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. 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 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.