Clipmarks | arifsali's Science Discovery collection

The Physics of Dance

Sat, 20 Oct 2007 16:42:24 GMT

clipped by: Kore7
clipper's remarks: Notes from a presentation by physics professor George Gollin on the physical laws which every ballet dancer must eventually master, whether explicitly aware of them or not.

It must be noted that professor Kenneth Laws has written three books on the physics of dance and just had an interesting interview with Studio 360 on the subject.

Clip Source: web.hep.uiuc.edu

Forces sum to zero.

Both forces "point through" the dancer's center of gravity, so torque is zero.

Forces on each dancer sum to zero.

Though some forces are "off-center", the torques also sum to zero.

Smaller floor contact area (en pointe, for example) makes balance more difficult.

Not all positions which are statically balanced can be held in a turn.

Centrifugal forces exert a torque, throwing the dancer off balance. Shift center of gravity to maintain dynamic (but not static) balance

Because of "conservation of angular momentum," you can change the speed of a turn when en pointe by extending or retracting a leg.

You push on the floor one way, the floor pushes back the other way. (You can't do this on a slippery floor!)

Dancers can also perform zero-angular-momentum turns.

Gravity only influences the vertical component of motion, not the horizontal:

Height vs. time is a parabola, while horizontal distance vs. time is a straight line:

The dancer can create an illusion of floating:

Tags: dance, dancers, ballet, physics, gravity, time, torque, force, balance

Origin of Vision discovered

Mon, 22 Oct 2007 08:32:10 GMT

clipped by: Oortcloud
clipper's remarks: Very cool stuff.

Clip Source: www.livescience.com

You are reading these words right now because 600 million years ago, an aquatic animal called a Hydra developed light-receptive genes—the origin of animal vision.

It wasn't exactly 20-20 vision back then though.

Hydras, a genus of freshwater animals that are kin to corals and jellyfish, measure only a few millimeters in diameter and have been around for hundreds of millions of years.

Though they don't have eyes or any specific light-receptive organs, researchers think that the light-sensing proteins concentrated in the mouth area of the Hydras help them to use light sensitivity to search out prey.

"We now have a time frame for the evolution of animal light sensitivity," said study leader David Plachetzki, a UC Santa Barbara graduate student. "We know its precursors existed roughly 600 million years ago.

These findings, detailed in a recent issue of the online journal PLoS ONE, counter arguments by anti-evolutionists that evolution can only eliminate traits and cannot produce new features

Tags: origin, vision, sight, eyes, biology, evolution

Out-of-body experience recreated

Fri, 24 Aug 2007 08:56:56 GMT

clipped by: Amergin

Clip Source: news.bbc.co.uk

Experts have found a way to trigger an out-of-body experience in volunteers.

The experiments, described in the Science journal, offer a scientific explanation for a phenomenon experienced by one in 10 people.

Two teams used virtual reality goggles to con the brain into thinking the body was located elsewhere.

The visual illusion plus the feel of their real bodies being touched made volunteers sense that they had moved outside of their physical bodies.

The researchers say their findings could have practical applications, such as helping take video games to the next level of virtuality so the players feel as if they are actually inside the game.

We feel that our self is located where the eyes are

UCL researcher Dr Henrik Ehrsson

Their work suggests a disconnection between the brain circuits that process visual and touch sensory information may thus be responsible for some OBEs.

We feel that our self is located where the eyes are

UCL researcher Dr Henrik Ehrsson

Tags: disconnect floating release near nirvana

Longest Living Animal? Clam -- 400 Years Old -- Found In Icelandic Waters

Mon, 29 Oct 2007 15:36:49 GMT

clipped by: bellapria
clipper's remarks: Scientists have found a 400 year old clam....

Clip Source: www.sciencedaily.com

ScienceDaily (Oct. 29, 2007) — A clam dredged from Icelandic waters had lived for 400 years - is this the longest-lived animal known to science?

Can you imagine living for four centuries? A team of scientists from Bangor University's School of Ocean Sciences believe they have found an animal which did just that, a quahog clam, Arctica islandica, which was living and growing on the seabed in the cold waters off the north coast of Iceland for around 400 years.

