Science & TechnologyS


Question

Neanderthals: Extinction by BBQ?

Neanderthal
© Pierre Andrieu/AFP/Getty ImagesA model representing a Neanderthal man is displayed at the National Museum of Prehistory in Eyzies-de-Tayac, Dordogne, France.
Humans today eat gorillas and chimpanzees, so why would our prehistoric ancestors flinch at sitting down to a nicely roasted Neanderthal?

That's the shocking new hypothesis being raised by anthropologists in Spain, who wonder if our closest extinct relative was exterminated in the same way as 178 other large mammals, so-called megafauna, which are suspected of going at least partially by the hand of hungry human hunters.

"Except in its native Africa, in the other continents Homo sapiens can be considered as an invasive alien species," write researchers Policarp Hortolà and Bienvenido Martínez-Navarro of the Universitat Rovira i Virgili in Tarragona, Spain. They published their hypothesis in the May issue of the journal Quaternary International.

Today, there are endless cases of invasive species decimating native species all over the world. So perhaps at the end of the Pliestocene, it was the same when humans spread into Europe and Asia, where Homo neanderthalensis was just another big, slow-reproducing mammal.

"We think that modern humans, who occupied a similar ecological niche as Neanderthals, but with more evolved technology, in their colonization of the new European territories directly competed with Neanderthals for the food and other natural resources," wrote Martínez-Navarro in an emailed response to Discovery News.

Fireball 4

Exploding meteorite may have sealed fate of the mammoths

Mammoth
© AlamyScientists have claimed an exploding meteorite may have sealed the fate of the woolly mammoth.
Researchers have found evidence that a large meteorite broke apart in the atmosphere around 12,800 years ago at around the time when mammoths died out.

Studying deposits at 18 archaeological sites around the world they found tiny spheres of carbon they say are characteristic of multiple impacts and mid-air explosions from meteorite fragments.

They claim that millions of tonnes of dust and ash thrown would have been thrown into the atmosphere by the event, which would have choked the atmosphere and altered the global climate.

Their findings cast doubt on claims that it was human hunting that was responsible for the demise of large ice age animals like woolly mammoths, woolly rhinos and sabre toothed tigers.

Many scientists now believe that it was a combination of changes in the climate and pressure from human hunting that led to the mass extinction of many of these species.

However, the cause of the abrupt change in the climate between 12,800 and 11,500 years ago, known as the Younger Dryas by geologists, has been a controversial topic.

Info

Rare particles give clue to ancient Earth

Sand
© Witswatersrand University, Johannesburg
Semi-precious minerals found in a bucket of sand from an island nation have cracked open a clue to the drifting movements and break-up of ancient Earth's massive continental plates.

The particles are zircons and the island - Mauritius - is now thought to be hiding a micro-continent which has been given the name Mauritia.

Zircons can be as old as four billion years and are almost never found in oceans, proving the likelihood that Mauritius sits on top of a fragment of continental plate which remained behind and was covered by huge masses of lava when Madagascar split apart from India about 90 million years ago.

Prof. Lewis Ashwal from Wits University studies the break-up process of continents. He was part of the group of geoscientists from Norway, South Africa, Britain and Germany who recently announced their finding of zircons in Mauritius. They've been working in the area for 15 years.

Fireball

The mammoth's lament: How cosmic impact sparked devastating climate change

Herds of wooly mammoths once shook Earth beneath their feet, sending humans scurrying across the landscape of prehistoric Ohio. But then something much larger shook Earth itself, and at that point these mega mammals' days were numbered.
Image
© Kenneth Tankersley/University of CincinnatiAn environmental scanning electron microscope image of a carbon spherule from Sheriden Cave.

Something -- global-scale combustion caused by a comet scraping our planet's atmosphere or a meteorite slamming into its surface -- scorched the air, melted bedrock and altered the course of Earth's history. Exactly what it was is unclear, but this event jump-started what Kenneth Tankersley, an assistant professor of anthropology and geology at the University of Cincinnati, calls the last gasp of the last ice age.

"Imagine living in a time when you look outside and there are elephants walking around in Cincinnati," Tankersley says. "But by the time you're at the end of your years, there are no more elephants. It happens within your lifetime."

Tankersley explains what he and a team of international researchers found may have caused this catastrophic event in Earth's history in their research, "Evidence for Deposition of 10 Million Tonnes of Impact Spherules Across Four Continents 12,800 Years Ago," which was published in the Proceedings of the National Academy of Sciences.

This research might indicate that it wasn't the cosmic collision that extinguished the mammoths and other species, Tankersley says, but the drastic change to their environment.

"The climate changed rapidly and profoundly. And coinciding with this very rapid global climate change was mass extinctions."

Galaxy

Is our universe merely one of billions?

Multiverse
© The Kashmir Monitor
London - Scientists believe they have found the first evidence that other universes exist after analysing the data gathered by the European Space Agency's Planck spacecraft.

Theories that our universe could be just one of billions -- perhaps an infinite number - have been discussed for decades but until now they have lacked any evidence.

However, a few weeks ago, scientists published a new map of the cosmic microwave background - the 'radiation' left behind after the Big Bang that created the universe 13.8 billion years ago.

