Sphere of the Universe

The "sphere of the universe" can be thought of as the observable universe, which appears as a vast, expanding bubble surrounding us. It is the part of space we can see and study, limited by how far light has traveled since the universe's beginning. This cosmic sphere contains all galaxies, stars, and matter we observe. Beyond this boundary, there may be more universe that we cannot see yet due to the finite speed of light and the universe's age. Essentially, it’s the visible "bubble" of everything we have access to through observation.