Date Posted: 2005-03-07
Web Address:
MOONBEAMS SHINE ON EINSTEIN, GALILEO AND NEWTON
Thirty-five years after Moon-walking astronauts placed special reflectors on the lunar surface, scientists have used these devices to test Albert Einstein's general theory of relativity to unprecedented accuracy. The findings, which also confirm theories from Galileo Galilei and Isaac Newton, may help to explain physical laws of the universe and benefit future space missions.
"Our research with the Lunar Laser Ranging experiment probes the equivalence principle, a foundation of Einstein's general theory of relativity, with extreme accuracy," said Dr. James Williams, a research scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. Galileo established this principle in 1604 when he dropped objects of various weights and composition from Italy's Leaning Tower of Pisa. All the objects were affected equally by gravity, so they fell at the same rate.
Newton published a supporting explanation in 1687 in his Principia, and Einstein extended the principle nearly 100 years ago. Einstein's premise, called the strong equivalence principle, holds that all forms of matter accelerate at the same rate in response to gravity. This principle became a foundation of Einstein's general theory of relativity.
The Lunar Laser Ranging experiment confirms that the Moon and Earth "fall toward" the Sun at the same rate, even though Earth has a large iron core below its rocky mantle, while the Moon is mostly rocky with a much smaller core. The findings by Williams and Drs. Slava Turyshev and Dale Boggs, also of JPL, have been published in the Physical Review Letters.
"Lunar laser ranging can conduct very accurate tests of gravity and fundamental physics," said Williams, who pointed out that small variations in gravity are difficult to study because the force is weak, unless very large masses are used. The new results of this experiment provide a bonanza for modern physics.
"An important property of gravity is its universal effect on massive objects, despite their size and composition. This is why, as we understand more about gravity in the solar system, we learn a lot about gravitational and cosmological processes in the entire universe," said Turyshev.
"In addition to providing the most accurate test yet of the strong equivalence principle, our experiment also limits any possible changes in Newton's gravitational constant," said Turyshev. The gravitational constant deals with the attraction between objects in space, and some theories suggest that this attraction would change over time. If so, the general theory of relativity would need modification.
"This latest research shows no evidence of such a change. Both findings -- about the strong equivalence principle and the gravitational constant -- boost Einstein's theory," added Turyshev.
Great strides have been made over the past decade in refining the theories of Einstein, Galileo and Newton. The latest findings are twice as accurate as any previous results on the strong equivalence principle, and 10 times as accurate as anything previously published on the variation of Newton's gravitational constant
The JPL team tested the theories by beaming laser pulses to four Moon reflectors from McDonald Observatory in western Texas, and an observatory in southern France. The lunar reflectors bounced the laser beams straight back to Earth, where the roundtrip travel time was measured. Three of the reflectors were installed by the Apollo 11, 14 and 15 astronauts, and one built by France was carried on the unmanned Soviet Lunokhod 2 rover.
The current Moon reflectors require no power and still work perfectly after 35 years. As NASA pursues the vision of taking humans back to the Moon, and eventually to Mars and beyond, new, more precise laser ranging devices could be placed first on the Moon and then on Mars. To guide a spacecraft to a precise location on the Moon and to navigate trips on its surface, the Moon's orbit, rotation and orientation must be accurately known. Lunar laser ranging measurements are helping future human and robotic missions to the Moon.
More information about the research is available online at http://arxiv.org/abs/gr-qc/0411113 or http://funphysics.jpl.nasa.gov/physics/index.html.
The research was conducted under NASA's Astronomy and Physics Research and Analysis program, part of the agency's Science Mission Directorate, Washington, D.C. JPL, is a division of the California Institute of Technology, Pasadena.
Comments on Did the Big Bang Really Happen? (below)
Did the Big Bang Really Happen?
has been added here to show several avenues of thought which
mimic some that are found in Behind Light's Illusion and
on my website. This is also one of a number of examples of the
confusion found today due to apparent inadequacies in the standard model.
Problems with redshift, the accepted age of the universe, the shape of the
universe, the nature of the cosmic background radiation, the reality behind
dark matter, the fact that the universe has a directional bias - all of these
are addressed in the article below.
The answers or conjectures given in the article are not exactly
what I have found to be true. However, they are not very far off.
Home| News| Solar System| Space Technology| Human Spaceflight| Astronomy|
Special Reports
Did the big bang really happen?
02 July 2005
From New Scientist Print Edition.
Marcus Chown
WHAT if the big bang never happened? Ask cosmologists this and they'll usually tell you it is a stupid question. The evidence, after all, is written in the heavens. Take the way galaxies are scattered across the sky, or witness the fading afterglow of the big bang fireball. Even the way the atoms in your body have come into being over the eons. They are all smoking guns that point to the existence 13.7 billion years ago of an ultra-hot, ultra-dense state known as the big bang.
Or are they? A small band of researchers is starting to ask the question no one is supposed to ask. Last week the dissidents met to review the evidence at the first ever Crisis in Cosmology conference in Monção, Portugal. There they argued that cosmologists' most cherished theory of the universe fails to explain certain crucial observations. If they are right, the universe could be a lot weirder than anyone imagined. But before venturing that idea, say the dissidents, it is time for some serious investigation into the big bang's validity and its alternatives.
"Look at the facts," says Riccardo Scarpa of the European Southern Observatory in Santiago, Chile. "The basic big bang model fails to predict what we observe in the universe in three major ways." The temperature of today's universe, the expansion of the cosmos, and even the presence of galaxies, have all had cosmologists scrambling for fixes. "Every time the basic big bang model has failed to predict what we see, the solution has been to bolt on something new - inflation, dark matter and dark energy," Scarpa says.
For Scarpa and his fellow dissidents, the tinkering has reached an unacceptable level. All for the sake of saving the notion that the universe flickered into being as a hot, dense state. "This isn't science," says Eric Lerner who is president of Lawrenceville Plasma Physics in West Orange, New Jersey, and one of the conference organisers. "Big bang predictions are consistently wrong and are being fixed after the event." So much so, that today's "standard model" of cosmology has become an ugly mishmash comprising the basic big bang theory, inflation and a generous helping of dark matter and dark energy.
The fact that the conference went ahead at all is an important step forward, say its organisers. Last year they wrote an open letter warning that failure to fund research into big bang alternatives was suppressing free debate in the field of cosmology (New Scientist, 22 May 2004, p 20).
The trouble, says Lerner, who headed the list of more than 30 signatories, is that cosmology is bankrolled by just a few sources, and the committees that control those purse strings are dominated by supporters of the big bang. Critics of the standard model of cosmology are not just uncomfortable about the way they feel it has been cobbled together. They also point to specific observations that they believe cast doubt on cosmology's standard model.
Take the most distant galaxies ever spotted, for example. According to the accepted view, when we observe ultra-distant galaxies we should see them in their youth, full of stars not long spawned from gas clouds. This is because light from these faraway galaxies has taken billions of years to reach us, and so the galaxies must appear as they were shortly after the big bang. But there is a problem. "We don't see young galaxies," says Lerner. "We see old ones."
