Einstein’s Universe Minus the Big Bang

Einstein’s Lost Theory Describes a Universe Without a Big Bang

By Amir Aczel | March 7, 2014 10:32 am

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Einstein with Edwin Hubble, in 1931, at the Mount Wilson Observatory in California, looking through the lens of the 100-inch telescope through which Hubble discovered the expansion of the universe in 1929. Courtesy of the Archives, Calif Inst of Technology.

In 1917, a year after Albert Einstein’s general theory of relativity was published—but still two years before he would become the international celebrity we know—Einstein chose to tackle the entire universe. For anyone else, this might seem an exceedingly ambitious task—but this was Einstein.

Einstein began by applying his field equations of gravitation to what he considered to be the entire universe. The field equations were the mathematical essence of his general theory of relativity, which extended Newton’s theory of gravity to realms where speeds approach that of light and masses are very large. But his math was better than he wanted to believe—his equations told him that the universe could not stay static: it had to either expand or contract. Einstein chose to ignore what his mathematics was telling him.

The story of Einstein’s solution to this problem—the maligned “cosmological constant” (also called lambda)—is well known in the history of science. But this story, it turns out, has a different ending than everyone thought: Einstein late in life returned to considering his disgraced lambda. And his conversion foretold lambda’s use in an unexpected new setting, with immense relevance to a key conundrum in modern physics and cosmology: dark energy.

The Static Universe Before Hubble

Einstein had what would have seemed a very good reason for ignoring what the math was telling him. Few people know that Einstein was not merely a superb theoretician, but also a physicist skilled in observations and experiments. In 1914, Einstein was wooing a young Scottish-German astronomer, Erwin Finlay Freundlich, to seek proof of relativity through shifts in apparent star locations during a total solar eclipse that was to take place in the Crimea (which ended badly because of the outbreak of World War I). Letters that Einstein wrote to Freundlich during 1913-4 reveal that Einstein had a burgeoning interest in astronomy and understood much about the field, including technical details of lenses and mirrors.* Ironically, his deep knowledge of astronomy would lead Einstein to make the greatest blunder of his entire career….Or not.

Astronomical knowledge of the time told Einstein that the universe was unchanging in its size. How could someone think that? Well, this was the second decade of the twentieth century, and telescopes were still relatively small and not very powerful. They were strong enough to allow astronomers to discover all the now-known planets in our solar system, to get good views of “cloudy patches” of the sky such as the Orion nebula, and to view several galaxies, including the Great Andromeda Galaxy—our nearest neighbor at 2.3 million light years’ distance.

But astronomers believed that all these fuzzy objects they were seeing were somehow part of our own Milky Way. (The great Eddington even believed at that time that the Sun was the center of this universe! And an idea about the distances to the most faraway stars only began to emerge through the work of Harlow Shapely on Cepheid variables, conducted at the Mount Wilson Observatory, in 1916.) Since astronomers could detect no expansion of stars or nebulas in the entire cosmos known to them, they assumed that the universe was static.

The Birth of the Cosmological Constant

To force his equations—which theoretically predicted the expansion of the universe—to remain still, Einstein invented the cosmological constant, λ. He multiplied the metric tensor in his equation, g, by the cosmological constant, leading to a term λg, which adjusted his metric tensor acting on space-time. This mathematical trick assured him that his equations would yield a universe that was prevented from expanding or contracting.

Unbeknownst to Einstein, at exactly the time he published his paper on the cosmological equations, across the world in California, the new 100-inch Hooker telescope was being fit in its place at the Mount Wilson Observatory. Within a little over a decade, Edwin Hubble, aided by Vesto Slipher and Milton Humason, would use this, the most powerful telescope on Earth, to study the redshift of distant galaxies and conclude from it definitively that our universe is expanding.

Einstein heard about these results, and in the early 1930s, he traveled to California and met with Hubble.  At the Mount Wilson Observatory he saw the massive data set on distant galaxies that had led to “Hubble’s law” describing the expansion of the universe and got angry at himself: had he not forced his equations to stay static with that cosmological-constant invention of his, he could have theoretically predicted Hubble’s findings! That would have been worth a second Nobel Prize for him (he deserved a few more, anyway)—in the same way, for example, that the CERN scientists’ 2012 experimental discovery of the Higgs boson recently won Peter Higgs the Nobel in 2013. In disgust, Einstein exclaimed after his Mount Wilson visit: “If there is no quasi-static world, then away with the cosmological term!” and never considered the cosmological constant again. Or so we thought until recently.

