Gravitational Lensed “Cosmic Mirage” Is Definitive Proof of Accelerated Expansion of Universe

The Universe is accelerating, says a team of researchers led by Masamune Oguri, Kavli IPMU and Naohisa Inada at Nara National College of Technology, courtesy the data acquired by observing distant quasars. This is supplementary to the studies of distant supernovae, which also showed that the Universe’s expansion is accelerating, and for which the 2011 Nobel Prize in Physics was given. This study with quasars again shows that dark energy is definitely present, but we still don’t know what it might be.

Larger Data and more inferences

The data is derived from the Sloan Digital Sky Survey (SDSS), the huge collaborative experiment responsible for tracking about 100,000 quasars for nearly 10 years, with nearly 50 new quasars discovered in the last few years. Quasars are bright objects, believed to be formed, or at least fuelled, by the accretion of gas and dust by a supermassive black hole. The infalling material glows due to the enormous heat produced and can thus be detected from very far away. This makes them ideal for mapping the gravitational lensing occurring in the Universe.

Prof. Oguri, heading the study, says:

In 2011, the Nobel Prize in Physics was awarded to the discovery of the accelerated expansion of the universe using observations of distant supernovae. A caution is that this method using supernovae is built on several assumptions… Our new result using gravitational lensing not only provides additional strong evidence for the accelerated cosmic expansion, but also is useful for accurate measurements of the expansion speed, which is essential for investigating the nature of dark energy.

The Science of Gravitational Lensing

Gravitational lensing refers to the bending of light due to the presence of matter in the path of light, as explained by Einstein’s General Theory of Relativity. This process creates (at least) two identical images of one object, separated by a gap, thus the name ‘Cosmic Mirage’, referring to the similar process by which mirages on Earth are created.

The formation of a Cosmic Mirage. The figure explains why the accelerated expansion increases the chances of gravitational lensing and why the images separate out further. (Courtesy: SDSS)

The farther away the quasar, the greater its chances to be gravitationally lensed. Accelerated expansion of the Universe increases the distance of the quasar from us and thus the images also seem to separate (refer to figure above). This can be used to deduce how fast the quasars are receding from us. By plotting the velocity graph (velocity versus distance curve), we can see the deviation from the straight line expected from Hubble’s law, if the Universe was expanding at a constant rate. Sure enough, there is deviation and all the deviations fall on a curve, showing that it’s not just a mere statistical fluctuation or measurement error. The Universe is indeed accelerating! And this suggests that the estimates for dark energy are also not very off.

Note the two distinct images formed by gravitational lensing in the zoomed in inset. This was captured by the Hubble Space Telescope and the quasar - SDSSJ1226-0006 - has been tracked by the SDSS. (Courtesy: SDSS and Hubble Space Telescope)

Dark Energy in Einstein’s Theory

Einstein’s theory of General Relativity allows for an expanding Universe without any extraneous assumptions. However, this expansion should have been at uniform speed. But it seems that the expansion rate is increasing. To get this prediction from Einstein’s equations, scientists tweak it a bit, adding a ‘cosmological constant’ term. This adds a bit of energy per unit volume of the Universe, contributing a lot to the entire energy of the Universe. By adjusting the sign of this extra term, the universe can be made to be accelerating.

In fact, it can be shown that we are exiting a phase dominated by matter, where the major contribution to energy comes from matter, and entering a phase dominated by the cosmological constant. This inevitably leads to accelerated expansion. We might not be able to see any galaxies in another 5-10 billion years, if the accelerated expansion of the Universe continues unabated.

The SDSS data also shows that treating dark energy as the cosmological constant is not such a wrong thing to do.

The future of the SDSS project is Planck and the SuMIRe projects. Both aim to study the distribution of cosmic dark energy and all this in the not-too-distant exciting future!

Source and more info at the IPMU original site:

Do Laws Of Physics Vary Across The Universe?

The warm smugness that a physicist often feels when he/she says that a phenomenon or a law is universal’ may be an illusion. If a team of researchers from Swinburne University of Technology is to be believed, then their data shows that the laws of physics might actually vary throughout the Universe. They have measured the value of the fine-structure constant, a fundamental dimensionless parameter occurring frequently in Quantum Electrodynamics, and have found that this varies throughout the Universe.

