Cosmological model
Cyclic & Bouncing Cosmologies
Cosmology & UniverseSpeculative Hypothesis
Definition
Models in which the Universe undergoes repeated cycles of expansion and contraction, or a 'bounce' instead of a singular beginning.
Scientific overview
Cyclic and bouncing models propose that the Big Bang was not the absolute beginning but a transition from a previous phase, potentially avoiding the initial singularity. Examples include the ekpyrotic model and various quantum-bounce scenarios.
Open questions
- Could a bounce leave an observable imprint?
- Do such models solve the problems inflation solves?
Related topics
Knowledge connections
- Related toThe Big Bang
- Related toCosmic Inflation
Sources & references
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.