SciTech Quiz

Barred spiral galaxy

2007-10-24T23:16:00.000-07:00

A barred spiral galaxy is a spiral galaxy with a band of bright stars emerging from the center and running across the middle of the galaxy..

For more information about the topic Barred spiral galaxy, read the full article at Wikipedia.org, or see the following related articles:

Radio telescope

2007-10-24T23:11:00.001-07:00

A radio telescope is a form of radio receiver used in astronomy.

In contrast to an "ordinary" telescope, which receives visible light, a radio telescope "sees" radio waves emitted by radio sources, typically by means of a large parabolic ("dish") antenna, or arrays of them.

Many celestial objects, such as pulsars or active galaxies (like quasars), produce radio-frequency radiation and so are best "visible" or even only visible in the radio region of electromagnetic spectrum.

By examining the frequency, power and timing of radio emissions from these objects, astronomers can improve our understanding of the Universe.

Radio telescopes are also the primary means to track space probes, and are used in the SETI project..

For more information about the topic Radio telescope, read the full article at Wikipedia.org, or see the following related articles:

Spitzer space telescope

2007-10-24T23:08:00.000-07:00

Spitzer Space Telescope (formerly the Space Infrared Telescope Facility [SIRTF]) is an infrared space observatory, the fourth and final of NASA's Great Observatories.

The first images taken by SST were designed to show off the abilities of the telescope and showed a glowing stellar nursery; a swirling, dusty galaxy; a disc of planet-forming debris; and organic material in the distant universe.

In March of 2006, astronomers reported an 80 light year-long nebula near the center of the Milky Way Galaxy, the Double Helix Nebula, which is, as the name implies, twisted into a double spiral shape.

This is thought to be evidence of massive magnetic fields generated by the gas disc orbiting the supermassive black hole at the galaxy's center, 300 light years from the nebula and 25,000 light years from Earth.

This nebula was discovered by the Spitzer Space Telescope..

For more information about the topic Spitzer space telescope, read the full article at Wikipedia.org, or see the following related articles:

Planetary nebula

2007-10-24T23:05:00.001-07:00

A planetary nebula is an astronomical object consisting of a glowing shell of gas and plasma formed by certain types of stars at the end of their lives.

They are in fact unrelated to planets; the name originates from a supposed similarity in appearance to giant planets.

They are a short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years.

About 1,500 are known to exist in the Milky Way Galaxy.

Planetary nebulae are important objects in astronomy because they play a crucial role in the chemical evolution of the galaxy, returning material to the interstellar medium which has been enriched in heavy elements and other products of nucleosynthesis (such as carbon, nitrogen, oxygen and calcium).

In other galaxies, planetary nebulae may be the only objects observable enough to yield useful information about chemical abundances..

For more information about the topic Planetary nebula, read the full article at Wikipedia.org, or see the following related articles:

Red supergiant star

2007-10-24T23:03:00.000-07:00

Red supergiants are supergiant stars of spectral type K-M and a luminosity class of I.

They are the largest stars in the universe in terms of physical size, although they are not the most massive.

Stars with more than about 10 solar masses, after burning their hydrogen become red supergiants during their helium-burning phase.

These stars have very cool surface temperatures (3500-4500 K), and enormous radii.

The four largest known red supergiants in the Galaxy are Mu Cephei, KW Sagitarii, V354 Cephei, and KY Cygni, which all have radii about 1500 times that of the sun (about 7 astronomical units, or 7 times as far as the Earth is from the sun).

The radius of most red giants is between 200 and 800 times that of the sun, which is still enough to reach from the sun to Earth and beyond..

For more information about the topic Red supergiant star, read the full article at Wikipedia.org, or see the following related articles:

Star cluster

2007-10-24T22:44:00.000-07:00

Star clusters are groups of stars which are gravitationally bound.

Two distinct types of star cluster can be distinguished: globular clusters are tight groups of hundreds of thousands of very old stars, while open clusters generally contain less than a few hundred members, and are often very young..

