Clipmarks | Aribeth's 'astronomy' clips

Secrets of Antikythera Mechanism, world's oldest calculating machine, revealed

Wed, 30 Jul 2008 19:45:58 GMT

clipped by: Beholder

The secrets of the worlds oldest calculating machine are revealed today, showing that it had dials to mark the timing of eclipses and the Olympic games.

The dictionary sized crumbly lump containing corroded fragments of what is now known to be a marvellous hand cranked machine is known as the 'Antikythera Mechanism' because it was discovered near the tiny island of Antikythera, between Crete and mainland Greece.

"We knew that this 2,100 year-old ancient Greek mechanism calculated complex cycles of mathematical astronomy. It really surprised us to discover that it also showed the four-year cycle of ancient Greek games," reports Dr Tony Freeth of Images First, a TV company, and three academic colleagues today in the journal Nature.

Earlier work on the mechanism, which dates to around 150 to 100 BC, showed it displays the date, positions of the Sun and Moon (including its variable motion), the phase of the Moon, a complex 19-year calendar and sophisticated eclipse prediction dials.

Tags: archeology, antiques, antikythera

Could Jupiter wreck the solar system?

Sun, 04 May 2008 12:13:24 GMT

clipped by: Aribeth
clipper's remarks: "So what's the likelihood Mercury could crash into the Earth? If it did, the asteroid that most likely wiped out the dinosaurs will seem like a drop in the ocean compared with a planet 4880 km in diameter slamming into us. There will be very little left after this wrecking ball impact.

But here's the kicker: There is only a 1% chance that these gravitational instabilities of the inner Solar System are likely to cause any kind of chaos before the Sun turns into a Red Giant and swallows Mercury, Venus, Earth and Mars in 7 billion years time. So, no need to look out for death-wish Mercury quite yet… there's a very low chance that any of this will happen. But some good news for Mars; the researchers have also found that if the chaos does ensue, the Red Planet may be flung out of the Solar System, possibly escaping our expanding Sun. So, let's get those Mars colonies started! Well, within the next few billions of years anyhow…"

Good stuff for the next science-fiction movie

Clip Source: www.universetoday.com

Could Jupiter Wreck the Solar System?

Happily orbiting the Sun, the eight planets (plus Pluto and other minor planets) appear to have a high degree of long-term gravitational stability. But Jupiter has a huge gravitational influence over its siblings, especially the smaller planets.

The huge gravitational pull of Jupiter seems to be bullying Mercury into an increasingly eccentric death-orbit, possibly flinging the cosmic lightweight into the path of Venus. To make things worse, there might be dire consequences for Earth…

The researchers

Jacques Laskar

Konstantin Batygin

and Gregory Laughlin

formulate four possible scenarios as to what may happen as Mercury gets disturbed:

Mercury will crash into the Sun
Mercury will be ejected from the solar system altogether
Mercury will crash into Venus
Mercury will crash into Earth

The last option is obviously the worst case scenario for us, but all will be bad news for Mercury, the small planet's fate appears to be sealed.

Tags: science, space, astronomy

The man who invented Mars

Mon, 28 Apr 2008 18:02:29 GMT

clipped by: Aribeth
clipper's remarks: It is Lowell's vision of Mars that has enthralled and inspired earthlings ever since.In 1895, Lowell published a book about what he believed he saw.He became famous and immensely popular.Lowell was born at 131 Tremont Street in Boston on March 13,1855,into a family at the pinnacle of what passed for American aristocracy.

The appearance of Lowell's book about Mars in 1895 came at a time of canal-building on earth. The Suez had recently been constructed; the Panama was in the works. For both Lowell and his adoring public, the prospect of canals on a neighboring planet was too captivating to dismiss.

He published his second book about the Red Planet, Mars and Its Canals, in 1906.In 1908, he published his third and final book on the planet, Mars as the Abode of Life.

Back at his observatory on Mars Hill, Lowell renewed his attention to another matter: the possibility of a ninth planet beyond Neptune, which he called "Planet X."

Clip Source: www.boston.com

The Man Who Invented Mars

Long before the space race and space shuttle, a brilliant, wealthy, charming Boston Brahmin named Percival Lowell popularized the idea that we are not alone in the universe.

At left, a colorized version of a 1905 drawing of Mars by Lowell; at right, an artist’s concept of the Phoenix Mars lander.

AT 7:36 P.M. ON May 25, if all goes well, a stranger from Earth will land near the north pole of Mars. It is called Phoenix.

Somewhere, a 19th century Boston Brahmin named Percival Lowell will be smiling.

Long before NASA was established in 1958

Percival Lowell devoted much of his career and considerable fortune to trying to prove that Mars hosted intelligent life. Viewed through his telescopes, the ancient, baleful Red Planet was about the size of a dime.

Lowell believed he was seeing a network of canals on its surface. Therefore, he declared, Mars holds intelligent life. It is not necessarily like human life, he emphasized, but it is intelligent enough to build canals.

