Is the Big Bang model true?

Reasons given for answering "Yes"
  • It predicted the microwave background radiation

      There is a Cosmic Background Radiation uniformely distributed throughout the Universe. This is relevant the Big Bang Theory predicted that the universe's beginning was unfathomably hot, and the universe filled with radiation as space expanded, leaving behind just such a footprint.1, 2

      1. “The temperature is uniform to better than one part in a thousand! This uniformity is one compelling reason to interpret the radiation as remnant heat from the Big Bang; it would be very difficult to imagine a local source of radiation that was this uniform. In fact, many scientists have tried to devise alternative explanations for the source of this radiation, but none have succeeded.” []
      2. “Since the universe was so very hot through most of its early history, there were no atoms in the early universe, only free electrons and nuclei. (Nuclei are made of neutrons and protons). The cosmic microwave background photons easily scatter off of electrons. Thus, photons wandered through the early universe, just as optical light wanders through a dense fog. This process of multiple scattering produces what is called a “thermal” or “blackbody” spectrum of photons. According to the Big Bang theory, the frequency spectrum of the CMB should have this blackbody form. This was indeed measured with tremendous accuracy by the FIRAS experiment on NASA's COBE satellite. FIRAS Spectrum This figure shows the prediction of the Big Bang theory for the energy spectrum of the cosmic microwave background radiation compared to the observed energy spectrum. The FIRAS experiment measured the spectrum at 34 equally spaced points along the blackbody curve. The error bars on the data points are so small that they can not be seen under the predicted curve in the figure! There is no alternative theory yet proposed that predicts this energy spectrum. The accurate measurement of its shape was another important test of the Big Bang theory.” []
      3. Stephen Hawking & G. Ellis: “Recent observations of the microwave background indicate that the universe contains enough matter to cause a time-reversed closed trapped surface. This implies the existence of a singularity in the past.” [Stephen W. Hawking and G. F. R. Ellis, The Large Scale Structures of Space-Time (Cambridge University Press, 1973), 3.] The proof that the singularity is in the past is given on p. 356-359.
  • It predicted helium 4, deuterium, helium 3, ithium 7

      The hot big bang model successfully predicted the early abundance of helium-4, deuterium, helium-3, and lithium-7.1 This is relevant because it is highly improbable that these specific abundances would be predicted accurately by chance.

      1. “The predicted abundance of deuterium, helium and lithium depends on the density of ordinary matter in the early universe, as shown in the figure at left. ... We generically expect about 24% of the ordinary matter in the universe to be helium produced in the Big Bang. This is in very good agreement with observations and is another major triumph for the Big Bang theory. ... Given a precise measurement of the abundance of ordinary matter, the predicted abundances of the other light elements becomes highly constrained. The WMAP satellite is able to directly measure the ordinary matter density and finds a value of 4.6% (±0.2%), indicated by the vertical red line in the graph. This leads to predicted abundances shown by the circles in the graph, which are in good agreement with observed abundances. This is an important and detailed test of nucleosynthesis and is further evidence in support of the Big Bang theory. ” []
  • It follows from General Relativity

      The Friedman solutions to Albert Einstein’s field equations for the General Theory of Relativity predicts a past time extremity to the universe known as the Big Bang “singularity.”1 This is relevant because the General Theory of Relativity is true (or empirically adequate).

      1. “The Big Bang model was a natural outcome of Einstein's General Relativity as applied to a homogeneous universe. However, in 1917, the idea that the universe was expanding was thought to be absurd. So Einstein invented the cosmological constant as a term in his General Relativity theory that allowed for a static universe. In 1929, Edwin Hubble announced that his observations of galaxies outside our own Milky Way showed that they were systematically moving away from us with a speed that was proportional to their distance from us. The more distant the galaxy, the faster it was receding from us. The universe was expanding after all, just as General Relativity originally predicted! Hubble observed that the light from a given galaxy was shifted further toward the red end of the light spectrum the further that galaxy was from our galaxy.” []
  • More fulfilled predictions

      Confirmed predictions made by Einstein's theory of relativity and Big Bang cosmology:
      • Relativity-related time-changes on satellite clocks
      • Curvature of light around stars due to matter
      • Observations that galaxies are receding from one another from some point of explosion.