1. a predicts that the strong, weak, and electromagnetic forces should become indistinguishable at high temperatures. 2. the is a single force that unifies the electromagnetic and weak forces. 3. was a dramatic expansion of the universe thought to have occurred when the universe was only a tiny fraction of a second old. 4. forces us to think about why the sky is dark at night. 5. observations of the provide a way to test our theory of the big bang. 6. when a particle of ordinary matter meets its precise opposite particle of antimatter, the result is with complete conversion of mass into energy.