July 29, 2006, 8:26 PM CT

Insights Into Scientific Revolution

With the "Genesis of General Relativity", the Max Planck Institute for the History of Science (MPIWG) has just published the most comprehensive study to date of the structures of a scientific revolution. As per the study, a scientific revolution is not a simple radical new beginning, but the result of a new organisation of transmitted knowledge. The result of 10 years of research, this four-volume, 2000-page work on the origins of Einstein's General Relativity Theory - one of the most important physical theories of the 20th century - will appear in the Springer Press. Jürgen Renn, Director at the Max Planck Institute, will present the work, of which he is also the editor, to the scientific public at the 11th Marcel Grossmann Meetings, which will take place in Berlin on 24 - 29 July, 2006. The work, which is the result of an international team of authors, contains new insights into the premises, assumptions, and preconditions that underlie Einstein's scientific revolution, as, for instance, insights into the role of Einstein's previously largely unknown precursors and competitors for a theory which today represents the basis of modern cosmology.

"Einstein did not achieve this revolution by means of a single stroke of genius-rather, he stood on the shoulders of dwarves and giants", says Jürgen Renn. Volumes 1 and 2 contain the facsimile and transcription of, as well as a scholarly commentary on, Einstein's famous Zurich Notebook from 1912-1913. The research by Einstein recorded in this notebook forms a pivotal part of his creation of the theory of general relativity. Complementing this core material are essays re-evaluating the genesis of Einstein's theory in light of the analysis of this notebook. Volumes 3 and 4 contain additional sources by Einstein and his contemporaries, who from the late nineteenth to the early twentieth century contributed to this groundbreaking development. These sources, most of which are presented here in translation for the first time, are accompanied by essays by leading historians of relativity offering new insights into the broader scientific context from which Einstein's theory emerged. The result of more than a decade of research, these four volumes provide a study of unprecedented depth of one of the most important revolutions in the history of science.........

Posted by: Sean      Permalink         Source

July 28, 2006, 9:48 PM CT

Making Clearer Pictures

Software makes pictures clearer.

Software helps astronomers see what's hidden in noisy and blurred images of stars and galaxies. Metropolis Data Consultants uses the same techniques to give doctors and the police clearer pictures to work on.

Astronomers use all sorts of telescopes to explore outer space. Some are optical telescopes - bigger and better versions of those you might have at home. Using lenses and mirrors, they make distant objects seem much nearer than they are.

Other telescopes look for radio waves, x-rays and other types of radiation. They give astronomers a different view of the universe - one that deepens their understanding.

But whichever they use, the problem for astronomers is the same. When they're looking at faint objects far out into space, they don't get perfect pictures.

Blur and noise.

To start with, things move. The Earth is rotating, for example, and the satellites that carry telescopes aren't absolutely stationary. Blurring is inevitable.

To make things even worse, some kinds of telescope add noise to the picture. When the image itself is faint, the result is the sort of picture you get when your TV isn't tuned in properly. You can see that something is there but you can't see it clearly.........

Posted by: Sean      Permalink         Source

July 25, 2006, 8:47 PM CT

Wide Awake on the Sea of Tranquillity

Neil Armstrong was supposed to be asleep. The moonwalking was done. The moon rocks were stowed away. His ship was ready for departure. In just a few hours, the Eagle's ascent module would blast off the Moon, something no ship had ever done before, and Neil needed his wits about him. He curled up on the Eagle's engine cover and closed his eyes.

But he could not sleep.

Neither could Buzz Aldrin. In the cramped lander, Buzz had the sweet spot, the floor. He stretched out as much as he could in his spacesuit and closed his eyes. Nothing happened. On a day like this, sleep was out of the question.

The day began on the farside of the Moon. Armstrong, Aldrin and crewmate Mike Collins flew their spaceship 60 miles above the cratered wasteland. No one on Earth can see the Moon's farside. Even today it remains a land of considerable mystery, but the astronauts had no time for sight-seeing. Collins pressed a button, activating a set of springs, and the spaceship split in two. The half named Columbia, with Collins on board, would remain in orbit. The other half, the Eagle, spiraled over the horizon toward the Sea of Tranquillity.