Dark Energy: Lambda Returns

When a genius such as Einstein makes a mistake, it tends to be a “good mistake.” (I am indebted to the mathematician Goro Shimura for this expression.) It can’t simply go away—there is too much thought that has gone into it. So, like a phoenix, Einstein’s cosmological constant made a remarkable comeback, very unexpectedly, in 1998.

That year, two groups of astronomers made an announcement that rocked the world of science. The “Supernova Cosmology Project,” based in California and headed by Saul Perlmutter, and the “High-Z SN Search” group at Harvard-Smithsonian and Australia, announced their results of the shifts of distant galaxies leading to a conclusion that nobody had expected: The universe, rather than slowing its expansion since the Big Bang, is actually accelerating its expansion!

And it turns out that the best theoretical way to explain the accelerating universe is to revive Einstein’s discarded lambda. The cosmological constant (acting differently from how it was designed, as a force stopping the expansion) is the best explanation we have for the mysterious “dark energy” seen to permeate space and push the universe ever outward at an accelerating rate. To most physicists today, lambda, cosmological constant, and dark energy are closely synonymous. But unfortunately Einstein was not there to witness the reversal of his “greatest blunder,” having died in 1955.

And it has been widely assumed that he died without ever reconsidering the cosmological constant. Until now.

Einstein’s Lost Manuscript

The Irish physicist Cormac O’Raifeartaigh was perusing documents at the Einstein Archives at the Hebrew University in Jerusalem in late 2013 when he discovered a handwritten manuscript by Einstein that scholars had never looked at carefully before. The paper, called “Zum kosmologischen Problem” (“About the Cosmological Problem”), had been erroneously filed as a draft of another paper, which Einstein published in 1931 in the annals of the Prussian Academy of Sciences. But it was not. It seems that even with Einstein, old notions die hard: This paper was his stubborn attempt to resurrect the cosmological constant he had vowed never to use again.

In a paper just filed on the electronic physics repository ArXiv, O’Raifeartaigh and colleagues show that in the early 1930s (the assumed date is 1931, but this is uncertain), Einstein was still trying to return to his 1917 analysis of a universe with a cosmological constant. Einstein wrote (the authors’ translation from the German):

“This difficulty [the inconsistency of the laws of gravity with a finite mean density of matter] also arises in the general theory of relativity. However, I have shown that this can be overcome through the introduction of the so-called “λ–term” to the field equations… I showed that these equations can be satisfied by a spherical space of constant radius over time, in which matter has a density ρ that is constant over space and time.”

But he was now aware of Hubble’s discovery of the expansion of the universe:

“On the other hand, Hubbel’s [sic**] exceedingly important investigations have shown that the extragalactic nebulae have the following two properties 1) Within the bounds of observational accuracy they are uniformly distributed in space 2) They possess a Doppler effect proportional to their distance”  (Quoted in O’Raifeartaigh, et al., 2014, p. 4)

And so Einstein proposed a revision of his model, still with a cosmological constant, but now the constant was responsible for the creation of new matter as the universe expanded (because Einstein believed that in an expanding universe, the overall density of matter had to still stay constant):

In what follows, I would like to draw attention to a solution to equation (1) that can account for Hubbel’s facts, and in which the density is constant over time.” And: “If one considers a physically bounded volume, particles of matter will be continually leaving it. For the density to remain constant, new particles of matter must be continually formed in the volume from space.”

Einstein achieves this property by the use of his old cosmological constant, λ:

“The conservation law is preserved in that by setting the λ-term, space itself is not empty of energy; as is well-known its validity is guaranteed by equations (1).”  (Quoted in O’Raifeartaigh, et al., 2014, p. 7.)

So Einstein keeps on using his discarded lambda—despite the fact that he invented it for a non-expanding universe. If the universe expands as Hubble showed, Einstein seems to be saying, then I still need my lambda—now to keep the universe from becoming less dense as it expands in volume.

Almost two decades later, a similar “steady state” universe would be proposed by Fred Hoyle, Hermann Bondi, and Tommy Gold, in papers  published in 1949. But these models of the universe are not supported by modern theories. In fact, a tenet of modern cosmology is that as the universe will expand a great deal (after an unimaginably long period of time), it will become very thinly populated, rather than dense, with stray photons and electrons zipping alone through immense expanses of emptiness, all stars having by then died and disappeared.

Views of the Cosmos, Old and New

As for why Einstein was so intent on maintaining the use of his discarded lambda, the constant represents the energy of empty space—a powerful notion—and Einstein in this paper wanted to use this energy to create new particles as time goes on.

Today we view the same energy of the vacuum as the reason for the acceleration of the universe’s expansion. Einstein presciently understood that the energy of the vacuum, unleashed by his cosmological constant, was too important to let die.