What is the Fine-Structure Constant?

The fine-structure constant, commonly called alpha’, is exactly 1/137 in its value. The constant manifests itself in the expansion parameter as one tries to expand in the theory of Quantum Electrodynamics, the physics explaining electrons, light and their interaction. The constancy of the value of alpha is crucial in establishing the universal strength of the electromagnetic force. It would mean that the strength of coupling (or interactions) between the photons (particles of light) and electrons varies throughout the Universe.

The circles represent Keck points, Triangles are both Keck and VLT. The size represents the confidence in the data points. Notice that most of the points to the middle - local to us - are black, indicating no deviation from the 1/137 value. The points farther off are not so. (Courtesy: Swinburne University of Techology, John Webb et al.)

The Research Team

A team of researchers comprising Professor John Webb, Professor Victor Flambaum and colleagues, all from University of South Wales (UNSW), Swinburne University of Technology and the University of Cambridge, had already got a hint of the supposed deviation from the accepted value of alpha as early as a decade ago. While they had used the Keck telescope in Hawaii to obtain all their data then, they’ve used the Very Large Telescope (VLT) in Chile this time. They’ve more than double their number of data points and it seems to support what they had initially thought. The confidence level has grown to a respectable 3 sigma. Professor Webb shares his excitement:

In one direction – from our location in the Universe – alpha gets gradually weaker, yet in the opposite direction it gets gradually stronger.

What Are The Consequences?

It is always the habit of scientists to back up initial observations with enough observations to fully confirm the fact. It is, thus, too early to comment what implication this will have on our understanding of the cosmos, As far as we know, the Universe is spatially homogenous (same from all points in space) and isotropic (looks the same in all directions there is no preferred direction) on a large scale (bigger than the length scale of galaxies). This is one of the basic principles of Einstein’s General Theory of Relativity  Cosmology (i.e. application of Einstein’s General Relativity – the modern theory of gravity- on the scale of the Universe). If alpha varies from point to point, then the homogeneity of space is destroyed. We can still have a weaker’ version of the homogeneity condition and General Relativity will still be true, but, having worked so well, we would like the homogeneity principle to be rigidly true. Only further observations, backed up by theory, can tell us more.

A pre-print of the arXiv paper by Webb et al is available here:
Astrophysicist Sean Carroll says that the value of alpha is probably constant. Here’s an article from him written a year ago:


Faster-Than-Light Neutrino Puzzle Solved Using Special Relativity and GPS Correction, Claims Scientist

Special Relativity may have saved itself from disaster. According to a scientist, the OPERA collaboration overlooked a crucial correction to the result, which exactly matches the discrepancy observed. It involved the effect of time dilation of the clocks aboard the GPS satellite.

Faster Than Light Neutrino Article Here:

The two frames

Ronald Van Elburg says that the two frames of reference the Gran Sasso laboratory on the ground and the clocks on the GPS satellite in orbit around the Earth – are in relative motion with respect to each other and thus special relativity effects come into the picture. The time of flight, thus, needs to be corrected for this factor too.

The paper on arXiv:

Van Elburg explains:

From the perspective of the clock, the detector is moving towards the source and consequently the distance travelled by the particles as observed from the clock is shorter

Magnitude of the Effect

Now, for the crucial magnitude of this effect. Van Elburg presents the analysis which shows that this timing should account for 32 ns for the time of flight. Further, this happens at CERN as well as the Gran Sasso Lab in Italy and thus, the number has to be doubled, yielding 64 ns, which exactly compensates the noticed discrepancy of 60 ns.

This solution has recently been released and is yet to be verified properly. The effect seems too obvious and it seems unlikely that OPERA has not taken it into account. OPERA has not responded as yet.

A theoretical attack on the results

Recently, there has been a theoretical attack on the experimental result by Sheldon Glashow (Nobel Laureate, Physics) and his Boston University colleague, Andrew Cohen. They dismiss the results by showing that if the result were true, no high energy neutrino would reach the detector at Gran Sasso. The fact that they detect high energy neutrino (above 12.5 GeV)  means that the neutrinos are not travelling faster than light. This is not an experimental result, but a theoretical bound.

