Hubble Movies Provide Unprecedented View of Supersonic Jets from Young Stars

The glowing, clumpy streams of material shown in these NASA/ESA Hubble Space Telescope images are the signposts of star birth. Ejected episodically by young stars like cannon salvos, the blobby material zips along at more than 700 000 kilometres per hour. The speedy jets are confined to narrow beams by the powerful stellar magnetic field. Called Herbig-Haro or HH objects, these outflows have a bumpy ride through space. When fast-moving blobs collide with slower-moving gas, bow shocks arise as the material heats up. Bow shocks are glowing waves of material similar to waves produced by the bow of a ship ploughing through water. In HH 2, at lower right, several bow shocks can be seen where several fast-moving clumps have bunched up like cars in a traffic jam. In HH 34, at lower left, a grouping of merged bow shocks reveals regions that brighten and fade over time as the heated material cools where the shocks intersect. In HH 47, at top, the blobs of material look like a string of cars on a crowded motorway, which ends in a chain-reaction accident. The smash up creates the bow shock, left. These images are part of a series of time-lapse movies astronomers have made showing the outflows’ motion over time. The movies were stitched together from images taken over a 14-year period by Hubble’s Wide Field Planetary Camera 2. Hubble followed the jets over three epochs: HH 2 from 1994, 1997, and 2007; HH 34 from 1994, 1998, and 2007; and HH 47 from 1994, 1999, and 2008. The outflows are roughly 1350 light-years from Earth. HH 34 and HH 2 reside near the Orion Nebula, in the northern sky. HH 47 is located in the southern constellation of Vela. (Credit: NASA, ESA, and P. Hartigan (Rice University))

Science Daily — Stars aren't shy about sending out birth announcements. They fire off energetic jets of glowing gas travelling at supersonic speeds in opposite directions through space. Although astronomers have looked at still pictures of stellar jets for decades, now they can watch movies, thanks to the NASA/ESA Hubble Space Telescope.

An international team of scientists led by astronomer Patrick Hartigan of Rice University in Houston, USA, has collected enough high-resolution Hubble images over a 14-year period to stitch together time-lapse movies of young jets ejected from three stars.

The moving pictures offer a unique view of stellar phenomena that move and change over just a few years. Most astronomical processes change over timescales that are much longer than a human lifetime.

The movies reveal the motion of the speedy outflows as they tear through the interstellar environments. Never-before-seen details in the jets' structure include knots of gas brightening and dimming and collisions between fast-moving and slow-moving material, creating glowing arrowhead features. These phenomena are providing clues about the final stages of a star's birth, offering a peek at how the Sun behaved 4.5 billion years ago.

"For the first time we can actually observe how these jets interact with their surroundings by watching these time-lapse movies," said Hartigan. "Those interactions tell us how young stars influence the environments out of which they form. With movies like these, we can now compare observations of jets with those produced by computer simulations and laboratory experiments to see which aspects of the interactions we understand and which we don't understand."

Hartigan's team's results appear in the 20 July 2011 issue of the Astrophysical Journal.

Jets are an active, short-lived phase of star formation, lasting only about 100 000 years. They are called Herbig-Haro (HH) objects, named after George Herbig and Guillermo Haro, who studied the outflows in the 1950s. Astronomers still don't know what role jets play in the star formation process or exactly how the star unleashes them.

A star forms from a collapsing cloud of cold hydrogen gas. As the star grows, it gravitationally attracts more matter, creating a large spinning disc of gas and dust around it. Eventually, planets may arise within the disc as dust clumps together.

The disc material gradually spirals onto the star and escapes as high velocity jets along the star's axis of spin. The speedy jets are confined to narrow beams by the star's powerful magnetic field. The jet phase stops when the disc runs out of material, usually a few million years after the star's birth.

Hartigan and his colleagues used Hubble's Wide Field Planetary Camera 2 to study jets HH 1, HH 2, HH 34, HH 46, and HH 47. HH 1-HH 2 and HH 46-HH 47 are pairs of jets emanating in opposite directions from single stars. Hubble followed the jets over three epochs: HH 1 and HH 2 in 1994, 1997, and 2007; HH 34 in 1994, 1998, and 2007; and HH 46 and HH 47 in 1994, 1999, and 2008. The jets are roughly ten times the width of the Solar System and zip along at more than 700 000 kilometres per hour.