For more information about the topic Star cluster, read the full article at Wikipedia.org, or see the following related articles:

Quasar

2007-10-24T22:41:00.000-07:00

A quasar is an astronomical source of electromagnetic energy, including light, which shows a very high redshift.

The scientific consensus is that this high redshift is the result of Hubble's law.

This implies that quasars are very distant.

To be observable at that distance, the energy output of quasars must dwarf that of almost every known astrophysical phenomenon with the exception of comparatively short-lived supernovae and gamma-ray bursts.

They may readily release energy in levels equal to the output of hundreds of average galaxies combined.

The output of light is equivalent to one trillion suns.

Quasars are believed to be powered by accretion of material onto supermassive black holes in the nuclei of distant galaxies, making these luminous versions of the general class of objects known as active galaxies.

No other currently known mechanism appears able to explain the vast energy output and rapid variability..

For more information about the topic Quasar, read the full article at Wikipedia.org, or see the following related articles:

Edwin Hubble

2007-10-24T22:36:00.000-07:00

Edwin Powell Hubble (November 20, 1889 - September 28, 1953) was an American astronomer, noted for his discovery of galaxies beyond the Milky Way and the cosmological redshift.

Edwin Hubble was one of the leading astronomers of modern times and laid down the foundation upon which physical cosmology now rests.

Hubble's observations in 1923–1924 with the Hooker Telescope established beyond doubt that the fuzzy "nebulae" seen earlier with less sensitive telescopes were not part of our galaxy, as had been thought, but were galaxies themselves, outside the Milky Way.

He announced this discovery on January 1, 1925. Hubble also devised a classification system for galaxies, grouping them according to their content, distance, shape, size and brightness.

Hubble was generally incorrectly credited with discovering the redshift of galaxies..

For more information about the topic Edwin Hubble, read the full article at Wikipedia.org, or see the following related articles:

Cepheid variable

2007-10-24T22:32:00.000-07:00

A Cepheid variable or Cepheid is a member of a particular class of variable stars, notable for a fairly tight correlation between their period of variability and absolute luminosity.

Since the period-luminosity relation can be calibrated with great precision using the nearest Cepheid stars, the distances found with this method are among the most accurate available..

For more information about the topic Cepheid variable, read the full article at Wikipedia.org, or see the following related articles:

Supergiant — Supergiants are the most massive stars. Supergiants can have masses from 10 to 70 solar masses and brightness from 30,000 up to hundreds of thousands ... > read more

Red giant — A red giant is a large non-main sequence star of stellar classification K or M; so-named because of the reddish appearance of the cooler giant stars. ... > read more

Luminosity — In general physics, luminosity (more properly called luminance) is the density of luminous intensity in a given ... > read more

Star cluster — Star clusters are groups of stars which are gravitationally bound. Two distinct types of star cluster can be distinguished: globular clusters are ... > read more

Supergiant

2007-10-24T22:28:00.000-07:00

Supergiants are the most massive stars.

Supergiants can have masses from 10 to 70 solar masses and brightness from 30,000 up to hundreds of thousands times the solar luminosity.

They vary greatly in radii, usually from 30 to 500, or even in excess of 1000 solar radii.

Because of their extreme masses they have short lifespans of only 10 to 50 million years and are only observed in young cosmic structures such as open clusters, the arms of spiral galaxies, and in irregular galaxies.

They are less abundant in spiral galaxy bulges, and are not observed in elliptical galaxies, or globular clusters, all of which are believed to be composed of old stars.

Currently, the largest known stars in terms of physical size, not mass or luminosity, are the supergiants VV Cephei, V354 Cephei, KW Sagitarii, KY Cygni, and the Garnet Star..

