Science & TechnologyS


Sherlock

Stone Age man used fire to make tools - 50,000 years earlier than we scientists thought


Telegraph UK
Fri, 14 Aug 2009 11:10 UTC
Image
© Photo: HULTON Scientists have discovered Stone Age blacksmiths were using fire to make tools at least 72,000 years ago
Just as raising temperature can change the properties of iron and other metals, early humans heated stone to make it easier to flake.

The process transformed a stone called silcrete into an outstanding raw material for tool manufacture.
Read More...
People

Less then 4% of Twitter content is news-related

Donna J. Tuttle
San Antonio Business Journal
Fri, 14 Aug 2009 06:05 UTC
A new Twitter study by San Antonio Web data analytics firm Pearanalytics confirmed what many talk show hosts have been joking about: there's a lot of pointless prattle going on in the microblogging sphere.

After randomly sampling a public timeline of tweets - 140 character comments on Twitter - for 10 days, Pearanalytics found that 40.5 percent of the updates fell in the "pointless babble" category. An example: "I am eating a sandwich now."
Read More...
People

Bipedal Humans Came Down From The Trees, Not Up From The Ground


Science Daily
Thu, 13 Aug 2009 19:40 UTC
A detailed examination of the wrist bones of several primate species challenges the notion that humans evolved their two-legged upright walking style from a knuckle-walking ancestor.

The same lines of evidence also suggest that knuckle-walking evolved at least two different times, making gorillas distinct from chimpanzees and bonobos.

"We have the most robust data I've ever seen on this topic," said Daniel Schmitt, a Duke University associate professor of evolutionary anthropology. "This model should cause everyone to re-evaluate what they've said before."
Knuckle walking ancestors - not
© Duke UniversityTracy Kivell relates how bones suggest human ancestors never knuckle-walked, while chimpanzees and gorillas evolved trait separately.
Read More...
Magnify

At 9,000 years old, Britain's oldest house gives a glimpse of post-Ice Age domesticity


The Daily Mail
Thu, 13 Aug 2009 19:25 UTC
Built 3,000 years before the miracle of Stonehenge, this is Britain's oldest and best preserved house.

The remains of the strongly built shelter, discovered on the Isle of Man, provide a rare window into the domestic life of hunter-gatherers 9,000 years ago.

Unearthed by accident during extension work to the island's airport runway, the 23ft wide pit is giving up extraordinary archaeological secrets.

Most exciting is the revelation that the people of the mesolithic age, long regarded as nomads who wandered ancient Britain in search of food, were actually very good at settling down.
9000 Year old house
© Oxford Archaeology NorthExcavation nears completion of the Mesolithic house, defined by a ring of holes which once contained wooden posts
Read More...
Telescope

Milky Way may have a huge hidden neighbour

Ken Croswell
New Scientist
Thu, 13 Aug 2009 16:16 UTC
Image
© M. Livio (STSCI)/ESA/NASAThe LMC now has a stealthy rival
A large satellite galaxy may be lurking, hidden from view, next door to our own.

Sukanya Chakrabarti and Leo Blitz of the University of California, Berkeley, suspected that the gravity of a nearby galaxy was causing perturbations that have been observed in gas on the fringes of the Milky Way. "We did a large range of simulations where we varied the mass of the perturber and the distance of closest approach," says Chakrabarti. In the best-fitting simulation, the unseen galaxy has about 1 per cent of the Milky Way's mass, or 10 billion times the mass of the sun.

That's a lot. It means the object has roughly the same mass as the Milky Way's brightest satellite galaxy, the Large Magellanic Cloud (LMC).

Right now, says Chakrabarti, the galaxy is roughly 300,000 light years away from us - about twice as far away as the LMC. But the simulations suggest it follows a highly elongated elliptical path, and about 300 million years ago it swept through our own galaxy just 16,000 light years from the galactic centre - closer in than Earth - disturbing the Milky Way's outskirts as it went.
Read More...
Telescope

Late light reveals what space is made of

Anil Ananthaswamy
New Scientist
Thu, 13 Aug 2009 14:47 UTC
On the night of 30 June 2005, the sky high above La Palma in Spain's Canary Islands crackled with streaks of blue light too faint for humans to see. Atop the Roque de los Muchachos, the highest point of the island, though, a powerful magic eye was waiting and watching.