We’ll just have to wait and watch. The van Elburg paper is a pre-print and is not yet peer-reviewed.

Fermilab To Check Own Data To Verify OPERA’s Faster-Than-Light Neutrino Claim

After the astonishing result from the OPERA collaboration of detecting neutrinos travelling faster than speed of light, Fermilab wants to double-check the claim. This is an inevitable step in the direction of validating the apparent finding. If Fermilab’s MINOS data doesn’t find anything that replicates the OPERA observations with high enough confidence, then the OPERA result, despite its hype, will become null and void.

The MINOS experiment at Fermilab


Here’s the reason why, despite the care and beauty of the OPERA experiment, it needs independent corroboration: every scientific result must be reproducible. Fermilab has an advantage over other neutrino research labs in the world since it already has the data sets from the famous MINOS experiment.

Neutrino Oscillations

MINOS was Fermilab’s version of the Super Kamiokande experiment,. Neutrinos come in three flavours or types electron, muon and tau. The curious thing is that neutrinos can oscillate’ or change between these types. An electron neutrino can become a muon neutrino. A theoretical mechanism, known as the see-saw mechanism, explains this, using certain unknown parameters, which need to be supplied experimentally. Super Kamiokande performed experiments in 1998 and confirmed the phenomenon of oscillation and measured the mixing angle’ too. Fermilab repeated this experiment and found consistent results. This was the MINOS experiment, MINOS standing for Main Injector Neutrino Oscillation Search.


Well known to scientists in the neutrino field, but virtually unthinkable to the outside world, is that fact that MINOS had actually detected neutrinos moving faster than light. However, these couldn’t survive analysis and presented only a 1.6 to 2 sigma confidence level, below the 3 sigma needed for validation and way below the 5 sigma needed for labeling it as a discovery. MINOS now plans to sift through their data and put it through rigorous analysis. MINOS should take less than 6 months, since the data is already available to them.

It won’t matter if the OPERA experiment isn’t proved wrong. If Fermilab and T2K don’t reproduce the data, OPERA will be up for grabs. Einstein, thou be still… at least for 6 months.

Challenging Einstein: Faster-Than-Light Neutrino Result From CERN And Explaining What It Really Means

So CERN has stunned us with a result and this one doesn’t even come from the LHC. The premier European high energy research institute has detected neutrinos that seem to move at a speed greater than that of light, violating one of the most sacred pillars of physics Einstein’s Special Relativity. You must have read about it we posted it here. So what about these faster-than-light neutrinos? Why are so many people all excited about them?

Faster Than Light Neutrinos, Claims CERN:
Yes? You Called? Say What!

In this article, I will try and explain that, touching upon four crucial points. First we need to understand why people are not ready to believe the result in the first place. Next, we’ll understand whether this is believable or not. Is CERN just tricking us or have they put real hard work behind this before publishing it? Next, we shall talk about the implications of this result, if it is proved right. Lastly, we discuss how there can still be flaws and where some glitches might be found in the coming days.

Unlike the popular media, scientists are treading softly on this result. They are not yet ready to say that Einstein was wrong, although that is what it would imply. They are merely reporting facts at this moment, stating the results as got in the experiment. The result is very possibly wrong, but let’s take a closer look.

What on earth are Neutrinos?

The real heroes of this story, Neutrinos are the slipperiest of all known particles. They carry no charge, almost no mass and interact extremely feebly with other matter and that too via the weak interaction. They’re nearly impossible to detect. They leave no tracks in bubble chambers (no charge), don’t interact with each other to form clumps (no strong interactions, like those of protons and neutrons) or speak with normal matter particles. Scientists were forced to assume its existence to solve a puzzle (the beta decay problem), and, even though neutrinos have been detected after that by several detectors, their properties remain largely mysterious. They are giving a headache once more.

Why are people not ready to believe it?

Simply put, it’s Einstein. People are not expecting anything new and now they find this! This is just too unexpected. Why take a result so flagrantly conflicting with all known physical results at face value? Well…

Is this result Believable?