Tags: science, space, astronomy

Pluto lovers,don't despair

Fri, 11 Apr 2008 08:13:29 GMT

clipped by: Aribeth

Clip Source: www.sciam.com

Is Rekindling the Pluto Planet Debate a Good Idea?

Pluto lovers, don't despair: Researchers have not given up the fight for the former ninth planet. Many of them put up a fuss two years ago when the International Astronomical Union (IAU) downgraded Pluto and other smaller bodies in the solar system to the status of mere dwarf planets. Now they plan to revive the debate, this time under the banner of public understanding of science.

Researchers on both sides of the issue are set to gather in August at Johns Hopkins University Applied Physics Laboratory in Laurel, Md., for what's being called "The Great Planet Debate: Science as Process."

Pluto has always stood out from the other planets. At roughly a fifth the mass of the moon, it is the largest of the icy bodies that make up the Kuiper belt beyond Neptune's orbit. Unlike the four inner (terrestrial) planets, it has a tenuous atmosphere at best.

Tags: astronomy, science

The Ancient Mechanics and How They Thought

Wed, 02 Apr 2008 11:12:51 GMT

clipped by: Aribeth
clipper's remarks: He also majored in astronomy as an undergraduate, and about nine years ago, feeling science-deprived, he joined a multinational research endeavor called the Archimedes Project, based at the Max Planck Institute for the History of Science in Berlin.

The Archimedes team studies the history of mechanics, how people thought about simple machines like the lever, the wheel and axle, the balance, the pulley, the wedge and the screw and how they turned their thoughts into theories and principles.

The textual record begins with “Mechanical Problems,” moves to Rome and then through the medieval Islamic world to the Renaissance. It ends, finally, with Newton, who described many of the basic laws of mechanics in the 18th century.

By following the historical record, the Archimedes researchers have discovered that the evolution of physics — or, at least, mechanics — is based on an interplay between practice and theory.

Clip Source: www.nytimes.com

LAW OF THE LEVER On triremes, the end oarsmen were the most effective.

“Think of the oar as a lever,” Prof. Mark Schiefsky of the Harvard classics department said. “Think of the oarlock as a fulcrum, and think of the sea as the weight.”

The longer the lever arm on the rower’s side of the fulcrum, the easier to move the weight. In the middle of the ship, as the rowers knew, the distance from hands to oarlock was longest.

This explanation is given in Problem 4 of the classical Greek treatise “Mechanical Problems,” from the third century B.C., the first known text on the science of mechanics and the first to explain how a lever works. It preceded, by at least a generation, Archimedes’ “On the Equilibrium of Plane Figures,” which presented the first formal proof of the law of the lever.

EARTHMOVER Archimedes said he could move the Earth if given a place to stand.

Dr. Schiefsky teaches Greek and Latin as his day job and reads Thucydides and Sophocles in ancient Greek for fun.

Tags: physics, ancient mechanics, science, classics, research, archimedes project

Great Moon Pics from Space.com

Fri, 08 Feb 2008 03:15:20 GMT

clipped by: CrazyRedHead

Clip Source: www.space.com

Moon over Tucson

a spectacular view of the Moon over Tucson from Kitt Peak National Observatory

Clip Source: www.space.com

Close Encounter

Mars and the Moon's close encounter, as viewed from Tampa, Florida

Clip Source: www.space.com

Red Hot Moon

Lunar Eclipse of 1996

Clip Source: www.space.com

Over Blue Skies

photo of the Moon visible in the blue sky

Clip Source: www.space.com

Crescent Moon

Reflecting sunlight ignites the moon's limb into a fiery crescent

Clip Source: www.space.com

Glowing Moon

The Moon is superimposed on a separate image of the sky.

Clip Source: www.space.com

Above the Airglow

A full moon is visible in this view above Earth's horizon and airglow

Clip Source: www.space.com

Earthshine

the Moon is illuminated solely by light from the Sun that is reflected from the Earth

The Sun is just behind the Moon, creating the glow.

Clip Source: www.space.com

Earthrise

One of the most famous pictures to come from Apollo is this view of Earth rising over the lunar surface as seen by the crew of Apollo 8

Clip Source: www.space.com

Moon in Shadow

Photo of Moon taken from Long Island, NY

Clip Source: www.space.com

Lunar Legacy

For some, the images of those moonwalks were unforgetable

Others still don't believe it happened.

Tags: science, space, moon, astronomy

Astronomy Picture of the Day

Fri, 04 Jan 2008 13:40:29 GMT

clipped by: mickfinn

Clip Source: antwrp.gsfc.nasa.gov

Water On Mars
Credit & Copyright: Ellen Roper (GCC)

Tags: april fool 2005

Black Holes Are Everywhere!

Sat, 10 Nov 2007 19:25:45 GMT

clipped by: Marcariel
clipper's remarks: So when do we all get swallowed up by a giant black hole? There is a black hole reportedly at the center of our own galaxy.