All of the outflows are roughly 1350 light-years from Earth. HH 34, HH 1, and HH 2 reside near the Orion Nebula, in the northern sky. HH 46 and HH 47 are in the southern constellation of Vela (The Sails).

Computer software has woven together these observations, taken over many years, and generated movies that show continuous motion. The movies support previous observations which revealed that the twin jets are not ejected in a steady stream, like water flowing from a garden hose. Instead, they are launched sporadically in clumps. The beaded-jet structure might be like a "ticker tape," recording episodes when material fell onto the star.

The movies show that the clumpy gas in the jets is moving at different speeds like traffic on a motorway. When fast-moving blobs collide with gas in the slow lane, bow shocks arise as the material heats up. Bow shocks are glowing waves of material similar to waves produced by the bow of a ship ploughing through water. In HH 2, for example, several bow shocks can be seen where several fast-moving clumps have bunched up like cars in a traffic jam. In another jet, HH 34, a grouping of merged bow shocks reveals regions that brighten and fade over time as the heated material cools where the shocks intersect.

In other areas of the jets, bow shocks form from encounters with the surrounding dense gas cloud. In HH 1 a bow shock appears at the top of the jet as it grazes the edge of a dense gas cloud. New glowing knots of material also appear. These knots may represent gas from the cloud being swept up by the jet, just as a swift-flowing river pulls along mud from the shoreline.

The movies also provide evidence that the inherent clumpy nature of the jets begins near the newborn stars. In HH 34 Hartigan traced a glowing knot to within about 14 billion kilometres of the star.

"Taken together, our results paint a picture of jets as remarkably diverse objects that undergo highly structured interactions between material within the outflow and between the jet and the surrounding gas," Hartigan explained. "This contrasts with the bulk of the existing simulations which depict jets as smooth systems."

The details revealed by Hubble were so complex that Hartigan consulted with experts in fluid dynamics from Los Alamos National Laboratory in New Mexico, the UK Atomic Weapons Establishment, and General Atomics in San Diego, California, as well as computer specialists from the University of Rochester in New York. Motivated by the Hubble results, Hartigan's team is now conducting laboratory experiments at the Omega Laser facility in New York to understand how supersonic jets interact with their environment.

"The fluid dynamicists immediately picked up on an aspect of the physics that astronomers typically overlook, and that led to a different interpretation for some of the features we were seeing," Hartigan explains. "The scientists from each discipline bring their own unique perspectives to the project, and having that range of expertise has proved invaluable for learning about this critical phase of stellar evolution."

[1] The international team of astronomers in this study consists of Patrick Hartigan (Rice University, Texas, USA), Adam Frank (University of Rochester, New York, USA); John Foster (Atomic Weapons Establishment, Aldermaston, UK); Paula Rosen (Atomic Weapons Establishment, Aldermaston, UK); Bernie Wilde (Los Alamos National Laboratory, New Mexico, USA); Rob Coker (Los Alamos National Laboratory, New Mexico, USA); Melissa Douglas (Los Alamos National Laboratory, New Mexico, USA); Brent Blue (General Atomics, San Diego, California, USA) and Freddy Hansen (General Atomics, San Diego, California, USA).

Videos 

Stellar jet HH 47

This video shows the evolution over time of Herbig-Haro object HH 47, a jet expelled from a newborn star in the southern constellation of Vela. The video was made by stitching together observations of HH 47 made in 1994, 1999 and 2008.

Credit:

NASA, ESA, P. Hartigan (Rice University), G. Bacon (STScI)

Bow shock in stellar jet HH 47

This video shows a close-up of a bow shock in Herbig-Haro object HH 47, a jet expelled from a newborn star in the southern constellation of Vela. Bow shocks like this are similar to the bow wave caused by a boat moving through water. They are produced by fast-moving material from the star colliding with slower-moving material.

The video was made by stitching together observations of HH 47 made in 1994, 1999 and 2008.

