"Phantom of the Universe" --Scientists Closing in on the Mystery of the Dark Side of the Cosmos (WATCH Today's "Galaxy" Stream)
From the journey of protons racing through the world's largest particle collider in Europe to up-close views of the Big Bang and emergent universe, and the nearly mile-deep descent to an underground experiment in South Dakota, sceintist around the world are in hot pursuit of dark matter --what some physicists are callling the "operating system" of the universe.
Our current cosmological standard model assumes that general relativity and the standard model of particle physics have been a good description of the basic physics of the universe throughout its history. It assumes that the large-scale geometry of the universe is flat: The total energy of the universe is zero. This implies that Euclidean geometry, the mathematics taught to most of us in middle school, is valid on the scale of the universe. Although the geometry of the universe is simple, its composition is strange: The universe is composed not just of atoms (mostly hydrogen and helium), but also dark matter and dark energy.
Dark matter, which we have so far detected only through its gravitational effects though it makes up an estimated 85 percent of the total mass of the universe -- is invisible and we don't yet know what it's made of. Researchers are scanning the night sky and designing ultrasensitive underground particle detectors in hopes of solving its mysteries.
Although general relativity is now a hundred-year-old theory, it remains a powerful, and controversial, idea in cosmology. It is one of the basic assumptions behind our current cosmological model: a model that is both very successful in matching observations, but implies the existence of both dark matter and dark energy. These signify that our understanding of physics is incomplete. We will likely need a new idea as profound as general relativity to explain these mysteries and require more powerful observations and experiments to light the path toward our new insights.
Image at the top of the page is a computerized rendering showing the distribution of dark matter as two galaxies collide. Credit: "Phantom of the Universe"
The Daily Galaxy via Berkeley Labs