Mass of the observable universe
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Mass of the Observable Universe: Key Estimates and Theoretical Approaches
Standard Cosmological Estimates of Universe Mass
Most modern cosmological models estimate the mass of the observable universe to be on the order of 10^55 grams, or about 10^22 solar masses. This value is supported by several independent approaches, including calculations based on the number of stars, protons, and electrons, as well as energy-density measurements. Early estimates by Eddington and others, using the average mass of stars and the number of protons and electrons, arrive at a total mass of approximately 2.6 × 10^55 grams, which is consistent with more recent calculations and is a common parameter in many cosmological theories Beadnell1940Whitrow1946.
Mass Formulas and Fundamental Constants
Several studies have derived expressions for the mass of the observable universe using fundamental physical constants. For example, the Hoyle-Carvalho formula, M ≈ c^3/(GH), where c is the speed of light, G is the gravitational constant, and H is the Hubble constant, provides a mass estimate that is independent of specific cosmological models and closely matches observational data Carvalho1995Valev2010. Other approaches link the mass of the universe to the Planck mass and Planck length, suggesting a deep connection between cosmological and quantum scales. In some models, the ratio of the universe's mass to its radius is found to be identical to the ratio of the Planck mass to the Planck length, highlighting a possible unification of cosmological and quantum physics Haug2022Pellis2023.
Finite Mass Universe and Gravitational Radius
Recent work has proposed that the universe may have a very large but finite mass, around 6 × 10^22 solar masses, and a corresponding gravitational radius. This approach interprets cosmic acceleration as a measurement of the universe's gravitational radius, offering an alternative to the standard dark energy explanation. In this view, the universe behaves similarly to a black hole, with its mass contained within a finite boundary, and the observed acceleration is linked to this gravitational property .
Energy Balance and Universe Dynamics
Calculations of the total gravitational and kinetic energy of the observable universe suggest that these energies are nearly balanced, resulting in a total mechanical energy close to zero. This supports the idea that the universe's expansion and its gravitational binding are in equilibrium, and it aligns with the observed density of dark energy .
Quantum and Alternative Theoretical Perspectives
Some quantum gravity models and alternative cosmological theories propose different mechanisms for determining the universe's mass. For instance, models based on quantum gravitational constraints or magnetic binding of fundamental particles yield mass estimates in the range of 4 × 10^21 to 6 × 10^22 solar masses, consistent with standard cosmological values Morsch2019Gorobey2022. These approaches often emphasize the connection between the universe's mass and its initial conditions or fundamental quantum properties.
Conclusion
Across a range of theoretical frameworks and observational methods, the mass of the observable universe is consistently estimated to be around 10^55 grams, or about 10^22 solar masses. This value emerges from both classical and quantum considerations, and is supported by calculations involving fundamental constants, energy-density measurements, and the observed structure of the universe. While some models offer alternative explanations for cosmic acceleration and the universe's boundary, the consensus on the mass scale remains robust across the literature Carvalho1995Gaztañaga2023Valev2010+6 MORE.
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