As an answer the first of our questions, I would go with a Yes‘. The result is totally believable in the sense that the experiment and analysis seem water-tight at this moment. Scientists of the OPERA collaboration have been looking at the data for three years! They have done everything scientifically possible to discredit their own finding, but have only managed to strengthen it.

Remember, we told you in the particle physics articles, what confidence level means? A confidence level, quoted as some n-sigma, n’ being an integer, refers to the amount of confidence the experimenter has on his/her own results. A 3-sigma result is one which is significant enough to be considered a potential for detection’. This means that the doubts are less than 0.3%. We’re just getting warmed up! For a discovery’ we need a minimum of 5-sigma, which is a confidence level of 99.9999%.

The current results are a 6-sigma, at 99.999999% confidence level, high and above the threshold required to get a discovered’ tag!! This still doesn’t mean that it is true. It just means that the possibility that this is merely a statistical fluctuation is extremely small. They two are very close, but not the same.

Schematic layout of the OPERA experiment.

The real motivation for believing in what CERN has found is the methodology they’ve applied in finding out the results. They had found this result 3 years back, but never jumped the gun in publishing it. They checked and re-checked everything, found crucial error bars and found that this result survives. They added more parameters contributing smaller errors, hoping that they’ll somehow add up and then give the necessary’ error bars. They didn’t.

We’ll just talk about the use of GPS and cesium atomic clocks to measure time and how accurately the distance was measured.  Since velocity is simply distance divided by time, we need both parameters accurately.

Particles Travelling Faster Than Light Detected, Claims CERN

CERN Has Just Made A Huge CLAIM!  

Particles travelling faster than the speed of light have been found. This startling claim comes from a source as respectable as CERN. This was supposedly observed in a neutrino experiment carried out by CERN. However, it is too early to confirm this startling result.


UPDATE: The ‘discovery’ was made by the OPERA experiment while the neutrinos were beamed from Geneva to a lab in Gran Sasso in Italy. The pre-print of the report, prepared by CERN and published today (23rd September) can be found here:

A news webcast by CERN will be available live later today. Details and URL of the webcast :
CERN Press Release by CMS:

Faster Than The Speed of Light? Real Life Tachyons?

Albert Einstein and his Special Theory of Relativity taught us that nothing having mass can travel at the speed of light or above. Massless particles can travel only at the speed of light. Thus, nothing can travel faster than the speed of light.

CERN’s scientists have now found that neutrinos, one of the most enigmatic particles, have breached this barrier. Neutrinos have nearly no mass, no charge and interact negligibly with ordinary matter. It is due to these properties that they cannot be easily detected. The scientists claim that a neutrino beam fired near Geneva to a lab 730 kilometers away in Italy reached its destination 60 nanoseconds earlier than expected. The experimental and statistical errors combine to deduct 10 nanoseconds, which still leaves 50 nanoseconds unexplained and makes this result significant. There are obvious checks and re-checks being performed.

What All Of This Really Means – Is Einstein Up For Grabs? A Close Look:

Confirmation Awaits

CERN is now depending on the colliders in America and the T2K neutrino experiment in Japan to reinforce its findings. The findings may need many runs and checks to be confirmed. Once confirmed, it raises many questions, including why such an effect wasn’t noticed before. The big question would be this: What happens to Special Relativity, which is an extremely reliable theory?

John Ellis, a theoretical physicist at CERN, gauges the magnitude of the find, if found true:

This would be such a sensational discovery if it were true that one has to treat it extremely carefully.

About the implication for Special Relativity, Ellis says that It has worked perfectly till now”.

Jury Out On Relativity? Not Really!

A knee-jerk reaction would provoke statements about revolutionizing the whole of physics, since stars to elementary particles, all rely on the Special Theory of Relativity. It has been wonderfully accurate, especially when combined with Quantum Mechanics to form Quantum Field Theory. Personally, at this moment, I don’t think this will throw Relativity out, even if the result is correct – Relativity is too beautiful and has been proved too correct in too many situations for that drastic step. I would even stick my neck out and add that this observation is some sort of experimental glitch and that faster-than-light particles have not really been detected. However, only more tests will testify to that.

The grand old man of physics has been challenged by a tiny, nearly massless particle.

What all of this really means:

Now, Light Can Travel Faster Than The Speed of Light!

