Clipmarks | arifsali's Science Discovery collection

Algebra, zero and algorithm - not a bad legacy.

Wed, 19 Dec 2007 02:36:42 GMT

clipped by: JohnWaterman

Clip Source: www-groups.dcs.st-and.ac.uk

Abu Ja'far Muhammad ibn Musa Al-Khwarizmi

about 790 - about 840

Click the picture above
to see two larger pictures

Al'Khwarizmi was an Islamic mathematician who wrote on Hindu-Arabic numerals and was among the first to use zero as a place holder in positional base notation. The word algorithm derives from his name. His algebra treatise Hisab al-jabr w'al-muqabala gives us the word algebra and can be considered as the first book to be written on algebra.

Clip Source: www-groups.dcs.st-and.ac.uk

We know few details of Abu Ja'far Muhammad ibn Musa al-Khwarizmi's life. One unfortunate effect of this lack of knowledge seems to be the temptation to make guesses based on very little evidence. In [1] Toomer suggests that the name al-Khwarizmi may indicate that he came from Khwarizm south of the Aral Sea in central Asia

Huge 'Ocean' Discovered Inside Earth

Sun, 09 Dec 2007 17:58:27 GMT

clipped by: ratilfar

Clip Source: www.livescience.com

Scientists scanning the deep interior of Earth have found evidence of a vast water reservoir beneath eastern Asia that is at least the volume of the Arctic Ocean.

The discovery marks the first time such a large body of water has found in the planet’s deep mantle.

Looking down deep

The pair analyzed more than 600,000 seismograms—records of waves generated by earthquakes traveling through the Earth—collected from instruments scattered around the planet.

They noticed a region beneath Asia where seismic waves appeared to dampen, or “attenuate,” and also slow down slightly. “Water slows the speed of waves a little,” Wysession explained. “Lots of damping and a little slowing match the predictions for water very well.”

“That’s a real back of the envelope type calculation,” Wysession said. “That’s the best that we can do at this point.”

Tags: science, earth, water, ocean

Amazingly detailed pictures of Mars

Wed, 05 Dec 2007 16:34:40 GMT

clipped by: arifsali

Clip Source: www.esa.int

This image was taken by the High-Resolution Stereo Camera (HRSC), onboard ESA’s Mars Express imaged the Noctis Labyrinthus region, the ‘Labyrinth of the Night’ on Mars.

The HRSC took these pictures on 25 June 2006 in orbit 3155, with a ground resolution of approximately 16 m/pixel.

This colour scene has been derived from the three HRSC colour channels and the nadir channel.

Credits: ESA/ DLR/ FU Berlin (G. Neukum)

Clip Source: esamultimedia.esa.int

Tags: mars, pictures

Bible Archaeology: Nehemiah's wall uncovered

Fri, 30 Nov 2007 16:00:54 GMT

clipped by: readmore

Clip Source: www.jpost.com

The remnants of a wall from the time of the prophet Nehemiah have been uncovered in an archeological excavation in Jerusalem's ancient City of David, strengthening recent claims that King David's palace has been found at the site

As a result of the excavation, both the 30 meter section of the wall and a six-by-three-meter part of the previously uncovered tower have now been dated to the fifth century BCE based on the rich pottery found during the dig under the tower, she said.

"This find opens a new chapter in the history of Jerusalem," Mazar said. "Until now, we have never had such an archeological wealth of finds from Nehemiah's period."

The Bible relates that despite the resistance of hostile neighbors who had occupied the area around Jerusalem in the Jews' absence, the whole wall was completed in a speedy 52-day period.

Tags: archaeology, bible

2400 years old merchantman ship found !!

Thu, 22 Nov 2007 02:38:18 GMT

clipped by: syncopath
clipper's remarks: Professor Elisha Linder:
"I am mad about the subject. I love to be at the sea, to look at ships, to deal with ships, and to study ships," he said. "And I would die to find an even older ship!"

Clip Source: maritime2.haifa.ac.il

The wreck was found at Kibbutz Maagan Mikhael, about 30 km south of Haifa, some 70 meters offshore, at a depth of 1.5 m, and under 1.5 m of sand. The ship was a 2400- year-old merchantman, 14 m in length and 4 m beam. A substantial portion of the wooden hull structure has survived in a remarkable state of preservation.
Among the artifacts found aboard were 70 items of ceramic ware, ropes, a lead ingot, a set of carpenter's tools, 12 tons of rocks, mainly blueschist, and a perfectly preserved one-armed wooden anchor, with ropes still attached.