According to the Guinness Book of Records, the existing record for the longest-lived animal belongs to a 220 year old Arctica clam collected in 1982 from American waters. Unofficially, the record belongs to a 374 year old Icelandic clam which was found in a museum. Both these records appear to have been eclipsed by the latest specimen, whose age, between 405 and 410 years, has been assessed by counting the annual growth lines in the shell.

Tags: 400 years old, clam, oldest animal

Hubble Heritage Image Gallery

Mon, 05 Nov 2007 20:56:06 GMT

clipped by: arifsali

Clip Source: heritage.stsci.edu

Tags: hubble, astronomy, pictures, space

Four dimensional picture of the Universe

Thu, 06 Sep 2007 10:44:03 GMT

clipped by: pokkets

Clip Source: aether.lbl.gov

Tags: universe, dimension, time space, big bang, history, picture

The universe... we're not the first

Fri, 27 Jul 2007 18:12:16 GMT

clipped by: BigBadWolf
clipper's remarks: I have always said there can't be something from nothingness without a grand creator. I am not sure which side of the fence I sit on now but in order to support my thoughts of the ever expanding and contracting universe, let me say that I don't feel time is what we think it is.

Clip Source: www.indiadaily.com

Physics finds what was there before the big bang – cyclical harmonic universe follows the echo of the chilled universe – birth, maintenance and implosion for rebirth
India Daily Technology Team
Jul. 26, 2007

Modern physics is finally clear about what there was before the big bang and what happened to initiate the big bang.

In the new research, Martin Bojowald of Pennsylvania State University pushes one of these theories back even further, to the time of a purported previous universe that contracted and "bounced" to form our own.

Our universe also follows the law of chilled universe physics. Everything is cyclical. They follow the rule of chilled universe physics. It is a cycle of birth, maintenance of life and then eventual destruction for rebirth.

Tags: space, universe, cosmos, science

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

The fish that can survive for months in a tree

Thu, 18 Oct 2007 11:26:25 GMT

clipped by: michellezm

Clip Source: www.dailymail.co.uk

t's one of the golden rules of the natural world – birds live in trees, fish live in water.

The trouble is, no one bothered to tell the mangrove killifish.

Scientists have discovered that it spends several months of every year out of the water and living inside trees

Hidden away inside rotten branches and trunks, the remarkable creatures temporarily alter their biological makeup so they can breathe air.

Biologists studying the killifish say they astonished it can cope for so long out of its natural habitat.

The discovery, along with its ability to breed without a mate, must make the mangrove killifish, Rivulus marmoratus Poey, one of the oddest fish known to man.

Around two inches long, they normally live in muddy pools and the flooded burrows of crabs in the mangrove swamps of Florida, Latin American and Caribbean.

The latest discovery was made by biologists wading through swamps in Belize and Florida who found hundreds of killifish hiding out of the water

Tags: fish, animals, fauna

Ancient Blueprints of Calculus Uncovered in Archimedes Text

Sat, 06 Oct 2007 19:20:11 GMT

clipped by: Kore7
clipper's remarks: Details have been released from the nine-year-long reconstruction project to recover the Greek mathematician's writings from this one-of-a-kind find and the results are fascinating.

Buried beneath the surface of this gilded palimpsest, researchers discovered more extensive demonstrations of concepts such as infinite series, approximations, limits, and integral calculus than had been known to exist in ancient times.

Archimedes wrote The Method almost two thousand years before Isaac Newton and Gottfried Wilhelm von Leibniz developed calculus in the 1700s. Reviel Netz, an historian of mathematics at Stanford University who transcribed the text, says that the examination of Archimedes' work has revealed "a new twist on the entire trajectory of Western mathematics."

Clip Source: www.sciencenews.org

A long-lost text by the ancient Greek mathematician shows that he had begun to discover the principles of calculus.

The top layer of writing in this 700-year-old book describes Christian prayers. But underneath, almost obliterated, are the only surviving copies of many of the works of the ancient Greek mathematician Archimedes.

The picture on the left is an ordinary photograph, with the Archimedes text barely visible. The picture on the right is a multi-spectral image, and the Archimedes text and diagrams are mostly legible.