"You are Go for powered descent," Houston radioed, and the Eagle's engine fired mightily. The bug-shaped Eagle was so fragile a child could poke a hole through its gold foil exterior. Jagged moonrocks could do much worse. So when Armstrong saw where the computer was guiding them--into a boulder field--he quickly took control. The Eagle pitched forward and sailed over the rocks.........

Posted by: Sean      Permalink         Source

July 19, 2006, 11:24 PM CT

Cluster Hits The Magnetic Bull's-eye

ESA's spacecraft constellation Cluster has hit the magnetic bull's-eye. The four spacecraft surrounded a region within which the Earth's magnetic field was spontaneously reconfiguring itself.

This is the first time such an observation has been made and gives astronomers a unique insight into the physical process responsible for the most powerful explosions that can occur in the Solar System: the magnetic reconnection.

When looking at the static pattern of iron filings around a bar magnet, it is difficult to imagine how changeable and violent magnetic fields can be in other situations.

In space, different regions of magnetism behave somewhat like large magnetic bubbles, each containing electrified gas known as plasma. When the bubbles meet and are pushed together, their magnetic fields can break and reconnect, forming a more stable magnetic configuration. This reconnection of magnetic fields generates jets of particles and heats the plasma.

At the very heart of a reconnection event, there must be a three dimensional zone where the magnetic fields break and reconnect. Researchers call this region the null point but, until now, have never been able to positively identify one, as it requires at least four simultaneous points of measurements.........

Posted by: Sean      Permalink         Source

July 17, 2006, 7:17 PM CT

Lightning Shared The Sky With A Rainbow

When a rainbow formed in the sky people stopped and stared at the natural wonder.

But then lightning sparked across the evening panorama as two of nature's most spectacular phenomenon created an unusual alliance.

The clash of weather was seen above the affluent city of Fort Smith, in the Southern state Arkansas.

One onlooker said: "It was awe inspiring. The lightning made a huge rumbling sound and when you looked up there was also this incredible rainbow forming on the horizon".........

Posted by: Sean      Permalink         Source

July 9, 2006, 8:36 PM CT

Gassendi crater

This mosaic of two images, taken by the advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, shows the inside of crater Gassendi on the Moon.

AMIE obtained these images on 13 January 2006, one minute apart from each other, from a distance of about 1220 kilometres (top frame) and 1196 kilometres (bottom frame) from the surface, with a ground resolution of 110 and 108 metres per pixel, respectively.

The area shown in the top image is centred at a latitude of 16.2º South and longitude 40.2º West, while the bottom images is centred at a latitude of 17.9º South and longitude 40.2º West.

Gassendi is an impact feature located on the near side of the Moon, at the northern edge of Mare Humorum. The crater is actually much larger than the field of view visible in this image. The hills on the lower right of the mosaic are the central peak of the crater, with a height of roughly 1.2 kilometres. The crater almost fully visible on the top is called 'Gassendi A'.

Gassendi is a scientifically interesting site because it offers lunar landers the possibility of sampling ancient highland rocks (in the crater's central peak) as well as providing ages for both the Humorum impact basin and the Gassendi crater itself. However, because the terrain just outside the crater is quite rough, if a crew landed in this region, it would be pretty difficult to reach Gassendi's central peaks for sampling. Gassendi was considered as one of the three potential sites for the Apollo 17 mission, that eventually touched ground in the Taurus-Littrow valley.........

Posted by: Sean      Permalink

June 26, 2006, 11:04 PM CT

Enceladus

Enceladus [en-SELL-ah-dus] is one of the brightest objects in our solar system. Covered in water ice that reflects sunlight like freshly fallen snow, Enceladus reflects almost 100 percent of the sunlight that strikes it. Because Enceladus reflects so much sunlight, the surface temperature is extremely cold, about -201 degree C (-330 degree F).

