Building a Map of Dark Energy
Written by Fraser Cain
Understanding dark energy is probably one of the largest mysteries in cosmology right now. Figure this out, and a Nobel Prize in physics is assured. But it won't give up its secrets so easily. Since they can't measure dark energy directly, astronomers can only measure its effects on the large-scale structures of the Universe, and then tease out some of its characteristics.
In a recent survey using the European Southern Observatory's Very Large Telescope, and international team of 51 astronomers from 24 institutions gathered the light from more than 13,000 galaxies. This survey contains galaxies within a 25 million cubic-light years volume.
Using this survey, they were able to map out the large scale structures in the nearby Universe, including clusters of galaxies and filamentary superclusters. By measuring the velocity of the different clusters as they speed away from us, at different times in the past, the astronomers were able to measure the speed distortion contributed by dark energy.
Their conclusions lend evidence to the so-called cosmological constant theory originally introduced by Albert Einstein - there's some constant repulsive force that exists throughout space. But the uncertainties in their calculations doesn't rule out other possibilities.
One of the most popular of these is known as modified gravity. In this situation, gravity just acts differently at large scales than it does in the small scale.
But the researchers feel that a measurement that might cover 10 times the volume of this survey could be able to tell the difference between a dark energy force of exotic origin or an actual modification of theory of gravity.
Original Source: ESO News Release
Filed under: Dark Energy
February 4th, 2008 at 11:50 am
Einstein really was prophetic in his theorizing about the future of the universe, but did you know that he missed the boat for years on the meaning of his own theory? Rock Colb wrote an amazing book about the evolution of cosmology called "Blind Watchers of the Sky" in which he describes how Einstein wrongly applied his own equations and it took others to tell him the true application
February 5th, 2008 at 4:51 am
This is the brain melter:
Roughly 70% of the universe is made of dark energy. Dark matter makes up about 25%. Everything on Earth, everything that we have ever observed with all of our instruments – normal matter – adds up to less than 5% of the universe.
http://science.hq.nasa.gov/universe/science/dark_energy.html
February 5th, 2008 at 7:37 am
Imagine the universe as an expanding, slanting and spinning table top with one of those slick table cloths. The big bang takes place at the center of the table, As matter and energy approach the edge, the effects are different because all the forces of physics are, in effect, behind them. And there are no forces as the approach the edge. That lack of physics at he outside edge cannot be measured but equals what we call dark energy.
February 5th, 2008 at 1:50 pm
Modified gravity! Maybe! Dark energy could also be what might best be described as a variable form of anti-gravity. Also, dark matter could simply be no more than right temparature material composed of non-reflective ice, dust and rocks. This stuff would be difficult to detect. This same stuff, if it pervades the universe, could be a major safety issue for long term space travel.
February 7th, 2008 at 11:23 am
Sub: Define the functions
Dark Energy is a mis-nomer. The subject is introduced in a systematic mode in
1. COSMOLOGY DEFINIION and
2. COSMOS YOGA VISION DEVELOPMENT SERIES I-IV.
• SEARCH BEYOND DARK MATTER-COSMOS YOGA SERIES-I 10^3 LY-Tamasoma Jyothirgamyam TXU 1-282-571(June 2005),Copy rights USA
• Centre of the Universe-Heart of the Universe-Nov 2006 - Copy Rights TXU 1-364-245 -The Science in Philosophy- Pridhvi Viswam Asya DharineemCosmos yoga vision series-II- cover upto 10^5 Light Years
• COSMOS YOGA VISION SERIES III- ALL PPT PROJECTIONS-COSMOLOGY VEDAS INTERLINKS KNOWLEDGE EXPANSION- OCT 2007
• HEART OF UNIVERSE TO DYNAMIC FUNCTION -COSMOS YOGA VISION SERIES IV (DEC 2007)-SPACE COSMOLOGY DIGEST- DIALOGUES AND DIRECTION
INDEX :Cosmology,Cosmogony,SpaceScience,Philosophy,consciousness,interlink fields, alternate cosmology, cosmology-vedas,Cosmology Interlinks, Space Exploration, Knowledge Expansion, Centre of the Universe , Vision Models of the Universe , Dynamic Universe
http://cosmologyvedas.blogspot.com/
February 19th, 2008 at 11:01 am
New results proposed by Dr. Murad Shibli at the German Jordanian University will be published this summer at the IEEE International Conference On Recent advances in Space Technologies and will be held in Turkey on June 14-16 2007. His Paper is entitled as "The Foundation of the Theory of Dark Energy: Einstein's Cosmological Constant, Universe Mass-Energy Densities, Expansion of the Universe, a New Formulation of Newtonian Kepler's Laws and the Ultimate Fate of the Universe". Dr. Shibli's paper presents a basis of the theory of universe dark energy, a solution of Einstein's cosmological constant problem, physical interpretation of universe dark energy and Einstein's cosmological constant Lambda (=0.29447×10^-52m^-2), values of universe dark energy density (=1.2622×10^-26kg/m^3=6.8023GeV), universe critical density (=1.8069×10^-26kg/m^3=9.7378GeV), universe matter density (=0.54207×10^-26kg/m^3=2.9213GeV), and universe radiation density (=2.7103×10^-26kg/m^3 = 1.4558MeV). The interpretation in his paper is based on geometric modeling of space-time as a perfect four-dimensional continuum cosmic fluid and the momentum generated by the time. In such a modeling, time is considered to have a mechanical nature so that the momentum associated with it is equal to the negative of the universe total energy. It is found that dark energy is a property of the space-time itself. Moreover, based on the fluidic nature of dark energy, the fourth law of thermodynamics is proposed, a new formulation and physical interpretation of Kepler's Three Laws are presented. Furthermore, based on the fact that what we are observing is just the history of our universe, on the Big Bang Theory, Einstein's General Relativity, Hubble Parameter, the estimated age of the universe, cosmic inflation theory and on NASA's observation of supernova 1a, then a second-order (parabolic) parametric model is obtained in Dr. Shibli's proposed paper to describe the accelerated expansion of the universe. This model shows that the universe is approaching the universe cosmic horizon line and will pass through a critical point that will influence significantly its fate. Considering the breaking symmetry model and the variational principle of mechanics, then the universe will witness an infinitesimally stationary state and a symmetry breaking. As result of that, a very massive impulse (Big Impulse of magnitude 10^33 x the linear momentum of the universe) will occur soon and, correspondingly, the universe will collapse. Finally, simulation results are demonstrated to verify the proposed models. see http://www.icrepq.com or [1] for full sccript.
February 21st, 2008 at 5:47 am
jackpots…
inaugurate rangers culpa consorted …
April 4th, 2008 at 9:58 am
Very impressive.
April 29th, 2008 at 9:01 pm
This is precisely what metaphysics describes
Metaphysics also describes how these energies are dispersed according to our understanding of fluid dynamics, including "fluidic friction" and how larger gravitational forces are influenced by what we believe are larger energy structures