Read More...
Telescope

Storms In The Tropics Of Saturn's Moon Titan Discovered


Science Daily
Wed, 12 Aug 2009 12:10 UTC
Image
© Emily Schaller et al./Gemini ObservatoryA major storm erupts in the desert tropics of Titan.
For all its similarities to Earth - clouds that pour rain (albeit liquid methane not liquid water) onto the surface producing lakes and rivers, vast dune fields in desert-like regions, plus a smoggy orange atmosphere that looks like Los Angeles's during fire season - Saturn's largest moon, Titan, is generally "a very bland place, weatherwise," says Mike Brown of the California Institute of Technology (Caltech).

"We can watch for years and see almost nothing happen. This is bad news for people trying to understand Titan's meteorological cycle, as not only do things happen infrequently, but we tend to miss them when they DO happen, because nobody wants to waste time on big telescopes - which you need to study where the clouds are and what is happening to them - looking at things that don't happen," explains Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy.
Read More...
Attention

Female Supervisors More Susceptible To Workplace Sexual Harassment.


Science Daily
Thu, 13 Aug 2009 12:00 UTC
Women who hold supervisory positions are more likely to be sexually harassed at work, according to the first-ever, large-scale longitudinal study to examine workplace power, gender and sexual harassment.

The study, which will be presented at the 104th annual meeting of the American Sociological Association, reveals that nearly fifty percent of women supervisors, but only one-third of women who do not supervise others, reported sexual harassment in the workplace. In more conservative models with stringent statistical controls, women supervisors were 137 percent more likely to be sexually harassed than women who did not hold managerial roles.
Read More...
Telescope

Earth could be blindsided by asteroids, panel warns

David Shiga
New Scientist
Wed, 12 Aug 2009 16:00 UTC
Image
© NEAR Project/NLR/JHUAPL/Goddard SVS/NASAAsteroid Eros, seen here by NASA's NEAR spacecraft, is 33 kilometres wide, making it the second largest near-Earth asteroid
Existing sky surveys miss many asteroids smaller than 1 kilometre across, leaving the door open to damaging impacts on Earth with little or no warning, a panel of scientists reports. Doing better will require devoting more powerful telescopes to asteroid hunting, but no one has committed the funds needed to do so, it says.

Near-Earth asteroids larger than 1 kilometre across could blast huge amounts of sunlight-blocking dust into Earth's atmosphere in an impact, causing devastating climate change. The US Congress asked NASA in 1998 to find 90 per cent of those in this size range within 10 years, a goal that has now nearly been reached.

Comment: See also: Confession: NASA can't keep up with killer asteroids

Read More...
Meteor

Aorounga Impact Crater, Chad


Earth Observatory
Thu, 13 Aug 2009 02:49 UTC
Aorounga Impact Crater
© NASAAstronaut photograph ISS020-E-26195 was acquired on July 25, 2009, with a Nikon D3 digital camera fitted with an 800 mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory, Johnson Space Center. The image was taken by the Expedition 20 crew.
Aorounga Impact Crater is located in the Sahara Desert, in north-central Chad, and is one of the best-preserved impact structures in the world. The crater is thought to be middle or upper Devonian to lower Mississippian (approximately 345 - 370 million years old) based on the age of the sedimentary rocks deformed by the impact. Spaceborne Imaging Radar (SIR) data collected in 1994 suggests that Aorounga is one of a set of three craters formed by the same impact event. The other two suggested impact structures are buried by sand deposits.

The concentric ring structure of the Aorounga crater - renamed Aorounga South in the multiple-crater interpretation of SIR data - is clearly visible in this detailed astronaut photograph. The central highland, or peak, of the crater is surrounded by a small sand-filled trough; this in turn is surrounded by a larger circular trough.
Read More...