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In 1920, Einstein invented the idea of dark energy to explain why the Universe feels a force that counteracts gravity. His explanation was quickly abandoned as unnecessary, and subsequently ignored for 70 years. Today we know that not only was Einstein correct, dark energy does exist, but also, that it is expanding the Universe into darkness.

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Astrophysics, abstract: astro-ph/9811454

From: Mike Turner
Date: Sun, 29 Nov 1998 17:23:50 GMT (122kb)

Dark Matter and Dark Energy in the Universe

Authors: Michael S. Turner (U. Chicago and Fermilab)
Comments: 22 pages LaTeX with 7 eps figures. To be published in The Third Stromlo Symposium: The Galactic Halo, eds. B.K. Gibson, T.S. Axelrod, and M.E. Putnam (Astron. Soc. Pac. Conf. Series, Vol. 666, 1999)
For the first time, we have a plausible, complete accounting of matter and energy in the Universe. Expressed a fraction of the critical density it goes like this: neutrinos, between 0.3% and 15%; stars, 0.5%; baryons (total), 5%; matter (total), 40%; smooth, dark energy, 60%; adding up to the critical density. This accounting is consistent with the inflationary prediction of a flat Universe and defines three dark-matter problems: Where are the dark baryons? What is the nonbaryonic dark matter? What is the nature of the dark energy? The leading candidate for the (optically) dark baryons is diffuse hot gas; the leading candidates for the nonbaryonic dark matter are slowly moving elementary particles left over from the earliest moments (cold dark matter), such as axions or neutralinos; the leading candidates for the dark energy involve fundamental physics and include a cosmological constant (vacuum energy), a rolling scalar field (quintessence), and light, frustrated topological defects.

"Dark Energy" Dominates The Universe

Date: January 2, 2003
Science Daily — HANOVER, NH - A Dartmouth researcher is building a case for a "dark energy"-dominated universe. Dark energy, the mysterious energy with unusual anti-gravitational properties, has been the subject of great debate among cosmologists.

Brian Chaboyer, Assistant Professor of Physics and Astronomy at Dartmouth, with his collaborator Lawrence Krauss, Professor of Physics and Astronomy at Case Western Reserve University, have reported their finding in the January 3, 2003, issue of Science. Combining their calculations of the ages of the oldest stars with measurements of the expansion rate and geometry of the universe lead them to conclude that dark energy dominates the energy density of the universe.

"This finding provides strong support for a universe which is dominated by a kind of energy we've never directly observed," says Chaboyer. "Observations of distant supernova have suggested for a few years that dark energy dominates the universe, and our finding provides independent evidence that the universe is dominated by this type of energy we do not understand."

The researchers came to this conclusion as they were refining their calculations for the age of globular clusters, which are groups of about 100,000 or more stars found in the outskirts of the Milky Way, our galaxy. Because this age (about 12 billion years old) is inconsistent with the expansion age for a flat universe (only about 9 billion years old), Krauss and Chaboyer came to the conclusion that the universe is expanding more quickly now than it did in the past.

The only explanation, according to Chaboyer and Krauss, for an accelerating universe is that the energy content of a vacuum is non-zero with a negative pressure, in other words, dark energy. This negative pressure of the vacuum grows in importance as the universe expands and causes the expansion to accelerate.


also see   www.as.utexas.edu/hetdex

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for a current in-depth article see The Universe's Invisible Hand from Scientific American magazine. Feb. 2007 below

Tesla's Discovery and Application
of Radiant/Dark Energy

Of all the great inventions and discoveries of Nikola Tesla, nothing stood out with greater potential benefit to the whole of humanity than his discovery of Radiant ("Dark") Energy in 1889. The series of observations that led to the discovery of Radiant energy initially grew out of experiments that Tesla had conducted in an attempt to duplicate the results that Heinrich Hertz had claimed to achieve in affirming the existence of electromagnetic waves, the discovery of which Hertz announced in 1887. While replicating Hertz's experiments, Tesla experimented with violently abrupt DC electrical discharges and discovered a new force in the process. Only after conducting exhaustive experimental trials for the next three years, did Tesla announce this stupendous discovery in a paper published in December, 1892, entitled "The Dissipation of Electricity". Incredibly, most academicians of the day completely missed the mark in understanding the true significance of his paper. Noted scientists such as Sir Oliver Lodge, mistakenly thought that Tesla was referring to high frequency AC electricity in the operation of the Tesla Transformer, a huge blunder that remains to this day in the misnaming and misinterpretation of the Tesla Coil. The transformer that Tesla referred to in the 1892 paper did not operate on magnetic/electric field induction created by alternating currents. It operated in an entirely new domain of physics based on abrupt discharges of electrostatic potentials and the subsequent release of kinetic Radiant Energy from the omnipresent ether. Tesla was now operating under entirely new rules which he referred to as "dynamic" electro-static forces and had, by now, completely abandoned any further interest in the AC waveform. The genesis of the Lodge misunderstanding, however, began a few years earlier with the publication of certain mathematical formulas by a brilliant Scotsman named James Clerk Maxwell.
 

