Here are some of the most surprising and interesting things about the universe we live in.
Astronomers calculated this figure by measuring the composition of matter and energy density in the universe, which enabled them to determine how fast the universe expanded in the past. As a result, researchers could turn back the hands of time and pinpoint when the Big Bang occurred. The time in between that explosion and now makes up the age of the universe. [Full Story]
In 1998, the Hubble Space Telescope studied very distant supernovas and found that, a long time ago, the universe was expanding more slowly than it is today. This puzzling discovery suggested that an inexplicable force, called dark energy, is driving the accelerating expansion of the universe. [Full Story]
While dark energy is thought to be the strange force that is pulling the cosmos apart at ever-increasing speeds, it remains one of the greatest mysteries in science because its detection remains elusive to scientists.
The universe's acceleration also confirms Albert Einstein's theory of general relativity, and lately, scientists have revived Einstein's cosmological constant to explain the strange dark energy that seems to be counteracting gravity and causing the universe to expand at an accelerating pace. [Full Story]
Three scientists won the 2011 Nobel Prize in Physics for their 1998 discovery that the expansion of the universe was accelerating. [Full Story]
If the density of the universe is less than the critical density value, then the shape of the universe is "open," like the surface of a saddle. In this case, the universe has no bounds and will continue to expand forever. [Full Story]
Yet, if the density of the universe is exactly equal to the critical density, then the geometry of the universe is "flat," like a sheet of paper. Here, the universe has no bounds and will expand forever, but the rate of expansion will gradually approach zero after an infinite amount of time. Recent measurements suggest that the universe is flat with roughly a 2 percent margin of error.
These elusive substances, called dark energy and dark matter, have not been detected, but astronomers base their existence on the gravitational influence that both exert on normal matter, the parts of the universe that can be seen. [Full Story]
The European Space Agency's Planck mission mapped the entire sky in microwave light to reveal new clues about how the universe began. Planck's observations are the most precise views of the cosmic microwave background ever obtained. Scientists are hoping to use data from the mission to settle some of the most debated questions in cosmology, such as what happened immediately after the universe was formed. [Full Story]
The concept is controversial and had been purely hypothetical until recent studies searched for physical markers of the multiverse theory in the cosmic microwave background, which is a relic of the Big Bang that pervades our universe. [Full Story]
Researchers searched the best available observations of the cosmic microwave background for signs of bubble universe collisions, but didn't find anything conclusive. If two universes had collided, the researchers say, it would have left a circular pattern behind in the cosmic microwave background.