The map, based on Planck data, showed anomalies in the background radiation that, some experts say, could only have been caused by the gravitational pull of other universes outside our own, The Sunday Times reported.

"These anomalies were caused by other universes pulling on our universe as it formed during the Big Bang," said Laura Mersini-Houghton, a theoretical physicist at the University of North Carolina at Chapel Hill.

Question

Discovery of mystery creature may provide clues to clarity of Lake Tahoe

Mystery Creature
© Gary Williams, CASAn unidentified creature has been found near Lake Tahoe. Now scientists are trying to figure out if it should be eradicated or preserved and studied.
A Lake Tahoe area scientist has found an unidentified life form in a high-altitude lake. Now agencies in the area are trying to figure out what it is.

University of Nevada Reno Professor Emeritus, John Kleppe pilots a remotely operated vehicle, or "ROV," into the frigid depths of Fallen Leaf Lake near Lake Tahoe. Particles whiz by the ROV's lights like stars.

"It is sort of amazing because when you think about it no humans have seen a lot of what we see. It is like walking on the moon," said Kleppe.

He discovered a 3-thousand-year-old hidden forest still standing. He says it's evidence of past mega droughts. As if that's not strange enough, he has found something living in the forest.

"What we are seeing here is a thing, which is like a balloon of green jell and it will eventually look like a baggie and then like it is creating a gas in it and then float away," said Kleppe.

Comet 2

Asteroidal belt comets rise from the dead

ABC Comets
© NASA/JPL/Deep Space 1The new study further blurs the line between comets and asteroids.
Astronomers have found a group of comets that have risen from the dead.

The asteroidal belt comets - or ABCs for short - lie in the main asteroid belt between Mars and Jupiter, report astronomers on the on the pre press website ArXiv.org.

Dr Ignacio Ferrin, Dr Jorge Zuluaga and Pablo Cuartas from Columbia's University of Antioquia, say the group of eleven objects behave like comets, but have asteroidal orbits.

They propose the objects they've dubbed 'Lazarus comets' are extinct comets that have been rejuvenated when their orbits changed.

"The asteroidal belt contains an enormous graveyard of ancient dormant and extinct rocky comets, that [are rejuvenated], in response to a diminution of their perihelion distance [closest orbital position to the Sun]," the authors write.

The findings, which are accepted for publication in the Monthly Notices of the Royal Astronomical Society, blurs the line between comets and asteroids.

Comets become dormant when they no longer emit volatile gases - they are then called asteroids. But previous research has shown these dormant comets can be rejuvenated into comets after collisions with asteroids, meteors or other comets, as well as high energy particle impacts.

Ferrin and colleagues now suggest a new comet rejuvenation theory.

2 + 2 = 4

How bilinguals switch between languages

Individuals who learn two languages at an early age seem to switch back and forth between separate "sound systems" for each language, according to new research conducted at the University of Arizona.

The research, to be published in a forthcoming issue of Psychological Science, a journal of the Association for Psychological Science, addresses enduring questions in bilingual studies about how bilingual speakers hear and process sound in two different languages.

"A lot of research has shown that bilinguals are pretty good at accommodating speech variation across languages, but there's been a debate as to how," said lead author Kalim Gonzales, a psychology doctoral student at the University of Arizona. "There are two views: One is that bilinguals have different processing modes for their two languages -- they have a mode for processing speech in one language and then a mode for processing speech in the other language. Another view is that bilinguals just adjust to speech variation by recalibrating to the unique acoustic properties of each language."

Arrow Up

CERN's Jasper Kirkby on the newest unpublished results of CLOUD: "The results are very interesting"

Earth
© NASA
The Latest On The CLOUD Experiment at CERN By Sebastian Lüning and Fritz Vahrenholt

On May 10, 2013, at the online Austrian ORF, there was a rare interview with the CLOUD Experiment director of the European Organization for Nuclear Research, Jasper Kirkby. Within the scope of the CLOUD project, it is being investigated to what extent solar activity has on cloud formation via the mechanism of cosmic radiation and the impact this could have on the Earth's climate (see Chapter 6 of our book Die kalte Sonne).

Here's an excerpt of the worthwhile interview:

Comet

Astronomers detect dust feature in Comet ISON's inner coma

Inner Core of ISON
© Nick Howes and Ernesto Guido, Remanzacco ObservatoryImage from May 7, 2013 of a the inner region of Comet ISON, as seen with the 2-meter La Palma Telescope.
In April, when the Hubble Space Telescope looked out towards Jupiter's orbit and observed what has been billed as the "Comet of the Century" - Comet C/2012 S1 ISON - the space telescope photographed a unique feature in the comet's coma. Now, a team of ground-based astronomers have performed follow-up observations, imaging Comet ISON as it heads towards the Sun and was just outside the orbit of Mars.

They, too, have seen this unique feature, which is thought to be a jet blasting dust particles off the sunward-facing side of the comet's nucleus. These very useful follow-up observations are providing more insight on this highly anticipated comet, as well as helping to predict what might happen it makes its closest approach to the Sun in November 2013.