Maxwell's Equations

Using mathematical models, James Clerk Maxwell had earlier suggested that two different types of electrical disturbances could possibly exist in Nature. One type was a longitudinal electric wave which required alternating concentrations of densified and rarefied pulsations of electrostatic fields that moved along a single vector (today, we refer to these as standing waves or scalar waves). Maxwell ultimately rejected this idea because he was convinced that this type of wave propagation was impossible to achieve, but his assumption was erroneous and would later portend formidable consequences for Tesla and the world at large.

Maxwell's second wave postulation was that of a transverse electromagnetic wave that exhibited a rapid alternation of electric fields along a fixed axis that radiated away from its point of origin at the speed of light and was detectable at great distances. Maxwell had more faith in the existence of this type of wave and encouraged experimenters to look in this direction. It was the discovery of this type of wave that Hertz had laid claim to, but Tesla was meticulous and fastidious in replicating Hertz's experimental parameters and he could not obtain the results claimed by Hertz.

Tesla discovered a fundamental flaw in Hertz's experiment: Hertz had failed to take into account the presence of air in his experiments. Hertz had mistakenly identified electrostatic inductions or electrified shockwaves as true electromagnetic waves. Tesla was saddened to bring this news to the distinguished academician, but felt scientific honesty was paramount if progress was to be achieved. Tesla visited Hertz in Germany and personally demonstrated the experimental error to him. Hertz agreed with Tesla and had planned to withdraw his claim, but reputations, political agendas, national pride, and above all, powerful financial interests, intervened in that decision and set the stage for a major rift in the 'accepted' theories that soon became transformed into the fundamental "laws" of the electric sciences that have held sway in industry and the halls of academia to the present day.

The blue spike phenomena

Tesla's introduction to the phenomena of Radiant Energy began with early observations by linesmen working for Thomas Edison, Tesla's former employer

Before Tesla's invention of the Polyphase AC generator became the industry standard and overtook Thomas Edison's use of DC generators, the DC electrical system was the only system available to deliver electricity to America's homes and factories. Due to the resistance offered by long transmission lines, Edison had to produce very high DC voltages from his generators in order to deliver enough voltage and current to its final destination. He also had to provide additional 'pumping' stations along the way to boost the sagging voltage which dwindled from line losses. A curious anomaly occurred in the very first instant of throwing the power switch at the generating station: Purple/blue colored spikes radiated in all directions along the axis of the power lines for just a moment. In addition, a stinging, ray-like shocking sensation was felt by those who stood near the transmission lines. In some cases, when very large DC voltages surged from the generators, the "stinging" sensation was so great that occasionally a blue spike jumped from the line and grounded itself through a workman, killing him in the process.

Tesla realized almost immediately that electrons were not responsible for such a phenomena because The blue spike phenomena ceased as soon as the current stated flowing in the lines. Something else was happening just before the electrons had a chance to move along the wire. At the time, no one seemed to be very interested in discovering why these dramatic elevations in static electrical potential were taking place, but rather, engineering design efforts were focused on eliminating and quenching this strange anomaly which was considered by everyone to be a nuisance-except Tesla. Tesla viewed it as a powerful, yet unknown form of energy which needed to be understood and harnessed if possible. The phenomena only exhibited itself in the first moment of switch closure, before the electrons could begin moving. There seemed to be a "bunching" or "choking" effect at play, but only briefly. Once the electrons began their movement within the wire, all would return to normal. What was this strange energy that was trying to liberate itself so forcefully at the moment of switch closure? .

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One guy experimenting today:
Bill Alek writes: Hello all,

I have some very encouraging information to report in regards to my spark gap experiments:
http://www.intalek.com/Index/Projects/SparkGapExp/SparkGapExp.htm

Excess electrical energy has been discovered in spark gaps using Carbon/Graphite - Tungsten rods. Assuming an ideal system, a maximum COP of 171% is possible using a Wimshurst Generator as the primary high-voltage dynamo.

A Tesla-like step-down transformer T1 with a ferrite rod is used to efficiently reduce the high-voltage down to safe practical levels, which can easily be distributed and measured. As shown in Fig. 1, successive electric discharges or Electrum Validum (EVs) discharges are generated, and their associated energy is collected in a 10uf low loss capacitor during a given period of time.


Bill Alek writes: Hello all,

I have some very encouraging information to report in regards to my spark gap experiments:

Excess electrical energy has been discovered in spark gaps using Carbon/Graphite - Tungsten rods. Assuming an ideal system, a maximum COP of 171% is possible using a Wimshurst Generator as the primary high-voltage dynamo.

