Cyclic model

Definition

The cyclic model is a theoretical framework in cosmology that suggests the universe undergoes an infinite series of expansions and contractions, resulting in a continuous cycle of big bangs and big crunches. This model challenges the traditional view of a singular beginning and end to the universe, proposing instead that time and cosmic events repeat indefinitely.

5 Must Know Facts For Your Next Test

1. In the cyclic model, each cycle begins with a big bang and ends with a big crunch, allowing for continual rebirths of the universe.
2. This model suggests that physical laws may change over cycles, leading to different properties of the universe in each iteration.
3. Cyclic models address certain cosmological problems such as dark energy and cosmic inflation by incorporating them into a repeating framework.
4. Some variants of the cyclic model propose modifications to general relativity to allow for smoother transitions between expansions and contractions.
5. Unlike some other cosmological models, the cyclic model can provide explanations for cosmic microwave background radiation patterns through repeated processes.

Review Questions

• How does the cyclic model differ from traditional models of the universe regarding its beginning and end?
  • The cyclic model differs from traditional models by suggesting that instead of a singular beginning (the big bang) and an eventual end (the big crunch), the universe experiences an infinite series of expansions and contractions. This means that time is not linear but cyclical, with each cycle leading to new big bangs after previous big crunches. This challenges our understanding of cosmic history and raises questions about what happens after each cycle.
• What are some implications of adopting a cyclic model on our understanding of cosmic phenomena such as dark energy?
  • Adopting a cyclic model impacts our understanding of cosmic phenomena like dark energy by suggesting that it might play different roles in various cycles. Rather than viewing dark energy as a constant force causing accelerated expansion in a one-time universe, it could be seen as influencing how each cycle unfolds, potentially altering the dynamics during expansion phases compared to contraction phases. This perspective opens up new avenues for research in cosmology and our understanding of fundamental forces.
• Evaluate how the cyclic model interacts with concepts like entropy and cosmic evolution compared to standard cosmological models.
  • Evaluating the cyclic model reveals intriguing interactions with concepts like entropy and cosmic evolution. In traditional models, entropy tends to increase over time, leading to a more disordered state in an ever-expanding universe. However, in a cyclic framework, one must consider how entropy is managed during cycles; it's suggested that each new cycle resets or reorganizes entropy in ways that could enable new forms of cosmic structures. This reevaluation prompts deeper discussions about the nature of time, disorder, and how life could potentially exist within repeated cycles.

Related terms

big bang: The big bang is the leading explanation for the origin of the universe, suggesting it began from an extremely hot and dense point around 13.8 billion years ago and has been expanding ever since.

big crunch: The big crunch is a theoretical scenario in which the expansion of the universe eventually reverses, leading to a collapse back into a singularity, potentially followed by another big bang.

ekpyrotic model: The ekpyrotic model is a cosmological theory that describes the universe's origin through the collision of two three-dimensional worlds in a higher-dimensional space, which can lead to cyclical behaviors similar to the cyclic model.