Clip Source: www.israel21c.org

Elisha Linder spent much of his career

scouring the Israel northern coastline in the hopes of uncovering an ancient trading ship. So it was with no small amount of well-appreciated irony that when he finally achieved his dream over 35 years later, it was literally in the own backyard of his kibbutz.

The ship

from the time of the construction of the Second Temple, is one of the most complete ancient ships ever recovered from the sea.

Clip Source: www.wolfson.ox.ac.uk

Tags: underwater, archeology

1,700-Year-Old Cemetery Found in Syria

Fri, 16 Nov 2007 05:42:49 GMT

clipped by: arifsali

Clip Source: www.physorg.com

Archeologists have unearthed a Roman-era cemetery dating from the 3rd century A.D. in northeast Syria, one of several recent archaeological discoveries in the history-rich country, a government newspaper reported Thursday.

The cross-shaped limestone cemetery was discovered in the Nasiriya area in the remote Hasaka province, some 440 miles northeast of the capital Damascus and contained coins, pottery shards and bracelets dating to the later Aramaic era, Al-Thawra newspaper reported.

Just on Tuesday, an even older cemetery from the 2nd century A.D. was discovered in the famed ruins of Palmyra, one of the region's most impressive sites from Classical antiquity.

A 2nd century rare limestone tablet unearthed by Syrian archaeologists of two Palmyraian young men standing near a camel with a long javelin, dragged by a child. It was discovered in the central ancient city of Palmyra that used to be the center of Middle East trade routes

Tags: syria, cemetery, archaeology, roman, discovery

Search for the Intergalactic Origins of Life

Wed, 14 Nov 2007 22:06:24 GMT

clipped by: invictus

Clip Source: www.dailygalaxy.com

Recent discoveries using The Paranal Observatory located in the Atacama Desert in the northern part of Chile have led astrophysicists believe that carbon-based molecules that once floated in interstellar space were present in the cloud of dust and gas from which our solar system formed, providing the raw materials for life on Earth. These molecules have been observed throughout our galaxy, which is one reason why many believe conditions may also be ripe for life in other parts of the Milky Way, and in billions of galaxies beyond.

By seeking out dusty galaxies – where organic molecules may form in greater abundance – galaxies similar to our own, but at an earlier stage of their evolution, astronomers hope to work out how long these molecules have been abundant in the universe, and therefore how long the conditions suitable for life as we know it have prevailed.

New evidence appears to support the theory that organic molecules are common elsewhere in the universe.

Tags: space, life, carbon, stellar dust, cosmology, universe, science

Fire Temple Found in Peru

Wed, 14 Nov 2007 19:35:21 GMT

clipped by: Goldwolf

Clip Source: news.nationalgeographic.com

Ancient "Fire Temple" Found in Peru

November 12, 2007—A massive clay temple with colorful paintings and an altar for fire worship has recently been unearthed in northern Peru, archaeologists announced Saturday.

The temple dates back 4,000 years and is among the oldest sites discovered in the Americas, said archaeologist Walter Alva, who led the team that made the find.

The temple was built by an "advanced civilization" that predated the Inca by several centuries, Alva told the Reuters news service.

"This discovery shows an architectural and iconographic tradition different from what has been known until now," he said.

The large, vibrant wall paintings found at the site are likely the oldest murals ever found in the Western Hemisphere, he added.

Some of the paintings feature red-and-white designs, and one depicts a deer being hunted with a net.

The large temple complex was unearthed near the city of Lambayeque, about 470 miles (755 kilometers) from the modern capital of Lima.

Tags: peru

Bat techniques could find tumours

Wed, 14 Nov 2007 14:27:10 GMT

clipped by: Fast T friend
clipper's remarks: The system could also have military applications, such as the detection and removal of underwater mines.

Clip Source: news.bbc.co.uk

Scientists in Scotland hope to mimic bat radar to locate and identify tumours hidden deep inside the body.

Bats navigate and hunt insect prey by sending out pulses of sound and listening to the reflected echoes.

The team is looking at using the same principle to identify hidden tumours with ultrasound.

According to a report in The Engineer magazine, the research is based on the way that bats, like dolphins and whales, have a sophisticated ability to tailor their ultrasound signals to individual targets.

These "acoustic codes" are used to identify different kinds of object.

Tags: bats, health, cancer, tumours

New evidence for extragalactic life-forming matter

Wed, 14 Nov 2007 10:02:41 GMT

clipped by: wildcat
clipper's remarks: Carbon-based molecules that once floated in interstellar space are thought to have been later incorporated into Earth, providing the raw materials for life

Clip Source: space.newscientist.com

Tantalising traces of the building blocks of life have been spotted in nearby galaxies. However, working out the identity of these carbon-containing molecules, and when they became abundant, is proving tricky, say astronomers.