Now light would lose to light, if it were to race against itself. Researchers have now made light propagate through special media at speeds faster than the conventional speed of light (a mind-boggling 299,792,458 m/s). However, Einstein and his many fans need not worry; this faster-than-light propagation doesn’t violate relativity, which states that the speed of light is the fastest speed possible.

Building Packets of Waves

The secret to such a feat is the building up of wave-packets. Wave-packets are exactly what their name suggests packets of waves. Interference of waves is the key phenomenon.

Waves have the unique property to interfere, whether it be constructively or destructively. When two waves overlap, peak to peak, the overlap or interference is maximal. This is called constructive interference. When the waves overlap, such that peak and trough coincide, they cancel each other’s contribution out, giving destructive interference.

Interference pattern formed by the interference of light from two sources. Notice the dark ridges, where light interferes destructively. The bright regions is due to constructive interference

By selecting a large number of waves (theoretically, an infinite number), differing from each other by fraction of their wavelengths, a wave-packet can be built, such that it has a central peak, smoothly falling off on either sides. The waves interfere constructively near the peak and destructively further away from it. Thus, we arrive at an important conclusion: The constituent waves determine the position and magnitude of the peak of the wave-packet, through their mutual interference.

Wave Packet formation.

If we could find a material, which would selectively allow only certain wavelengths to go through, a wave-packet can be suddenly deformed when it enters a medium. Also, we could shift the location of the peak.

Shifting peaks and moving fast

Enter Vitaliy Lomakin of the University of California, San Diego and his colleagues at the Public University of Navarre in Pamplona, Spain. They used Teflon as the propagating medium. Microwave radiation was made to pass through a copper disc sandwiched between two Teflon discs. It was noticed that the wave jumps forward, emerging from the back Teflon plate, before it enters the metal plate. The team reported sending 10% of the light 10 picoseconds earlier than usual.

Einstein still stands tall

Physicists interpret the postulate of relativity to mean that information cannot be transferred faster than light. Here, no useful information can be transferred for that the entire wave-packet has to be transferred, not some part of it. The wave-packet is highly distorted, and also markedly reduced. Causality is not violated.

Einstein still stands, even though light can now travel faster than itself. The findings will soon be published in the prestigious Physical Review Letters.

Dark Matter an Illusion, Can Be Explained by Gravitational Polarization of Quantum Vacuum, Says CERN Scientist

Reality, aren’t thou a heartless beast! A scientist from CERN, Dragan Slavkov Hajdukovic, has claimed that dark matter may be an illusion and that its supposed effect can be explained away by more known kinds of particles simple matter particles and their corresponding anti-particles.

Option 1: Dark Matter

A startling observation in astronomy set out the hunt for an unknown form of matter, just because the gravitating effect of such hypothetical matter could explain the observations. Galactic arms were seen to be moving too rapidly for them to stay attached to the rest of the galaxy, if Newton’s law of gravitation (or even Einstein’s General Relativity) is to hold. Scientists could save the situation by postulating the presence of a large amount of non-luminous or dark matter, interacting with the rest of the Universe only by the gravitational force. No candidate for this kind of matter was proposed and people have come up with various conjectures and models. Right now, we know nothing about the composition of dark matter. It is said that dark matter comprises 23% of the known matter of the Universe. 73% is dark energy and only the rest 4% is normal matter as we know it.

The relative composition of the known Universe

Option 2: Modified Newtonian Dynamics

There was another way to resolve the puzzle modify Newton’s law of gravity. This new school of thought, called MOND or MOdified Newtonian Dynamics, said that the power law dependence of the gravitational force on distance (which is inverse-square for Newton’s law) depends on acceleration. MOND doesn’t need any dark matter. The problem with MOND is that it doesn’t seem to work at all scales of acceleration. Inherent inconsistencies prevent MOND from taking over from Newton’s gravity law.

