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That So-Called Alien Megastructure Could Just Be a Distorted Star


Post 7188

George Dvorsky

http://gizmodo.com/that-so-called-alien-megastructure-could-just-be-a-dist-1738979646

That So-Called Alien Megastructure Could Just Be a Distorted Star

That So-Called Alien Megastructure Could Just Be a Distorted Star 

The Kepler Space Telescope recently picked up unprecedented flickering behavior from a distant star, leading to speculation that—among other things—it might be an alien megastructure. Now, some astronomers are saying it might just be caused by a rapidly spinning and irregularly shaped star.

Star KIC 8462852—recently dubbed “Tabby’s Star”—is emitting a transit signature that defies explanation. Normally, the luminosity of a star drops at a consistent rate when an alien planet passes in front, but not Tabby’s star. This object is dimming at irregular intervals and at levels that far exceed anything seen before.

Kepler astronomer Tabetha Boyajian and her colleagues suggest that this could the remnants of a planetary collision, or maybe a massive cometary cloud. More radically, Penn State astronomer Jason Wright and his colleagues have speculated that it might be an alien megastructure, like a Dyson Sphere. But even Wright admits this is a “perilous approach to science”—one that could lead to an “alien in the gaps” fallacy, and unfalsifiable hypotheses.

A number of other theories have been tossed about, but there’s one in particular that’s starting to attract some attention. It’s the phenomenon of gravity darkening and spin-orbit misalignment.

That So-Called Alien Megastructure Could Just Be a Distorted Star 

Paul Gilster from Centauri Dreams explains:

In this scenario, we have a star that is spinning fast enough to become oblate; i.e., it has a larger radius at the equator than it does at the poles, producing higher temperatures and ‘brightening’ at the poles, while the equator is consequently darkened. The transits of a planet in this scenario can produce asymmetrical light curves, a process the Wright paper notes, and one that [astronomer Michael] Million began to discuss as early as the 17th in the comments here [at Centauri Dreams]. That discussion was picked up in Did the Kepler space telescope discover alien megastructures? The mystery of Tabby’s star solved, which appeared in a blog called Desdemona Despair. The author sees the case as clear-cut: “There are four discrete events in the Kepler data for KIC 8462852, and planetary transits across a gravity-darkened disk are plausible causes for all of them.”

Meanwhile, Centauri Dreams reader Jim Galasyn uncovered a paper by a team led by Shoya Kamiaka (University of Tokyo) studying gravity darkening of the light curves for the transiting system PTFO 8-8695, also studied by Barnes, which involves a ‘hot Jupiter’ orbiting a rapidly rotating pre-main-sequence star. Gravity darkening appears to be very much in play, and we can, as the Desdemona Despair blog does, cite the Barnes paper: “An oblique transit path across a gravity-darkened, oblate star leads to the long transit duration and asymmetric lightcurve evident in the photometric data [for the PTFO 8-8695 system].”

That So-Called Alien Megastructure Could Just Be a Distorted Star 

Astronomers are indeed familiar with oblate stars. For example, a massive, bright young star called VFTS 102 spins around a million miles per hour, which is about 100 times faster than our own Sun. The resulting G-forces have flattened the star into an oblate shape, producing a disk of hot plasma (see artist’s depiction in top banner).

It’s a fascinating explanation, but Wright isn’t buying the gravity darkening hypothesis. Here’s what he had to say in the comments section of the Centauri Dreams post:

Gravity darkening might be a small part of the puzzle, but it does not explain the features of this star. Tabby’s star does not rotate fast enough to experience significant gravity darkening. That post also suggests that planets could be responsible, but planets are not large enough to produce the observed events, and there are too many events to explain with planets or stars.

Apparently Boyajian did consider the gravity darkening hypothesis, but it was rejected given the reasons cited by Wright. However, he admits it might be a “small part of the puzzle.” Other astronomical phenomena could be involved, either known or unknown.

Whatever’s going on, this is a significant scientific discovery, and it most definitely deserves the attention it’s getting. Unless, of course, the data used in the Kepler study is somehow flawed or insufficient. Tabby’s Star is currently being studied by several groups, so future analyses are forthcoming.

For more on the gravity darkening hypothesis, check out Jim Galasyn’sDesdemona Despair post. And check out the published literature on the subject: “Measurement of Spin-Orbit Misalignment and Nodal Precession for the Planet around Pre-Main-Sequence Star PTFO 8-8695 From Gravity Darkening” and “Revisiting a gravity-darkened and precessing planetary system PTFO 8-8695: spin-orbit non-synchronous case.”