He cites recent observations of high-red-shift galaxies from NASA's Spitzer space telescope. A galaxy's red shift is a measure of how much the universe has expanded since it emitted its light. As the light travels through an expanding universe, its wavelength gets stretched, as if the light wave were drawn on a piece of elastic. The increase in wavelength corresponds to a shift towards the red end of the spectrum.
The Spitzer galaxies have red shifts that correspond to a time when the universe was between about 600 million and 1 billion years old. Galaxies this young should be full of newborn stars that emit blue light because they are so hot. The galaxies should not contain many older stars that are cool and red. "But they do," says Lerner.
Spitzer is the first telescope able to detect red stars in faraway galaxies because it is sensitive to infrared light. This means it can detect red light from stars in high-red-shift galaxies that has been pushed deep into the infrared during its journey to Earth. "It turns out these galaxies aren't young at all," says Lerner. "They have pretty much the same range of stars as present-day galaxies."
And that is bad news for the big bang. Among the stars in today's galaxies are red giants that have taken billions of years to burn all their hydrogen and reach this bloated phase. So the Spitzer observations suggest that some of the stars in ultra-distant galaxies are older than the galaxies themselves, which plunges the standard model of cosmology into crisis. Fog-filled universe
Not surprisingly, cosmologists have panned Lerner's theories. They put the discrepancy down to large uncertainties in estimating the ages of galaxies. But Lerner has a reply. He points to other distant objects that appear much older than they ought to be. "At high red shift, we also observe clusters and huge superclusters of galaxies," he says, arguing that it would have taken far longer than a billion years for galaxies to clump together to form such giant structures.
His solution to the puzzle is extreme. Rather than being caused by the expanding universe, he believes that the red shift is down to some other mechanism. But at this stage it is only a guess. "I admit I don't know what that mechanism might be," Lerner says, "though I believe it is intrinsic to light."
To test his idea, he would like to see sensitive experiments on Earth capable of detecting minute changes in light. One possibility would be to modify the LIGO detector in Hanford, Washington state. LIGO is designed to detect gravitational waves, the warps in space-time created by events such as neutron star collisions. To do this it bounces perpendicular beams of laser light hundreds of times between mirrors 4 kilometres apart, looking for subtle shifts in the beams' lengths. With a few tweaks, Lerner believes that LIGO could be modified to measure any intrinsic red-shifting that light might undergo.
If the experiment ever gets the go-ahead and Lerner is proved right, the implications would be immense, not least because the tapestry of cosmology as we know it would unravel. Without an expanding universe, there would be no need to invoke dark energy to account for the apparent acceleration of that expansion. Nor would there be any reason to suppose the big bang was the ultimate beginning. "I can prove that the universe wasn't born 13.7 billion years ago," says Lerner. "The big bang never happened."
However, Lerner's claims leave plenty of awkward questions. Among them is the matter of the cosmic microwave background. First detected in 1965, the vast majority of cosmologists believe that this faint, all-pervading soup of microwaves is the dying glow of the big bang, and proof of the ultimate beginning. According to big bang theory, the hot radiation that filled space after the birth of the universe has been trapped inside ever since because it has nowhere else to go. As the universe expanded over the past 13.7 billion years, the radiation has cooled to today's temperature of less than 3 kelvin above absolute zero.
So if there was no big bang, where did the cosmic microwave background come from? Lerner believes that cosmologists have got the origin of the microwave glow all wrong. "If you wake up in a tent and everything around you is white, you don't conclude you've seen the start of the universe," he says. "You conclude you're in fog."
Rather than coming from the big bang, Lerner believes that the cosmic background radiation is really starlight that has been absorbed and re-radiated. It is an old idea that was widely promoted by the late cosmologist and well-known big bang sceptic Fred Hoyle. He believed that starlight was absorbed by needle-like grains of iron ejected by supernovae and then radiated as microwaves. But Hoyle never found any evidence to back up his ideas and many cosmologists dismissed them.
Lerner's idea is similar, though he thinks that threads of electrically charged gas called plasma are responsible, rather than iron whiskers. Jets of plasma are squirted into intergalactic space by highly energetic galaxies known as quasars, and Lerner believes that such plasma filaments continually fragmented until they filled the universe like fog. This fog then scattered the infrared light radiated by dust that had in turn absorbed starlight. By doing so, Lerner believes, the infrared radiation became uniform in all directions, just as the cosmic microwave background appears to be.
All this is possible, he argues, because standard cosmology theory has overlooked processes involving plasmas. "All astronomers know that 99.99 per cent of matter in the universe is in the form of plasma, which is controlled by electromagnetic forces," he says. "Yet all astronomers insist on believing that gravity is the only important force in the universe. It is like oceanographers ignoring hydrodynamics." To make progress, Lerner is calling for theories that include plasma phenomena as well as gravity, and for more rigorous testing of theory against observations.
Of course, Lerner's ideas are extremely controversial and few people are convinced, but that doesn't stop other researchers questioning the standard theory too. They have their own ideas about what is wrong with it. In Scarpa's case, the mysterious dark matter is at fault.
Dark matter has become an essential ingredient in cosmology's standard model. That's because the big bang on its own fails to describe how galaxies could have congealed from the matter forged shortly after the birth of the universe. The problem is that gas and dust made from normal matter were spread too evenly for galaxies to clump together in just 13.7 billion years. Cosmologists fix this problem by adding to their brew a vast amount of invisible dark matter which provides the extra tug needed to speed up galaxy formation.
The same gravitational top-up helps to explain the rapid motion of outlying stars in galaxies. Astronomers have measured stars orbiting their galactic centres so fast that they ought to fly off into intergalactic space. But dark matter's extra gravity would explain how the galaxies hold onto their speeding stars. Similarly, dark matter is needed to explain how clusters of galaxies can hold on to galaxies that are orbiting the cluster's centre so fast they ought to be flung away.
But dark matter may not be the cure-all it seems, warns Scarpa. What worries him are inconsistencies with the theory. "If you believe in dark matter, you discover there is too much of it," he says. In particular, his observations point to dark matter in places cosmologists say it shouldn't exist. One place no one expects to see it is in globular clusters, tight knots of stars that orbit the Milky Way and many other galaxies. Unlike normal matter, the dark stuff is completely incapable of emitting light or any other form of electromagnetic radiation. This means a cloud of the stuff cannot radiate away its internal heat, a process vital for gravitational contraction, so dark matter cannot easily clump together at scales as small as those of globular clusters.
Scarpa's observations tell a different story, however. He and his colleagues have found evidence that the stars in globular clusters are moving faster than the gravity of visible matter can explain, just as they do in larger galaxies. They have studied three globular clusters, including the Milky Way's biggest, Omega Centauri, which contains about a million stars. In all three, they find the same wayward behaviour. So if isn't dark matter, what is going on?
