The solar wind - the stream of charged particles billowing away from the Sun - is at its weakest for 50 years.
Scientists made the assessment after studying 18 years of data from the Ulysses satellite which has sampled the space environment all around our star.

They expect the reduced output to have effects right across the Solar System.

Indeed, one impact is to diminish slightly the influence the Sun has over its local environment which extends billions of kilometres into space.
Confirmation of that prediction should come from the far-distant Voyager spacecraft which were launched in the 1970s and are now bearing down on the edge of the heliosphere - the great "bubble" of wind material that surrounds the Sun.

Scientists now predict the Voyagers will hit the edge and cross over into interstellar space - that region considered to be "between the stars" - sooner than anticipated.

Space age
The solar wind, which originates in the Sun's hot outer atmosphere known as the corona, gusts and calms with the star's familiar 11-year cycle of activity (but also over its less well known longer cycles, too).

Calmer wind conditions would be expected to prevail right now, but the Ulysses data indicates circumstances unprecedented in recent times.
"This is a whole Sun phenomenon," said Dave McComas, Ulysses solar wind instrument principal investigator, from Southwest Research Institute, San Antonio, US.

"The entire Sun is blowing significantly less hard - about 20-25% less hard - than it was during the last solar minimum 10-15 years ago.

"That's a very significant change. In fact, the solar wind we're seeing now is blowing the least hard we've see it for a prolonged time, since the start of those observations in the 1960s at the start of the space age."

In addition to being calmer, the wind measured at Ulysses is 13% cooler.

However, judging from Sun activity data collected by non-satellite methods over the past 200 years, the current behaviour is thought to be well within the long-term norm.

Nonetheless, scientists expect the weakened wind to have a wide range of impacts.

Energetic rays
The charged wind particles also carry with them the Sun's magnetic field, and this has a protective role in limiting the number of high-energy cosmic rays that can enter the Solar System.

More of them will probably now make their way through.

Many of these rays, which include electrons and atomic nuclei, originate in exploding stars and at black holes, and move at colossal speeds.
They pose no major risk to people on Earth because our atmosphere also works to reduce their intensity; but they are a consideration for space operations.

The rays can damage satellite electronics, and if current solar wind conditions persist, engineers would have to take this into account when deciding how to "harden" their spacecraft. Astronauts, too, are at risk from the higher doses of radiation associated with cosmic rays.

"The Sun also puts out cosmic rays in the form of bursts and these bursts are much less frequent at solar minimum. However, when they do occur at solar minimum, they are more lethal, so this is not a good time to be travelling in space owing to both kinds of cosmic rays," explained Professor Nancy Crooker, from Boston University, Massachusetts, US.

"Reduced solar activity also leads to the cooling of Earth's upper atmosphere and if Earth's upper atmosphere is cooler then there is less drag up there on satellites and this means we are left with much more debris up there - which is also something astronauts have to look out for."

Some researchers have attempted to link the intensity of cosmic rays at Earth to cloudiness and climate change. Current conditions may be a good opportunity to test these ideas further.
The Ulysses mission is a co-operative venture between the US space agency and the European Space Agency (Esa). Launched by the shuttle in 1990, it was the first satellite to study the space environment above and below the Sun's poles.

It samples the solar wind and solar magnetic field as it circles the star in a six-year orbit that also carries it out to Jupiter and back.

But the harsh conditions of space are now slowly taking their toll on the spacecraft.

Ulysses' main transmitter no longer works and it is struggling to put enough power into its heating systems. With the satellite currently moving away from the Sun, it is gradually getting colder; and engineers expect the hydrazine fuel used in its thrusters to freeze very soon.

When this happens, Ulysses will no longer be able to orientate itself and its antenna, and contact will be lost with Earth.

"Even though the end is now in sight, every day's worth of new data is adding to our knowledge of the Sun and its environment; and it's been a great and exciting mission," said Richard Marsden, Esa's Ulysses project scientist and mission manager.
source :http://news.bbc.co.uk/

Paul Steinhardt's universe is a lot like the workaday world of many people, a cycle of early vigor, spent energy, exhausted return, and new beginnings. However, in Steinhardt's universe, there is absolutely no end to the cycle.