Option 3: Gravitational polarization of Quantum Vacuum

Now, Hajdukovic postulates another possibility that space itself might be repulsive. He says that if particles and anti-particles were to repel each other gravitationally, rather than universally attract, then it would solve the problem. Vacuum could be polarized, i.e. particles and anti-particles could be created at will, governed by the Heisenberg’s Uncertainty Principle. Now, if these were to act as gravitational dipoles that repel, then the problem of amplifying gravitational fields would be solved. He gives an example of a dielectric slab inserted inside a parallel plate capacitor as an example. In this case, the electric field within the dielectric would decrease. Hajdukovic argues that, if unlike charges repelled instead of attracting, the field would increase in strength. The same, he concludes, is true with gravity.

The Gravitational Dipole (Courtesy: Wikipedia Commons)

Hajdukovic put it precisely:

Concerning gravity, mainstream physics assumes that there is only one gravitational charge (identified with the inertial mass) while I have assumed that, as in the case of electromagnetic interactions, there are two gravitational charges: positive gravitational charge for matter and negative gravitational charge for antimatter

As alien as that might sound to a reader versed in Physics, mainstream labs are actually working to find out whether anti-matter repels matter gravitationally. Primary amongst these is the AEGIS experiment at CERN.

Closing Remarks

The proposal also has a very pleasing symmetry. Gravitational force is unlike the electromagnetic force, since electromagnetic forces both repel (like charges or magnetic poles) and attract (unlike charges/magnetic poles). If Hajdukovic is right, then even gravity will have a repulsive component, but this might mean that we have to take another look at Einstein’s equations of General Relativity.

There are many issues, however. Things like gravitational lensing is explained best by assuming dark matter than without it.

Hajdukovic published his paper Is dark matter an illusion created by the gravitational polarization of the quantum vacuum?in the journal Astrophysics and Space Science.

CERN’s New Einstein Observatory To Detect Gravitational Waves

CERN’s at it again, but it’s not particle physics. Einstein’s also at it again, but this time, it isn’t the famed grizzly haired scientist. A group of European scientists working with CERN will soon propose a design for a telescope the Einstein Observatory  – which will be much better than any other known telescope of its kind. The catch: This one will detect gravitational waves rather than optical radiation or radio waves.

What is the Einstein Observatory

The Einstein Observatory (EO) is a ‘third-generation’ gravitational wave detector and it is designed to be at least a 100 times more sensitive that its existing predecessors. The principle of detection is simple and classic. The arms of the Observatory, each several kilometers long and each being a laser beam will shrink or expand ever so slightly if a gravitational wave passes. This will cause a change in the interference pattern in a central photo-detector. Let’s look at this in more detail.

Einstein’s theory of General Relativity predicts that gravitational energy, stored in gravitational fields, should be released as waves, just like energy in electromagnetic fields is released by electromagnetic waves (which we call light). The problem is that, unlike light, the energy of a gravitational wave is so small that if a typical one passes by earth right now, the earth will shrink and then expand by the breadth of a proton which is much much smaller than even an atom. Detecting such small perturbations is a huge challenge that has so far been unconquered. Relativity predicts that gravitational waves of comparatively large magnitude are emitted by violent cosmic events, like merging of black holes, or fusing of neutron stars, or even supernova explosions. These will be the typical gravitational waves scientists hope to detect with EO. The success of Einstein’s theory has been such that no one doubts the existence of gravitational waves, even though one hasn’t been detected inspite of dedicated search.

Gravity waves are generated by violent cosmic event, like neutron stars merging (An artist's impression)

What EO intends to do is this: there is a particular way two beams of light interfere with each other.

Apparatus for the MM experiment

They form a well-known pattern called an interference pattern (you might see these patterns when water waves interfere). A slight shift in the path a beam of light travels will disturb these patterns. The process is extremely sensitive – and if the beams travel a long distance before interfering, the sensitivity increases. (For science buffs: This is the same principle first used by Michelson in his famous experiment for measuring the speed of light and later, the most famous ‘failed’ experiment in history. This failed experiment, known simply as Michelson-Morley experiment, aimed to detect a change in the speed of light in different directions so as to confirm the aether hypothesis. None was detected. Einstein would later build his Special Theory of Relativity around this result.)

More on the EO

The EO will be housed 100 to 200 meters below ground, in order to minimize the seismic activity of the ground and its effect on the telescope. The EO will be extremely sensitive in the range 1 Hz to 10 kHz, which is the frequency band for the gravitational waves. The Einstein Observatory will lead a scientific revolution, is what Michele Punturo, scientific coordinator of the design, says. The data from the EO will be corroborated and complemented by data from various gamma-ray and X-ray telescopes.