Scarpa's team believes the answer might be a breakdown of Newton's law of gravity, which says an object's gravitational tug is inversely proportional to the square of your distance from it. Their observations of globular clusters suggest that Newton's inverse square law holds true only above some critical acceleration. Below this threshold strength, gravity appears to dissipate more slowly than Newton predicts.
Exactly the same effect has been spotted in spiral galaxies and galaxy-rich clusters. It was identified more than 20 years ago by Mordehai Milgrom at the Weizmann Institute in Rehovot, Israel, who proposed a theory known as modified Newtonian dynamics (MOND) to explain it. Scarpa points out that the critical acceleration of 10-10 metres per second per second that was identified for galaxies appears to hold for globular clusters too. And his work has led him to the same conclusion as Milgrom: "There is no need for dark matter in the universe," says Scarpa.
It is a bold claim to make. And not surprisingly, MOND has had plenty of critics over the years. One of cosmologists' biggest gripes is that MOND is not compatible with Einstein's theory of relativity, so it is not valid for objects travelling close to the speed of light or in very strong gravitational fields. In practice, this means MOND has been powerless to make predictions about pulsars, black holes and, most importantly, the big bang. But this has now been fixed by Jacob Bekenstein at the Hebrew University of Jerusalem in Israel.
Bekenstein's relativistic version of the theory already appears to be
bearing fruit. In May a team led by Constantinos Skordis of the University
of Oxford showed that relativistic MOND can make cosmological predictions.
The researchers have reproduced both the observed properties of the cosmic
microwave background and the distribution of galaxies throughout the
universe (www.arxiv.org/abs/astro-ph/0505519
Scarpa believes that MOND is a crucial body blow for the big bang. "It means
that the law of gravity from which we derive the big bang is wrong," he
says. He insists that cosmologists are interpreting astronomical
observations using the wrong framework. And he urges them to go back to the
drawing board and derive a cosmological model based on MOND.
For now, his plea seems to be falling mostly on deaf ears. Yet there is more
evidence that there could be something wrong with the standard model of
cosmology. And it is evidence that many cosmologists are finding harder to
dismiss because it comes from the jewel in the crown of cosmology
instruments, the Wilkinson Microwave Anisotropy Probe. "It could be telling
us something fundamental about our universe, maybe even that the simplest
big bang model is wrong," says João Magueijo of Imperial College London.
Since its launch in 2001, WMAP has been quietly taking the temperature of
the universe from its vantage point 1.5 million kilometres out in space. The
probe measures the way the temperature of the cosmic microwave background
varies across the sky. Cosmologists believe that the tiny variations from
one place to another are an imprint of the state of the universe about
300,000 years after the big bang, when matter began to clump together under
gravity. Hotter patches correspond to denser regions, and cooler patches
reflect less dense areas. These density variations began life as quantum
fluctuations in the vacuum in the first split second of the universe's
existence, and were subsequently amplified by a brief period of phenomenally
fast expansion called inflation.
Because the quantum fluctuations popped up at random, the hot and cold spots
we see in one part of the sky should look much like those in any other part.
And because the cosmic background radiation is a feature of the universe as
a whole rather than any single object in it, none of the hot or cold regions
should be aligned with structures in our corner of the cosmos. Yet this is
exactly what some researchers are claiming from the WMAP results.
Earlier this year, Magueijo and his Imperial College colleague Kate Land
reported that they had found a bizarre alignment in the cosmic microwave
background. At first glance, the pattern of hot and cold spots appeared
random, as expected. But when they looked more closely, they found something
unexpected. It is as if you were listening to an anarchic orchestra playing
some random cacophony, and yet when you picked out the violins, trombones
and clarinets separately, you discovered that they are playing the same
tune.
Like an orchestral movement, the WMAP results can be analysed as a blend of
patterns of different spatial frequencies. When Magueijo and Land looked at
the hot and cold spots this way, they noticed a striking similarity between
the individual patterns. Rather than being spattered randomly across the
sky, the spots in each pattern seemed to line up along the same direction.
With a good eye for a newspaper headline, Magueijo dubbed this alignment the
axis of evil. "If it is true, this is an astonishing discovery," he says.
That's because the result flies in the face of big bang theory, which rules
out any such special or preferred direction. So could the weird effect be
down to something more mundane, such as a problem with the WMAP satellite?
Charles Bennett, who leads the WMAP mission at NASA's Goddard Space Flight
Center in Greenbelt, Maryland, discounts that possibility. "I have no reason
to think that any anomaly is an artefact of the instrument," he says.
Another suggestion is that heat given off by the Milky Way's dusty disk has
not been properly subtracted from the WMAP signals and mimics the axis of
evil. "Certainly there are some sloppy papers where insufficient attention
has been paid to the signals from the Milky Way," warns Bennett. Others
point out that the conclusions are based on only one year's worth of WMAP
signals. And researchers are eagerly awaiting the next batch, rumoured to be
released in September.
Yet Magueijo and Land are convinced that the alignment in the patterns does
exist. "The big question is: what could have caused it," asks Magueijo. One
possibility, he says, is that the universe is shaped like a slab, with space
extending to infinity in two dimensions but spanning only about 20 billion
light years in the third dimension. Or the universe might be shaped like a
bagel. Another way to create a preferred direction would be to have a
rotating universe, because this singles out the axis of rotation as
different from all other directions.
Bennett admits he is excited by the possibility that WMAP has stumbled on
something so important and fundamental about the universe. His hunch,
though, is that the alignment is a fluke. "However, it's always possible the
universe is trying to tell us something," he says.
Clearly, such a universe would flout a fundamental assumption of all big
bang models: that the universe is the same in all places and in all
directions. "People made these assumptions because, without them, it was
impossible to simplify Einstein's equations enough to solve them for the
universe," says Magueijo. And if those assumptions are wrong, it could be
curtains for the standard model of cosmology.
That may not be a bad thing, according to Magueijo. "The standard model is
ugly and embarrassing," he says. "I hope it will soon come to breaking
point." But whatever replaced it would of course have to predict all the
things the standard model predicts. "This would be very hard indeed,"
concedes Magueijo.
Meanwhile the axis of evil is peculiar enough that Bennett and his colleague
Gary Hinshaw have obtained money from NASA to carry out a five-year
exhaustive examination of the WMAP signals. That should exclude the
possibilities of the instrumental error and contamination once and for all.
"The alignment is probably just a fluke but I really feel compelled to
investigate it," he says. "Who knows what we will find."
Lerner and his fellow sceptics are in little doubt: "What we may find is a
universe that is very different than the increasingly bizarre one of the big
bang theory."
Marcus Chown is the author of The Universe Next Door published by Headline
Editorial: Big bang doubts fuel cosmology boom
COSMOLOGY has come a long way. Once upon a time it was akin to theology, and
models in which the universe rested on the back of a giant turtle were as
plausible as any other. Now we have a sophisticated mathematical model
backed up by hard observations. The universe, it says, exploded into
existence 13.7 billion years ago, and entities such as dark matter and dark
energy are orchestrating its evolution.
