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Posts Tagged ‘dark energy’

Einstein presented a set of equations, now known as the Einstein field equations, that became the framework of his theory of general relativity. The equations explain how matter and energy warp the fabric of space and time to create the force of gravity. At the time, both Einstein and astronomers agreed that the universe was fixed in size and that the overall space between galaxies did not change. However, when Einstein applied general relativity to the universe as a whole, his theory predicted an unstable universe that would either expand or contract. To force the universe to be static, Einstein tacked on the cosmological constant.

A single number, called the cosmological constant, bridges the microscopic world of quantum mechanics and the macroscopic world of Einstein’s theory of general relativity. But neither theory can agree on its value.

A decade later Edwin Hubble discovered that our universe is not static, but expanding. The light from distant galaxies showed they were all moving away from each other. This revelation persuaded Einstein to abandon the cosmological constant from his field equations as it was no longer necessary to explain an expanding universe. In 1998, observations of distant supernovas showed the universe wasn’t just expanding, but the expansion was speeding up. Galaxies were accelerating away from each other as if some unknown force was overcoming gravity and shoving those galaxies apart. Physicists have named this enigmatic phenomenon dark energy.

It is so dark no one has come up with a plausible answer. Think of the Emperors New clothes. Predicament of royal tailors must be somewhat like Physics grappling with the problem of dark energy.

So one way is to simply call the cosmological constant as dark energy. “The cosmological constant [or dark energy] currently constitutes about 70% of the energy content in our universe, which is what we can infer from the observed accelerated expansion that our universe is presently undergoing. Yet this constant is not understood,” Lombriser* said. “Attempts to explain it have failed, and there seems to be something fundamental that we are missing in how we understand the cosmos. (*Lucas Lombriser, an assistant professor of theoretical physics at the University of Geneva in Switzerland)

What is certain is that there is a fundamental problem in physics.  One need not be surprised if we have Hubble constant also showing different readings ( see my posts titled Hubble (In)constant ) It is like missing a single buttonhole in my shirt and always getting button through the button holes thereafter is a waste of time. It is thus with Science trying to explain how our physical universe works.( Ack: Live Science/tom childers/Einstein’s biggest blunder etc.,)

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In 1998, two teams of astronomers discovered the expansion of the Universe was accelerating, rather than slowing down, as the theory at the time suggested. Physicists speculated that the acceleration was caused by something they named dark energy.

Since then, observations have indicated that dark energy and dark matter together account for 96% of the Universe. The challenge has been to find ways of studying these invisible phenomena in detail.

The Dark Energy Survey DES is the most ambitious effort to date. It began in 2004 and involves 400 scientists from 26 institutions in seven countries.

The survey involves taking pictures of 26 million galaxies across a large expanse of the sky using the Blanco telescope in Chile. To do this, the research team had to build one of the most sensitive cameras ever built. The 570-megapixel camera is capable of detecting light from galaxies that are eight billion light-years away.

By studying the way in which the light was distorted by the intervening dark matter, researchers were able to calculate its distribution. And by studying the way in which the distribution changes over time they can calculate the way in which dark energy acts on it.

The team was also able to infer the amounts of dark energy and dark matter from the density and locations of galaxies.

The results show support for previous studies that indicate the Universe is made up of 4% ordinary matter, 26% dark matter and 70% dark energy.

The hope is that a detailed study of the map will give clues about what dark matter and dark energy might be and so lead to a more complete theory of physics.

The data released today draws from just one year of observations. The researchers plan to collect data for four more years over an even larger area of the sky. Professor Ofer Lahav of University College London (UCL), and chair of the DES Advisory Board, says “Once we have the full survey, 300 million galaxies and a thousand supernovae, we may be providing input for a new Einstein to tell us what does it all mean – why is the Universe made the way it is?”(BBC news/Pallab Ghosh-Aug.3,2017)

Now you know science doesn’t have all the answers. Yet there are know nothings to deny God merely because science hasn’t found proof for Him.

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