And the inflationary and cyclic theories do make one significantly different observational prediction, which may one day figure prominently in adjudicating between them: The burst of inflationary expansion at the big bang would likely have so vigorously disturbed the fabric of space that the gravitational waves produced might still be detectable. The more gentle expansion of the cyclic model results in gravitational waves too mild to be observed. In the not-too-distant future, observations may thus have the capacity to tip the balance between the two cosmological approaches.