Yet there remains something disquieting about this model. It contains a huge
array of variables that can be changed pretty much at will. So flexible is
it that some claim the model can be stretched to fit any observation. It
also makes the highly unsatisfying prediction that only 4 per cent of all
matter is accounted for by ordinary, familiar atoms. The rest is made up of
utterly mysterious forms of dark matter and dark energy.
Cosmologists' unease is increasing following a host of recent observations
that are testing the standard model and, arguably, finding it wanting.
Measurements from space experiments such as NASA's Wilkinson Microwave
Anisotropy Probe (WMAP) and the Spitzer infrared telescope are constraining
the model, showing us where our thinking may be flawed and forcing us to ask
new questions (see "End of the beginning"). To accommodate the new findings,
some scientists speculate that not just gravity but also electrical forces
may play a role in shaping the universe at large scales. Others argue that
Einstein's theory of gravity is wrong. Some even suggest that the big bang
never happened.
Calling for a wholesale rethink of the big bang model is still an extreme
view, but even mainstream cosmologists would accept that we may be missing a
"big idea". They are just unwilling to venture what that idea might be.
This may all sound like bad news for cosmology - an indication that it is
falling apart. Nothing could be further from the truth. These are exciting
times, bursting with ideas that will be put to the test by the next
generation of data-gathering instruments. The European Space Agency's Planck
probe will confirm or dispel some surprising anomalies in the WMAP's
readings of relic radiation from the big bang. And by observing how dark
energy has evolved over time, NASA's Supernova/Accelerator Probe (SNAP) may
finally shed light on what exactly it is.
Cosmology has moved on from the realm of theological speculation. It is well
and truly an experimental science, complete with its own turmoil of testable
theories. It has entered a golden age.
Whirling Atoms Dance into Physics Textbooks
J.D. Harrington/Michael Braukus
Jane Platt
RELEASE: 05-163
WHIRLING ATOMS DANCE INTO PHYSICS TEXTBOOKS
NASA-funded researchers at the Massachusetts Institute of Technology,
Cambridge, Mass., have created a new form of superfluid matter. This
research may lead to improved superconducting materials, useful for
energy-efficient electricity transport and better medical diagnostic tools.
The research marks the first time scientists have positively created a
friction-free superfluid using a gas of fermionic atoms, atoms with an odd
number of electrons, protons and neutrons. The breakthrough happened on the
night of April 13.
"It's a night I won't forget. It was overwhelming to watch on our computers
as the lithium atoms behaved in a way that no one had ever seen before,"
said Dr. Wolfgang Ketterle, a Nobel prize-winning physics professor at MIT
who led the team of researchers.
To accomplish this experiment, Ketterle's team cooled a gas cloud of lithium
atoms to nearly absolute zero (about minus 459 degrees Fahrenheit). They
used an infrared laser beam to trap the gas, then a green laser to spin it.
A normal gas simply spins, but a superfluid can rotate only by forming
quantum whirlpools. A rotating superfluid looks like Swiss cheese; the holes
are the cores of the whirlpools. This is exactly what the MIT physicists
observed that night.
In 1995, Ketterle and his team were among the first to create a
Bose-Einstein condensate, composed of bosonic atoms that have an even number
of electrons, neutrons and protons. In Bose-Einstein condensates, particles
act as one big wave, a phenomenon predicted by Albert Einstein in 1925. That
discovery earned Ketterle a shared Nobel Prize in Physics in 2001.
Bose-Einstein condensates were later shown to be superfluids.
The new frontier became fermions. Fermions must pair up to have an even
number of electrons, neutrons and protons, which allows them to form a
Bose-Einstein condensate. Breakthroughs at MIT and several other
institutions, including Duke University, Durham, North Carolina, produced
Bose-Einstein condensation of fermion pairs loosely bound as molecules, but
found no concrete evidence of superfluidity.
Over the past two years researchers have been looking for the "smoking gun"
for fermionic superfluidity. Despite some hints and indirect evidence, it
was not found until this research team's discovery.
Superconductivity is superfluidity for charged particles instead of atoms.
High-temperature superconductivity is not fully understood, but the MIT
observations open up opportunities to study the microscopic mechanisms
behind this phenomenon.
"Pairing electrons in the same way as our fermionic atoms would result in
room-temperature superconductors," Ketterle explained. "It is a long way to
go, but room-temperature superconductors would find many real-world
applications, from medical diagnostics to energy transport," he added.
Superfluid Fermi gas might also help scientists test ideas about other Fermi
systems, like spinning neutron stars and the primordial soup of the early
universe.
The MIT research was supported by the National Science Foundation, the
Office of Naval Research, the Army Research Office, and NASA's Fundamental
Physics in Exploration Systems Mission Directorate, in support of the Vision
for Space Exploration. NASA's Jet Propulsion Laboratory, Pasadena, Calif.,
Pasadena, manages the Fundamental Physics program.
The research was published in the June 23 issue of Nature. Ketterle's
co-authors include grad students Schirotzek, Schunck and Zwierlein, and
former grad student Abo-Shaeer. They are all members of the NSF-funded
MIT-Harvard Center for Ultracold Atoms.
See article and pictures below. This seems to prove that light
Comments as of February 23, 2005
According to articles written on the latest experiments regarding the
equations of relativity the equations of relativity still work. These
same equations have been derived from the foundations of the theory
found on this website. Therefore, the new data confirms what is here
as well as relativity, although relativity has been found to be
incorrect in some instances while nether theory is still intact.
National Science Foundation - Posted January 9, 2004.
Science News, January 3, 2004.
Taking snapshots of a light wave
FERENC KRAUSZ'S picture looks just the way you might draw a light wave - a
brief wiggle on a dark background, with an ethereal, transient quality to
it. But it becomes all the more impressive when you realise it isn't a
drawing of a light wave. It is the first ever photograph of one.
The photo was published last August to surprisingly little fanfare,
considering that Hungarian-born Krausz is already a scientific celebrity for
work on ultra-fast lasers. Yet he says this picture probably represents the
most profound scientific achievement of his life, for one simple reason:
"This is the most direct experimental evidence for light being an
electromagnetic wave," he says.
Until now evidence for the wave nature of light has been circumstantial. In
1801, Thomas Young carried out his famous double-slit experiment in an
attempt to find out if light was made of waves or particles. He saw that
passing a beam of sunlight through two parallel narrow slits casts a pattern
of light and dark stripes. His findings were taken as evidence that light is
made of waves - the stripes are caused by light waves spreading out from
each slit and interfering with each other, in the same way that ripples in a
pond create swells and troughs when they cross. Sixty years later, James
Clerk Maxwell proposed that light consists of oscillating electric and
magnetic fields travelling through space.
Despite this understanding, no one has ever tried to capture the quivering
wave motion of light because it is simply too fast. A beam of visible light
completes a cycle of oscillation in about a millionth of a billionth (10-15)
of a second. This means the electromagnetic field imaged by Krausz's group
changes direction one million billion times each second.
