The universe’s expansion is a fundamental concept in modern astrophysics. Contrary to popular imagination, it doesn’t expand into external space but rather continues expanding within itself. This idea can be challenging to grasp, especially when considering the universe as an entity that includes everything.
A helpful way to understand the universe’s expansion is by examining how galaxies move. Scientists define expansion based on how fast galaxies drift away from each other, rather than needing a container for it to expand into. The Big Bang theory describes the universe’s origin, and Edwin Hubble’s work confirmed its expansion in 1922.
However, the universe’s acceleration due to dark energy remains a mystery. Dark energy accounts for about 68% of the total energy in the universe, while everyday matter makes up only 5%. Scientists have not directly measured where this dark energy originates from.
Theoretical models predict the existence of multiple universes, which could help resolve current physics issues. The integration of quantum mechanics and gravity is a major challenge, as these two theories describe different scales of the universe. Researchers are exploring various theories, including string theory and brane cosmology, to bridge this gap.
In conclusion, the universe’s expansion is an ongoing process that continues to expand within itself. Understanding its acceleration and the role of dark energy remain essential for advancing our knowledge of the cosmos.
Source: https://scitechdaily.com/expanding-into-what-the-universes-infinite-growth-explained