The Princeton physicist and his colleague, Neil Turok of Cambridge University, have developed a whole new theory for how the universe came to be. Their proposal seeks to explain recently uncovered flaws in the scientifically accepted model for the origin and evolution of all known things. It describes a series of big bangs and equally significant crunches that form a never-ending cycle of rejuvenation and destruction.

In this universe -- our universe -- time never ends.

The current leading theory for the universe holds that it emerged from a single Big Bang sometime around 12 billion to 15 billion years ago, undergoing an early and rapid period of inflation. That much remains widely accepted.

"However, the standard model has some cracks," Steinhardt and Turok write in a paper published today in the online version of the journal Science.

Astronomers have in recent years learned that the universe is not just expanding, but is doing so at an ever-increasing pace. This can't be explained given the known matter and energy that exists. To account for the acceleration, theorists have conjured a product they call dark energy, which supposedly repels things rather than attracting, as gravity does.

No one has seen this dark energy, and scientists don't even know what it is. But they say it's all around us.

More important, it shouldn't be there.

"The recent discoveries of cosmic acceleration and gravitationally self-repulsive dark energy were not predicted and have no particular role in the standard model," Steinhardt and Turok argue. "Furthermore, the standard model does not explain the beginning of time,' the initial conditions of the universe, or what will happen in the long-term future."

So to patch some of the theoretical cracks, Steinhardt and Turok envision a universe based on perpetual expansion and contraction.

Here's how it works, and keep in mind we're jumping into the middle of the explanation: A big bang sends everything outward. Matter and radiation develop. Dark energy drives an expansion -- as is presently underway -- that lasts trillions of years. Finally, the matter, radiation, and even black holes are "diluted away," leaving the universe smooth, empty, and flat.

Then everything contracts in a so-called big crunch, and a fresh cycle begins.

"In this picture, space and time exist forever, Steinhardt says. "The big bang is not the beginning of time. Rather, it is a bridge to a pre-existing contracting era."

Curiously, the cyclic universe, as it is called, puts the origin of some present-day structures and events prior to the Big Bang.

While existing theory states that galaxies and large clusters of galaxies developed from lumps and filaments that formed in the otherwise smooth fabric of space and time shortly after the Big Bang, Steinhardt thinks the seeds of galaxy formation were created by instabilities that arose during the last contraction, before the crunch that led to "our" bang.

The new model "turns the conventional picture topsy-turvy," he says.

The cyclic universe has roots in even more complex thoughts like so-called superstring theory, which suggests there are as many as 10 spatial dimensions, not just the three we know of. The seemingly inexplicable physics of a big crunch and a big bang might be explained with the aid of these extra dimensions, which are otherwise invisible to us, several theorists believe.

In fact, Steinhardt, Turok and others proposed last year that our universe might have sprung from the collapse of an extra dimension, an idea they called the Ekpyrotic Universe. The cyclic universe builds on this former work but, Steinhardt says, does a better job explaining observations of our present universe.

Other theorists are not quick to give up their standard model, so the concept of a cyclic universe faces an uphill battle for prominence. Even Steinhardt acknowledges that the prospect of unseating a well established cosmological theory "would seem extremely dim."

Meanwhile, the new concept is not free of cracks, either: Even the cyclic universe does not address when the cycles began, so "the problem of explaining the beginning of time remains," the researchers say.
Source :http://www.space.com/

New and feasible experiments are suggested in order to demonstrate the inaccuracy of Albert Einstein’s Theory of Relativity, especially the so-called Space Michelson-Morley.

Also, Global Physics presents new physics experiments to support its principles, such as the Giga-Chron experiment.

For this reason and for being designed with a different understanding of nature, the Theory of Global Equivalence is a scientific theory within Modern Physics that puts forth a new paradigm.

The known experiments are categorized and outlined with or without a new interpretation, like the famous three predictions of General Relativity, the tunnel effect and double slit experiment.