Credit:

NASA, ESA, P. Hartigan (Rice University), G. Bacon (STScI)

Bow shock in stellar jet HH 34

This video shows a close-up of a bow shock in Herbig-Haro object HH 34, a jet expelled from a newborn star in the constellation of Orion. Bow shocks like this are similar to the bow wave caused by a boat moving through water. They are produced by fast-moving material from the star colliding with slower-moving material.

The video was made by stitching together observations of HH 34 made in 1994, 1998 and 2007.

Credit:

NASA, ESA, P. Hartigan (Rice University), G. Bacon (STScI)

Tiny Oxygen Generators Boost Effectiveness of Anticancer Treatment

Researchers have created and tested a miniature device, seen here, that can be implanted in tumors to generate oxygen, boosting the killing power of radiation and chemotherapy. The technology is designed to treat solid tumors that are hypoxic at the center, meaning the core contains low oxygen levels. The device (right) fits inside a tube (left) that can then be inserted into a tumor with a biopsy needle. (Credit: Birck Nanotechnology Center, Purdue University)

Science Daily  — Researchers have created and tested miniature devices that are implanted in tumors to generate oxygen, boosting the killing power of radiation and chemotherapy.

"This is not good because radiation therapy needs oxygen to be effective," said Babak Ziaie, a Purdue University professor of electrical and computer engineering and biomedical engineering. "So the hypoxic areas are hard to kill. Pancreatic and cervical cancers are notoriously hypoxic. If you generate oxygen you can increase the effectiveness of radiation therapy and also chemotherapy."

The technology is designed to treat solid tumors that are hypoxic at the center, meaning the core contains low oxygen levels.

The new "implantable micro oxygen generator" is an electronic device that receives ultrasound signals and uses the energy to generate a small voltage to separate oxygen and hydrogen from water ╨ a chemical operation called water electrolysis.

"We are putting these devices inside tumors and then exposing the tumors to ultrasound," Ziaie said. "The ultrasound energy powers the device, generating oxygen.

The devices were created at the Birck Nanotechnology Center in the university's Discovery Park. Purdue researchers are working with Song-Chu (Arthur) Ko, an assistant professor of clinical radiation oncology at the Indiana University School of Medicine.

Researchers have tested the devices in pancreatic tumors implanted in mice, showing they generated oxygen and shrunk tumors faster than tumors without the devices. The devices are slightly less than one centimeter long and are inserted into tumors with a hypodermic biopsy needle.

"Most of us have been touched by cancer in one way or another," Ziaie said. "My father is a cancer survivor, and he went through many rounds of very painful chemotherapy. This is a new technology that has the potential to improve the effectiveness of such therapy."

Findings are detailed in a research paper appearing online this month in Transactions on Biomedical Engineering. The paper was written by research assistant professor Teimour Maleki, doctoral students Ning Cao and Seung Hyun Song, Ko and Ziaie.

"The implantable mini oxygen generator project is one of 11 projects the Alfred Mann Institute for Biomedical Development at Purdue University (AMIPurdue) has sponsored," Ziaie said. "AMIPurdue has been instrumental in providing the development funding of roughly $500,000 on this project. And beyond funding, the AMIPurdue team has also helped us with market research, physician feedback, industry input, as well as intellectual property and regulatory strategy. We have been able to accomplish a great deal in a short time due to the collaborative effort with AMIPurdue."

A patent application has been filed for the design.

Future work may focus on redesigning the device to make it more practical for manufacturing and clinical trials.

'Gene Overdose' Causes Extreme Thinness

Artist's rendering of chromosomes. Researchers have identified that duplication of a part of chromosome 16 is associated with being underweight. (Credit: © Sebastian Kaulitzki / Fotolia)

Science Daily  — Scientists have discovered a genetic cause of extreme thinness for the first time, in a study published August 30 in the journal Nature. The research shows that people with extra copies of certain genes are much more likely to be very skinny. In one in 2000 people, part of chromosome 16 is duplicated, making men 23 times and women five times more likely to be underweight.