Einstein was far from the only person to wonder about the universe and whether it has always existed or was born at some point in the past and would die at a future time. This question has been pondered by people ever since the dawn of civilization. The origin and ultimate fate of the universe are highly interlinked with its overall geometry—the actual shape of the space-time manifold. In a closed geometry, the universe was born and will someday recollapse on itself. In an open geometry, it was born and will expand forever, and the same happens in a flat (Euclidean) geometry. Based on modern theories supported by satellite observations of the microwave background radiation in space, space-time is nearly perfectly Euclidean, meaning that the universe was born in a Big Bang and will expand forever, becoming less dense with time. Eventually, matter may decay into few kinds of elementary particles and photons, the distances among them growing to infinity.

Cosmology in Context

Between 1917 and 1929—the year Hubble and his colleagues discovered the expansion of the universe, implying the possibility of a beginning for the cosmos—Einstein and most scientists held that the universe was “simply there” with no beginning or end. But it’s interesting to note that creation myths across cultures tell the opposite story. Traditions of Chinese, Indian, pre-Colombian, and African cultures, as well as the biblical book of Genesis, all describe (clearly in allegorical terms) a distinct beginning to the universe—whether it’s the “creation in six days” of Genesis or the “Cosmic Egg” of the ancient Indian text the Rig Veda.

This is an interesting example of scientists being dead wrong (for a time) and primitive ancient observers having an essentially correct intuition about nature. And with the present explosion of models of the universe and sometimes outrageous “scientific speculations” about its origin and future, some commentators are clearly overstating what science has done. One recent example is the book by the physicist Lawrence M. Krauss, A Universe From Nothing, which claims that science has shown that the universe somehow sprang out of sheer nothingness.***

A century ago, Einstein’s powerful field equations of gravitation showed the way forward. His uncanny intuition about the universe prevailed despite temporary reversals, and his decades-old insights are now at the cutting edge of modern physics and cosmology, helping us shed light on the greatest mysteries of all: the nature of matter, gravity, time, space, and the mysterious dark energy pushing it all outwards.

from:    http://blogs.discovermagazine.com/crux/2014/03/07/einsteins-lost-theory-describes-a-universe-without-a-big-bang/#.UyHnhl5Rall

Black Holes Before the Big Bang? New Theory

“Some Primordial Black Holes Have Existed Before the Big Bang” — A Radical Theory Proposed

 

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In recent years, cosmologists have begun to think seriously about processes that occurred before the Big Bang. Alan Coley from Canada’s Dalhousie University and Bernard Carr from Queen Mary University in London, published a paper in 2011, where they theorized that some so-called primordial black holes might have been created in the Big Crunch that came before the Big Bang, which supports the theory that the Big Bang was not a single event, but one that occurs over and over again as the Universe crunches down to a single point, then blows up again.

In some circumstances, they say, black holes of a certain mass could avoid this fate and survive the crunch as separate entities. The masses for which this is possible range from a few hundred million kilograms to about the mass of our Sun.

The theory is based on the fact that the Earth, and the rest of the known Universe is occasionally bombarded with unexplained bursts of gamma rays — something that could, according to Coley and Carr, be the result of primordial black holes running out of energy and disintegrating. These small black holes ought to evaporate away in relatively short period of time, finally disappearing in a violent explosion of gamma rays. Some cosmologists say this thinking might explain the gamma ray bursts that we already see from time to time.

Primordial black holes are thought to be of a different type than the regular kind that are formed when a supernova occurs but rather formed in the first “moments” after the Big Bang. Primordial black holes would be smaller and created by the energy of the Big Bang itself and would then have been widely dispersed as the Universe expanded.

In their theory, however, Coley and Carr suggest that some of these black holes, if they actually exist, might have been created by the collapsing Universe as part of the Big Crunch, and then somehow escaped being pulled into the pinpoint singularity comprised of everything else. And then, after the Big Bang, they simply assimilated with the newly formed Universe.

A key problem they agree on is that it would likely be impossible to tell the difference between pre- and post Big Bang primordial black holes.

The theory raises major questions for cosmologists: if the Universe contracts, then blows up, over and over, has this gone on forever? Or is it possible that our view of the Universe is so limited that we’re only seeing one tiny fraction of it, and thus, any theories or explanations we offer, are little more than guesses.

Image at the top of page shows co-orbiting supermassive black holes powering the giant radio source 3C 75. Surrounded by multimillion degree x-ray emitting gas, and blasting out jets of relativistic particles the supermassive black holes are separated by 25,000 light-years. At the cores of two merging galaxies in the Abell 400 galaxy cluster they are some 300 million light-years away.
Such spectacular cosmic mergers are thought to be common in crowded galaxy cluster environments in the distant Universe. In their final stages the mergers are expected to be intense sources of gravitational waves.