There is a table that summarizes the experiments in Modern Physics by subject matter and theories that explain them.

The physics experiments have scientific and not mental or philosophical character.



From another perspective, it is important to make it clear that, in order to talk about Quantum Mechanics and the Theory of Relativity, it is not necessary to be a mathematical genius or to know about tensors, since in order to talk about evolution it is not necessary to know about molecular biology, to have studied in the university to be able to talk about philosophy or to talk about religion to do it in Latin.

In all of the pages appear the related links where the free on-line books are included, in which the exposition of the new theory of unification, theory of everything or, yet better, Global Physics. This division is due to numerous reasons such as: metaphysical or scientific experimental character, mathematical difficulty, the subject dealt with and presentation on the Internet.

Brief summary of the mentioned on-line science books about Global Physics are:

* The Equation for Love

In this book, perspectives of modern science and metaphysics are combined; besides the introduction about the relativity of love there are two titles dedicated to time and the Equation for Love and gravity, respectively.

There is a brief discussion about the new concept used by the physics sciences and, more thoroughly, the personal conception of metaphysical time and the time line as something real and subjective in contrast to the imaginary nature of time in Modern Physics.

In other words, the new theory attempts to replace the correct duality of subjective and objective reality in the realm of philosophy, separating them from other, let’s say, imaginary realities. It is not to say that imaginary realities are incorrect to certain extent, but they do not correspond to the standard, common and simpler form of the operation of human logic and, as a epistemological result, of the scientific method.

The book ends with a quick recapitulation about philosophy, science and religion given that the formulas allow us to develop various interpretations from different - especially from the objective and subjective - points of view, helping our mind to better understand the global model.

*

Theory of Relativity, Elements and Criticism

The clear objective of this second digital book is to reveal that the explanations about the Theory of Relativity and relativistic time are actually inadequate if not completely wrong, contributing to the widening of the pre-existing rift between the knowledge of Modern Physics and the scientific community of the society as a whole. There is an attempt to develop a destructive criticism while in some way still acknowledging its positive points.

It is funny that, on the one hand, relativity in of itself is not as wrong as the explanations given by its defenders, and, on the other hand, it is much more wrong than they could imagine. In fact, it has some aspects that are correct because they are conventionally consistent; for example, time, as it is currently defined, is relative; but what does not make much sense is the official definition of the unit of time being sensitive to the gravitational field or to speed since it would have been logical to establish it including, among others, these two specific conditions.

After so much destruction and massive confusion about whether the speed of light is or the speed of light is not, I hope that the Theory of Relativity within modern science and its weak points are somewhat better understood in relation to the normal relationships between space-time or speed on one side and gravity-mass-energy on the other.

*

The Theory of Global Equivalence

The development of the Theory of Global Equivalence has implied changes in numerous principles and laws of physics. We can divide the modifications of the new paradigm in two large groups.

On one hand, the physics principles will be related to space and time and all the implications concerning other magnitudes, such as movement, force, gravity force and energy. On the other hand, the affected physics principles will define matter and its various states of aggregation such as gravity and mass.

In this Modern Physics book, the new theory of gravitation is presented: the Theory of Global Equivalence. The intention is to constructively include the proposed ideas concerning the first group of physics principles mentioned above.

In the book, the new theory of gravitation includes ideas about the basic elements from the new model of Modern Physics: space, time, light, mass, energy and gravity.

The previous points imply some alterations of the Newton’s Laws of Dynamics and the concept of movement.

The fundamental equation of the new theory of gravitation relies on the direct relation between gravity force and the four most notable physics constants.

g = c² * h * R / G

The Law of Global Gravity deserves special mention for implying a different explanation, which is consistent with common sense, about the decisive predictions of the General Theory of Relativity by means of a small adjustment of Newton’s Law of Universal Gravitation.

*

Global Mechanics

This online book studies the second group of previously cited physics principles, regarding the equivalence between gravity, energy and mass (GEM) within a perspective of its material support, physical constitution or physical reality.

If the Theory of Global Equivalence deals with space and time, the Global Mechanics is more concerned with subjects closer to Quantum Mechanics or Quantum Physics.