In a study examining the DNA of over 95,000 people, researchers at Imperial College London and the University of Lausanne have identified that duplication of a part of chromosome 16 is associated with being underweight, defined as a a body mass index below 18.5. Half of all children with the duplication in the study have been diagnosed with a 'failure to thrive', meaning that their rate of weight gain is significantly lower than normal. A quarter of people with the duplication have microcephaly, a condition in which the head and brain are abnormally small, which is associated with neurological defects and shorter life expectancy. Last year, the same researchers discovered that people with a missing copy of these genes are 43 times more likely to be morbidly obese.

Each person normally has a copy of each chromosome from each parent, so we have two copies of each gene. But sometimes sections of a chromosome can be duplicated or deleted, resulting in an abnormal 'dosage' of genes.

Professor Philippe Froguel, from the School of Public Health at Imperial College London, who led the study, said: "The dogma is that we have two copies of each gene, but this isn't really true. The genome is full of holes where genes are lost, and in other places we have extra copies of genes. In many cases, duplications and deletions have no effect, but occasionally they can lead to disease.

"So far, we have discovered a large number of genetic changes that lead to obesity. It seems that we have plenty of systems that increase appetite since eating is so important -- you can suppress one and nothing happens. This is the first genetic cause of extreme thinness that has been identified.

"One reason this is important is that it shows that failure to thrive in childhood can be genetically driven. If a child is not eating, it's not necessarily the parents' fault.

"It's also the first example of a deletion and a duplication of one part of the genome having opposite effects. At the moment we don't know anything about the genes in this region. If we can work out why gene duplication in this region causes thinness, it might throw up new potential treatments for obesity and appetite disorders. We now plan to sequence these genes and find out what they do, so we can get an idea of which ones are involved in regulating appetite."

The part of chromosome 16 identified in the study contains 28 genes. Duplications in this region have previously been linked with schizophrenia, and deletions with autism.

The study was funded by the Medical Research Council, the Wellcome Trust, and other sources.

Cutting Soot Emissions: Fastest, Most Economical Way to Slow Global Warming?

Reducing soot emissions from diesel engines and other sources could slow melting of sea ice in the Arctic faster and more economically than any other quick fix, new research suggests. (Credit: © lustil / Fotolia)

Science Daily  — A new study of dust-like particles of soot in the air -- now emerging as the second most important, but previously overlooked, factor in global warming -- provides fresh evidence that reducing soot emissions from diesel engines and other sources could slow melting of sea ice in the Arctic faster and more economically than any other quick fix, a scientist reported in Denver, Colorado on August 31, 2011.

In a presentation at the 242nd National Meeting & Exposition of the American Chemical Society (ACS), Mark Z. Jacobson, Ph.D., cited concerns that continued melting of sea ice above the Arctic Circle will be a tipping point for Earth's climate, a point of no return. That's because the ice, which reflects sunlight and heat back into space, would give way to darker water that absorbs heat and exacerbates warming. And there is no known way to make the sea refreeze in the short term.

Jacobson's calculations indicate that controlling soot could reduce warming above parts of the Arctic Circle by almost 3 degrees Fahrenheit within 15 years. That would virtually erase all of the warming that has occurred in the Arctic during the last 100 years.

"No other measure could have such an immediate effect," said Jacobson, who is with Stanford University. "Soot emissions are second only to carbon dioxide (CO₂) in promoting global warming, but its effects have been underestimated in previous climate models. Consequently, soot's effect on climate change has not been adequately addressed in national and international global warming legislation. Soot emissions account for about 17 percent of global warming, more than greenhouse gases like methane. Soot's contribution, however, could be reduced by 90 percent in 5-10 years with aggressive national and international policies."

Soot or "black carbon" consists of particles, nearly invisible on an individual basis, released in smoke from combustion of fossil fuels and biofuels. Major sources include exhaust from diesel cars, buses, trucks, ships, aircraft, agricultural machines, construction equipment and the wood/animal dung fires that hundreds of millions of people in developing countries use for used for cooking and heating. Black carbon particles become suspended in the atmosphere and absorb sunlight, just like a black t-shirt on a sunny day. The particles then radiate that heat back into the air around it. Black carbon also can absorb light reflected from Earth's surface, which helps make it such a potent warming agent.