Astrophysicists believe that organic molecules were present in the cloud of dust and gas from which our solar system formed, providing the raw materials for life on Earth. Astronomers can see these molecules throughout our galaxy, which is one reason why many believe conditions may also be ripe for life in other parts of the Milky Way, and perhaps further afield.

So the hunt is on to find these molecules in other galaxies. By looking at galaxies similar to our own, but at an earlier stage of their evolution, astronomers hope to work out how long these molecules have been abundant in the universe, and therefore how long the conditions suitable for life as we know it have prevailed.

Conflicting evidence

Tags: life, carbon based molecules, earth, extra-galactic

Life, 90% unknown

Wed, 14 Nov 2007 09:52:21 GMT

clipped by: wildcat
clipper's remarks: "We live, in short, on a little-known planet."

Clip Source: www.livescience.com

After 250 Years of Classifying Life, 90 Percent Remains Unknown

BRONX, NEW YORK--Most people can tell the difference between some types of berries, or bugs or trees, but much of the planet's life remains unnamed and unseen.

A stunningly egotistical Swedish naturalist, Carl Linnaeus, tried long ago to set humanity on track to remedy that.

His book, "Systema Naturae," first published in 1735 at 13 pages long, proposed a hierarchical system for classifying plants, animals and minerals (we later chipped away minerals into the domain of geology) and launched an effort to identify and inventory all the world's living things.

Now 250 years after publication of the book's latter editions, scientists still have discovered as few as 10 percent of the species now living on Earth, said Harvard biologist Edward O. Wilson, who spoke here last week at an event at the New York Botanical Garden to celebrate a visit of Linnaeus' personal copy of the book's first edition.

Tags: life, earth, ecology, species, classification, biology

"Exploding Comet" Photo Gallery

Sun, 11 Nov 2007 17:20:07 GMT

clipped by: invictus
clipper's remarks: Many good shots of Comet 17P/Holmes, taken by backyard astronomers around the world.

Clip Source: spaceweather.com

Summary: Comet 17P/Holmes shocked astronomers on Oct. 24, 2007, with a spectacular eruption. In less than 24 hours, the 17th magnitude comet brightened by a factor of nearly a million becoming a naked-eye object in the evening sky. Look for a golden 2.5th magnitude fuzzball in the constellation Perseus after sunset.

Tags: astronomy, comets, comet holmes, images, photography

Homo Ludens: Why We Get High

Fri, 09 Nov 2007 11:03:16 GMT

clipped by: abailart
clipper's remarks: Thought provoking - one may say, playful - article. Worth reading. Fun.

Clip Source: www.bruceeisner.com

A Dutch professor, JohanHuizinga, in the 'Thirties commented that humans might better have been called Homo Ludens than Homo Sapien. Homo Sapien means thinking man. while Homo Lundens names our species playful man.

Almost all of you have gotten "high." You might call it "getting stoned" or "tripping" or "having a session" or "going on vision quest" or "partying" but the urge to switch channels and move to another and less usual state of consciousness is as old as our species itself. Actually the quest for intoxication is even older!

Siegel proposes that after food, drink and sex, "Intoxication is the fourth drive." He demonstrates through zoological and sociological evidence, that the urge to get high is among the most basic of motivations.

Human beings it seems, are born with the need for periodic variations in consciousness.

The attractiveness of drugs is that they provide an easy quick route to these experiences.

Tags: intoxication, hulzinga, homo ludens, sport, play, drugs

Microscopic 'Hands'

Wed, 07 Nov 2007 20:20:31 GMT

clipped by: rj3sp

Clip Source: www.tfot.info

Microscopic 'Hands'

Professor Chang-Jin Kim, of the UCLA Henry Samueli School of Engineering and Applied Science, has recently invented a microscopic "hand". The microhand is capable of handling microscopic objects thanks to it's tiny size - only one millimeter wide, making it a potentially invaluable tool for future microsurgery.

Tags: technology

In Our Time - Intelligent talk radio from the BBC

Wed, 07 Nov 2007 16:35:22 GMT

clipped by: JohnWaterman

Clip Source: www.bbc.co.uk

Melvyn Bragg and guests investigate the history of ideas. Thursday 9.00-9.45am, repeated 9.30pm.
Select programmes from the In Our Time archives using the new subject pages. Just scroll down to select a subject. You can also listen to programmes from the current series.

Read a profile of Melvyn Bragg

Join the debate on the
BBC History messageboard

Tags: podcasts, bbc, melvyn bragg, science, history, culture, religion, philosophy