It's a bit like trying to take a picture of a friend sprinting on the
football field. They come out blurred in the pictures because they move
appreciably in the time that the shutter on your camera stays open. Krausz,
however, has the ultimate in sports photography at his disposal: an
attosecond photographic shutter, developed in 2003. It opens and closes
every few hundred billion billionths of a second - one-tenth the length of a
light cycle (New Scientist, 6 November 2004, p 34).
Of course, Krausz's shutter is no ordinary camera aperture. He uses a laser
that creates identical short X-ray pulses that last just a few hundred
attoseconds (10-18 seconds). "A couple of groups worldwide can make
attosecond pulses, but we were the only ones to have them come out one pulse
at a time," says Reinhard Kienberger who is a member of the team.
This was an important step in creating the picture, which was published in
the journal Science last year (vol 305, p 1267). Eleftherios Goulielmakis
and others in Krausz's group at the Vienna University of Technology in
Austria and the University of Bielefeld in Germany sent a light wave into a
chamber of neon gas. Along with the light wave, they sent in an attosecond
X-ray pulse to image it. To be sure which part of the wave they were
imaging, the pulse was synchronised to the light.
The X-rays knock electrons from the atoms in the gas, which then move
towards a detector. But the electric field of the passing light beam either
slows or speeds up the motion of these electrons, depending on its direction
and intensity (see Diagram). So each electron's arrival time at the detector
provides an instantaneous picture of the light beam on its journey through
the chamber.
Many readings have to be added together to create an image of the whole
light wave. So just as celebrities posing for photographs in the 19th
century had to stand still for several minutes, Goulielmakis and Kienberger
ran the laser pulses for as long as an hour. The final picture was made of
about 6 million independent exposures of identical passing light waves.
"When we first saw the trace it was a very special moment, because it had
never been done before," says Kienberger. "In basic physics class you learn
about the waveform of light, but you only measure its intensity. You never
actually capture the trace in such a beautiful way."
Sandu Popescu at the University of Bristol in the UK points out that such
oscillations have been imaged for electromagnetic waves with longer
wavelengths, such as radio waves, but this is a first for visible light.
"It's a nice way of seeing a wave as a wave," says Tony Short, also at
Bristol. "To actually see it waving is as direct as we've got so far."
Physicists, of course, knew in advance exactly what the shape of a light
wave would be, but they still got a kick out of actually seeing it take
shape. "It's like when you get a present and you know what's inside the box,
but then you open the box and hold it in your hands," says Kienberger.
It is that power that has researchers excited. Being able to capture the
quivering field of light means they might also be able to capture atomic
processes on the same timescale, many of which are not as well understood as
light waves. By changing the conditions in the chamber - for example by
filling it with atoms undergoing various physical processes - they can see
the effect of those processes written onto their light pulse (see "From
light to matter").
For now, though, imaging light beams is bringing other rewards. Krausz has
co-founded a company based in Vienna called Femtolasers to sell his
synchronised lasers, at around half a million dollars a pop. There is
interest from scientists who want to take their own photos of fleeting light
beams, and those who want to try their hand at imaging other quivering
fields. "It's impressive," says Stephen Leone, a laser chemist at the
University of California in Berkeley. "We're buying them."
What could possibly top taking a picture of a light wave? Well, Krausz's
group has already used their attosecond photographic shutter to image neon
atoms immediately after electrons had been kicked out of their inner shells
(Nature, vol 427, p 817).
The process of kicking an electron out of a shell is inherently quantum in
nature - one photon of light is absorbed by an atom. But Krausz's group is
able to take freeze frames of the excited atoms just as an electron is being
emitted and those that are left behind change electronic shells to take its
place. These quantum processes are not instantaneous - they take about 150
attoseconds - but with enough freeze frames, the researchers begin to get a
picture of the excitement and relaxation of the atom.
Apart from excited neon atoms, there are many other short-lived atoms and
molecules whose exact lifetimes and interactions with photons are poorly
understood. The prospect of being able to take pictures of them in action is
exciting for Stephen Leone, a laser chemist at the University of California
in Berkeley. "There's a lot of potential there in terms of learning about
light fields and learning something new about atoms and molecules," he
says.
Far-flung galaxy breaks record
18:34 01 March 04
NewScientist.com news service
A small, faint galaxy may claim the title of the most distant object known
- breaking a record that was set just two weeks ago.
The new find appears to lie 13.2 billion light-years away from Earth and
reveals what the earliest galaxies looked like.
Light from this galaxy may have formed a mere 460 million years after the
Big Bang, which formed the Universe 13.7 billion years ago, say its
discoverers.
The previous record-holder, reported in February 2004, dates back to 750
million years after the birth of the Universe.
"We are approaching the youngest ages of galaxies," says Roser Pelló, an
astronomer at the Observatoire Midi-Pyrénées in France and co-leader of
the discovery team.
Astronomers have been steadily probing further back in time and space to
see when and how the first stars and galaxies formed from dense gas
clouds. This murky period was known as the Dark Ages and lasted about one
billion years. The radiation from these first stellar objects may have
broken apart the clouds' atomic hydrogen into ions - a process known as
re-ionisation - to make space transparent.
So far only 30 or so objects have been found that date to the universe's
first billion years. But Pelló believes observations such as hers show
early galaxies "could be one of the main sources of re-ionisation if they
are numerous".
Bent and magnified
The far-flung galaxy was discovered using one of the four 8.2-metre
telescopes comprising the European Southern Observatory's Very Large
Telescope (VLT) in Chile. Focusing on a single region of sky for an
average of three to six hours at a time, the international team used an
infrared imager and spectrograph called ISAAC to detect a single telling
emission line that appeared to arise from hydrogen.
But the distant galaxy was only visible because of a chance geometric
alignment. A massive galaxy cluster called Abell 1835 lies between the new
galaxy and Earth. Abell 1835's gravity bent and magnified the distant
galaxy's light, making it between 25 and 100 times brighter.
Early galaxies actively form stars, producing a telltale spike of
ultraviolet radiation from hydrogen. But the light from distant objects
gets stretched by the expansion of the Universe, which allows astronomers
to calculate vast distances using a measure called redshift.
This galaxy appears to lie at a redshift of 10.0. The previous record
holder for the most distant object is a galaxy at redshift 7.0, reported
just two weeks ago by a team led by one of the researchers in this study.
This result is "very exciting," says Andrew Bunker, an astronomer at the
University of Exeter, UK. "A jump to redshift ten from redshift six is
significant and unprecedented."
Researchers also urge caution in interpreting the result. "The authors are
to be congratulated on their approach and observational technique," says
Donald Schneider, an astronomer at Pennsylvania State University, US. But
he says the redshift of 10.0 is "not ironclad" and points out that some
previous claims of high-redshift discoveries have been "retracted when
additional observations were obtained."
Building blocks
The researchers themselves acknowledge the galaxy might lie closer than
redshift 10.0. That could occur if the emission line arises not from
hydrogen but from other elements, such as oxygen or nitrogen. A
star-forming galaxy at redshift 2.5, for example, could account for the
observed emission - but this would be unlikely to reveal the distinctive
spectra seen, they say.
