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Latest Dark energy Stories

2009-08-12 12:42:02

The stellar explosions known as type 1a supernovae have long been used as "standard candles," their uniform brightness giving astronomers a way to measure cosmic distances and the expansion of the universe. But a new study published this week in Nature reveals sources of variability in type 1a supernovae that will have to be taken into account if astronomers are to use them for more precise measurements in the future.The discovery of dark energy, a mysterious force that is accelerating the...

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2009-08-07 09:30:00

Several ways have been proposed to examine dark energy, in hopes of finding out just what it is. One of them, "supernovae" for short, certainly works: it's how dark energy was discovered in the first place. Other independent techniques, such as weak gravitational lensing and baryon acoustic oscillation, also promise great power but are as yet unproven.These three techniques all have a share of the proposed Joint Dark Energy Mission (JDEM), a satellite design managed by NASA with the...

2009-06-11 09:31:01

U.S. astronomers using radio telescopes to measure the distance to a distant galaxy have created a yardstick for calibrating large astronomical distances. The radio astronomers said their yardstick also demonstrates an important method that could help determine the nature of the so-called dark energy that pervades the universe. We measured a direct, geometric distance to the galaxy, independent of the complications and assumptions inherent in other techniques, James Braatz of the National...

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2009-05-19 07:20:00

A simple new method standardizes the brightness of Type Ia supernovae Members of the international Nearby Supernova Factory (SNfactory), a collaboration among the U.S. Department of Energy's Lawrence Berkeley National Laboratory, a consortium of French laboratories, and Yale University, have found a new technique that establishes the intrinsic brightness of Type Ia supernovae more accurately than ever before. These exploding stars are the best standard candles for measuring cosmic distances,...

2009-05-13 13:23:00

Book Also Examines True Origins of Dark Matter and Dark Energies in our Universe POCKING, Germany, May 13 /PRNewswire/ -- In the new book titled 96 % Dark Universe - Lost and Found, available today from Lulu.com, scientist Dr. Henryk Frystacki is setting new directions in cosmic super-symmetry - proposing solutions for dark matter and dark energies, which account for 96% of our universe according to current models of cosmology. Previously a neglected topic, these days the quest for the...

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2009-05-09 07:15:37

New dark energy model includes cosmological phase transition Imagine a time when the entire universe froze. According to a new model for dark energy, that is essentially what happened about 11.5 billion years ago, when the universe was a quarter of the size it is today. The model, published online May 6 in the journal Physical Review D, was developed by Research Associate Sourish Dutta and Professor of Physics Robert Scherrer at Vanderbilt University, working with Professor of Physics Stephen...

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2009-05-07 09:13:00

Whatever dark energy is, explanations for it have less wiggle room following a Hubble Space Telescope observation that has refined the measurement of the universe's present expansion rate to a precision where the error is smaller than five percent. The new value for the expansion rate, known as the Hubble constant, or H0 (after Edwin Hubble who first measured the expansion of the universe nearly a century ago), is 74.2 kilometers per second per megaparsec (error margin of...

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2009-04-01 15:20:00

An orbiting satellite has detected an anomalous energy signal that European astronomers say could be a sign of dark matter, the AFP reported. The researchers said they may have picked up a signature of this strange phenomenon, but more work is needed. Ordinary material such as atoms comprise perhaps as little as five percent of what makes up the cosmos, according to previous studies by astrophysicists calculating the amount of matter in the Universe. Data suggests the remainder...

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2009-02-16 08:40:00

During the next decade, a delicate measurement of primordial light could reveal convincing evidence for the popular cosmic inflation theory, which proposes that a random, microscopic density fluctuation in the fabric of space and time gave birth to the universe in a hot big bang approximately 13.7 billion years ago. Among the cosmologists searching for these weak signals will be John Carlstrom, the S. Chandrasekhar Distinguished Service Professor in Astronomy & Astrophysics at the...

2009-02-05 08:26:00

HAMPTON, Va., Feb. 5 /PRNewswire-USNewswire/ -- Most of the universe remains mysterious to scientists and researchers everywhere. More than 90 percent of the universe is "dark," composed of dark energy and dark matter observed only by their gravitational interaction with both light and "normal" matter. (Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO) Understanding the nature of dark energy and matter is one of the most significant challenges in science -- one that researcher...


Latest Dark energy Reference Libraries

Cosmology
2014-01-12 00:00:00

Image Caption: The Hubble Extreme Deep Field (XDF) was completed in September 2012 and shows the farthest galaxies ever photographed by humans. Each speck of light in the photo is an individual galaxy, some of them as old as 13.2 billion years; the observable universe is estimated to contain more than 200 billion galaxies. Credit: NASA/Wikipedia What is Cosmology? I once commented to an acquaintance that I was fascinated by the field of Cosmology, and mused that if I had more time, I...

6_702981515d3a0633aa71150cbf2d7a4d2
2004-10-19 04:45:41

Quintessence (Dark Energy) -- Quintessence or dark energy is a hypothetical form of energy postulated to exist in order to explain observations of an accelerating universe. This energy would act like a vacuum pressure, pushing things apart. Other attempts to explain these recent observations involve a non-zero cosmological constant, which has the same effect. Indeed, sometimes quintessence is said to result in a non-zero cosmological constant, and conversely a non-zero cosmological...

2_7b2d00975ae3d143d38faa72be2951362
2004-10-19 04:45:40

Wilkinson Microwave Anisotropy Probe (WMAP) -- The Wilkinson Microwave Anisotropy Probe (WMAP) was launched on June 30, 2001 at 3:46 p.m. EDT at Cape Canaveral Air Force Station, Florida, USA. The goal of WMAP was to map out minute differences in the Cosmic Microwave Background (CMB) radiation which would help test theories of the nature of the universe. On February 11, 2003, the public relations group from NASA made a press release regarding the age and composition of the universe....

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