For more information about the topic Supergiant, read the full article at Wikipedia.org, or see the following related articles:

Blue supergiant star — Blue supergiants are supergiant stars (class I) of spectral type O. They are extremely hot and bright, with surface temperatures of between 20,000 - ... > read more

Red supergiant star — Red supergiants are supergiant stars of spectral type K-M and a luminosity class of I. They are the largest stars in the universe in terms of ... > read more

Red giant — A red giant is a large non-main sequence star of stellar classification K or M; so-named because of the reddish appearance of the cooler giant stars. ... > read more

Stellar classification — In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral ... > read more

Supernovae Not What They Used To Be; Distant Supernovae Distinctly Brighter

2007-10-24T22:21:00.001-07:00

Using the NASA/ESA Hubble Space Telescope, astronomers pinpointed a blaze of light from the farthest supernova ever seen, SN 1997ff -- a dying star that exploded 10 billion years ago. (Credit: NASA/ESA, Adam Riess (Space Telescope Science Institute))

(Oct. 24, 2007) — Exploding stars that light the way for research on dark energy aren’t as powerful or bright, on average, as they once were, says a new study by University of Toronto astronomers.

The study, which compared supernovae in nearby galaxies with those that exploded up to nine billion light years away in the distant universe, found the distant supernovae were an average of 12 per cent brighter. The distant supernovae were brighter because they were younger, the study found.

Since uniformly bright exploding stars help astronomers study the nature of dark energy – an unknown type of energy that causes the universe to accelerate its expansion – the team’s findings suggest it could become more difficult to study dark energy in the future. Astronomers can correct for supernovae of varying brightness, but it will prove challenging.

“The findings do not call into question that the universe is accelerating but the evolving mix of supernovae could limit future attempts to determine the nature of dark energy,” said Andrew Howell, lead author of the study and post-doctoral researcher.

“You can think of supernovae as light bulbs,” he said. “We found that the early universe supernovae had a higher wattage, but as long as we can figure out the wattage, we should be able to correct for that. Learning more about dark energy is going to take very precise corrections though and we aren’t sure how well we can do that yet.”

The paper, Predicted and Observed Evolution in the Mean Properties of Type Ia Supernovae with Redshift, was co-authored by post-doctoral researchers Mark Sullivan and Alex Conley and Professor Ray Carlberg of astronomy and astrophysics. It appears in the Sept. 20 issue of the Astrophysical Journal Letters.

Adapted from materials provided by University Of Toronto.

Massive Star's Afterlife: A Supernova Seeds New Planets

2007-10-24T22:13:00.000-07:00

G292.0+1.8 is a young supernova remnant located in our galaxy. This deep Chandra image shows a spectacularly detailed, rapidly expanding shell of gas that is 36 light years across and contains large amounts of oxygen, neon, magnesium, silicon and sulfur. Supernovas are of great interest because they are a primary source of the heavy elements believed to be necessary to form planets and life. (Credit: X-ray: NASA/CXC/Penn State/S. Park et al. Optical: Palomar/DSS)

(Oct. 24, 2007) — A spectacular new image shows how complex a star's afterlife can be. By studying the details of this image made from a long observation by NASA's Chandra X-ray Observatory, astronomers can better understand how some stars die and disperse elements like oxygen into the next generation of stars and planets.

At a distance of about 20,000 light years, G292.0+1.8 is one of only three supernova remnants in the Milky Way known to contain large amounts of oxygen. The image shows a rapidly expanding, intricately structured, debris field that contains, along with oxygen, other elements such as neon and silicon that were forged in the star before it exploded.

"We are finding that, just like snowflakes, each supernova remnant is complicated and beautiful in its own way," said Sangwook Park of Penn State who led the work, released in conjunction with the "8 Years of Chandra" symposium in Huntsville, Ala.

By mapping the distribution of X-rays in different energy bands, the Chandra image traces the distribution of chemical elements ejected in the supernova. The results imply that the explosion was not symmetrical. For example, blue (silicon and sulfur) and green (magnesium) are seen strongly in the upper right, while yellow and orange (oxygen) dominate the lower left. These elements light up at different temperatures, indicating that the temperature is higher in the upper right portion of G292.0+1.8.

Slightly below and to the left of the center of G292.0+1.8 is a pulsar, a dense, rapidly rotating neutron star that remained behind after the original star exploded. Assuming that the pulsar was born at the center of the remnant, it is thought that recoil from the lopsided explosion may have kicked the pulsar in this direction.