A Tesla-like step-down transformer T1 with a ferrite rod is used to efficiently reduce the high-voltage down to safe practical levels, which can easily be distributed and measured. As shown in Fig. 1, successive electric discharges or Electrum Validum (EVs) discharges are generated, and their associated energy is collected in a 10uf low loss capacitor during a given period of time.

Bill


William S. Alek
Exploring Gravitational and Inertial Mass fluctuations,
Radiant Energy, and Temporal Anomalies
http://groups.yahoo.com/group/intalek

INTALEK, INC. PHONE/FAX: 219.924.2742
3506-43rd. Place EMAIL: mailto:wsalek01@intalek.com
Highland, IN 46322 USA HOME PAGE: http://www.intalek.com/

----------------

Hello all,

I added a close-up view of the Carbon/Graphite - Tungsten spark gap shown in Fig. 3:
http://www.intalek.com/Index/Projects/SparkGapExp/SparkGapExp.htm

Secondly, the Wimshurst Generator is powered by hand.

In regards to the COP calculation, I placed a "black box" ONLY around the Carbon/Graphite - Tungsten spark gap, and I'm observing ONLY the energy difference between the spark gap and NO spark gap.

The key here is the Carbon electric discharge.

Bill

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The "fountain effects" which surrounded his station are not responsible for the ever-growing power observed by Tesla. This was the result of an incoming aetheric supply for which his Transmitter gave low-resistance passage. The incoming aetheric flow preferred the transmitter terminal to adjacent, more resistant rock. This gradual flow process soon evidenced itself in magnification effects, ever increasing volumes of flowing aether being measured in his system. Some have argued that Tesla merely stored energy in the earth, extracting it for use later. This is a basic error, the result of imagining the Colorado Springs experiment to be one consisting entirely of electrical effects (Grotz). It is in this light alone that we may comprehend the evident anomalous magnification of aetheric phenomena in his Colorado Springs photographs.

Once aetheric energy had been obtained from space, it had to be conveyed to consumers. Tesla had arranged for the automatic activation of aether-rebroadcast circuits in the station. The down pouring aether was automatically shunted to side circuits through capacitors. In these side branches, aether pulsed through dielectrics and expanded over the surfaces of his smaller coils. Thus stimulated to more rapid pulsation rates, they were ready for "rebroadcast". Being rebroadcast away from the station through large vacuum globes, poised on elevated platforms, these were the aetheric pulsations, which would be utilized in home and industry. Simple and compact receivers would be established in every home and factory, set to receive aetheric current through the ground. Tests were thrilling. The distant appliances, lamps and motors responded to the powerful pulsations, as if they were physically connected to the station by wire. A small house-like structure was established some 26 miles away from the station. In it, an aetheric power receiver was tuned to one of the rebroadcast rates. The 200 lamps housed within this structure, each of 50 watts rating, all remained brilliantly illuminated throughout the test runs. This apparently stimulated enough excitement and concern for word of this development to get back east.

Engineers were enraged. Those who had missed his most early shift from alternations to impulses, failed to comprehend the vast distinction between "stationary waves" and " standing waves". The quizzical use of specific terms such as these was a Tesla trademark, one designed to puzzle the minds of those who criticized him the most. With the exception of a very few colleagues who continually made related discoveries in aether physics, most academes had chosen to remain totally ignorant of the new study area. This for example was the case with the Teslian use of the term "frequency" and of "resonance" words which had completely different meanings for Tesla. Teslian "frequency" refers to the repetition of pulses per second. Teslian "resonance" refers to conditions in which aether flows with little or no resistance through systems, whether proximal or widely separated.

Photographs, which Tesla sent to his "financiers", were analyzed and reexamined repeatedly for their encrypted meaning. None could decipher the cunning puzzle which Tesla had set before them. Tesla stated that photographs of the aetheric white fire streamers required several minutes' exposure time before registering the faintest sort of impression. Most of the plates were therefore the results of more than 20 minutes' exposure time. There are a very few plates which, though stated to be the result of "one brief switch closure", are covered with dense, thick white streamers. One fraction of a second closure on the system switch resulted in a twenty-minute or more aether avalanche. Magnifying Transformers continued discharging long after the initial impulse had been withdrawn.

AETHER POWER RECEIVERS

Tesla returned to New York exultant. He was about to establish a new world precedent. Venture capitalists were everywhere, looking for their opportunity to enter the "new energy" market. Unknown to Tesla, his station, its tower, the large coils, the capacitors, and all the other marvelous apparatus, which demonstrated free aetheric power to the world, had been acquired for demolition. Tesla simply went forward, securing new funds from Morgan and others toward the development of a fully functional industry sized station in Long Island. Wardenclyffe Station. Wardenclyffe would be his greatest achievement. Here he would broadcast power to the world, along with a communications network, which could span the globe with innumerable available channels. Aether wave communications. Several stations would augment the power of this first station, from which he proposed to rebroadcast 10,000 horsepower. The Station, a wonderful visionary structure, which dominated the view of Shoreham, Long Island, was not quite complete before it too was seized by court injunctions and torn down.

