Nonsense. It doesn't take "faith" at all, it takes knowledge, understanding of the relevant processes, and familiarity with the evidence. When something can and has been confirmed by multiple validation tests by having its detailed consequences compared against the real world and found to match to a great degree of closeness, and survived multiple attempts at falsification, it's nowhere near in the same category as something that "takes faith" to accept, like ancient myths.
Here, read this and learn something: Evidence for the Big Bang.
Excerpts:
And:COBE was actually several experiments in one. The DMR instrument measured the anisotropies in the CMBR [Cosmic Microwave Background Radiation] temperature across the sky (see more below) while the FIRAS experiment measured the absolute temperature of the CMBR and its spectral energy distribution. As we mentioned above, the prediction from BBT [Big Bang Theory] is that the CMBR should be a perfect blackbody. FIRAS found that that this was true to an extraordinary degree. The plot below (provided by Ned Wright) shows the CMBR spectrum and the best fit blackbody. As one can see, the error bars, which are quite small, are actually 400 standard deviations. In fact, the CMBR is as close to a blackbody as anything we can create here on Earth.
The link examines fourteen independent lines of evidence which confirm the Big Bang Theory. Get back to us when you have as much hard evidence, along multiple independently cross-confirming lines, supporting a literal reading of Genesis -- only *then* would the claim that it takes "as much faith" to accept the Big Bang "as for a literal belief in Genesis" approach something like a sensible statement, instead of the arrant nonsense it actually is.However, if we recall that the largest size for the hot spots corresponds to the size of the visible universe at any given time, that tells us that, if we can find the angular size of these variations on the sky, then that largest angle will correspond to the size of the visible universe at the time of decoupling. To do this, we measure what is known as the angular power spectrum of the CMBR. In short, we find all of the points on the sky that are separated by a given angular scale. For all of those pairs, we find the temperature difference and average over all of the pairs. If our basic picture is correct, then we should see an enhancement of the power spectrum at the angular scale of the largest compression, another one at the size of the largest scale that has gone through compression and is at maximum rarefaction (the power spectrum is only sensitive to the square of the temperature difference so hot spots and cold spots are equivalent), and so on. This leads to a series of what are known as "acoustic peaks", the exact position and shape of which tell us a great deal about not only the size of the universe at decoupling, but also the geometry of the universe (since we are looking at angular distance; see 1b) and other cosmological parameters.
The figure below from the NASA/WMAP Science Team shows the results of the WMAP measurement of the angular power spectrum using the first year of WMAP data. In addition to the angular scale plotted on the upper x-axis, plots of the angular power spectrum are generally shown as a function of "l". This is the multipole number and is roughly translated into an angle by dividing 180 degrees by l. For more detail on this, you can do a Google search on "multipole expansion" or check this page. The WMAP science pages also provide an introduction to this way of looking at the data.
As with the COBE temperature measurement, the agreement between the predicted shape of the CMBR power spectrum and the actual observations is staggering. The balloon-borne experiments (particularly BOOMERang, MAXIMA, and DASI) were able to provide convincing detections of the first and second acoustic peaks before WMAP, but none of those experiments were able to map a large enough area of the sky to match with the COBE DMR data. WMAP bridged that gap and provided much tighter measurement of the positions of the first and second peaks. This was a major confirmation of not only the Lambda CDM version of BBT, but also the basic picture of how the cosmos transitioned from an early radiation-dominated, plasma-filled universe to the matter-dominated universe where most of the large scale structure we see today began to form.
Also see: Explaining the Scientific Method.