Surrounding the pulsar is a so-called pulsar wind nebula, a magnetized bubble of high-energy particles. The narrow, jet-like feature running from north to south in the image is likely parallel to the spin axis of the pulsar. This structure is most easily seen in high energy X-rays. In the case of G292.0+1.8, the spin direction and the kick direction do not appear to be aligned, in contrast to apparent spin-kick alignments in some other supernova remnants.

Another intriguing feature of this remnant is the bright equatorial belt of X-ray emission that extends across the center of the remnant. This structure is thought to have been created when the star - before it died - expelled material from around its equator via winds. The orientation of the equatorial belt suggests that the parent star maintained the same spin axis both before and after it exploded.

"The detection of the pulsar and its wind nebula confirms that the supernova that led to G292 produced a neutron star through the collapse of the core of a massive star," said coauthor John Hughes of Rutgers University, "The ability to study the asymmetry of the original explosion using X-ray images of the remnant gives us a powerful new technique for learning about these cataclysmic events."

These results will appear in the December 1st issue of The Astrophysical Journal Letters.

Adapted from materials provided by Chandra X-ray Center.

Solar Telescope Soars Into Sky On Jumbo-jet-sized Balloon

2007-10-24T22:03:00.000-07:00

Slender hoses, blown into arcs by the wind, partially fill
theballoon with helium before launch. A large portion of
the balloon is left unfilled so it can expand as it ascends into the
stratosphere, where air pressure is considerably lower.
(Credit: Photo by Carlye Calvin, Copyright UCAR)

(Oct. 24, 2007) — In a landmark test flight, the National Center for Atmospheric Research (NCAR) and a team of research partners this month successfully launched a solar telescope to an altitude of 120,000 feet, borne by a balloon larger than a Boeing 747 jumbo jet. The test clears the way for long-duration polar balloon flights beginning in 2009 that will capture unprecedented details of the Sun's surface.

"This unique research project will enable us to view features of the Sun that we've never seen before," says Michael Knölker, director of NCAR's High Altitude Observatory and a principal investigator on the project. "We hope to unlock important mysteries about the Sun's magnetic field structures, which at times can cause electromagnetic storms in our upper atmosphere and may have an impact on Earth's climate."

The project, known as Sunrise, is an international collaboration involving NCAR, NASA, Germany's Max Planck Institute for Solar System Research and Kiepenheuer Institute for Solar Physics, Spain's Astrophysics Institute of the Canary Islands, and the Swedish Space Corporation. Additional U.S. partners include the Lockheed Martin Corporation and the University of Chicago. Funding for NCAR's work on the project comes from NASA and from the National Science Foundation, which is NCAR's primary sponsor.

The project may usher in a new generation of balloon-borne scientific missions that cost less than sending instruments into space. Scientists also can test an instrument on a balloon before making a commitment to launch it on a rocket.

The balloon, with its gondola of scientific instruments, was launched successfully on the morning of October 3 from the Columbia Scientific Balloon Facility in Fort Sumner, New Mexico. It flew for about 10 hours, capturing stable images of the solar surface and additional data from the various instruments of the sophisticated payload. The gondola then separated from the balloon and descended with a parachute, landing safely in a field outside Dalhart, Texas.

"We were able to verify the workings of the entire system end to end," says David Elmore, an NCAR engineer who oversaw the test flight. "We can now move on to planning the first full-scale mission with confidence."

Observing the midnight Sun

The ultimate goal of the Sunrise project is to investigate the structure and dynamics of the Sun's magnetic fields. The fields fuel solar activity, including plasma storms that buffet Earth's outer atmosphere and affect sensitive telecommunications and power systems. The fields also cause variations in solar radiation, which may be significant factors in long-term changes in Earth's climate.

The Sunrise project is scheduled next for a multiday flight over the Arctic in the summer of 2009, launching from Kiruna, Sweden. By taking advantage of the midnight Sun, the telescope will be able to capture continuous images for a period of several days to as long as two weeks, possibly orbiting the Arctic. It may be launched later on another long-distance flight over the Arctic or the Antarctic.