Email the author at george@gizmodo.com and follow him at @dvorsky. Top image by NASA, ESA, and G. Bacon (STScI)

 

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Ancient Greek Warrior’s Tomb Yields Eye-Popping Treasures George Dvorsky


Post 7187

Ancient Greek Warrior’s Tomb Yields Eye-Popping Treasures

George Dvorsky

http://gizmodo.com/ancient-greek-warriors-tomb-yields-eye-popping-treasure-1739020894

Ancient Greek Warrior's Tomb Yields Eye-Popping Treasures

An American husband-and-wife team working in Greece has uncovered the 3,500-year-old remains of a prominent ancient warrior who was buried alongside an assortment of riches. It’s being called the most important discovery made in continental Greece in over 65 years.

The undisturbed tomb, found in southwestern Greece by University of Cincinnati archaeologists Sharon Stocker and Jack Davis, was discovered back in May of this year. News of the discovery was kept under wraps until yesterday when the announcement was made by the Greek authorities.

Stocker and Davis made the discovery while working near the Palace of Nestor, a site initially discovered back in 1939.

Ancient Greek Warrior's Tomb Yields Eye-Popping Treasures

Four solid gold rings were uncovered, which is more than has been found in any other single burial in all of Greece (Credit: Greek Culture Ministry)

The team’s excavation revealed a single Mycenaean-era burial pit measuring 5 feet deep, 4 feet wide, and 8 feet long. The skeletal remains of a single individual—an unknown male between the age of 30 to 35 years—was found buried alongside an astounding assortment of riches, a strong indication that he was likely a warrior of significant importance.

Analysis of his remains suggests he was, in the words of the archaeologists, “strong, robust…well-fed.” The unnamed warrior may have been royalty, the founder of a new dynasty, or even a trader who acquired his riches through commerce.

Ancient Greek Warrior's Tomb Yields Eye-Popping Treasures

Ancient Greek Warrior's Tomb Yields Eye-Popping Treasures

A stunning solid-gold necklace, measuring more than 30 inches long. It features two gold pendants on each end, decorated with ivy leaves. (Credit: Greek Culture Ministry)

The warrior was laid to rest with his many belongings, including fine gold jewellery, an ornate string of pearls, signet rings, silver vases, ivory combs, and a bronze sword with a gold and ivory handle. The fact that he was buried alone and not in a common pit with others is yet another indication of his social importance.

Ancient Greek Warrior's Tomb Yields Eye-Popping Treasures

A bronze mirror featuring an ivory handle. (Credit: University of Cincinnati)

The jewellery, adorned with figures of deities, animals, and floral motifs, was crafted in the style of the Minoans, a civilization that lived on the island of Crete from around 2,000 BC.

Ancient Greek Warrior's Tomb Yields Eye-Popping Treasures

One of nearly 50 seal stones discovered. In all, some 1,400 objects were recovered from the grave. (Credit: Greek Culture Ministry)

The Mycenaean people spread from the Peloponnese across the eastern Mediterranean in the 2nd millennium BC, and represent the first advanced civilization in mainland Greece. Mycenaean Greece came to end with the collapse of Bronze-Age culture around 1,100 BC, and inspired ancient Greek society, literature and mythology.

[ AFP | LA Times | ABC News ]


Email the author at george@gizmodo.com and follow him at @dvorsky. Top image of ivory comb via Greek Culture Ministry

 

Get Lost in This Jaw-Dropping View of the Eagle Nebula


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Get Lost in This Jaw-Dropping View of the Eagle Nebula

Falling Space Junk Will Burn Up In Earth’s Atmosphere Next Month


Post 7185

Falling Space Junk Will Burn Up In Earth’s Atmosphere Next Month

This Breathtaking New Footage Of The B-2 Stealth Bomber Is The Best Ever


Post 7184

Tyler Rogoway

http://foxtrotalpha.jalopnik.com/this-is-the-most-breathtaking-footage-of-the-b-2-stealt-1738473367

This Breathtaking New Footage Of The B-2 Stealth Bomber Is The Best Ever

This Breathtaking New Footage Of The B-2 Stealth Bomber Is The Best Ever

With the announcement of who will build the Long Range Strike Bomber (LRS-B) seemingly imminent, it is interesting that Northrop Grumman, the builder of the famed B-2 Stealth Bomber, just released this incredible high-definition footage of their legendary flying wing design weaving through the skies gracefully.

http://foxtrotalpha.jalopnik.com/ajax/inset/iframe?id=youtube-video-P30Jf6bN2EA&start=0

This incredible imagery that looks to be shot over the deserts of the America’s Southwest, shows all the different angles of the B-2, an aircraft that seemingly changes its look totally depending on what aspect you view it from. Even the back of the jet, an area that the USAF has been very sensitive about photographing as of late, is showcased brilliantly.

The timing of the video is extremely interesting. Maybe Northrop Grumman,who has used its marketing abilities to the max during this high-stakes bomber contract competition, is just reminding us one more time who has actually built and maintained the world’s only known combat-proven stealth bomber and manned flying-wing aircraft.