Sometime after Johan Heiberg examined the book in 1906, someone painted gold-leaf images over four of the pages (left). Multispectral imaging couldn't peer beneath the reflective metal paint, but x-ray fluorescence imaging revealed the underlying text (right).

Archimedes computed the area of the curved figure (left) by enclosing it in a bigger one with straight edges (right). He then examined random slices to compute the volume—using the concept of actual infinity.

Tags: math, science, archimedes, calculus, infinity, greek, ancient, history, x-ray, book

Chakras and their meanings

Sun, 22 Jul 2007 06:39:46 GMT

clipped by: clipette
clipper's remarks: pretty interesting to see how they relate to the glands in the body.

Clip Source: www.crystalinks.com

The highest crown chakra is said to be the chakra of consciousness, the master chakra that controls all the others.

The Ajna Chakra, or third eye, is linked to the pineal gland. Ajna is the chakra of time and awareness and of light.

The throat chakra, Vishuddha, is said to be related to communication and growth, growth being a form of expression.

The heart chakra, Anahata, is related to love, equilibrium, and well-being. I

The solar plexus chakra, Manipura, is related to energy, assimilation and digestion

The sacral chakra, Swadhisthanna, is located in the groin, and is related to emotion, sexuality and creativity

The base or root chakra, Muludhara, is related to security, survival and also to basic human potentiality

Tags: chakras, glands

Da Vinci's masterpiece "The Last Supper" Online (Fantastic)

Sun, 28 Oct 2007 23:34:03 GMT

clipped by: BobbyDelray
clipper's remarks: Absolutely fantastic. High resolution. Must be seen. Please share with friends.

Clip Source: news.aol.com

Can't get to Milan to see Leonardo Da Vinci's masterpiece "The Last Supper?" As of Saturday, all you need is an Internet connection. Officials put online an image of the "Last Supper" at 16 billion pixels - 1,600 times stronger than the images taken with the typical 10 million pixel digital camera.

The high resolution will allow experts to examine details of the 15th century wall painting that they otherwise could not - including traces of drawings Leonardo put down before painting.

Clip Source: www.haltadefinizione.com

Clip Source: news.aol.com

See It for Yourself: 'The Last Supper' in Detail

Photo Gallery: Da Vinci Mysteries

Antonio Calanni, AP

Now that a detailed copy of Leonardo Da Vinci's 'The Last Supper' is online, experts are likely to discover more about the famous 15th-century painting. In July, Slavisa Pesci claimed he found hidden figures in it.

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Tags: da vinci, masterpiece, "the last supper", the last supper, haltadefinizione

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

The Society to Save Rocks

Mon, 20 Aug 2007 17:35:44 GMT

clipped by: adamc

Clip Source: saverocks.org

The Society to Save Rocks aims to preserve and protect the spectacular ancient granite formations of the Deccan Plateau, India - a natural wonder of stony ridges and hillocks shaped into picturesque balancing forms.

To prevent the indiscriminate destruction of this natural, historical, and environmental heritage, a group of artists, photographers and environmentalists from Hyderabad* has been working for the protection of this rocky landscape since 1992.

Tags: rocks, india

India's air-powered car

Mon, 20 Aug 2007 16:41:30 GMT

clipped by: killer_bunny

Clip Source: www.engadget.com

The first commercial car to be powered by compressed air could be about to hit the production lines, as Indian automaker Tata Motors prepares to build ex-Formula One engineer Guy Nègre's design. We're not certain if it's the same air car that we hit just under three years ago, but if it is, it's about time! The City Cat runs on nothing but compressed air -- which can be refueled at "air stations," and overnight using a built-in compressor -- with a not too shabby top speed of 68MPH and a range of 125 miles. The Air Car designers are working on a hybrid version that can compress air while it's operating, potentially making cross-India journeys possible: Toyota Prius, eat your hybrid heart out. As EcoGeek points out, the game ain't up just yet for completely emissions free travel since the problem of the source of the electricity (usually acquired from fossil fuels) has yet to be solved. Plus, the fugly design really doesn't do it any favours: why does "green" have to mean "gah?"

Tags: car, automobile, green, india