Posts Tagged ‘Dark Matter’

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.

Read Full Post »

Even though scientists have managed to quantify how much dark matter lurks in distant galaxies, astronomers have been hard-pressed to figure out how much of the mysterious stuff lies within our own.

But in a paper published in the journal Nature Physics, a team of researchers has managed to measure the amount of dark matter in the inner Milky Way, which could shed light on the structure and evolution of our galaxy, and perhaps of others as well. Dark matter is that mysterious stuff that accounts for 84.1% of the matter in the universe, while normal matter – all the stuff we can see, from galaxies to stars and planets and black holes and us – makes up a mere 15.9%. Because it doesn’t interact with light, it is completely invisible to us, and the only way to tell it’s there is by looking for its powerful gravitational influence on the normal matter around us. For example, astronomers are able to calculate how much dark matter is in far-off galaxies by looking at their spin. Basically, astronomers can tell how much mass is in a spiral galaxy by watching how fast it rotates. The faster the spin, the more massive the galaxy. And if they’re more massive, the galaxies should be brighter, too, because they should be filled with more stars. But astronomers noticed galaxies that were spinning really fast, even though they weren’t bright. If the mass causing these galaxies to spin so fast wasn’t from stars or gas, then what exactly was it? Scientists need to measure how much of it there is in a given galaxy in order to understand the behavior of galaxies and the large-scale structure of the cosmos. For distant galaxies, that’s relatively easy to do. Ironically, for the galaxy we live in, that’s a much more difficult measurement to make, said UC Irvine astrophysicist James Bullock, who was not involved the study. [Measuring] anything is hard when you’re inside of it,” Bullock said. “It’s kind of like trying to figure out what kind of house you live in without ever leaving your house.”

Our knowledge of the forces that in certain phases seem to go contrary to our expectations as well as helpful at times is woefully inadequate. We call it luck. If we were lucky to hit a jackpot only to be burgled of the winnings why call it luck? On the other side of the coin if we have been led through a short leash in our adolescence and in old age face with what little we have, in a happy frame of mind, what do we call those years of restraint?

In short when life negates your chances as well as compensates later on must owe to forces that are at play. These forces are such reason cannot adequately explain these switch off/on phenomenon. Reason is simple: We are too much involved as to be impartial. If we cannot measure the dark matter inside our galaxy we may as well consider it as a possibility. If one born is in a log cabin and suffers hardships reason may explain it as something owing to the way circumstances are. If the same person could finally occupy the highest office of the land how reason shall explain it? Taking a leaf out of nature one might say, hardship as necessary as to make one toughen up. It makes sense, does it not? If President Lincoln’s life is synonymous with slave question it might add an additional insight: Life of hardship made him sensitive to the sufferings of the slaves. But actual details of the life show he was not moved by the plight of the slaves as much as he thought slave question was a question mark in the democratic credentials of the nation. How can a nation be half free and half slaves? Indeed it is a matter of personal integrity that he dared to make a change knowing that he was a marked man. Life of a man is not to be really measured by superficial details of birth, death, honors received etc., but in what manner the life could make positive changes. (LATimes-science Now-Heart of darkness: Scientists probe dark matter near Milky Way’s core)

Read Full Post »

Physicists still have no proof that dark matter exists at all, but the evidence for it is substantial. The movements of stars and galaxies can apparently be explained only if there is much more gravitating matter in the universe than the visible stuff of atoms and molecules. Attempts to correct the discrepancy by rewriting the rules of gravity in Einstein’s general theory of relativity have repeatedly failed.

WMIPs (weakly interacting massive particles) and Theoretical particles called axions are other oft-mentioned candidates. Dark Matter must be the hand that rocks the cradle of Cosmos, the verb in the sentence I AM THAT I AM.

This reminds me of the lines:

There are more things in heaven and earth, Horatio,

Than are dreamt of in your philosophy..’ (Hamlet Act I. Sc.v)

Shall we insert Science in place of the last word?



Read Full Post »