Tesla was summoned to appear in court. Mr. Leland Anderson who has since published a wonderful treatise with this transcript as the centerpiece has secured the amazing transcript of this proceeding. Tesla said he wept when he saw the ruined tower at Wardenclyffe. The train ride back from Shoreham was filled with tears and the recounting of every tragedy, which marked his life. But the dreams did not die there. In the absence of financial means to construct his gigantic stations, Tesla found ways to build small systems, which accomplished the very same objectives. Replacing the large overhead capacity terminal with material substitutes, radioactive metals in combination with other dense elements, Tesla was able to accrete and focus aether pulsations of super short duration.

Tesla was then plunged into a hellish time, where all but one would neither help nor hear him. Dr. John Hammond requested Tesla to be the permanent guest on his family estate. There, amid the family life of Hammond Castle, Tesla shared his dreams and technology. Together, he and Dr. Hammond developed the science of robots and remote guidance. Tesla, impoverished by the inhuman treatment wrought on him by the financial establishment, was nonetheless quite alive and valuable to those having singular ambition to dominate the world radio trade. For a very long time, Nikola Tesla was considered "out of circulation."

But later years turned a kindlier edge toward him. Long after his principle foe had died, other sought him out. Employed by the Rockefellers in their RCA venture, Tesla was given the task of restructuring the now failing Marconi System. David Sarnoff did not permit Tesla the dignity of working under his own name! Nevertheless it was Tesla, not Sarnoff, who redesigned the insufficient RCA radio systems to sufficiently turn a profit for the owners. It is significant that Tesla was not allowed to change the basic design from wave radio to radiant communications. What he achieved required certain strange conversions within the wave radio circuitry, intensifying radiant signals until the operation was much improved, and then converting the amplified signals back to waves once again. All of this was achieved within the chassis, certain of which are now being studied. These Tesla experimental models are typical of the Tesla style, containing no resistors or other such components. These models use simple transmitter tubes and employ a great number of symmetrically disposed conical air coils.

While working for RCA under the name "Terbo", Tesla maintained his two penthouse suites atop the Hotel New Yorker. One penthouse was his living quarters, the other a full-scale research laboratory. Tesla designed and built small compact and portable aether energy receivers, a developmental path, which he pursued to his passing. Tesla had long investigated the use of pure dielectric field energy, a stream of aether whose individual pulsations were so very ultra short that science had never found a means to harness the energy impulses. Tesla later held the opinion that dielectric current was composed of radiant particles, aetheric in nature. He therefore sought natural sources in which native dielectric fields could be used as they were, without the need for mammoth voltage "shocks" to stigmata aetheric currents. Tesla knew that if dielectric aether streams could be directly engaged, a true world of the future would be in his grasp. Furthermore, the mass-production of thousands and ten of thousands of such power receivers would be an unstoppable army. An army of miniatures, which could never be torn down.

The implications were fathomless. Tesla had found a truly new and wonderful approach to an old problem. Once because his technology had not yet grown to the level where this was possible, he had to settle for impressing the naturally prolific aether streams with "extra" pulsations. The Transmitter method was costly, gargantuan, and an easy target for those who hated the notion of a future world where dreams rule humanity. Dielectric energy fascinated Tesla. It was everywhere, a natural emanation whose potentials far out proportioned conventional notions of power. Indeed, the early conception of natural radioactivity as an energetic source was nothing in comparison to the potential power inherent in dielectric streams. The new technology would use ultra-short pulsing aether streams, energies that occupied most of his latter press conferences in latter years. Study had convinced Tesla that the apparently smooth and native force characteristic of dielectric field energy was actually a particulate flux, a succession of ultra-short impulses. The derivation of such an impulse train would solve all energy needs for eternity with an elegance far out-reaching his own

Magnifier Transmitter

Of a truth, dielectric energy was native source of incredible proportion and virtually eternal duration. Able to use such a kinetic source, one could dispense entirely with the Power Transmitters necessary in stimulating and impressing "extra pulsations" on the aether flow. Tesla often defined the dielectric field as a natural flow of aether particles, one that seemed impossible to utilize through lack of appropriate resistive materials. In order to obtain momentum from the flowing particles of a dielectric field, one required special matter poised in equally special symmetries. The otherwise continuous flow could be absorbed directly, being exchanged to utilities, appliances, and other applications.

