The belief that the entire universe is a sphere is not supported by the current scientific understanding of the universe's shape. In fact, the shape and structure of the universe on the largest scales are still topics of active research and debate among cosmologists. The prevailing scientific consensus, based on various observations and measurements, suggests that the overall shape of the universe is likely to be flat or very close to flat.
Here are some key pieces of evidence and observations that support the idea of a flat or nearly flat universe:
Cosmic Microwave Background (CMB): The CMB is the afterglow of the Big Bang and is observed as faint microwave radiation that permeates the entire universe. Detailed measurements of the CMB, such as those obtained by the Planck satellite, indicate that the temperature fluctuations in the CMB are consistent with a flat geometry for the universe. This suggests that the overall spatial curvature of the universe is close to zero.
Large-Scale Structure: The distribution of galaxies and galaxy clusters across the universe provides further evidence for a flat or nearly flat universe. Surveys of the large-scale structure of the universe, such as the Sloan Digital Sky Survey, have revealed patterns of galaxy clustering that align with the predictions of a flat universe. These observations indicate that the universe is homogeneous and isotropic on the largest scales.
Baryon Acoustic Oscillations (BAO): BAO refers to periodic fluctuations in the distribution of matter in the early universe. These fluctuations left imprints on the large-scale structure of the universe. Measurements of BAO by various surveys, including the Baryon Oscillation Spectroscopic Survey (BOSS), have provided additional evidence for a flat universe. The observed BAO scale is consistent with a flat geometry.
It is important to note that while these observations support a flat universe, they do not necessarily provide evidence for a spherical universe. The shape of the universe on its largest scales is still a subject of ongoing research, and alternative possibilities, such as a toroidal (donut-shaped) or a more complex geometry, are also being considered and explored.
In summary, the current scientific evidence, based on observations of the cosmic microwave background, large-scale structure, and baryon acoustic oscillations, suggests that the overall shape of the universe is likely to be flat or very close to flat. The belief in a spherical universe as a whole is not widely supported by the scientific community.