In the first moments of the universe, matter overpowered antimatter, its mirror opposite. We may soon find out why.by Frank Close / September 19, 2012 / Leave a comment
Published in October 2012 issue of Prospect Magazine
All cultures have wondered about their origins. Modern physics posits that space and time were born in the Big Bang, some 13.6bn years ago. Science gives no definite answer for why that event occurred, but observations with powerful telescopes and experiments at places like Cern, the particle physics laboratory near Geneva, give us a good understanding of what happened next. We know that matter is, in effect, the result of energy being converted into substantial forms. We know how the energy in the heat of the Big Bang created the basic seeds of matter, and how over the eons these particles have formed galaxies of stars, including our own Milky Way and solar system.
Here on Earth, clusters of septillions of atoms are able to think, and although they are not yet able to comprehend what makes them—us—conscious, they can look out in wonder at the universe, and build machines that can revisit our origins in the Big Bang. Out of this has come an astonishing discovery. Matter is not the Big Bang’s only child. It was born with a long-lost twin: antimatter.
Matter and antimatter are the yin and yang of reality. When an infant on the seashore digs a hole in wet, hard, flat sand to build a sandcastle, the castle is a metaphor for matter and the hole for antimatter. When the energy of the Big Bang congealed into the fundamental particles of matter, an imprint in the form of metaphorical holes, their antimatter siblings, was also formed.
While all the evidence points towards this being how matter was born, it raises a paradox. The transmutation of radiant energy into matter and antimatter, which occurred in those first instants of time, is not a one-way voyage. When played in reverse order, the meeting of any material substance with its antimatter doppelgänger leads to mutual annihilation; the sandcastle refills the hole, perfectly. When antimatter destroys matter, the energy that was previously trapped within them is liberated as radiation. In the dense cauldron of the infant universe, such collisions would have been very common, and the newborn material would not have survived long. Yet the universe has survived, and appears to be made of matter, such as the familiar stuff which makes air, rocks and living things, and not antimatter.