The proposed design of the Einstein Observatory

The EO is actually two interferometers one to detect gravitational wave signals from 2-40 Hz and the other to detect till 10 kHz. This is required, since detecting at low frequencies is a very difficult job and needs dedicated instruments tuned for doing only that.

EO will hope to improve upon existing gravitational wave telescopes like LIGO, Virgo and TAMA (all first generation), and even Advanced LIGO and Advanced Virgo (second generation). The design will be presented at European Gravitational Observatory site in Pisa, Italy.

It is of utmost importance to the progress of cosmology that the telescope, like the illustrious scientist it is named after, becomes as successful as his theories.

Einstein Confirmed Again: Dark Energy Present In The Universe

The grand old man of Physics is proved right once again. Albert Einstein was vindicated yet again by a survey, which confirmed the presence of Dark Energy in the Universe. The ‘WiggleZ Dark Energy Survey’ was conducted by 26 astronomers from 14 countries using the latest in spectrograph technologies to map out more than 200,000 galaxies, many halfway across the Universe to confirm this startling fact.

What is Dark Energy?

Dark Energy is the name given to the unknown entity believed to be behind the acceleration of the expansion of the Universe. It was Edwin Hubble, who in 1932, first noticed that the Universe was actually expanding. This gave a huge boost to the Big Bang theory, which says that the Universe came out of an ultra-dense singularity 14-15 billion years ago. Scientists have been expecting the expansion to slow down as time wears on, as then gravity will eventually dominate. What scientists found, instead, was that the Universe was expanding at an ever-increasing rate. It is believed that some mysterious source of energy was aiding the expansion process, thus named Dark Energy.

No one has come up with a proper explanation of Dark Energy, despite there being a number of hypotheses and models. Dark Energy supposedly makes up 73% of the Universe, Dark Matter 23 % (which is NOT the same as Dark Energy; Dark Matter slows down the expansion) and the rest 4% – is ordinary matter – stars, galaxies, nebulae and super-clusters.

Where Einstein fits in…

Einstein had almost predicted the expansion of the Universe in his Theory of General Relativity, but in an uncharacteristic situation in which his nerves weakened, he introduced a factor in his equations which predicted a static Universe. This amounted to including in his equations, a cosmological constant a ‘fudge factor’ which gives vacuum a repelling force, effectively enabling the Universe to counter its own gravity and preventing self-collapse. Later, Einstein would rue this as his ‘greatest blunder’. Now, it seems that the great man was not wrong!

Inflationary theories of modern cosmology use this idea of a cosmological constant to explain the supposed period of rapid expansion right after the Big Bang called inflation. Now, with the increasing rate of expansion, it seems that the cosmological constant was the genius’ masterstroke rather than a botch-up.

The WiggleZ survey

The WiggleZ survey, conducted by an Australian-based group led by Dr. Michael Drinkwater, used the latest in spectrography, thanks to latest Australian technology to survey galaxies more than 200000 of them some 7 billion light years away. Light takes a finite time to travel from one place to another, because of its finite speed. Thus the light from 7 billion light years away took 7 billion years to reach here. This means that we are seeing galaxies in the form they were 7 billion years ago, essentially looking back in time! (Thus, the easiest way to glance into the past is to just see. The farther away the object you see, the farther away in time it is!). The WiggleZ survey can map 392 galaxies in an hour!

Do Structures such as these give clues to Dark Matter and Energy?

Though, this doesn’t tell us the constituents of Dark Energy (or Dark Matter, which is also a mystery), it gives definitive confirmation of its existence. It gives scientists confidence that Einstein’s theory is not failing, and that Dark Energy can indeed be reconciled with General Relativity. The survey is exhaustive measuring both the pattern of distribution of galaxies in the Universe and the rate of formation of the galaxy clusters, essentially giving scientists a two-way confirmatory proof of Dark Energy.

So, there it is again! Einstein is proved right again, and in spectacular fashion. 96% of the stuff in the Universe is unknown, but at least we know that it’s there. Some consolation and a lot of work to be done!