At an altitude of 120,000 feet, the telescope will rise above most of the turbulence of the atmosphere and ultraviolet-absorbing water vapor and ozone. It will be able to view stable images in the ultraviolet range, which allow for higher resolution than can be obtained from Earth's surface.

The telescope will capture features on the solar surface as small as 30 kilometers across (about 19 miles), more than double the resolution achieved by any other instrument to date. This will enable scientists to examine structures on the Sun that are believed to be key to understanding the mechanisms driving solar activity. In addition, by observing the same area during an entire flight over high latitudes in summer, the telescope will enable scientists to continually witness changes in the magnetic fields without the interruption of night.

The Sunrise project has presented engineers with a number of extraordinary challenges. The balloon is designed to carry 6,000 pounds of equipment, including a 1-meter (39-inch) solar telescope, additional observing instruments, communications equipment, computers and disk drives, solar panels, and roll cages and crush pads to protect the payload on landing. The equipment must be able to withstand dramatic changes in temperature, and the steel and aluminum gondola cannot vibrate in ways that could interfere with the operation of the telescope.

One of the most difficult aspects of the engineering work was to design the gondola in such a way that the telescope in flight would remain focused on a specific and relatively tiny area of the Sun, even while twisting on a soaring balloon for a week or longer during the full-scale research missions. To accomplish this, the gondola includes both a torque motor drive to keep the gondola and telescope in the correct orientation and a precision guiding and compensation system to constantly correct the telescope's aim.

In addition to the telescope, the gondola on its full-scale research missions will carry a polarimetric spectrograph that will measure wavelengths in the Sun's electromagnetic spectrum and enable scientists to make inferences about its magnetic fields. Another instrument, known as an imaging magnetograph, will provide two-dimensional magnetic field maps.

Because the gondola is designed to withstand considerable force when it lands, the instruments can be launched on repeated missions.

"This is a very economical way of rising above the atmosphere and capturing images that cannot be captured from Earth," Knölker says. "What we are doing is laying the groundwork for the next generation of space flights."

Adapted from materials provided by National Center for Atmospheric Research.

China And ESA Launch Moon Mission -- Chang'e-1

2007-10-24T21:57:00.000-07:00

Artist's impression of SMART-1 . SMART-1 is Europe's first mission to the Moon. (Credit: ESA)

(Oct. 25, 2007) — A bold new mission to the Moon was launched by the Chinese National Space Administration (CNSA). Chang’e-1 blasted off from the Xichang Satellite Launch Centre, Sichuan, atop a Long March 3A rocket on October 24, 2007.

Chang’e-1 represents the first step in the Chinese ambition to land robotic explorers on the Moon before 2020.

Chang’e-1 has four mission goals to accomplish. The first is to make three-dimensional images of many lunar landforms and outline maps of major lunar geological structures. This mapping will include the first detailed images taken of some regions near the lunar poles.

Chang’e-1 is also designed to analyze the abundance of up to 14 chemical elements and their distribution across the lunar surface. Thirdly it will measure the depth of the lunar soil and lastly it will explore the space weather between the Earth and the Moon.

The spacecraft is large, weighing in at 2350 kg and it will operate from a low, circular lunar orbit, just 200 km above the surface of the Moon. From here, it will perform its science mission for a full year.

ESA is collaborating with the Chinese on this mission by providing spacecraft and ground operations support services to CNSA. The two agencies will also share data and encourage a visitors’ programme so that researchers can learn from each other.

During ESA’s SMART-1 mission, the Agency provided the Chinese with details of the spacecraft's position and transmission frequencies, so that the Chinese could test their tracking stations and ground operations by following it. This was part of their preparation for Chang’e-1. Now it is time for Chang’e-1 itself to fly.