The good news is that decreasing soot could have a rapid effect, Jacobson said. Unlike carbon dioxide, which remains in the atmosphere for years, soot disappears within a few weeks, so that there is no long-term reservoir with a continuing warming effect. And the technology for controlling black carbon, unlike that for controlling CO₂, already is available at relatively modest cost. Diesel particulate filters, for instance, can remove soot from car and truck exhaust. Government and other agencies also are trying to introduce low-soot cookstoves in developing countries. "Converting gasoline- and diesel-burning cars and trucks to electric or hydrogen vehicles and reducing emissions from diesel generators could have an immediate effect on warming," according to Jacobson.

Jacobson, who developed the first detailed climate model to include the global effects of soot, reported on use of the model to gain new insights into the effects of soot particles trapped inside and between the water droplets that make up clouds. Previous research on black carbon and climate overlooked that topic. Jacobson said the information is important because black carbon within clouds makes the clouds "burn off" and disappear over heavily polluted urban and other areas. Climate models that ignore this "cloud absorption" phenomenon underestimate the effects of black carbon on climate.

The Star That Should Not Exist

At the center of this picture is a very unremarkable looking faint star, too faint to be seen through all but the largest amateur telescopes. This ancient star, in the constellation of Leo (The Lion), is called SDSS J102915+172927 and has been found to have the lowest amount of elements heavier than helium of all stars yet studied. It has a mass smaller than that of the Sun and is probably more than 13 billion years old. (Credit: ESO/Digitized Sky Survey 2)

Science Daily — A faint star in the constellation of Leo (The Lion), called SDSS J102915+172927 [1], has been found to have the lowest amount of elements heavier than helium (what astronomers call "metals") of all stars yet studied. It has a mass smaller than that of the Sun and is probably more than 13 billion years old.

"A widely accepted theory predicts that stars like this, with low mass and extremely low quantities of metals, shouldn't exist because the clouds of material from which they formed could never have condensed," [2] said Elisabetta Caffau (Zentrum fur Astronomie der Universitat Heidelberg, Germany and Observatoire de Paris, France), lead author of the paper. "It was surprising to find, for the first time, a star in this 'forbidden zone', and it means we may have to revisit some of the star formation models."

The team analysed the properties of the star using the X-shooter and UVES instruments on the VLT [3]. This allowed them to measure how abundant the various chemical elements were in the star. They found that the proportion of metals in SDSS J102915+172927 is more than 20 000 times smaller than that of the Sun [4][5].

"The star is faint, and so metal-poor that we could only detect the signature of one element heavier than helium -- calcium -- in our first observations," said Piercarlo Bonifacio (Observatoire de Paris, France), who supervised the project. "We had to ask for additional telescope time from ESO's Director General to study the star's light in even more detail, and with a long exposure time, to try to find other metals."

Cosmologists believe that the lightest chemical elements -- hydrogen and helium -- were created shortly after the Big Bang, together with some lithium [6], while almost all other elements were formed later in stars. Supernova explosions spread the stellar material into the interstellar medium, making it richer in metals. New stars form from this enriched medium so they have higher amounts of metals in their composition than the older stars. Therefore, the proportion of metals in a star tells us how old it is.

"The star we have studied is extremely metal-poor, meaning it is very primitive. It could be one of the oldest stars ever found," adds Lorenzo Monaco (ESO, Chile), also involved in the study.

Also very surprising was the lack of lithium in SDSS J102915+172927. Such an old star should have a composition similar to that of the Universe shortly after the Big Bang, with a few more metals in it. But the team found that the proportion of lithium in the star was at least fifty times less than expected in the material produced by the Big Bang.

"It is a mystery how the lithium that formed just after the beginning of the Universe was destroyed in this star." Bonifacio added.

The researchers also point out that this freakish star is probably not unique. "We have identified several more candidate stars that might have metal levels similar to, or even lower than, those in SDSS J102915+172927. We are now planning to observe them with the VLT to see if this is the case," concludes Caffau.

Notes

[1] The star is catalogued in the Sloan Digital Sky Survey or SDSS. The numbers refer to the object's position in the sky.

