Non-baryonic matter

Definition

Non-baryonic matter refers to forms of matter that do not consist of baryons, which are particles such as protons and neutrons that make up atomic nuclei. This type of matter is significant in cosmology because it includes dark matter, which plays a crucial role in the structure formation of the universe, influencing how galaxies and clusters of galaxies develop over time through its gravitational effects.

5 Must Know Facts For Your Next Test

1. Non-baryonic matter makes up approximately 85% of the total matter in the universe, while baryonic matter constitutes only about 15%.
2. The existence of non-baryonic matter is inferred from its gravitational effects on visible objects, such as stars and galaxies, rather than through direct observation.
3. Non-baryonic matter is believed to play a critical role in the formation of large-scale structures in the universe by providing the necessary gravitational pull to attract baryonic matter.
4. Current models suggest that weakly interacting massive particles (WIMPs) are a leading candidate for non-baryonic dark matter.
5. Research into non-baryonic matter is ongoing, with various experiments aimed at detecting its effects or directly observing potential candidates for dark matter.

Review Questions

• How does non-baryonic matter influence the formation and evolution of cosmic structures like galaxies?
  • Non-baryonic matter, primarily in the form of dark matter, exerts gravitational forces that significantly influence the formation and evolution of cosmic structures. During the early universe, regions with higher concentrations of dark matter provided the gravitational wells necessary for baryonic matter to clump together and form galaxies. As these structures evolved, non-baryonic matter continued to affect their dynamics and interactions, leading to the complex network of galaxies observed today.
• Discuss the implications of non-baryonic matter on our understanding of the universe's composition and fate.
  • The presence of non-baryonic matter fundamentally alters our understanding of the universe's composition. It suggests that most of the universe's mass is invisible and not made up of ordinary atoms. This challenges traditional models and prompts scientists to rethink how galaxies interact and evolve. Furthermore, as non-baryonic dark matter contributes to cosmic expansion dynamics, it has implications for predicting the ultimate fate of the universe—whether it will continue to expand indefinitely or eventually collapse.
• Evaluate how current research on non-baryonic matter could reshape our theories about fundamental physics and cosmology.
  • Current research on non-baryonic matter has the potential to dramatically reshape theories in fundamental physics and cosmology. Discovering properties or candidates for dark matter could lead to new physics beyond the Standard Model. Furthermore, a deeper understanding of how non-baryonic matter interacts with baryonic matter may reveal insights into gravity's role at cosmic scales and enhance our knowledge about forces governing structure formation and evolution in the universe. Such breakthroughs could unify disparate areas within physics and refine our models about everything from particle physics to galactic dynamics.

Related terms

Dark Matter:

A type of non-baryonic matter that does not emit, absorb, or reflect light, making it invisible and detectable only through its gravitational influence on visible matter.

Baryonic Matter:

Matter that is composed of baryons, including all atoms that form stars, planets, and living beings, contrasting with non-baryonic forms.

Cosmic Microwave Background (CMB): The afterglow radiation from the Big Bang that provides evidence for the early universe's conditions and the influence of dark matter in cosmic structure formation.