Euclid telescope to seek source of dark energy —the biggest mystery in the universe

When the Euclid space telescope blasts off from Cape Canaveral in Florida early next month, it will embark on an unprecedented effort to survey 1 billion galaxies—and perhaps solve cosmology’s greatest mystery. The search will cover more than one-third of the sky and look back in time to galaxies shining when the universe was just one-quarter of its current age of 13.8 billion years. Although the task is immense, Euclid’s primary goal is surprisingly simple. The data it collects will be boiled down to a single number, denoted by w . And cosmologists are hoping, maybe even a bit desperately, that it is not –1. w describes the effect of dark energy, the mysterious antigravitational force that is accelerating the expansion of the universe. All measures so far suggest that w is close to –1. If it proves to be exactly that, it will confirm the vanilla solution to dark energy: that it’s a simple tweak—a cosmological constant—added to Albert Einstein’s theory of gravity, which bestows empty space with an innate springiness of its own. As the universe expands, giving birth to more space, the total amount of dark energy also grows—so that the energy density always remains constant. That solution is anathema to cosmologists because it is simply a fudge factor that does not explain where dark energy comes from and why it has that value. “If w does equal –1, we still don’t know what it is,” says astrophysicist ...
Source: Science of Aging Knowledge Environment - Category: Geriatrics Source Type: research