[2] Widely accepted star formation theories state that stars with a mass as low as SDSS J102915+172927 (about 0.8 solar masses or less) could only have formed after supernova explosions enriched the interstellar medium above a critical value. This is because the heavier elements act as "cooling agents," helping to radiate away the heat of gas clouds in this medium, which can then collapse to form stars. Without these metals, the pressure due to heating would be too strong, and the gravity of the cloud would be too weak to overcome it and make the cloud collapse. One theory in particular identifies carbon and oxygen as the main cooling agents, and in SDSS J102915+172927 the amount of carbon is lower than the minimum deemed necessary for this cooling to be effective.

[3] X-shooter (http://www.eso.org/public/news/eso0920/) and UVES (http://www.eso.org/sci/facilities/paranal/instruments/uves/) are VLT spectrographs -- instruments used to separate the light from celestial objects into its component colours and allow detailed analysis of the chemical composition. X-shooter can capture a very wide range of wavelengths in the spectrum of an object in one shot (from the ultraviolet to the near-infrared). UVES is the Ultraviolet and Visual Echelle Spectrograph, a high-resolution optical instrument.

[4] The star HE 1327-2326, discovered in 2005, has the lowest known iron abundance, but it is rich in carbon. The star now analysed has the lowest proportion of metals when all chemical elements heavier than helium are considered.

[5] ESO telescopes have been deeply involved in many of the discoveries of the most metal-poor stars. Some of the earlier results were reported in eso0228 (http://www.eso.org/public/news/eso0920/) and eso0723 (http://www.eso.org/public/news/eso0723/) and the new discovery shows that observations with ESO telescopes have let astronomers make a further step closer to finding the first generation of stars.

[6] Primordial nucleosynthesis refers to the production of chemical elements with more than one proton a few moments after the Big Bang. This production happened in a very short time, allowing only hydrogen, helium and lithium to form, but no heavier elements. The Big Bang theory predicts, and observations confirm, that the primordial matter was composed of about 75% (by mass) of hydrogen, 25% of helium, and trace amounts of lithium.

More information

This research was presented in a paper, "An extremely primitive halo star," by Caffau et al. to appear in the 1 September 2011 issue of the journal Nature.

The team is composed of Elisabetta Caffau (Zentrum fur Astronomie der Universitat Heidelberg [ZAH], Germany and GEPI -- Observatoire de Paris, Universite Paris Diderot, CNRS, France [GEPI]), Piercarlo Bonifacio (GEPI), Patrick François (GEPI and Universite de Picardie Jules Verne, Amiens, France), Luca Sbordone (ZAH, Max-Planck Institut fur Astrophysik, Garching, Germany, and GEPI), Lorenzo Monaco (ESO, Chile), Monique Spite (GEPI), François Spite (GEPI), Hans-G. Ludwig (ZAH and GEPI), Roger Cayrel (GEPI), Simone Zaggia (INAF, Osservatorio Astronomico di Padova, Italy), François Hammer (GEPI), Sofia Randich (INAF, Osservatorio Astrofisico di Arcetri, Firenze, Italy), Paolo Molaro (INAF, Osservatorio Astronomico di Trieste, Italy), and Vanessa Hill (Universite de Nice-Sophia Antipolis, Observatoire de la Cote d'Azur, CNRS, Laboratoire Cassiopee, Nice, France).

You Will Actually Be Able to Buy Sony's Crazy 3-D Head-Mounted Display

By Dan Nosowitz

Sony HMZ-T1 Sony

We caught a preview of Sony's odd, space-agey head-mounted viewer (appealingly named the HMZ-T1) back at CES in January, but we were pretty surprised to learn that not only is it not a mere demo, Sony's actually planning on, like, putting the thing in stores, where you can exchange currency for it and then take it home. Sony claims it offers an incredibly immersive 3-D experience, better than any TV. We've now played with it twice, and in some ways, that's true.

The idea here is for a personal, extremely high-definition 3-D display. It looks something like a visor, and has two small screens (one in front of each eye) along with non-replaceable headphones. A cable, both for power and data, runs from the headset to a small black box, about the size of a Nintendo Wii, which in turn plugs into any gadget you want (though Sony would undoubtedly prefer you use a PS3 or Blu-ray player). It'll cost somewhere between $750 and $800 when it's released this fall, but the experience--for one person--should be a bargain, compared to buying a high-end 3-D HDTV and stereo.

