Science & TechnologyS


Blackbox

Discovery that quasars don't show time dilation mystifies astronomers

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© NASAThis X-ray image shows the quasar PKS 1127-145, a highly luminous source of X-rays and visible light located about 10 billion light years from Earth. Its X-ray jet extends at least a million light years from the quasar.
The phenomenon of time dilation is a strange yet experimentally confirmed effect of relativity theory. One of its implications is that events occurring in distant parts of the universe should appear to occur more slowly than events located closer to us. For example, when observing supernovae, scientists have found that distant explosions seem to fade more slowly than the quickly-fading nearby supernovae.

The effect can be explained because (1) the speed of light is a constant (independent of how fast a light source is moving toward or away from an observer) and (2) the universe is expanding at an accelerating rate, which causes light from distant objects to redshift (i.e. the wavelengths to become longer) in relation to how far away the objects are from observers on Earth. In other words, as space expands, the interval between light pulses also lengthens. Since expansion occurs throughout the universe, it seems that time dilation should be a property of the universe that holds true everywhere, regardless of the specific object or event being observed. However, a new study has found that this doesn't seem to be the case - quasars, it seems, give off light pulses at the same rate no matter their distance from the Earth, without a hint of time dilation.

Telescope

New Moon Rock is Fit for a King

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© Wikimedia CommonsSpinel the gem comes in a rainbow of colors, such as these crystals in a white marble/calcite matrix.
People don't discover a new type of moon rock every day, so consider the odds of finding one rich in a mineral that England's King Henry V wore on his battle helmet. And then imagine spotting, right on the Man in the Moon's nose, huge and previously unknown deposits of another mineral from the same family. Using data from NASA's Moon Mineralogy Mapper (M3) on India's Chandrayaan-1 spacecraft, a team of researchers recently did just that.

The new rock is a unique mixture of plain-old plagioclase -- plentiful in the Earth's crust and the moon's highlands -- and pink spinel, an especially beautiful arrangement of magnesium, aluminum and oxygen that, in its purest forms, is prized as a gemstone here on Earth. The rock was discovered on the far side of the moon by Carlé Pieters, a planetary scientist at Brown University, Providence, R.I. and the principal investigator for the M3 science team. Shortly after, massive deposits of a different type of spinel were identified on the near side by other M3 team members, led by Jessica Sunshine at the University of Maryland-College Park.

Info

New research reconstructs ancient history of Island Southeast Asia

An article in this month's Current Anthropology challenges the controversial idea that Island Southeast Asia was settled 5,000 years ago by a migration of farmers from Taiwan.

The article, by Mark Donohue of the Australian National University and Tim Denham of Monash University (Melbourne, Australia), also questions the broader idea that farming technology and language spread together in many parts of the world as a "cultural package."

Scholars have debated for years about the history of Island Southeast Asia - the present-day countries of the Philippines, Indonesia and Malaysia. The most prominent theory about the region's history is the "out of Taiwan" model. According to the model, people from Taiwan migrated south into the region about 5,000 years ago. Advanced farming technology enabled the migrants to displace indigenous hunter-gatherers, and establish their culture and language as the dominant one in the region. Linguistic evidence seems to support that version of events. All of the languages spoken in the region - called the Austronesian languages - can be traced back to a Taiwanese origin.

Influential scholars, including Guns, Germs and Steel author Jared Diamond, believe that the "out of Taiwan" model is a prime example of how prehistoric farming cultures tended to expand their territories, bringing their language and other cultural traditions with them. Advocates of the model believe similar scenarios explain language patterns in areas of Europe and Sub-Saharan Africa.

But Donohue and Denham present a very different history of Island Southeast Asia.

Info

Ancient Supervolcano Created Giant Underwater Mountain Chain

A supervolcano on the ocean floor might have spewed massive amounts of lava in a rapid amount of time, new findings that could help reveal the mysterious origin of some of these ancient goliaths, which may have triggered mass extinctions through Earth's history.

Roughly a dozen supervolcanoes currently exist. Some are on land, while others lie at the bottom of the ocean. Each has produced several million cubic miles of lava - about three hundred times the volume of all the Great Lakes combined - dwarfing the amount of lava produced by the Hawaiian volcanoes or the Icelandic volcano that erupted recently.

These eruptions have dramatically shaped life on Earth, pumping huge amounts of ash, dust and gas into the atmosphere that have killed off species and altered global climate. Despite their global impact, the cause of the massive eruptions from supervolcanoes at times remains unknown.

Meteor

Could a Comet Tail Have Scarred the Earth in the Recent Past?

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© UnknownDrumlins
One of the puzzles that geologists occasionally ponder is the nature of eskers and drumlins.

Eskers are winding ridges a few tens of metres high that look remarkably like railway embankments. Indeed they are often used as readymade roads and run up and down hills over distances that sometimes stretch to hundreds kilometres.

Drumlins, on the other hand, are tear drop-shaped hills a few tens of metres high and a hundreds of metres long. They often appear in large numbers with the same orientation in drumlin fields .

Geologists have long assumed that eskers and drumlins are formed by glaciers and left behind after these ice giants retreated.