Contemplating the subatomic world has led me to create some clarifications about the states of aggregation of matter which configure the concepts of mass and gravity.

Two aspects deserve special attention; matter and mass exist as physics entities with a discrete form regardless of the observer. The second point, virtual mathematical forces of the gravity field are no longer necessary.

Among the aspects of the Global Mechanics that stand out the most, we can cite the following:
o

A new definition of the structure of matter, addressing gravity, energy and mass.
o

Unification of gravitational and electromagnetic fields.
o

Explanation of the wave-particle duality, why the speed of light is constant and, at the same time, the possible variation of speed of light with gravity field intensity.
o

Unification of gravity force with weak and strong nuclear forces and new model of the atom.
o

These principles of Physics affect some aspects of Astronomy like the concepts of a star, black holes, supernova, expansion and contraction of the universe, dark matter and dark energy.
o

Contemplations on Cosmology about the origin of the universe or the Big Bang theory.

Despite it specific nature, the Global Mechanics has to be understood as immersed in the Theory of Global Equivalence, which it is formed at the same time as the theory of unification, a theory of multiple substitution (Quantum Mechanics and Theory of Relativity)

Moreover, a new science seems to appear due to the new proposals not only imply a Grand Unification Theory (GUT) but a Theory of Everything (TOE) when adding to the previous unification the gravity force. The idea of Global Physics or Globics comes out from the perspective of the new physics principles that refutes both Theory of Relativity and Quantum Mechanics.

* Global Scientific Method

The on-line book about the philosophy of science includes the design of new scientific methods and the classification of the stages and steps of the scientific method; understanding the scientific method in the broad sense as the application of logic to the generation of common knowledge with a high level of reliability.

The scientific method works fine in general, but it works much better in its developmental phase than in its phase of general acceptance. All types of social interests affect the last phase, from the realm of sociology as in the case of Darwin’s theory, to the technician nature as in the case of the Theory of Relativity.
In the case of physics, in order to optimize the brain resources, it would be helpful to eliminate the fictitious forces, the magical or distant forces such as current gravity, the negative energies, the straight lines that are curved, the accelerated time and the confusion between the magnitude and the measurements that the instruments carry out; especially, when it is known that the instruments are sensitive to specific conditions.
Source:http://www.molwick.com

He is best known as the past century's most famous genius. But as well as devising the theory of relativity, Albert Einstein was also responsible, it emerged yesterday, for a less celebrated discovery - a fridge. 

Nearly 80 years after he invented it, a group of German physicists have begun making Einstein's unique alcohol-powered fridge. 

The existence of the fridge shows that the great scientist was not only a theoretician but also a down-to-earth practical inventor. 

Jürgen Renn, director of the Max-Plank Institute in Berlin, said: "He came from a merchant family, he had to worry about money, and he was supposed to take over the family business." 

Einstein wrote his theory of relativity in 1905, while working in the Swiss patent office. It was not until 1926, when he was living in Berlin and had won the Nobel prize, that he came up with his fridge. 

He invented it after reading a news report about how an ordinary fridge had poisoned a sleeping Berlin family. Its pump had leaked sulphur dioxide. 

Together with his fellow physicist Leo Szilard, Einstein built a fridge that used harmless alcohol gas. 

Although Einstein took the trouble to patent his design, new technology meant his model never went into production. The only prototype built vanished. Only a handful of photographs exist. 

The historian Peter Galison told the German science magazine ZeitWissen yesterday: "As a young man Einstein corresponded with friends about helicopters and measuring equipment, tinkered with small experiments, and filed patents." 

Germany is gearing up for a double Einstein celebration next year. Events are planned to mark the centenary of his theory of relativity and the 50th anniversary of his death.
 Source : Guardian Newspaper

ScienceDaily (Sep. 11, 2008) — Eta Carinae, the galaxy's biggest, brightest and perhaps most studied star after the sun, has been keeping a secret: Its giant outbursts appear to be driven by an entirely new type of stellar explosion that is fainter than a typical supernova and does not destroy the star.