The researchers have requested observing time on the Hubble Space
Telescope to confirm their result.
Named Abell 1835 IR1916, the new galaxy appears to form stars at the rate
of between one and five suns per year and contains ten thousand times less
matter than our Milky Way. Such small, star-forming galaxies are expected
in the early Universe as they are thought to be the building blocks of the
large galaxies seen today.
Journal reference: Astronomy & Astrophysics (vol 416, p L35)
Maggie McKee
Science News
Week of Jan. 3, 2004; Vol. 165, No. 1
Topsy Turvy: In neutrons and protons, quarks take wrong turns
Peter Weiss
Physicists peering inside the neutron are seeing glimmers of what
appears to be an impossible situation. The vexing findings pertain to
quarks, which are the main components of neutrons and protons. The
quarks, in essence, spin like tops, as do the neutrons and protons
themselves.
Now, experimenters at the Thomas Jefferson National Accelerator
Facility in Newport News, Va., have found hints that a single quark
can briefly hog most of the energy residing in a neutron, yet spin in
the direction opposite to that of the neutron itself.
"That's very disturbing," comments theoretical physicist Xiangdong Ji
of the University of Maryland at College Park.
The finding suggests that scientists may have erred in calculations
using fundamental theory to predict quark behavior within neutrons,
he says. It might also indicate that orbital motions of particles
within neutrons, in addition to those particles' spins, are more
important than previously recognized. Those motions might be akin to
the moon's rotation around Earth as the satellite also spins about
its own axis.
Given that neutrons and protons are sister particles, called
nucleons, the new findings apply to both, says Xiaochao Zheng, a
member of the experimental team who's now at Argonne (Ill.) National
Laboratory.
Nucleons are the building blocks of atomic nuclei. A typical nucleon
includes three quarks: two down quarks and one up quark for a
neutron; two up quarks and one down quark for a proton. In addition
to those so-called valence quarks, each nucleon contains multitudes
of gluons-particles that bind quarks-and of short-lived
quark-antiquark pairs, known collectively as the quark sea.
Each of these constituents of a nucleon carries some share of the
nucleon's energy, although the distribution of that energy among the
constituents constantly shifts, Ji explains.
From previous experiments, scientists knew that only valence quarks
can grab major portions of a nucleon's total energy content, says
Jian-Ping Chen of the Jefferson lab, a coleader of the experiment.
The new spin-detecting experiment is the first to measure the state
of the neutron when most of its energy momentarily resides in a
single quark.
Calculations based on the prevailing theory of quark behavior predict
that any quark holding more than about half the energy of a nucleon
should spin in the same direction as the nucleon. However, when the
new experiment probed valence quarks temporarily laden with up to 60
percent of a neutron's energy, it revealed that only the up quarks
behaved as expected. The down quarks somehow carried most of the
energy yet rotated in a direction opposite to that of the neutron as
a whole.
Electrons and entire atoms also have spins. To arrive at the new
findings, the experimenters made a target of helium gas in which
nearly all atoms were forced to spin in the same direction and
bombarded it with a beam of high-energy electrons, whose spins were
also forced to have uniform orientations.
The researchers determined the spin orientations of the quarks in the
helium atoms by placing detectors in specific positions where they
are more likely to make detections when the orientations of the
electron's spin and the quark's spin are opposite, Zheng says. She
and her colleagues present their results in the Jan. 9 Physical
Review Letters.
Since the late 1980s, experiments have revealed that no more than 20
to 30 percent of a nucleon's spin comes from the spin of its valence
quarks. Physicists have been struggling to identify which of the
nucleon's other constituents contribute to nucleon spin and how
much-a puzzle known as the proton-spin crisis (SN: 9/6/97, p. 158).
These long-awaited neutron-spin data indicate that, under some
conditions, the previously overlooked orbital motions of valence
quarks make a major contribution to nucleon spin, comments theorist
Gerald A. Miller of the University of Washington in Seattle.
Date: Tue, 11 Feb 2003 14:30:40 -0500 (EST)
NASA today released the best "baby picture" of the
Universe ever taken; the image contains such stunning detail
that it may be one of the most important scientific results
of recent years.
Scientists using NASA's Wilkinson Microwave Anisotropy Probe
(WMAP), during a sweeping 12-month observation of the entire
sky, captured the new cosmic portrait, capturing the
afterglow of the big bang, called the cosmic microwave
background.
"We've captured the infant universe in sharp focus, and from
this portrait we can now describe the universe with
unprecedented accuracy," said Dr. Charles L. Bennett of the
Goddard Space Flight Center (GSFC), Greenbelt Md., and the
WMAP Principal Investigator. "The data are solid, a real gold
mine," he said.
One of the biggest surprises revealed in the data is the
first generation of stars to shine in the universe first
ignited only 200 million years after the big bang, much
earlier than many scientists had expected.
In addition, the new portrait precisely pegs the age of the
universe at 13.7 billion years old, with a remarkably small
one percent margin of error.
The WMAP team found that the big bang and Inflation theories
continue to ring true. The contents of the universe include 4
percent atoms (ordinary matter), 23 percent of an unknown
type of dark matter, and 73 percent of a mysterious dark
energy. The new measurements even shed light on the nature of
the dark energy, which acts as a sort of an anti-gravity.
"These numbers represent a milestone in how we view our
universe," said Dr. Anne Kinney, NASA director for astronomy
and physics. "This is a true turning point for cosmology."
The light we see today, as the cosmic microwave background,
has traveled over 13 billion years to reach us. Within this
light are infinitesimal patterns that mark the seeds of what
later grew into clusters of galaxies and the vast structure
we see all around us.
Patterns in the big bang afterglow were frozen in place only
380,000 years after the big bang, a number nailed down by
this latest observation. These patterns are tiny temperature
differences within this extraordinarily evenly dispersed
microwave light bathing the universe, which now averages a
frigid 2.73 degrees above absolute zero temperature. WMAP
resolves slight temperature fluctuations, which vary by only
millionths of a degree.
Theories about the evolution of the universe make specific
predictions about the extent of these temperature patterns.
Like a detective, the WMAP team compared the unique
"fingerprint" of patterns imprinted on this ancient light
with fingerprints predicted by various cosmic theories and
found a match.
WMAP will continue to observe the cosmic microwave background
for an additional three years, and its data will reveal new
insights into the theory of Inflation and the nature of the
dark energy.
"This is a beginning of a new stage in our study of the early
universe," said WMAP team member Prof. David N. Spergel of
Princeton University, N.J. "We can use this portrait not only
to predict the properties of the nearby universe, but can
also use it to understand the first moments of the big bang,"
he said.
WMAP is named in honor of David Wilkinson of Princeton
University, a world-renown cosmologist and WMAP team member
who died in September 2002.
Launched on June 30, 2001, WMAP maintains a distant orbit
about the second Lagrange Point, or "L2," a million miles
from Earth.
