The Big Bang Theory Is True

In this round, I will post various proofs for the validity of the Big Bang Theory (BBT). I. Homogeneity of the Universe While the universe is not homogeneous in small regions, the universe as a whole is relativity homogeneous. This was a predicted result of the Big Bang Theory and his been confirmed by the WMAP probe: [1]This ties in to the thing known as the Cosmic Microwave Background Radiation (CMBR), shown below: [2]The CMBR is isotropic (the same) to roughly one part in 100,000, further confirming universial homogeneity. This spectrum has been redshifted by the expansion of the universe, and today corresponds to approximately 2.725 K. [3][4]II. Galatic EvolutionThe above information leads into my second point. Populations of stars have been aging and evolving, so that distant galaxies (which are observed as they were in the early Universe) appear very different from nearby galaxies (observed in a more recent state). Moreover, galaxies that formed relatively recently appear markedly different from galaxies formed at similar distances but shortly after the Big Bang. These observations are strong arguments against the steady-state model. Observations of star formation, galaxy and quasar distributions and larger structures agree well with Big Bang simulations of the formation of structure in the Universe and are helping to complete details of the theory. [8][9]Here is a visual representation of this: This is indeed observed in galaxies throughout the universe, and confirms another prediction of the Big Bang Theory. III. Abundance of Elements Using the Big Bang model it is possible to calculate the concentration of helium-4, helium-3, deuterium, and lithium-7 in the Universe as ratios to the amount of ordinary hydrogen. The relative abundances depend on a single parameter, the ratio of photons to baryons. This value can be calculated independently from the detailed structure of CWMB fluctuations. The ratios predicted (by mass, not by number) are about 0.25 for 4He/H, about 10−3 for 2H/H, about 10−4 for 3He/H and about 10−9for 7Li/H. The measured abundances all agree at least roughly with those predicted from a single value of the baryon-to-photon ratio. The agreement is excellent for deuterium, close but formally discrepant for 4He, and off by a factor of two 7Li; in the latter two cases there are substantial systematic uncertainties. Nonetheless, the general consistency with abundances predicted by Big Bang nucleosynthesis is strong evidence for the Big Bang, as the theory is the only known explanation for the relative abundances of light elements, and it is virtually impossible to "tune" the Big Bang to produce much more or less than 20–30% helium. Indeed there is no obvious reason outside of the Big Bang that, for example, the young Universe (i. e. , before star formation, as determined by studying matter supposedly free of stellar nucleosynthesis products) should have more helium than deuterium or more deuterium than 3He, and in constant ratios, too. [5][6]Here is a graph showing the abundance of elements in the universe (abundance versus atomic number): [7]Notice how the abundancies roughly decrease asymptotically as the atomic numbers of the various elements go up. This further confirms the predictions of the Big Bang Theory with regards to the abundance of elements in the universe. IV. Dark Matter and the Integrated Sachs-Wolfe EffectIn addition to the Sunyaev-Zel'dovich effect, photons from the CMBR can also be subtly affected by the Integrated Sachs-Wolfe effect. The basis for this effect is gravitational redshift, one of the most basic predictions from GR and first demonstrated experimentally by Pound and Rebka in 1960. The basic idea is that, as photons enter a gravitational potential well, they pick up extra energy and when they exit they lose energy. Hence, scientists refer to photons "falling into" and "climbing out of" gravitational wells. As CMBR photons pass through the foreground large scale structure, they pass through many such gravitational wells. If the depth of the well is static (or rather if the depth of the well is increasing at the same rate as the expansion of the universe), then the net energy change is zero. All of the energy they gained falling in is lost climbing out. However, if the universe contains dark energy (or has an open geometry), then the universe expands faster than the gravitational wells around massive objects can grow. As a result, the CMBR photons do not lose all of the energy they gained falling into the potentials. This makes the CMBR look very slightly hotter in the direction of these potentials, which also contain the highest concentrations of galaxies. Following the release of the WMAP data, studies measured this effect using galaxies selected in a number of different ways. The signal-to-noise in any one of the measurements was not very large. However, taken together (and combined with the WMAP observation that the geometry of the universe was best fit by a flat universe), they provide significant evidence that this effect is real and is best explained by the standard Lambda CMD model of BBT. [1][10][11][12]V. Hubble's LawHubble's Law states that v = H0D where v is the recessional velocity of the galaxy or other distant object, D is the comoving distance to the object, H0 is Hubble's Constant, measured to be 70.4 (errors +1.3, -1.4) km/s/Mpc The only plausible explanation for this is the expansion of the universe, which we are currently expericing. It is one of the cornerstones of the Big Bang Theory, and its validity is more proof of the Big Bang Theory. [13][14][15]Sources [1]: . http://www.talkorigins.org...[2]: Weinburg, S. The First Three Minutes: A Modern View Of The Origin Of The Universe. [3]: Spergel, D. N. et al. (2006). "Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology"[4]: . http://arxiv.org...[5]: Kolb, E. ; Turner, M. (1988). The Early Universe. [6]: . http://arxiv.org...[7]: Croswell, Ken (February 1996). Alchemy of the Heavens. [8]: . http://arxiv.org...[9]: Bertschinger, E. (1998). "Simulations of Structure Formation in the Universe". [10]: . http://arxiv.org...[11]: S. Boughn and R. Crittenden, A correlation between the cosmic microwave background and large-scale structure in the Universe, Nature 427 (2004) pp. 45[12]: . http://arxiv.org...[13]: . http://dx.doi.org...[14]: . http://lambda.gsfc.nasa.gov...[15]: . http://en.wikipedia.org...