Reporting in the Sept. 11 issue of Nature, University of California, Berkeley, astronomer Nathan Smith proposes that Eta Carinae's historic 1843 outburst was, in fact, an explosion that produced a fast blast wave similar to, but less energetic than, a real supernova. This well-documented event in our own Milky Way Galaxy is probably related to a class of faint stellar explosions in other galaxies recognized in recent years by telescopes searching for extragalactic supernovae.

"There is a class of stellar explosions going off in other galaxies for which we still don't know the cause, but Eta Carinae is the prototype," said Smith, a UC Berkeley postdoctoral fellow.

Eta Carinae (η Car) is a massive, hot, variable star visible only from the Southern Hemisphere, and is located about 7,500 light years from Earth in a young region of star birth called the Carina Nebula. It was observed to brighten immensely in 1843, and astronomers now see the resulting cloud of gas and dust, known as the Homunculus nebula, wafting away from the star. A faint shell of debris from an earlier explosion is also visible, probably dating from around 1,000 years ago.

Presumably blown off by the star's fierce wind, the shells of gas and dust are moving slowly - at speeds of 650 kilometers per second (1.5 million miles per hour) or less - compared to the blast shell of a supernova.

Smith's recent observations using the international Gemini South 8-meter telescope and the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile reveal something new: Extremely fast filaments of gas moving five times faster than the debris in the Homunculus nebula were propelled away from Eta Carinae in the same event. The amount of mass in the relatively slow-moving Homunculus was already at the edge of plausibility in terms of what an extreme stellar wind could do physically, Smith said. The much faster and more energetic material he discovered poses even harsher difficulties for current theories.

Instead, the speeds and energies involved are reminiscent of material accelerated by the fast blast wave of a supernova explosion.

The fast speeds in this blast wave could roughly double earlier estimates of the energy released in the 1843 eruption of Eta Carinae, an event that Smith argues was not just a gentle surface eruption driven by the stellar wind, but an actual explosion deep in the star that sent debris hurtling into interstellar space. In fact, the fast-moving blast wave is now colliding with the slow-moving cloud from the 1,000-year-old eruption and generating X-rays that have been observed by the orbiting Chandra Observatory.

"These observations force us to modify our interpretation of what happened in the 1843 eruption," he said. "Rather than a steady wind blowing off the outer layers, it seems to have been an explosion that started deep inside the star and blasted off its outer layers. It takes a new mechanism to cause explosions like this."

If Smith's interpretation is correct, supermassive stars like Eta Carinae may blow off large amounts of mass in periodic explosions as they approach the end of their lives before a final, cataclysmic supernova blows the star to smithereens and leaves behind a black hole.

Much fainter than a supernova, the explosion that generated the fast-moving blast wave around Eta Carinae would have been similar to faint stellar explosions, sometimes called "supernova imposters," now being discovered in other galaxies by Earth-based robotic telescopes and other supernova searches. Such searches have been looking primarily for Type Ia supernovae that could help astronomers understand the accelerating expansion of the universe, but they also find other gems along the way, Smith said.

"Looking at other galaxies, astronomers have seen stars like Eta Carinae that get brighter, but not quite as bright as a real supernova," he said. "We don't know what they are. It's an enduring mystery as to what can brighten a star that much without destroying it completely."

Eta Carinae is a rare supermassive star in our galaxy, probably once having had a mass 150 times that of the sun. Such large stars burn brightly for only a few million years, all the while shedding mass as the intense light pushes the outer layers of the star away in a stellar wind. After 2 to 3 million years of this, Eta Carinae now weighs about 90 to 100 solar masses, having shed about 10 solar masses in its most recent 1843 eruption alone.

"These explosions may be the primary way by which massive stars can shed their outer hydrogen layers before they die," Smith said. "If Eta Carinae is able to shed 10 solar masses every thousand years or so, that's an efficient mechanism for peeling off a large fraction of the star."