WMAP is the result of a partnership between the GSFC and
Princeton University. Additional Science Team members are
located at Brown University, Providence R.I., the University
of British Columbia, Vancouver, BC, the University of
Chicago, and the University of California, Los Angeles. WMAP
is part of the Explorer program, managed by GSFC.
For more information, including high-quality images, videos
and press products, refer to:
-end-
Nancy Neal
Bill Steigerwald
RELEASE: 03-224
EINSTEIN'S GRAVITATIONAL WAVES MAY SET SPEED LIMIT FOR PULSAR
SPIN
Gravitational radiation, ripples in the fabric of space
predicted by Albert Einstein, may serve as a cosmic traffic
enforcer, protecting reckless pulsars from spinning too fast
and blowing apart, according to a report published in the
July 3 issue of Nature.
Pulsars, the fastest spinning stars in the Universe, are the
core remains of exploded stars, containing the mass of our
Sun compressed into a sphere about 10 miles across. Some
pulsars gain speed by pulling in gas from a neighboring star,
reaching spin rates of nearly one revolution per millisecond,
or almost 20 percent light speed. These "millisecond" pulsars
would fly apart if they gained much more speed.
Using NASA's Rossi X-ray Timing Explorer, scientists have
found a limit to how fast a pulsar spins and speculate that
the cause is gravitational radiation: The faster a pulsar
spins, the more gravitational radiation it might release, as
its exquisite spherical shape becomes slightly deformed. This
may restrain the pulsar's rotation and save it from
obliteration.
"Nature has set a speed limit for pulsar spins," said Prof.
Deepto Chakrabarty of the Massachusetts Institute of
Technology (MIT) in Cambridge, lead author on the journal
article. "Just like cars speeding on a highway, the fastest-
spinning pulsars could technically go twice as fast, but
something stops them before they break apart. It may be
gravitational radiation that prevents pulsars from destroying
themselves."
Chakrabarty's co-authors are Drs. Edward Morgan, Michael
Muno, and Duncan Galloway of MIT; Rudy Wijnands, University
of St. Andrews, Scotland; Michiel van der Klis, University of
Amsterdam; and Craig Markwardt, NASA Goddard Space Flight
Center, Greenbelt, Md. Wijnands also leads a second Nature
letter complementing this finding.
Gravitational waves, analogous to waves upon an ocean, are
ripples in four-dimensional spacetime. These exotic waves,
predicted by Einstein's theory of relativity, are produced by
massive objects in motion and have not yet been directly
detected.
Created in a star explosion, a pulsar is born spinning,
perhaps 30 times per second, and slows down over millions of
years. Yet if the dense pulsar, with its strong gravitational
potential, is in a binary system, it can pull in material
from its companion star. This influx can spin up the pulsar
to the millisecond range, rotating hundreds of times per
second.
In some pulsars, the accumulating material on the surface
occasionally is consumed in a massive thermonuclear
explosion, emitting a burst of X-ray light lasting only a few
seconds. In this fury lies a brief opportunity to measure the
spin of otherwise faint pulsars. Scientists report in Nature
that a type of flickering found in these X-ray bursts, called
"burst oscillations," serves as a direct measure of the
pulsars' spin rate. Studying the burst oscillations from 11
pulsars, they found none spinning faster than 619 times per
second.
The Rossi Explorer is capable of detecting pulsars spinning
as fast as 4,000 times per second. Pulsar breakup is
predicted to occur at 1,000 to 3,000 revolutions per second.
Yet scientists have found none that fast. From statistical
analysis of 11 pulsars, they concluded that the maximum speed
seen in nature must be below 760 revolutions per second.
This observation supports the theory of a feedback mechanism
involving gravitational radiation limiting pulsar speeds,
proposed by Prof. Lars Bildsten of the University of
California, Santa Barbara. As the pulsar picks up speed
through accretion, any slight distortion in the star's dense,
half-mile-thick crust of crystalline metal will allow the
pulsar to radiate gravitational waves. (Envision a spinning,
oblong rugby ball in water, which would cause more ripples
than a spinning, spherical basketball.) An equilibrium
rotation rate is eventually reached where the angular
momentum shed by emitting gravitational radiation matches the
angular momentum being added to the pulsar by its companion
star.
Bildsten said that accreting millisecond pulsars could
eventually be studied in greater detail in an entirely new
way, through the direct detection of their gravitational
radiation. LIGO, the Laser Interferometer Gravitational-Wave
Observatory now in operation in Hanford, Wash. and in
Livingston, La., will eventually be tunable to the frequency
at which millisecond pulsars are expected to emit
gravitational waves.
"The waves are subtle, altering spacetime and the distance
between objects as far apart as the Earth and the Moon by
much less than the width of an atom," said Prof. Barry
Barish, LIGO director from the California Institute of
Technology, Pasadena. "As such, gravitational radiation has
not been directly detected yet. We hope to change that soon."
For animation, images and more information, visit the
Internet at:
Donald Savage
Steve Roy
Megan Watzke
RELEASE: 03-284
CHANDRA "HEARS" A BLACK HOLE
NASA's Chandra X-ray Observatory detected sound waves,
for the first time, from a super-massive black hole. The
"note" is the deepest ever detected from an object in the
universe. The tremendous amounts of energy carried by these
sound waves may solve a longstanding problem in
astrophysics.
The black hole resides in the Perseus cluster, located 250
million light years from Earth. In 2002, astronomers
obtained a deep Chandra observation that shows ripples in
the gas filling the cluster. These ripples are evidence for
sound waves that have traveled hundreds of thousands of
light years away from the cluster's central black hole.
"We have observed the prodigious amounts of light and heat
created by black holes, now we have detected the sound,"
said Andrew Fabian of the Institute of Astronomy (IoA) in
Cambridge, England, and leader of the study.
In musical terms, the pitch of the sound generated by the
black hole translates into the note of B flat. But, a human
would have no chance of hearing this cosmic performance,
because the note is 57 octaves lower than middle-C (by
comparison a typical piano contains only about seven
octaves). At a frequency over a million, billion times
deeper than the limits of human hearing, this is the deepest
note ever detected from an object in the universe.
"The Perseus sound waves are much more than just an
interesting form of black hole acoustics," said Steve Allen,
also of the IoA and a co-investigator in the research.
"These sound waves may be the key in figuring out how galaxy
clusters, the largest structures in the universe, grow,"
Allen said.
For years astronomers have tried to understand why there is
so much hot gas in galaxy clusters and so little cool gas.
Hot gas glowing with X-rays should cool, and the dense
central gas should cool the fastest. The pressure in this
cool central gas should then fall, causing gas further out
to sink in towards the galaxy, forming trillions of stars
along the way. Scant evidence has been found for such a flow
of cool gas or star formation. This forced astronomers to
invent several different ways to explain why the gas
contained in clusters remained hot, and, until now, none of
them was satisfactory.
Heating caused by a central black hole has long been
considered a good way to prevent cluster gas from cooling.
Although jets have been observed at radio wavelengths, their
effect on cluster gas was unclear since this gas is only
detectable in X-rays, and early X-ray observations did not
have Chandra's ability to find detailed structure.