Tesla had already considered the condition of charged particles, each representing a tightly constricted whorl of aether. The force necessarily exerted at close distances by such aetheric constrictions was incalculably large. Aetheric ponderance maintained particulate stability. Crystalline lattices were therefore places within which one could expect to find unexpected voltages. Indeed, the high voltages inherent in certain metallic lattices, intra-atomic field energies, are enormous. The close Coulomb gradient between atomic centers are electrostatic potentials reaching humanly unattainable levels. By comparison, the voltages, which Tesla once succeeded in releasing, were quite insignificant. In these balanced lattices, Tesla sought the voltages needed to initiate directed aetheric streams in matter. Once such a flow began, one could simply tap the stream for power. In certain materials, these aether streams might automatically produce the contaminating electrons, a source of energy for existing appliances. One could theoretically then "tailor" the materials needed to produce unexpected aetheric power with or without the attendant detrital particles. Tesla did mention the latent aetheric power of charge forces, the explosive potentials of bound aether, and the aetheric Power inherent in matter. In these studies, Tesla sought replacement for the 100,000,000 volt initiating pulses for the implementation of space aether.

next:
Make a Radiant Energy Machine

From BNE

(Original article by Sol Millin, BNE coordinator, Byron Bay, Australia)

The ‘radiant energy engine’ is the creation of a very sudden and frequent interruption to a dc voltage. Various dc voltage sources and voltage interruption devices have been used by researchers. Apparently, if you interrupt the dc voltage 10,000 times a second you have a potential ‘radiant energy engine’. Now 100 microseconds is a time interval of 1/10,000th of a second which with current electronic circuit design is considered trivial to produce. Using the most common oscillator chip in the world the NE555 this can be achieved easily.

A simple circuit will output a variable frequency dc 12 volt square wave between 1kHz and 40kHz for experimentation. You can use this wave form to drive your radiant energy engine through a simple Mosfet circuit which allows this wave form to be delivered at a very high amperage (up to 20 amps). The output wave form can be designed to be ‘ON’ for a very very short period of time, thus consuming very little current in the primary circuit. Back emf from the primary circuit and some of the radiant energy from the secondary circuit can be used to charge a potential source (eg. 12 volt battery) which can alternate with the primary current source (another 12 volt battery) to hopefully produce an OU (over unity) radiant energy machine.

What we have to do then apparently is raise the primary voltage to some thousands of volts and apply this clean cut off (with no back emf) to our ‘radiant energy transceiver’ which apparently creates a disturbance in Space itself that 'moves' electrons in the output (transmitter) aspect of the ‘radiant energy transceiver’. The input and output circuits of the transceiver are electrically isolated from each other. The load of the ‘radiant energy machine’ is run off of the output of the radiant transmitter.

So the potential interruptions in the primary circuit which by the way use very very little current, 'move' the radiant energy in the secondary circuit which supplies energy to the load.

Sounds like the same concept of oscillation that Stanley Meyer was using to fracture water. From what I understand by watching a video about Meyer he used very high DC voltage and very low amperage (milliamps) to get water to split into Hydrogen and Oxygen. In the video it talks about the oscillation of the current and I believe he used some sort of dielectric to prevent emf, from what I have read. I am a novice at all of this so please forgive me if I have stated something technically incorrect. I am attempting to build his original fuel cell from the patent blueprints but am not sure of exactly how to deliver the DC current wave form. If any one knows what type of device I could use to vary the current and interrupt it at the correct rate please post here. Unfortunately I understand Meyer was murdered. The video alludes to the idea that he was offered a billion dollars for his invention and he turned it down. I’m not interested in the money either. I want free energy for everyone.

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Scientific American magazine.

Feb. 2007
The Universe's Invisible Hand
Dark energy does more than hurry along the expansion of the universe.
It also has a stranglehold on the shape and spacing of galaxies
By Christopher J. Conselice

What took us so long? Only in 1998 did astronomers discover we had been missing nearly three quarters of the contents of the universe, the so-called dark energy--an unknown form of energy that surrounds each of us, tugging at us ever so slightly, holding the fate of the cosmos in its grip, but to which we are almost totally blind. Some researchers, to be sure, had anticipated that such energy existed, but even they will tell you that its detection ranks among the most revolutionary discoveries in 20th-century cosmology. Not only does dark energy appear to make up the bulk of the universe, but its existence, if it stands the test of time, will probably require the development of new theories of physics.

Scientists are just starting the long process of figuring out what dark energy is and what its implications are. One realization has already sunk in: although dark energy betrayed its existence through its effect on the universe as a whole, it may also shape the evolution of the universe's inhabitants--stars, galaxies, galaxy clusters. Astronomers may have been staring at its handiwork for decades without realizing it.

Ironically, the very pervasiveness of dark energy is what made it so hard to recognize. Dark energy, unlike matter, does not clump in some places more than others; by its very nature, it is spread smoothly everywhere. Whatever the location--be it in your kitchen or in intergalactic space--it has the same density, about 10-26 kilogram per cubic meter, equivalent to a handful of hydrogen atoms. All the dark energy in our solar system amounts to the mass of a small asteroid, making it an utterly inconsequential player in the dance of the planets. Its effects stand out only when viewed over vast distances and spans of time.