Astronomers now believe that Eta Carinae and other luminous blue variable stars are nearing the end of their lives, having burned hydrogen in their cores into helium. If they explode at the stage where they still have an envelope of hydrogen shrouding the helium core, the resulting supernova will look vastly different from one that results from a star that sloughs off all its hydrogen before exploding.

Smith suggests that it is still unclear if supernova impostors are scaled-down versions of supernovae, failed supernovae, precursor events or entirely different kinds of explosions.

"This could be an important clue for understanding the last violent phases in the lives of massive stars," he said, noting that astronomers still cannot accurately predict the fate of stars that are 30 or more times the mass of the sun.

The observations reported in the Nature paper included visible spectra from the Blanco telescope, which is part of the U.S. National Optical Astronomy Observatory (NOAO), and near-infrared spectra taken with the Gemini South telescope. Both telescopes are in Chile's Andes mountains near an elevation of 9,000 feet. NOAO and the Gemini Observatory are operated by the Association of Universities for Research in Astronomy.

The research was supported in part by the National Aeronautics and Space Administration and the National Science Foundation.

A new theory of the universe suggests that space and time may not have begun in a big bang, but may have always existed in an endless cycle of expansion and rebirth.

Princeton physicist Paul Steinhardt and Neil Turok of Cambridge University described their proposed theory in an article published April 25 in an online edition of Science.

The theory proposes that, in each cycle, the universe refills with hot, dense matter and radiation, which begins a period of expansion and cooling like the one of the standard big bang picture. After 14 billion years, the expansion of the universe accelerates, as astronomers have recently observed. After trillions of years, the matter and radiation are almost completely dissipated and the expansion stalls. An energy field that pervades the universe then creates new matter and radiation, which restarts the cycle.

The new theory provides possible answers to several longstanding problems with the big bang model, which has dominated the field of cosmology for decades. It addresses, for example, the nagging question of what might have triggered or come "before" the beginning of time.

The idea also reproduces all the successful explanations provided by standard picture, but there is no direct evidence to say which is correct, said Steinhardt, a professor of physics. "I do not eliminate either of them at this stage," he said. "To me, what's interesting is that we now have a second possibility that is poles apart from the standard picture in many respects, and we may have the capability to distinguish them experimentally during the coming years."

The big bang model of the universe, originally suggested over 60 years ago, has been developed to explain a wide range of observations about the cosmos. A major element of the current model, added in the 1980s, is the theory of "inflation," a period of hyperfast expansion that occurred within the first second after the big bang. This inflationary period is critical for explaining the tremendous "smoothness" and homogeneity of the universe observed by astronomers, as well as for explaining tiny ripples in space that led to the formation of galaxies.

Scientists also have been forced to augment the standard theory with a component called "dark energy" to account for the recent discovery that the expansion of the universe is accelerating.

The new model replaces inflation and dark energy with a single energy field that oscillates in such a way as to sometimes cause expansion and sometimes cause stagnation. At the same time, it continues to explain all the currently observed phenomena of the cosmos in the same detail as the big bang theory.

Because the new theory requires fewer components, and builds them in from the start, it is more "economical," said Steinhardt, who was one of the leaders in establishing the theory of inflation.

Another advantage of the new theory is that it automatically includes a prediction of the future course of the universe, because it goes through definite repeating cycles lasting perhaps trillions of years each. The big bang/inflation model has no built-in prediction about the long-term future; in the same way that inflation and dark energy arose unpredictably, another effect could emerge that would alter the current course of expansion.

The cyclic model entails many new concepts that Turok and Steinhardt developed over the last few years with Justin Khoury, a graduate student at Princeton, Burt Ovrut of the University of Pennsylvania and Nathan Seiberg of the Institute for Advanced Study.

"This work by Paul Steinhardt and Neil Turok is extraordinarily exciting and represents the first new big idea in cosmology in over two decades," said Jeremiah Ostriker, professor of astrophysics at Princeton and the Plumian Professor of Astronomy and Experimental Philosophy at Cambridge.

"They have found a simple explanation for the observed fact that the universe on large scales looks the same to us left and right, up and down -- a seemingly obvious and natural condition -- that in fact has defied explanation for decades."

