Is Our Universe Just a Bubble within a Larger and Older Universe?
Imagine the concept of the universe as a thought-provoking puzzle, where the puzzle pieces might extend far beyond what we currently can perceive. The idea that our universe could be just one bubble within an even larger cosmic reality is both intriguing and perplexing. We might never know if these bubbles, or black holes, pop at any moment, leaving us clueless about the bigger picture.
The Definition of the Universe
The term “universe” can be defined in a dual sense: spatially, it is the infinite space out there; and ontologically, it is the multitude of structures and entities embedded within this space. From my perspective, the spatial universe is infinite, delineating boundaries but also suggesting endless possibilities.
However, the 'known universe' is limited by the reach of our current technology and the speed of light. The edges of what we can observe in our universe are the points where light from beyond has not yet reached us. This horizon signifies the known edge of the universe, expanding and changing as new parts of the cosmos come within our observational range.
Expanding Black Holes and Infinite Space
The expansion of black holes offers an interesting dynamic within the fabric of our known universe. A conjecture suggests that if the density of material surrounding a black hole equals the average density inside the black hole, the black hole expands at the speed of light. This concept can help us envision regions within the universe that are constantly evolving and expanding.
Universe as an Infinite Space of Uniform Density
Imagining an infinite space with uniform density, we can explore the likelihood of this space containing an infinite number of black holes. Each spherical region, regardless of the specific density (e.g., the FLRW critical density), might encapsulate a black hole, contributing to a vast and ever-expanding cosmic landscape.
The FLRW Metric and Modern Cosmology
The Friedmann-Lema?tre-Robertson-Walker (FLRW) metric forms the backbone of modern cosmology. However, there are interpretations that challenge how the FLRW metric is used to describe the universe. The standard model often involves adding the composition of the universe, including radiation, baryonic matter, dark matter, and dark energy, to the density of curvature.
A refined viewpoint could suggest that the mass of curvature is not additional but rather equal to the total mass. This is supported by the observation that once matter falls into a black hole, its mass is not lost but is reinterpreted as the curvature of the black hole. This reinterpretation simplifies cosmological models and suggests that the FLRW metric, when solved for curvature alone, could describe a universe expanding at the speed of light.
Implications and Future Research
The implications of this perspective are profound. If the universe is described by a black hole-like expanding model, it could significantly alter our understanding of phenomena such as the accelerating expansion of the universe and the cosmic microwave background (CMB). The analysis of CMB fluctuations, which often support the flatness of the universe, may need to be reconsidered in this new context.
The discussion around these concepts encourages us to reevaluate fundamental assumptions in cosmology and to explore the possibility that our universe is one of an infinite number of expanding black holes. This idea challenges our current understanding of the universe and opens new avenues for research and discovery.