Since the days of American astronomer Edwin Hubble, observers have known that all but the nearest galaxies are moving away from us at a rapid rate. This rate is proportional to distance: the more distant a galaxy is, the faster its recession. Such a pattern implied that galaxies are not moving through space in the conventional sense but are being carried along as the fabric of space itself stretches [see "Misconceptions about the Big Bang," by Charles H. Lineweaver and Tamara M. Davis; Scientific American, March 2005]. For decades, astronomers struggled to answer the obvious follow-up question: How does the expansion rate change over time? They reasoned that it should be slowing down, as the inward gravitational attraction exerted by galaxies on one another should have counteracted the outward expansion.

The first clear observational evidence for changes in the expansion rate involved distant supernovae, massive exploding stars that can be used as markers of cosmic expansion, just as watching driftwood lets you measure the speed of a river. These observations made clear that the expansion was slower in the past than today and is therefore accelerating. More specifically, it had been slowing down but at some point underwent a transition and began speeding up [see "Surveying Space-time with Supernovae," by Craig J. Hogan, Robert P. Kirshner and Nicholas B. Suntzeff; Scientific American, January 1999, and "From Slowdown to Speedup," by Adam G. Riess and Michael S. Turner; Scientific American, February 2004]. This striking result has since been cross-checked by independent studies of the cosmic microwave background radiation by, for example, the Wilkinson Microwave Anisotropy Probe (WMAP).

One possible conclusion is that different laws of gravity apply on supergalactic scales than on lesser ones, so that galaxies' gravity does not, in fact, resist expansion. But the more generally accepted hypothesis is that the laws of gravity are universal and that some form of energy, previously unknown to science, opposes and overwhelms galaxies' mutual attraction, pushing them apart ever faster. Although dark energy is inconsequential within our galaxy (let alone your kitchen), it adds up to the most powerful force in the cosmos.

Cosmic Sculptor
As astronomers have explored this new phenomenon, they have found that, in addition to determining the overall expansion rate of the universe, dark energy has long-term consequences for smaller scales. As you zoom in from the entire observable universe, the first thing you notice is that matter on cosmic scales is distributed in a cobweb-like pattern -- a filigree of filaments, several tens of millions of light-years long, interspersed with voids of similar size. Simulations show that both matter and dark energy are needed to explain the pattern.

That finding is not terribly surprising, though. The filaments and voids are not coherent bodies like, say, a planet. They have not detached from the overall cosmic expansion and established their own internal equilibrium of forces. Rather they are features shaped by the competition between cosmic expansion (and any phenomenon affecting it) and their own gravity. In our universe, neither player in this tug-of-war is overwhelmingly dominant. If dark energy were stronger, expansion would have won and matter would be spread out rather than concentrated in filaments. If dark energy were weaker, matter would be even more concentrated than it is.

The situation gets more complicated as you continue to zoom in and reach the scale of galaxies and galaxy clusters. Galaxies, including our own Milky Way, do not expand with time. Their size is controlled by an equilibrium between gravity and the angular momentum of the stars, gas and other material that make them up; they grow only by accreting new material from intergalactic space or by merging with other galaxies. Cosmic expansion has an insignificant effect on them. Thus, it is not at all obvious that dark energy should have had any say whatsoever in how galaxies formed. The same is true of galaxy clusters, the largest coherent bodies in the universe--assemblages of thousands of galaxies embedded in a vast cloud of hot gas and bound together by gravity.

Yet it now appears that dark energy may be the key link among several aspects of galaxy and cluster formation that not long ago appeared unrelated. The reason is that the formation and evolution of these systems is partially driven by interactions and mergers between galaxies, which in turn may have been driven strongly by dark energy.

To understand the influence of dark energy on the formation of galaxies, first consider how astronomers think galaxies form. Current theories are based on the idea that matter comes in two basic kinds. First, there is ordinary matter, whose particles readily interact with one another and, if electrically charged, with electromagnetic radiation. Astronomers call this type of matter "baryonic" in reference to its main constituent, baryons, such as protons and neutrons. Second, there is dark matter (which is distinct from dark energy), which makes up 85 percent of all matter and whose salient property is that it comprises particles that do not react with radiation. Gravitationally, dark matter behaves just like ordinary matter.

According to models, dark matter began to clump immediately after the big bang, forming spherical blobs that astronomers refer to as "halos." The baryons, in contrast, were initially kept from clumping by their interactions with one another and with radiation. They remained in a hot, gaseous phase. As the universe expanded, this gas cooled and the baryons were able to pack themselves together. The first stars and galaxies coalesced out of this cooled gas a few hundred million years after the big bang. They did not materialize in random locations but in the centers of the dark matter halos that had already taken shape.

