Weight of the universe
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Understanding the Weight of the Universe
Estimating the Mass of the Universe
The mass of the universe has been a subject of extensive research and debate. One of the foundational estimates comes from Eddington, who calculated the mass of the universe based on the number of stars and their average mass. According to Eddington, the universe contains approximately (10^{22}) stars, each with an average mass similar to that of our sun, which is about (2.0 \times 10^{27}) tons. This leads to an estimated total mass of (2.0 \times 10^{49}) tons.
Proton and Electron Contributions
Further calculations consider the mass contributions from fundamental particles such as protons and electrons. The universe is estimated to contain around (1.575 \times 10^{79}) protons and an equal number of electrons. Given the mass of a proton is approximately (1.65 \times 10^{-24}) grams and that of an electron is (9.038 \times 10^{-28}) grams, the combined mass of these particles is about (2.599 \times 10^{55}) grams, or (2.55 \times 10^{49}) tons. This closely aligns with the mass calculated based on stars.
Cosmological Theories and Mass Parameters
Cosmological theories, despite their differences, often converge on a similar mass parameter for the universe. Both Eddington's and Milne's cosmologies suggest a mass of the order of (10^{55}) grams, which corresponds to about (10^{79}) protons. This consistency across different models indicates a fundamental aspect of the universe's mass.
Hubble Constant and Density Measurements
Recent advancements in measuring the Hubble constant and the density of the universe have significantly improved the accuracy of these estimates. These measurements are crucial for determining the size, luminosity, and mass of galaxies, which in turn help refine the total mass of the universe.
Critical Density and the Fate of the Universe
The concept of critical density is essential in understanding whether the universe will continue to expand indefinitely or eventually collapse. Current evidence suggests that the universe has a subcritical density, meaning it does not have enough mass to halt its expansion. Various methods, including the study of galaxy clusters, indicate that the universe's mass density is only about 20-30% of the critical density required to stop its expansion. This implies that the universe is likely to expand forever.
Vector Model for Gravitational Field
In the vector model for the gravitational field, the total mass density and the mass of the universe are consistent with observed values. The total mass density is approximately (1.0 \times 10^{-29}) grams per cubic centimeter, and the mass of the universe is around (10^{53}) kilograms.
Conclusion
The weight of the universe, estimated through various methods and models, consistently points to a mass of the order of (10^{55}) grams or (10^{49}) tons. Despite the different approaches, the convergence of these estimates highlights a fundamental understanding of the universe's mass. Current evidence suggests that the universe has a subcritical density, indicating it will continue to expand indefinitely.
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