Does the Universe Have an ‘Edge’?

Check out this answer from Consensus:

The question of whether the universe has an edge remains open to interpretation and further research. Hyperbolic geometry and the concept of a closed universe provide compelling arguments against the existence of a traditional edge. As our understanding of cosmology and theoretical physics evolves, so too will our grasp of the universe’s true nature.

The question of whether the universe has an edge has intrigued scientists, philosophers, and curious minds for centuries. This article explores the concept of the universe’s edge through the lens of modern cosmology and theoretical physics, drawing on recent research to provide a comprehensive understanding of this profound question.

The Concept of an Edge in the Universe

The idea of an edge to the universe often conjures images of a boundary beyond which nothing exists. However, this simplistic view is challenged by the principles of hyperbolic geometry and general relativity. One argument against the existence of an edge is the notion that if you could reach the edge and extend your hand, the space beyond would also be part of the universe, thus negating the concept of an edge1.

Hyperbolic Geometry and the Universe

Hyperbolic geometry offers a fascinating perspective on the universe’s structure. In this framework, as one approaches the supposed edge of the universe, both the observer and their measuring instruments would shrink in such a way that the edge would never be reached. This concept suggests that the universe could be infinite in extent without having a traditional edge1.

The Universe as a Closed System

Einstein’s general theory of relativity has been pivotal in studying the universe’s structure. One significant question is whether the universe is geometrically closed or open. A closed universe would mean that it is finite but unbounded, much like the surface of a sphere. This idea aligns with observations of distant cosmic sources and could solve many problems regarding the universe’s nature and origin2.

The Universe as a Black Hole

An intriguing hypothesis is that the universe itself could be a black hole. This theory posits that the universe is confined to a localized region of space that cannot expand without limit. If true, this would imply that the universe is a closed structure, perceived as such by its inhabitants at the present epoch2.