Since the 1980s a number of theorists have done detailed computer simulations of this process, including groups led by Simon D. M. White of the Max Planck Institute for Astrophysics in Garching, Germany, and Carlos S. Frenk of Durham University in England. They have shown that most of the first structures were small, low-mass dark matter halos. Because the early universe was so dense, these low-mass halos (and the galaxies they contained) merged with one another to form larger-mass systems. In this way, galaxy construction was a bottom-up process, like building a dollhouse out of Lego bricks. (The alternative would have been a top-down process, in which you start with the dollhouse and smash it to make bricks.) My colleagues and I have sought to test these models by looking at distant galaxies and how they have merged over cosmic time.

Galaxy Formation Peters Out
Detailed studies indicate that a galaxy gets bent out of shape when it merges with another galaxy. The earliest galaxies we can see existed when the universe was about a billion years old, and many of these indeed appear to be ­merging. As time went on, though, the fusion of massive galaxies became less common. Between two billion and six billion years after the big bang--that is, over the first half of cosmic history--the fraction of massive galaxies undergoing a merger dropped from half to nearly nothing at all. Since then, the distribution of galaxy shapes has been frozen, an indication that smashups and mergers have become relatively uncommon.

In fact, fully 98 percent of massive galaxies in today's universe are either elliptical or spiral, with shapes that would be disrupted by a merger. These galaxies are stable and comprise mostly old stars, which tells us that they must have formed early and have remained in a regular morphological form for quite some time. A few galaxies are merging in the present day, but they are typically of low mass.

The virtual cessation of mergers is not the only way the universe has run out of steam since it was half its current age. Star formation, too, has been waning. Most of the stars that exist today were born in the first half of cosmic history, as first convincingly shown by several teams in the 1990s, including ones led by Simon J. Lilly, then at the University of Toronto, Piero Madau, then at the Space Telescope Science Institute, and Charles C. Steidel of the California Institute of Technology. More recently, researchers have learned how this trend occurred. It turns out that star formation in massive galaxies shut down early. Since the universe was half its current age, only lightweight systems have continued to create stars at a significant rate. This shift in the venue of star formation is called galaxy downsizing [see "The Midlife Crisis of the Cosmos," by Amy J. Barger; Scientific American, January 2005]. It seems paradoxical. Galaxy formation theory predicts that small galaxies take shape first and, as they amalgamate, massive ones arise. Yet the history of star formation shows the reverse: massive galaxies are initially the main stellar birthing grounds, then smaller ones take over.

Another oddity is that the buildup of supermassive black holes, found at the centers of galaxies, seems to have slowed down considerably. Such holes power quasars and other types of active galaxies, which are rare in the modern universe; the black holes in our galaxy and others are quiescent. Are any of these trends in galaxy evolution related? Is it really possible that dark energy is the root cause?

The Steady Grip of Dark Energy
Some astronomers have proposed that internal processes in galaxies, such as energy released by black holes and supernovae, turned off galaxy and star formation. But dark energy has emerged as possibly a more fundamental culprit, the one that can link everything together. The central piece of evidence is the rough coincidence in timing between the end of most galaxy and cluster formation and the onset of the domination of dark energy. Both happened when the universe was about half its present age.

The idea is that up to that point in cosmic history, the density of matter was so high that gravitational forces among galaxies dominated over the effects of dark energy. Galaxies rubbed shoulders, interacted with one another, and frequently merged. New stars formed as gas clouds within galaxies collided, and black holes grew when gas was driven toward the centers of these systems. As time progressed and space expanded, matter thinned out and its gravity weakened, whereas the strength of dark energy remained constant (or nearly so). The inexorable shift in the balance between the two eventually caused the expansion rate to switch from deceleration to acceleration. The structures in which galaxies reside were then pulled apart, with a gradual decrease in the galaxy merger rate as a result. Likewise, intergalactic gas was less able to fall into galaxies. Deprived of fuel, black holes became more quiescent.

This sequence could perhaps account for the downsizing of the galaxy population. The most massive dark matter halos, as well as their embedded galaxies, are also the most clustered; they reside in close proximity to other massive halos. Thus, they are likely to knock into their neighbors earlier than are lower-mass systems. When they do, they experience a burst of star formation. The newly formed stars light up and then blow up, heating the gas and preventing it from collapsing into new stars. In this way, star formation chokes itself off: stars heat the gas from which they emerged, preventing new ones from forming. The black hole at the center of such a galaxy acts as another damper on star formation. A galaxy merger feeds gas into the black hole, causing it to fire out jets that heat up gas in the system and prevent it from cooling to form new stars.