Sir Martin Rees, Royal Society Research Fellow at Cambridge, noted that the physics concerning key properties of the expanding universe remain "conjectural, and still not rooted in experiment or observation."

"There have been many ideas over the last 20 years," said Rees. "Steinhardt and Turok have injected an imaginative new speculation. Their work emphasizes the extent to which we may need to jettison common sense concepts, and transcend normal ideas of space and time, in order to make real progress.

"This work adds to the growing body of speculative research which intimates that physical reality could encompass far more than just the aftermath of 'our' big bang."

The cyclic universe theory represents a combination of standard physical concepts and ideas from the emerging fields of string theory and M-theory, which are ambitious efforts to develop a unified theory of all physical forces and particles. Although these theories are rooted in complex mathematics, they offer a compelling graphic picture of the cyclic universe theory.

Under these theories, the universe would exist as two infinitely large parallel sheets, like two sheets of paper separated by a microscopic distance. This distance is an extra, or fifth dimension, that is not apparent to us. At our current phase in the history of the universe, the sheets are expanding in all directions, gradually spreading out and dispersing all the matter and energy they contain. After trillions of years, when they become essentially empty, they enter a "stagnant" period in which they stop stretching and, instead, begin to move toward each other as the fifth dimension undergoes a collapse.

The sheets meet and "bounce" off each other. The impact causes the sheets to be charged with the extraordinarily hot and dense matter that is commonly associated with the big bang. After the sheets move apart, they resume their expansion, spreading out the matter, which cools and coalesces into stars and galaxies as in our present universe.

The sheets, or branes, as physicists call them, are not parallel universes, but rather are facets of the same universe, with one containing all the ordinary matter we know and the other containing "we know not what," said Steinhardt. It is conceivable, he said, that a material called dark matter, which is widely believed to make up a significant part of the universe, resides on this other brane. The two sheets interact only by gravity, with massive objects in one sheet exerting a tug on matter in the other, which is what dark matter does to ordinary matter.

The movements and properties of these sheets all arise naturally from the underlying mathematics of the model, noted Steinhardt. That is in contrast to the big bang model, in which dark energy has been added simply to explain current observations.

Steinhardt and Turok continue to refine the theory and are looking for theoretical or experimental ideas that might favor one idea over the other.

"These paradigms are as far apart as you can imagine in terms of the nature of time," said Steinhardt. "On the other hand, in terms of what they predict about the universe, they are as close as you can be up to what you can measure so far.

"Yet, we also know that, with more precise observations that may be possible in the next decade or so, you can distinguish them. That is the fascinating situation we find ourselves in. It's fun to debate which ones you like better, but I really think nature will be the final arbiter here."

For further information and a graphic animation of the cyclic scenario, see http://feynman.princeton.edu/~steinh/

Albert Einstein (German: IPA: [ˈalbɐt ˈaɪ̯nʃtaɪ̯n] (Audio file) (help·info); English: IPA: /ˈælbɝt ˈaɪnstaɪn/) (14 March 1879 – 18 April 1955) was a German-born theoretical physicist. He is best known for his theory of relativity and specifically mass–energy equivalence, E = mc 2. Einstein received the 1921 Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect."[1]

Einstein's many contributions to physics include his special theory of relativity, which reconciled mechanics with electromagnetism, and his general theory of relativity, which was intended to extend the principle of relativity to non-uniform motion and to provide a new theory of gravitation. His other contributions include relativistic cosmology, capillary action, critical opalescence, classical problems of statistical mechanics and their application to quantum theory, an explanation of the Brownian movement of molecules, atomic transition probabilities, the quantum theory of a monatomic gas, thermal properties of light with low radiation density (which laid the foundation for the photon theory), a theory of radiation including stimulated emission, the conception of a unified field theory, and the geometrization of physics.

Einstein published over 300 scientific works and over 150 non-scientific works.[2][3] Einstein is revered by the physics community,[4] and in 1999 Time magazine named him the "Person of the Century". In wider culture the name "Einstein" has become synonymous with genius.