In comparison, Nothrop Grumman’s opponents, a consortium of Boeing andLockheed Martin, have been much quieter when it comes to publicly winning support for their ability to build America’s next bomber.

Regardless of this intense but shadowy competition, it is amazing to think that in the not so distant future, the B-2 Spirit, even though it will remain in service for decades to come, will be America’s “old stealth bomber.”

This will very well be a true statement, but boy does the design still look amazingly otherworldly.

Contact the author Tyler@Jalopnik.com

 

 

Magnets Might ‘Unlock’ Paralyzed Arm After Stroke


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Magnets Might ‘Unlock’ Paralyzed Arm After Stroke

Organs on Demand? 3D Printers Could Build Hearts, Arteries


Post 7182

Organs on Demand? 3D Printers Could Build Hearts, Arteries

Off-the-shelf 3D printers could one day help create living organs to aid in repairing the human body, researchers say.

Scientists have developed a way to 3D print models of various anatomical structures, including hearts, brains, arteries and bones. In the future, this process could be used to create 3D-printed soft implants in which living tissue can grow to form organs. Another application for this innovative technology could be food printers, reminiscent of the replicators seen on the TV show “Star Trek,” the scientists added.

A 3D printer is a machine that creates items from a wide variety of materials: plastic, ceramic, glass, metal and even more unusual ingredients, such as living cells. The device works by depositing layers of material, just as ordinary printers lay down ink, except 3D printers can also lay down flat layers on top of each other to build 3D objects. [7 Cool Uses of 3D Printing in Medicine]

Conventional 3D printers manufacture objects from rigid materials, with each layer receiving a sturdy foundation from the layers below. However, printing soft materials has proven to be difficult, akin to building an object out of Jell-O.

“Metals, ceramics and stiff polymers have been 3D printed for many, many years, but soft materials, those that can deform under their own weight, have been more challenging to support during the print process,” said Adam Feinberg, a biomedical engineer at Carnegie Mellon University and senior author of the new study.

Researchers have used 3D printers to create rigid medical devices customized for individual patients; those devices include hearing aids, dental implants and prosthetic hands. However, using 3D printers to create soft implants, a process known as bioprinting, could provide alternatives to traditional transplants for repairing or replacing damaged organs, Feinberg said.

“The potential applications we envision are in the area of tissue engineering — essentially, 3D printing scaffolds and cells to regrow tissues and organs,” Feinberg told Live Science.

The scientists have developed a way of 3D printing soft materials inside a bath of supportive fluid that contains gelatin powder, similar to the type that can be found in a supermarket.

“We print one gel inside of another gel, which allows us to accurately position the soft material as it’s being printed, layer by layer,” Feinberg said in a statement.

Using medical imaging data, the researchers used their new technique, called FRESH, or “Freeform Reversible Embedding of Suspended Hydrogels,” to print simplified, proof-of-concept anatomical structures. These were made of a variety of biological materials, such as the collagen found in tendons and ligaments. The test structures included a human femur, a human coronary artery, a five-day embryonic chick heart and the external folds of a human brain. [5 Crazy Technologies That Are Revolutionizing Biotech]

The models were printed with a resolution of about 200 microns, the researchers said. (In comparison, the average human hair is about 100 microns wide.)

“We can take materials like collagen, fibrin and alginate, which are the types of materials the body uses to build itself, and 3D print them,” Feinberg said. “We can now build tissue-engineering scaffolds using these materials in incredibly complex structures that more closely match those of real tissues and organs in the body.” (Fibrin helps make up blood clots, while alginate is found in many seaweeds.)

In this new technique, the support gel around the 3D structures can be easily melted away and removed by heating it to body temperature. Such temperatures would not damage any delicate biological molecules or living cells printed out in the method, the scientists said.

The researchers cautioned that they have not yet bioprinted organs. “This work is an important step in that direction by enabling us to use biological materials that we believe are necessary to do this,” Feinberg said. “However, years of research are still required.”

In the future, the researchers plan to incorporate real heart cells into their work, they said. The 3D-printed structures will serve as scaffolds in which the cells can grow and form heart muscle.

Bioprinting living cells is a growing field, but, until now, most 3D bioprinters retailed for more than $100,000, or required specialized expertise to operate (or both), limiting the possibilities for the technique’s widespread adoption. However, this new method can be done with consumer-level 3D printers that cost less than $1,000. It also uses open-source software that the researchers say they invite others to hack and improve.

“Our vision is that other research groups can take this technology and apply it broadly to other tissue-engineering and soft-materials 3D-printing challenges,” Feinberg said.

The scientists detailed their findings online today (Oct. 23) in the journal Science Advances.

Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.