Hermann Opgenoorth, Head of ESA’s Solar System Missions Division says, “Participation in Chang’e-1 gives European scientists and ESA experts a welcome opportunity to maintain and pass on their expertise and to continue their scientific work. Based on the experience gained with this first mission, we intended to cooperate on the next missions in China's Chang’e line of lunar explorers.”

To perform its science mission, Chang’e-1 carries a variety of instruments: a CCD stereo camera, a laser altimeter, an imaging interferometer, a gamma-ray/X-ray spectrometer, a microwave radiometer, a high-energy particle detector, and a solar wind particle detector.

Named after the Chinese goddess of the Moon, Chang’e-1 represents the first phase in the Chinese Lunar Exploration Programme (CLEP). This programme is expected to last until around 2020 and the next phase will include a lander and associated rover. Looking farther into the future, plans are being drawn up for a sample return mission to bring lunar rocks to Earth for analysis.

"ESA's expertise in tracking Chang'e-1 sets the stage for future cooperation with China. The Agency's tracking station network, ESTRACK, is a resource that benefits not only the Agency but also all space science through such international cooperation," said Erik Soerensen, Head of the System Requirements and Validation Section at ESA's European Space Operations Centre.

Adapted from materials provided by European Space Agency.

Climate Change Research Recognized In 2007 Nobel Peace Prize

2007-10-22T21:13:00.000-07:00

The Norwegian Nobel Committee has decided that the Nobel Peace Prize for 2007 is to be shared, in two equal parts, between the Intergovernmental Panel on Climate Change (IPCC) and Albert Arnold (Al) Gore Jr. for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change.

Indications of changes in the earth's future climate must be treated with the utmost seriousness, and with the precautionary principle uppermost in our minds. Extensive climate changes may alter and threaten the living conditions of much of humanity. They may induce large-scale migration and lead to greater competition for the earth's resources. Such changes will place particularly heavy burdens on the world's most vulnerable countries. There may be increased danger of violent conflicts and wars, within and between states.

Through the scientific reports it has issued over the past two decades, the IPCC has created an ever-broader informed consensus about the connection between human activities and global warming. Thousands of scientists and officials from over one hundred countries have collaborated to achieve greater certainty as to the scale of the warming. Whereas in the 1980s global warming seemed to be merely an interesting hypothesis, the 1990s produced firmer evidence in its support. In the last few years, the connections have become even clearer and the consequences still more apparent.

Al Gore has for a long time been one of the world's leading environmentalist politicians. He became aware at an early stage of the climatic challenges the world is facing. His strong commitment, reflected in political activity, lectures, films and books, has strengthened the struggle against climate change. He is probably the single individual who has done most to create greater worldwide understanding of the measures that need to be adopted.

By awarding the Nobel Peace Prize for 2007 to the IPCC and Al Gore, the Norwegian Nobel Committee is seeking to contribute to a sharper focus on the processes and decisions that appear to be necessary to protect the world’s future climate, and thereby to reduce the threat to the security of mankind. Action is necessary now, before climate change moves beyond man’s control.

The Nobel Prize in Physiology or Medicine 2007

2007-10-16T11:00:00.000-07:00

"for their discoveries of principles for introducing specific gene modifications in mice by the use of embryonic stem cells"

1/3 of the prize
Mario R. Capecchi USA
University of Utah
Salt Lake City, UT, USA; Howard Hughes Medical Institute
b. 1937
(in Italy)

Sir Martin J. Evans
1/3 of the prize
United Kingdom
Cardiff University
Cardiff, United Kingdom
b. 1941

Oliver Smithies
1/3 of the prize
USA
University of North Carolina at Chapel Hill
Chapel Hill, NC, USA
b. 1925
(in United Kingdom)

Nobel prize in Physics 2007

2007-10-16T09:54:00.000-07:00

German, Frenchman share 2007 Nobel Prize in physics for discovery used in hard disks

STOCKHOLM, Sweden_France's Albert Fert and German Peter Gruenberg won the 2007 Nobel Prize in physics on Tuesday for a discovery that has shrunk the size of hard disks found in computers, iPods and other digital devices.
The duo discovered a totally new physical effect that has let the computer industry develop sensitive reading tools for information stored on computer hard drives from the tiniest laptops to feature-rich portable music and video players.