About as wide as Arizona, Enceladus is quite similar in size to Mimas but has a smoother, brighter surface. Unlike Mimas, Enceladus displays at least five different types of terrain. Parts of the moon show craters no larger than 35 kilometers (about 22 miles) in diameter. Other areas show regions with no craters indicating major resurfacing events in the geologically recent past. There are fissures, plains, corrugated terrain and other crustal deformations. All of this indicates that the interior of the moon may be liquid today, even though it should have been frozen eons ago. Enceladus' surface is thought to begeologically "young," possibly less than 100 million years old.........

Posted by: Sean      Permalink         Source

June 18, 2006, 11:56 AM CT

Astronomers Planning Close-ups Of Mars

The two Mars rovers, Spirit and Opportunity, have accomplished more than their creators thought possible. Stoic, plodding and reliable, they have muscled across the planet's rugged terrain for more than two years, collecting data about the composition of its rocks and soils in the process.

Even the most dogged workhorses, however, have limitations. In their entire time on the planet, the slow-moving rovers have traversed less than 10 square miles, and their sensors cannot collect data more than a few feet above the ground.

To survey areas of the planet that remain unknown, scientists affiliated with the privately financed German Mars Society in Munich are proposing a different kind of explorer: a vehicle inspired more by dirigibles like the Hindenburg than by land-rover predecessors. Projected to reach Mars in 2009, the balloon craft, named Archimedes, would hover much closer to the planet's surface than a satellite, snapping crisp, full-color images similar to those that an Earth photographer might take from a helicopter.........

Posted by: Sean      Permalink         Source

June 18, 2006, 11:51 AM CT

The Sky is Falling

Every day, more than a metric ton of meteoroids hits the Moon," says Bill Cooke of the Marshall Space Flight Center's Meteoroid Environment Office. They literally fall out of the sky, in all shapes and sizes, from specks of comet dust to full-blown asteroids, traveling up to a hundred thousand mph. And when they hit, they do not disintegrate harmlessly in the atmosphere as most would on Earth. On the airless Moon, meteoroids hit the ground.

Apollo astronauts were never bothered by these projectiles. The Moon has a surface area roughly equal to the continent of Africa. "If you spread the impacts over so much terrain, the probability of being hit is very low," says Cooke. It helped that the astronauts didn't stay long: Adding all Apollo missions together, they were on the lunar surface less than two weeks. "The odds of being hit during such a short time were, again, very low".

But what about next time? Following the Vision for Space Exploration, NASA is sending astronauts back to the Moon to stay longer and build bigger bases (read: bigger targets) than Apollo astronauts ever did. The odds of something precious being hit will go up. Should NASA be worried?

That's what Cooke and MSFC colleague Anne Diekmann are trying to find out.

The truth is, "we really don't know how a number of meteoroids hit the Moon every day," he says. "Our best estimates come from the 'Standard Meteoroid Model,' which NASA uses to evaluate hazards to the space station and the space shuttle." Problem: The Standard Model is based mainly on Earth-data, e.g., satellite observations of meteoroids hitting Earth's upper atmosphere and human observations of meteors flitting across the night sky. "The Standard Model may not work well for the Moon".........

Posted by: Sean      Permalink         Source

June 18, 2006, 11:35 AM CT

Russia to Land on Mars in 2009

The Russians are gearing up for a mission to Mars and one of its moons in 2009. As per Russia's space agency, it is planning to send a space exploration capsule up to the Red Planet to analyze its surface and also collect test samples from one of its moons.

The launching of the space exploration capsule, 'Phobos-Grunt' is scheduled for October 2009. It will take three years for the expedition to complete. At its first stage, the capsule will be bringing back samples of soil from Mars' natural satellite planet Phobos to Earth.

The samples will help research in details in laboratory conditions. The scientists think that this study will be able to answer or come close to decoding a wide spectrum of scientific questions on the physics of the solar system, the space agency hopes.........

Posted by: Sean      Permalink         Source

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