Apparently, once star formation in massive galaxies shuts down, it does not start up again--most likely because the gas in these systems becomes depleted or becomes so hot that it cannot cool down quickly enough. These massive galaxies can still merge with one another, but few new stars emerge for want of cold gas. As the massive galaxies stagnate, smaller galaxies continue to merge and form stars. The result is that massive galaxies take shape before smaller ones, as is observed. Dark energy perhaps modulated this process by determining the degree of galaxy clustering and the rate of merging.

Dark energy would also explain the evolution of galaxy clusters. Ancient clusters, found when the universe was less than half its present age, were already as massive as today's clusters. That is, galaxy clusters have not grown by a significant amount in the past six billion to eight billion years. This lack of growth is an indication that the infall of galaxies into clusters has been curtailed since the universe was about half its current age--a direct sign that dark energy is influencing the way galaxies are interacting on large scales. Astronomers knew as early as the mid-1990s that galaxy clusters had not grown much in the past eight billion years, and they attributed this to a lower matter density than theoretical arguments had predicted. The discovery of dark energy resolved the tension between observation and theory.

An example of how dark energy alters the history of galaxy clusters is the fate of the galaxies in our immediate vicinity, known as the Local Group. Just a few years ago astronomers thought that the Milky Way and Andromeda, its closest large neighbor, along with their retinue of satellites, would fall into the nearby Virgo cluster. But it now appears that we shall escape that fate and never become part of a large cluster of galaxies. Dark energy will cause the distance between us and Virgo to expand faster than the Local Group can cross it.

By throttling cluster development, dark energy also controls the makeup of galaxies within clusters. The cluster environment facilitates the formation of a zoo of galaxies such as the so-called lenticulars, giant ellipticals and dwarf ellipticals. By regulating the ability of galaxies to join clusters, dark energy dictates the relative abundance of these galaxy types.

This is a good story, but is it true? Galaxy mergers, black hole activity and star formation all decline with time, and very likely they are related in some way. But astronomers have yet to follow the full sequence of events. Ongoing surveys with the Hubble Space Telescope, the Chandra X-ray Observatory and sensitive ground-based imaging and spectroscopy will scrutinize these links in coming years. One way to do this is to obtain a good census of distant active galaxies and to determine the time when those galaxies last underwent a merger. The analysis will require the development of new theoretical tools but should be within our grasp in the next few years.

Striking a Balance
An accelerating universe dominated by dark energy is a natural way to produce all the observed changes in the galaxy population--namely, the cessation of mergers and its many corollaries, such as loss of vigorous star formation and the end of galactic metamorphosis. If dark energy did not exist, galaxy mergers would probably have continued for longer than they did, and today the universe would contain many more massive galaxies with old stellar populations. Likewise, it would have fewer lower-mass systems, and spiral galaxies such as our Milky Way would be rare (given that spirals cannot survive the merger process). Large-scale structures of galaxies would have been more tightly bound, and more mergers of structures and accretion would have occurred.

Conversely, if dark energy were even stronger than it is, the universe would have had fewer mergers and thus fewer massive galaxies and galaxy clusters. Spiral and low-mass dwarf irregular galaxies would be more common, because fewer galaxy mergers would have occurred throughout time, and galaxy clusters would be much less massive or perhaps not exist at all. It is also likely that fewer stars would have formed, and a higher fraction of our universe's baryonic mass would still be in a gaseous state.

Although these processes may seem distant, the way galaxies form has an influence on our own existence. Stars are needed to produce elements heavier than lithium, which are used to build terrestrial planets and life. If lower star formation rates meant that these elements did not form in great abundance, the universe would not have many planets, and life itself might never have arisen. In this way, dark energy could have had a profound effect on many different and seemingly unrelated aspects of the universe, and perhaps even on the detailed history of our own planet.

Dark energy is by no means finished with its work. It may appear to benefit life: the acceleration will prevent the eventual collapse that was a worry of astronomers not so long ago. But dark energy brings other risks. At the very least, it pulls apart distant galaxies, making them recede so fast that we lose sight of them for good. Space is emptying out, leaving our galaxy and its immediate neighbors an increasingly isolated island. Galaxy clusters, galaxies and even stars drifting through intergalactic space will eventually have a limited sphere of gravitational influence not much larger than their own individual sizes.

Worse, dark energy might be evolving. Some models predict that if dark energy becomes ever more dominant over time, it will rip apart gravitationally bound objects, such as galaxy clusters and galaxies. Ultimately, planet Earth will be stripped from the sun and shredded, along with all objects on it. Even atoms will be destroyed. Dark energy, once cast in the shadows of matter, will have exacted its final revenge. CHRISTOPHER J. CONSELICE is an astronomer and lecturer at the University of Nottingham in England, where he recently moved from the California Institute of Technology. He specializes in the formation of galaxies and leads several observational programs in infrared and visible light with telescopes both on the ground and in space. A lover of both the heavens and the earth, he comes from a family of Pennsylvanian farmers and spends his free time boating, fishing, biking and caving.