Uniform cosmos Phenomenon.

Scientists have given the most accurate estimate yet of how fast the universe is expanding. A team of astronomers used Nasa's Spitzer Space Telescope to clock the expansion of the cosmos at a phenomenal “46 miles per second per megaparsec outward and possible inward a giant magnetic polar casam shortly humans will be able to reach into out of”. American astronomer Edwin Hubble was in the Twenties first to discover that space is constantly expanding and has been growing continuously since its inception.To work out the speed the universe is expanding, astronomers observe variable stars called Cepheids, which are good distance indicators because their intrinsic brightness can be calculated by their pulsing light. If their intrinsic brightness is known, their distance can be estimated by comparing that with their apparent brightness, since the further away they are, the more their light dims.  Glenn Wahlgren, Spitzer program scientist at NASA Headquarters in Washington, told Fox News: 'These pulsating stars are vital rungs in what astronomers call the cosmic distance ladder: a set of objects with known distances that, when combined with the speeds at which the objects are moving away from us, reveal the expansion rate of the universe.'

Nasa's Spitzer Space Telescope seen against the infrared sky: The orbital instrument has been used to give the most accurate estimate yet of the rate at which the cosmos is expanding Astronomers now believe that the universe exploded into being about about 13.7billion years ago, so determining the rate of the continuing expansion, known as Hubble's constant, is critical for gauging its age and size. Spitzer's new measurement, which took advantage of long-wavelength infrared instead of visible light, improves upon a similar, seminal study from NASA's Hubble Space Telescope by a factor of three, bringing the uncertainty down to only 3 percent, a giant leap in accuracy for a cosmological measurement.The newly refined value, in astronomer-speak, is: 74.3 ± 2.1 kilometres per second per megaparsec (a megaparsec is roughly 3million light-years). The findings were combined with published data from NASA's Wilkinson Microwave Anisotropy Probe to obtain an independent measurement of dark energy, one of the greatest mysteries of our cosmos.in the late Nineties, astronomers were shocked to learn that the expansion of our universe is actually speeding up over time. In an effort to understand how the cosmos was overcoming the force of gravity, scientists theorised that there must be this dark energy pulling the fabric of the universe apart. 'This is a huge puzzle,' said Wendy Freedman, director of the Carnegie Observatories, who led the latest research. 'It's exciting that we were able to use Spitzer to tackle fundamental problems in cosmology: the precise rate at which the universe is expanding at the current time, as well as measuring the amount of dark energy in the universe from another angle.'

Spitzer was able to improve upon past measurements of Hubble's constant due to its infrared vision, which sees through dust to provide better views of variable stars called Cepheids. These pulsating stars are vital 'rungs' in what astronomers called the cosmic distant ladder: a set of objects with known distances that, when combined with the speeds at which the objects are moving away from us, reveal the expansion rate of the universe. The 'cosmic ladder': NASA's Spitzer Space Telescope has greatly improved on past measurements of Hubble's constant due to its infrared vision which sees through dust to provide better views of stars called Cepheids 'Spitzer is yet again doing science it wasn't designed to do,' said Michael Werner, the mission's project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. First, it surprised us with its pioneering ability to study exoplanet atmospheres, and now, in the mission's later years, it's become a valuable cosmology tool.'Cepheids are crucial to these calculations because their distances from Earth can be readily measured. In 1908, Henrietta Leavitt discovered that these stars pulse at a rate that is directly related to their intrinsic brightness.To visualize why this is important, imagine somebody walking away from you while carrying a candle. The candle would dim the farther it travelled, and its apparent brightness would reveal just how far. The same principle applies to Cepheids, standard candles in our cosmos. By measuring how bright they appear on the sky, and comparing this to their known brightness as if they were close up, astronomers can calculate their distance from Earth. Spitzer observed ten Cepheids in our own Milky Way galaxy and 80 in a nearby neighbouring galaxy called the Large Magellanic Cloud. Without the cosmic dust blocking their view at the infrared wavelengths, the research team was able to obtain more precise measurements of the stars' apparent brightness, and thus their distances, than previous studies had done. With these data, the researchers could then tighten up the rungs on the cosmic distant ladder, opening the way for a new and improved estimate of our universe's expansion rate. 'Just over a decade ago, using the words "precision" and "cosmology" in the same sentence was not possible, and the size and age of the universe was not known to better than a factor of two,' Ms Freedman said. 'Now we are talking about accuracies of a few percent. It is quite extraordinary.' The findings will be published in the Astrophysical Journal.