Previous Chandra observations of the Perseus cluster showed
two vast, bubble-shaped cavities in the cluster gas
extending away from the central black hole. Jets of material
pushing back the cluster gas have formed these X-ray
cavities, which are bright sources of radio waves. They have
long been suspected of heating the surrounding gas, but the
mechanism was unknown. The sound waves, seen spreading out
from the cavities in the recent Chandra observation, could
provide this heating mechanism.
A tremendous amount of energy is needed to generate the
cavities, as much as the combined energy from 100 million
supernovae. Much of this energy is carried by the sound
waves and should dissipate in the cluster gas, keeping the
gas warm and possibly preventing a cooling flow. If so, the
B-flat pitch of the sound wave, 57 octaves below middle-C,
would have remained roughly constant for about 2.5 billion
years.
Perseus is the brightest cluster of galaxies in X-rays, and
therefore was a perfect Chandra target for finding sound
waves rippling through the hot cluster gas. Other clusters
show X-ray cavities, and future Chandra observations may yet
detect sound waves in these objects.
For images and additional information on the Internet,
visit:
-end-
NASA
Subject: BIGGEST 'ZOOM LENS' IN SPACE EXTENDS HUBBLE'S REACH
Donald Savage
Mark Hess
Ray Villard
RELEASE: 03-003
BIGGEST 'ZOOM LENS' IN SPACE EXTENDS HUBBLE'S REACH
The Advanced Camera for Surveys (ACS), aboard NASA's
Hubble Space Telescope, has used a natural "zoom lens" in
space to boost its view of the distant universe. Besides
offering an unprecedented and dramatic new view of the
cosmos, the results promise to shed light on galaxy
evolution and dark matter in space.
Hubble peered straight through the center of one of the most
massive known galaxy clusters, called Abell 1689. This
required Hubble to gaze at the distant cluster, located more
than 2.2 billion light-years away, for more than 13 hours.
The gravity of the cluster's trillion stars, plus dark
matter, acts as a 2-million-light-year-wide "lens" in space.
This "gravitational lens" bends and magnifies the light of
the galaxies located far behind it.
The Advanced Camera's IMAX movie-quality sharpness, combined
with the behemoth lens, reveals remote galaxies previously
beyond even Hubble's reach. A few may be twice as faint as
those photographed in the Hubble Deep Field, which
previously pushed the telescope to its sensitivity limits.
Though much more analysis is needed, Hubble astronomers
speculate that some of the faintest objects in the picture
are probably over 13 billion light-years away.
In the image, hundreds of galaxies, many billions of light-
years away, are smeared by the gravitational bending of
light into a spider-web tracing of blue and red arcs of
light. Though gravitational lensing has been studied
previously, with Hubble and ground-based telescopes, this
phenomenon has never been seen in such detail.
The Advanced Camera picture reveals 10 times more arcs than
would be seen by a ground-based telescope. The ACS is five
times more sensitive, and provides pictures that are twice
as sharp, as the previous workhorse Hubble cameras. It can
see the very faintest arcs with greater clarity. The picture
presents an immense jigsaw puzzle for Hubble astronomers to
spend months untangling. Interspersed with the foreground
cluster are thousands of galaxies, which are lensed images
of the galaxies in the background universe.
Detailed analysis of the images promises to shed light on
the mystery of dark matter. Dark matter is an invisible form
of matter. It is the source of most of the gravity in the
universe, because it is much more abundant than the "normal
matter" that makes up planets, stars and galaxies. The
lensing allows astronomers to map the distribution of dark
matter in galaxy clusters. This should offer new clues to
the nature of dark matter. By studying the lensed distant
galaxies, astronomers expect to better trace the history of
star formation in the universe over the past 13 billion
years.
The picture is an exquisite demonstration of Albert
Einstein's prediction that gravity warps space and therefore
distorts a beam of light, like a rippled shower curtain.
When the laws of relativity were formulated in the early
20th century, scientists did not know that stars were
organized into galaxies beyond our own Milky Way. Great
clusters of galaxies are massive enough to warp space and
deflect light in a way that is detectable from Earth. The
Abell cluster is the ideal target because it is so massive.
The more massive a cluster is, the larger the effects of
gravitational lensing.
Electronic image files and additional information are
available at:
The Space Telescope Science Institute is operated by the
Association of Universities for Research in Astronomy, Inc.,
for NASA, under contract with the Goddard Space Flight
Center, Greenbelt, Md. The Hubble Space Telescope is a
project of international cooperation between NASA and the
European Space Agency.
-end-
(2003)
02 July 2005
From New Scientist Print Edition.
Comments on Whirling Atoms (below)
has been added here because some people have scoffed
at the idea of frictionlessness. This is one of a number
of examples where lack of friction has proven to be a reality.
Headquarters, Washington June 24, 2005
(Phone: 202/358-5241/1979)
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-0880)
Taking snapshots of a light wave
09 April 2005
From New Scientist Print Edition.
Eugenie Samuel Reich
is a series of waves and not particulate in nature.
There have been so many articles written on confirmations of what
theoretical physicists call "dark energy" and "dark matter" (two separate
things) that I am no longer keeping track. To date, the
mainline physicists
have no idea what either is and are placing more and more band-aids
on their theories. Nothing has been found that refutes the theory
on this website - in fact, everything to date merely provides more
proof that this theory is correct.
Astronomers See Era of Rapid Galaxy Formation, New Findings a
Pose Challenge for Cold Dark Matter Theory
This is one step in ridding us of the erroneous Dark Matter theory.
See Constant Velocity Point (Dark Matter Solution) on this website.
Topsy Turvy - In neutrons and protons quarks take wrong turn.
1. The down quark in the neutron and the positron can have most
of the energy in the nucleon.
2. The down quark spins in the opposite direction to that of the nucleon.
These findings are in accord with the model of the proton shown on page
40 of Book Six of Behind Light's Illusion.
09 April 2005
From New Scientist Print Edition.
Eugenie Samuel Reich
More About the Electron
Wiggly light
From light to matter
From: NASANews@hq.nasa.gov
Subject: NASA RELEASES STUNNING IMAGES OF OUR INFANT UNIVERSE
Headquarters, Washington July 2, 2003
(Phone: 202/358-1547)
Goddard Space Flight Center, Greenbelt, Md.
(Phone: 301/286-5017)
-end-
Headquarters, Washington
(Phone: 202/358-1727) September 9, 2003
Marshall Space Flight Center, Huntsville, Ala.
(Phone: 256/544-6535)
Chandra X-ray Observatory Center, CfA, Cambridge, Mass.
(Phone: 617/496-7998)
Date: Tue, 7 Jan 2003 12:59:16 -0500 (EST)
Headquarters, Washington January 7, 2003
(Phone: 202/358-1547)
Goddard Space Flight Center, Greenbelt, Md.
(Phone: 301/286-8982)
Space Telescope Science Institute, Baltimore
(Phone: 410/338-4514)
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