The HMZ-T1 is particularly notable because its screens use OLED displays--OLEDs are increasingly used for smaller gadgets like smartphones, due to the screen tech's clarity and deep, dark blacks, but get exponentially more expensive the bigger they get, to the point where the biggest OLED displays are only around 30 inches big and cost tens of thousands of dollars. But the HMZ-T1 uses two 0.7-inch OLEDs, close enough to your face that it appears about the same size as a 150-inch screen at 12 feet--basically, you can't see anything but the screen, and that screen is a very premium OLED.

Sound comes in the form of built-in headphones that slide down from the headset, providing 5.1 surround sound. In our previews, they sounded pretty good, and were comfortable enough, but keep in mind that you're stuck with these--there's no way to use your own headphones, let alone plug into a stereo.

So how does it feel to watch a movie or play a video game with the display strapped to your face? Mostly okay, really, with a few moments of "this feels weird." The 3-D is some of the better quality I've come across on a home system, though I did come away with a slight headache (admittedly, I'm particularly susceptible to 3-D-induced pain). The headset itself is pretty heavy, especially on the nose, where too much of the weight rests--I'm not sure how it'd fare for a two-hour movie. But the back is adjustable, and others seemed to find it more comfortable than I did.

What I wonder is who this is for--it can only be used by one person, and it's kind of expensive for that. It's really best suited--like 3-D itself--for video games, especially of the 3-D variety. It's extremely immersive; you can't see anything besides the screen, or hear anything besides what's coming out of your headphones, which is great for gaming. At the same time, though, it's extremely unnerving to move your head and find that the entire screen moves with you. You don'tneed to move your head, since you have a perfect view of the entire screen, but it's a natural reaction, and it broke the immersive spell every time. It's also chained by its power/data cord to a set-top box, so forget about blindly roaming around your house or even taking it on a plane unless you're prepared to set up a power strip with several full-sized pieces of home A/V equipment.

The HMZ-T1 lands in Japan on November 11th, with no word just yet on availability elsewhere.

Japanese Researchers Develop a Way to Turn Biological Tissue Transparent

Can be used to study brain function, or just to look cool

By Rebecca Boyle

Mouse Embryos This photo shows two mouse embryos. The clear one at right has been rendered transparent by a new chemical reagent developed by Japanese researchers. RIKEN

All the new breakthroughs in microscopy we’ve seen recently are designed to help scientists see deeper, inside individual cells and into the depths of the brain. Of course, this would be easier to do if there wasn’t a bunch of other tissue blocking the cells you want to see. Japanese researchers have a new solution: Make it all transparent.

A new chemical reagent makes the brain see-through, allowing fluorescent tags to light up neurons and blood vessels deep inside. This enables 3-D images of entire structures, without having to cut anything away or divide anything into smaller sections.

It doesn’t work on living tissue, at least not yet — researchers at RIKEN, Japan’s major research institute, are investigating another, milder reagent that could allow them to study live tissue in this way.

The reagent, called Scale, has specific clarifying properties that do not alter the overall shape or proportion of the sample being washed, according to a news release from RIKEN. First you would have to genetically modify the sample by adding fluorescent proteins to tag certain cells. While it turns the tissue transparent, the Scale method also prevents decreasing the intensity of those fluorescent signals. So once the tissue is washed with Scale, researchers can see the fluorescent proteins flashing.

The fluorescent tags have made it possible to visualize brain regions at a depth of several millimeters, far better than before, and to reconstruct neural networks, RIKEN says. Atsushi Miyawaki and his team at the RIKEN Brain Science Institute have already used it to study neuronal networks among the cerebral cortex, hippocampus and white matter of mouse brains.

It can work on several other tissues besides the brain, the researchers say — they plan to try Scale on the heart, muscles and kidneys, and on tissues from primate and human biopsy samples. The work was published this week in Nature Neuroscience.

Nuclei in the Brain: This image shows nuclei of proliferating neural stem cells (green) and blood vessels (red) tunneling into the transparent hippocampus. The green signal comes from a fluorescent marker. RIKEN