Can Dark Energy Kill Galaxies ? - Issue 46 : Balance
http://54.197.248.184/issue/46/balance/can-dark-energy-kill-galaxies
The universe is not just expanding; it’s accelerating. When cosmologists first realized this in 1998, it was alarming. The attractive gravitational pull of matter should cause the expansion to slow down. But this isn’t what we see. The galaxies in the universe are not only moving away from us—they’re moving away faster today than yesterday. We’re not sure what is causing the expansion to accelerate, so we’ve called it “dark energy.” Our best theories of what matter is and does give us a candidate for what dark energy might be—something called vacuum energy. It’s the energy in a region of space, contained in the electromagnetic field and its cousins, even when there are no particles. But when physicists attempted to calculate the amount of vacuum energy, they got a shock. The answer was about (...)