More information: Persistence of black holes through a cosmological bounce, B. J. Carr, A.A. Coley, arXiv:1104.3796v1 [astro-ph.CO] http://arxiv.org/abs/1104.3796

The Daily Galaxy via MIT Technology Review

from site:    http://www.dailygalaxy.com/my_weblog/2012/03/some-primordial-black-holes-have-existed-before-the-big-bang-a-radical-theory-says-yes.html#more

 

Antimatter Surprise

Is the New Physics Here? Atom Smashers Get an Antimatter Surprise

by Clara Moskowitz, LiveScience Senior Writer
Date: 17 November 2011 Time: 06:05 PM ET
The LHCb team stands in front of their experiment, the LHCb detecor, at the Large Hadron Collider in Geneva.
The LHCb team stands in front of their experiment, the LHCb detecor, at the Large Hadron Collider in Geneva.
CREDIT: CERN/Maximilien Brice, Rachel Barbier

The world’s largest atom smasher, designed as a portal to a new view of physics, has produced its first peek at the unexpected: bits of matter that don’t mirror the behavior of their antimatter counterparts.

The discovery, if confirmed, could rewrite the known laws of particle physics and help explain why our universe is made mostly of matter and not antimatter.

Scientists at the Large Hadron Collider, the 17-mile (27 km) circular particle accelerator underground near Geneva, Switzerland, have been colliding protons at high speeds to create explosions of energy. From this energy many subatomic particles are produced.

Now researchers at the accelerator’s LHCb experiment are reporting that some matter particles produced inside the machine appear to be behaving differently from their antimatter counterparts, which might provide a partial explanation to the mystery of antimatter.

Missing antimatter

Scientists think the universe started off with roughly equal amounts of matter and antimatter. (Particles of antimatter have the same mass of their twins but an opposite charge.) Somehow over the ensuing 14 billion years, most of the antimatter was destroyed, leaving a leftover universe of mainly matter.

One potential explanation for this outcome is called “charge-parity violation.”  CP violation means that particles of opposite charge behave differently from one another.

The LHCb researchers found preliminary evidence that this is happening when particles called D-mesons, which contain “charmed quarks,” decay into other particles. The whimsically named charmed quarks, like many exotic particles, are so unstable, they last only a fraction of a second. They quickly decay into other particles, and it is these products that the experiment detects. (“LHCb” is short for LHC-beauty, another flavor of quark.)

From the experiment, the researchers found a 0.8 percent difference in the probabilities that the matter and antimatter versions of these particles would decay into a particular end state.

Ruling out a fluke

When it comes to particle physics, it’s all about the quality of statistics. Measuring something once is meaningless because of the high degree of uncertainty involved in such exotic, small systems. Scientists rely on taking measurements over and over again — enough times to dismiss the chance of a fluke.

The new finding ranks as a “3.5 sigma” result, meaning the statistics are solid enough that there is only a 0.05 percent likelihood that the pattern they see isn’t really there. For something to count as a true discovery in particle physics, it must reach a 5 sigma level of confidence.

“It’s certainly exciting, and certainly worth pursuing,” LHCb researcher Matthew Charles of England’s Oxford University told LiveScience. “At this point it’s a tantalizing hint. It’s evidence of something interesting going on, but we’re keeping the champagne on ice, let’s say.”

By the end of 2012, Charles said, the Large Hadron Collider should have collected enoughdata to either confirm or reject the result.

LHC’s birthright

If the finding is borne out, it would be a big deal, because it would mean the reigning theory of particle physics, called the Standard Model, is incomplete. Currently the Standard Model does allow for some minor CP violation, but not at the level of 0.8 percent. To explain these results, scientists would have to alter their theory or add some new physics to the existing picture.

In either case, the LHC would have begun to claim its birthright.

“The whole driving purpose of the LHC is to discover and understand new physics beyond the Standard Model,” Charles said. “This sort of analysis is exactly why I joined LHCb.”

One possible example of the kind of new physics that might explain such CP violation is called supersymmetry. This theory suggests that in addition to all the known particles, there are supersymmetric partner particles that differ by half a unit of spin. Spin is one of the fundamental characteristics of elementary particles.

So far, no one has found direct evidence of supersymmetry. But if supersymmetric particles exist, they might be created instantaneously and disappear again during the particle-decay process. That way they could interfere with the decay process, potentially explaining why matter and antimatter decay differently.