suited for these measurements, which are difficult to assess by other means.

Brookhaven National Laboratory

This Is What Happens When You Dissolve an Antacid On the Space Station

Ever see an antacid dissolve in water…in space? Read more via io9.