Clip Source: time-blog.com

The circled galaxies all contain giant black holes. / NASA/JPL-Caltech/ Commissariat a l'Energie Atomique

Theory says that most of the galaxies formed shortly after the Big Bang should have giant black holes lurking in their cores--but until now, astronomers haven't seen much evidence. You can't see a black hole directly, but when gas falls into its voraciously powerful gravitational field, the gas heats up and glows brilliantly. Except that so far, it hasn't, as far as observers could tell.

But it turns out that at least some black holes have been blazing all along; they were just shrouded by dust. It took the infrared-sensitive Spitzer Space Telescope to peer through the dust, and the Chandra X-Ray Observatory (also in space) to find the telltale X-rays that betray the presence of super-hot gas that surrounds the black holes.

That's one mystery down. Luckily for science reporters, there are always more.

Tags: astronomy, black holes, galaxies, space dust, big bang

The Moon in Amazing Detail

Sun, 21 Oct 2007 13:47:28 GMT

clipped by: axelsenzon

Clip Source: www.boredstop.com

Tags: pics, astronomy

Giant Diamond in Space

Wed, 17 Oct 2007 07:09:46 GMT

clipped by: AndreaJoRush

Clip Source: www.dailygalaxy.com

A Diamond Bigger than Earth Discovered in Constellation Centaurus

The Harvard-Smithsonian Center for Astrophysics has announced the discovery of a mass of crystallized carbon formerly known as star BPM 37093, now known as the biggest diamond in the galaxy, fifty light years away from Earth in the constellation Centaurus.

The star, named "Lucy" after the Beatles song, "Lucy in the Sky with Diamonds," is estimated to be 2,500 miles across and weighs approximately 10 billion-trillion-trillion-carats

The diamond is actually the crystallized interior of a white dwarf – or the hot core of a star that is left over after the star uses up its nuclear fuel and dies. It is made mostly of carbon and is coated by a thin layer of hydrogen and helium gases.

Tags: astronomy

Sunspot Photo

Tue, 16 Oct 2007 23:30:44 GMT

clipped by: AndreaJoRush

Clip Source: antwrp.gsfc.nasa.gov

The Sharpest View of the Sun
Credit: SST, Royal Swedish Academy of Sciences

This stunning image shows remarkable and mysterious details near the dark central region of a planet-sized sunspot in one of the sharpest views ever of the surface of the Sun.

Along with features described as hairs and canals are dark cores visible within the bright filaments that extend into the sunspot, representing previously unknown and unexplored solar phenomena. The filaments' newly revealed dark cores are seen to be thousands of kilometers long but only about 100 kilometers wide. Resolving features 100 kilometers wide or less is a milestone in solar astronomy

Recorded on 15 July 2002, the sunspot shown is the largest of the group of sunspots cataloged as solar active region AR 10030.

Tags: photos, sun, astronomy

The Worst Mistake in the History of the Human Race

Sat, 16 Jun 2007 18:17:24 GMT

clipped by: chiggles
clipper's remarks: An oldie but a goodie, not on clipmarks elsewhere (so far as my searches have shown). Written by Jared Diamond two decades back. Before being critical, read the entire article please. If you think the anthropology is somehow flawed, I suggest Anthropik's Thirty Theses ( http://anthropik.com/thirty ), which cover a lot of ground.

Clip Source: www.agron.iastate.edu

To science we owe dramatic changes in our smug self-image. Astronomy taught us that our earth isn’t the center of the universe but merely one of billions of heavenly bodies. From biology we learned that we weren’t specially created by God but evolved along with millions of other species. Now archaeology is demolishing another sacred belief: that human history over the past million years has been a long tale of progress. In particular, recent discoveries suggest that the adoption of agriculture, supposedly our most decisive step toward a better life, was in many ways a catastrophe from which we have never recovered. With agriculture came the gross social and sexual inequality, the disease and despotism, that curse our existence.

Tags: diamond, agriculture, progress, hunting, collapse, doom

The Hubble Deep Field: The Most Important Image Ever Taken

Wed, 18 Apr 2007 22:50:03 GMT

clipped by: mcgraf

Clip Source: video.stumbleupon.com

[Video]

Tags: astronomy, science

The Heliocentric system on the ancient floor of the Tholos of Epidaurus!

Tue, 17 Apr 2007 10:14:04 GMT

clipped by: astronkyttaron

Clip Source: www.altani.gr

The pavement in the interior of the Tholos

Clip Source: www.altani.gr

Heliocentric system
In the interior pavement

Clip Source: www.altani.gr

TOTAL DATA OF THE PLANETARY SYSTEM
ON THE PAVEMENT OF THE THOLOS

Clip Source: www.altani.gr

Precession of the Equinoxes

Clip Source: www.altani.gr

The apparent course of the Sun
on the outer coronna of the Tholos

Clip Source: www.altani.gr

The labyrinth of the Tholos

Clip Source: www.altani.gr

The hidden meaning of the name "Epidaurus"

In this sacred name all the letters, used in different combinations, give additional details, concerning the quality of the vibrations of the supreme holy, healing sanctuary of Epidaurus, and that of the activities, which used to take place there.

Tags: ancient greece, civilization, culture, geometry, mathematics, math, astronomy