"The MP3 and iPod industry would not have existed without this discovery," Borje Johansson, a member of the Royal Swedish Academy of Sciences told The Associated Press. "You would not have an iPod without this effect."
Fert, 69, is scientific director of the Mixed Unit for Physics at CNRS/Thales in Orsay, France, while Gruenberg, 68, is a professor at the Institute of Solid State Research in Juelich, Germany. They will share the $1.5 million prize.

Gruenberg told reporters he was not too surprised to win the Nobel. "Because I have received a lot of awards, I was often asked, `When will the big award come?'" Gruenberg said.

Asked if he'd thought his discovery would have such wide application, Fert told The Associated Press: "You can never predict in physics. ... These days when I go to my grocer and see him type on a computer, I say, `Wow, he's using something I put together in my mind.' It's wonderful."

Here's how it works.

As a metal disk spins inside a hard drive, an arm with a sensitive electromagnetic head at its tip hovers over the disk, somewhat like the needle on a record player (though it doesn't make contact). This head reads bits of data by registering the magnetic bearing of individual particles; it writes data by changing that magnetic orientation.

For disk drives to increase in capacity, those magnetic particles must become smaller, so more can be packed into the same amount of space. But these ever-tinier materials produce fainter magnetic signals, which means the read-write head in the disk drive has to become more sensitive.

What Fert and Gruenberg independently discovered was that extremely thin layers of alternating metals could detect remarkably weak changes in magnetism _ and translate them into "giant" changes in electrical resistance.

In other words, the particles used in data storage could get much denser and still produce the electrical signals that computers read as ones or zeros as they do their business.

It took until 1997 for giant magnetoresistance (GMR) to get translated from Fert and Gruenberg's raw science into a product for the disk market. That was led by IBM Corp., where researcher Stuart Parkin developed a way to incorporate Fert and Gruenberg's findings into the cost-effective manufacturing process already used to produce disk drives.

One result can be measured in disk-drive density _ the number of bits that can be squeezed into a given area. In the 1990s, disk density was generally improving about 60 percent a year. But GMR sparked a few years in which density doubled _ a 100 percent rise _ and costs still fell.

The steep ramp explains how today's top iPods pack more storage than desktop computers of just a few years ago. (For instance, Apple Inc. offers a 160-gigabyte iPod _ 10 times the capacity of IBM's first GMR drive for PCs a decade ago.)

GMR also helped herald the promise of nanotechnology in computing, said John Best, chief technologist for Hitachi Ltd.'s data-storage unit.

"It showed you could do really interesting things on a nanoscale," he said. "That wasn't so clear."

GMR does not deserve sole credit for recent improvements in data storage. For one thing, it's not used in solid-state "flash" memory that has less capacity than hard drives. Fert joked about that in an interview Tuesday, when he said his iPod, loaded with jazz, was busted.

"It's my fault because I got an iPod with a GMR hard drive," he said. "If I had an iPod with a simple flash memory, it wouldn't be broken."

Yet physicists say the full influence of what Fert and Gruenberg began is still to be felt.

That's because the surprising property of giant magnetoresistance is one of many "quantum effects" that crop up when atoms are confined to really small spaces. Researchers are beginning to master methods for manipulating and measuring these other factors as well, which could prompt still more sophisticated ways of cramming data into minuscule spaces.

The field is known as "spintronics" because it harnesses the electromagnetic property of electrons known as spin.

"What we're discovering with spintronics, compared with GMR," said Mark Dean, director of IBM's Almaden Research Center in San Jose, Calif., "is like comparing silicon to the vacuum tube."

The Nobel Prize in Chemistry 2007

2007-10-16T09:29:00.000-07:00

"for his studies of chemical processes on solid surfaces"

Gerhard Ertl
Germany
Fritz-Haber-Institut der Max-Planck-Gesellschaft Berlin, Germany
b. 1936