There are essentially two problems. The first is the internal structure of these formations. Eskers and drumlins have have an outer layer of water-borne clay and silt with attendant fossil debris. This covers an inner core made of unsorted boulders and rocks which are entirely free of fossils. These inner cores do not appear to have been affected by the action of water. How does this structure arise?

The second is that if glaciers are responsible for eskers and drumlins, they ought to be forming now. And yet nobody can find anywhere on Earth where these structures are currently forming.

Today, Milton Zysman and Frank Wallace publish on the arXiv their explanation for the formation of these objects and it makes for fascinating, if not entirely convincing, reading.

Comment: For more information, read Laura Knight-Jadczyk's"Meteorites, Asteroids, and Comets: Damages, Disasters, Injuries, Deaths, and Very Close Calls".


Cow Skull

Scientists discover 'missing link between man and apes'

The discovery of a 'missing link' between man and apes could revolutionise our understanding of how we evolved, scientists say.

They believe the two-million-year-old fossilised skeleton of a child, found in South Africa, is that of an entirely new species and an intermediate stage between our ape-like ancestors and modern man.

And they claim it could help us crack one of the great mysteries of our evolutionary tree - exactly when humans began to walk on two feet.

evolution

Magnify

Secrecy in Science is Corrosive

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© Science Progress
Secrecy undermines the practice of good science, charges Michael Schrage in an opinion piece published in the Financial Times, and governments need to step in and provide more incentives for open sharing of data.

"On issues of the greatest importance for public policy, science researchers are less transparent than they should be," Schrage writes. "That behavior undermines science, policy and public trust."

Schrage cites the recent scandal over emails stolen from the computers of climate researchers at the University of East Anglia as an example of the distortions caused by a modern climate of secrecy and competition in science. Although there is no evidence that researchers falsified data as some climate skeptics have alleged, the Associated Press concluded that "One of the most disturbing elements suggests an effort to avoid sharing scientific data with critics skeptical of global warming. ... It raises a science ethics question because free access to data is important so others can repeat experiments as part of the scientific method."

Schrage also notes that only recently have many U.S. universities begun to require that drug researchers expose financial ties to the companies that make the products they are testing.

Telescope

Hubble snaps heavyweight of the Leo Triplet

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© ASA, ESA and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration.
Hubble has snapped a spectacular view of the largest "player" in the Leo Triplet, a galaxy with an unusual anatomy: it displays asymmetric spiral arms and an apparently displaced core. The peculiar anatomy is most likely caused by the gravitational pull of the other two members of the trio.

The unusual spiral galaxy, Messier 66, is located at a distance of about 35 million light-years in the constellation of Leo. Together with Messier 65 and NGC 3628, Messier 66 is one third of the Leo Triplet, a trio of interacting spiral galaxies, part of the larger Messier 66 group. Messier 66 wins out in size over its fellow triplets - it is about 100 000 light-years across.

Magnify

Researchers Shed Light on Ancient Assyrian Tablets

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© J. JacksonCuneiform tablets unearthed by archaeologists has been found to contain a largely intact Assyrian treaty from the early 7th century BCE.
A cache of cuneiform tablets unearthed by a team led by a University of Toronto archaeologist has been found to contain a largely intact Assyrian treaty from the early 7th century BCE.

"The tablet is quite spectacular. It records a treaty -- or covenant -- between Esarhaddon, King of the Assyrian Empire and a secondary ruler who acknowledged Assyrian power. The treaty was confirmed in 672 BCE at elaborate ceremonies held in the Assyrian royal city of Nimrud (ancient Kalhu). In the text, the ruler vows to recognize the authority of Esarhaddon's successor, his son Ashurbanipal," said Timothy Harrison, professor of near eastern archaeology in the Department of Near & Middle Eastern Civilizations and director of U of T's Tayinat Archaeological Project (TAP).

Telescope

Mystery Object Found Orbiting Brown Dwarf

brown dwarf
© NASA, ESA, and K. Todorov and K. Luhman (Penn State University)This Hubble Space Telescope image of young brown dwarf 2M J044144 show it has a companion object at the 8 o'clock position that is estimated to be 5-10 times the mass of Jupiter.
Big planet or companion brown dwarf? Using the Hubble Space Telescope and the Gemini Observatory, astronomers have discovered an unusual object orbiting a brown dwarf, and its discovery could fuel additional debate about what exactly constitutes a planet. The object circles a nearby brown dwarf in the Taurus star-forming region with an orbit approximately 3.6 billion kilometers (2.25 billion miles) out, about the same as Saturn from our sun. The astronomers say it is the right size for a planet, but they believe the object formed in less than 1 million years - the approximate age of the brown dwarf - and much faster than the predicted time it takes to build planets according to conventional theories.

Kamen Todorov of Penn State University and his team conducted a survey of 32 young brown dwarfs in the Taurus region.

The object orbits the brown dwarf 2M J044144 and is about 5-10 times the mass of Jupiter. Brown dwarfs are objects that typically are tens of times the mass of Jupiter and are too small to sustain nuclear fusion to shine as stars do.