Re: Atheism:
Well, first of all, there is a ton of evidence suggesting a "big bang". In fact, it was a Christian that first proposed the big bang theory. One major evidence was discovered in 1919 by Edwin Powell Hubble when he was observing the sky that light emitted from distant galaxies was shifted towards the "red" end of the color spectrum. He soon then discovered that the farther away a galaxy was from Earth, the more "red shifted" it appeared to be. These two observations that Hubble discovered were later observed and scrutinized by other scientists and found to be true, and they were later dubbed "Hubble's law". The "red shift" (wavelength) was due to the relative motion, away from the Earth of course, of the distant galaxies. The red shift in galaxy's spectrum increased in proportion to the galaxy's distance from our home planet. Hubble concluded that the further away the galaxy was, the faster was its total motion. He also found that ALL GALAXIES are quickly receding from planet Earth, and from other galaxies as well. So if you use logic for 2 seconds, you will see that if a galaxy was closer to the Earth yesterday, it is farther away today. This concludes that sometime in the very distant past that all matter, logically, must have been in a relatively small area in the universe, relatively small in volume and density.
Also, in 1965, Arno Penzias and Robert Wilson that both worked for Bell telephone companies in NJ, both detected very subtle microwave background radiation pervading from the universe IN ALL DIRECTIONS. This microwave activity was later found out to be a sort of "electromagnetic fossil" of the former "big bang". This provided a very good, independent evidence of an expanding universe.
In 1992, The NASA COBE satellite recorded faint, slight asymmetries in the background radiation of the universe. This would explain why matter in the universe is not distributed evenly. This explains that the big bang was not a perfect, everyday, symmetric "explosion". Albert Einstein actually concluded way before any of that that the universe was expanding with general relativity.
Those ^^^^^ are just a few, more simple evidences for the big bang. If you want more, read the wiki article about it. It contains much more independent proofs of it.
Big Bang - Wikipedia, the free encyclopedia
On your gripe about physics: Its alllll about
the conservation of Mass-Energy. Matter cannot be created, nor can it be destroyed, all it can do is change states. Coal into gas, water into ice, etc etc etc. If a bomb explodes, none of the mass is lost, it simply changes its state, and yadda yadda yadda. So anyways, A lot of this was found out by a French scientist, Antoine Becquerel. He was studying Uranium in his laboratories, and he found that when in close vicinity of his element, energy seemed to appear out of nowhere, and uranium mass seemingly disappeared into thin air, this was discovered to be "natural radioactivity". Einstein came along later, and concluded that no, mass from radioactive elements do not simply "disappear", nor do they arise from "ex nihilo" (out of nothing). He showed that MASS and ENERGY are two in the same, just explain into two different natures. In his most famous equation: E=MC2, Albert created the concept of
the conservation of Mass-Energy. This concept actually explain the universe's origins quite well. People such as Dr. Stephen Hawking have introduced such concepts as "vacuum fluctuations", which DO occur naturally in the universe where matter occurs and comes into existence out of basically nothing, a perfect vacuum. He discovered that even in a seemingly EMPTY vacuum (space), where no understood forms of matter or energy exist, there are ALWAYS random, electromagnetic oscillations present in the vacuum of space. These oscillations are now called "vacuum fluctuation energy", which can be converted into matter in complete harmony with the mass energy conservation laws.
"SO WHAT DOES ALL OF THAT JIVE MEAN!?" you ask? Well, based upon our findings, and since mass-energy can neither be created nor destroyed, logic tells us this: The universe in one form or anther, has ALWAYS existed. There was never ever ever ever a time when the mass-energy that makes up our beautiful universe did NOT exist, if only in the form of a seemingly empty, oscillating vacuum, or a theoretical infinite density known as singularity. At the "big bang", the entirety of the universe was beyond-comprehension-hot, and incredibly dense. The very primitive elements that are now chemical elements could not have possibly survived in such a hot environment, so it is put forth that the ever expanding universe was solely comprised of energy, with matter coming along later and condensing when further expansion away from all the volatile conditions allowed for further cooling where they could thrive.
REGARDLESS OF ITS FORM, The universe, the sum of all mass-energy, could not come from "ex nihilo", or from nothing in the way that creationists and Intelligent design believers will have you think. There was always the universe, and oscillating vacuum electromagnetism. To believe in "scientific" creationism, is to totally and utterly overlook (or ignore) the law of the conservation of mass-energy. It is the creationist that disregards physics, not the scientist or atheist! 
IF creationists and Intelligent design advocates have empirical evidence to completely contradict the law of the conservation of mass-energy, which they seemingly propose when they say the big bang came from nothing, I am eagerly waiting for them to share this evidence with the scientific community. Until then, the FUNDAMENTAL doctrine of creationism and Intelligent design, that the universe was created out of nothing by god, MUST BE RECOGNIZED AS PURE THEOLOGY, AND NOT SCIENCE, OR SCIENTIFIC THEORY.
So to answer your question, Scott: how are you able to put your faith so soundly into something that if looked at with the scientific method legitimately would be discarded immediately as faulty theory?
It doesn't take faith to believe in something that has so much evidence behind it. Its simply self-evident. The major problem here is the fact that mist people don't understand the big bang. if you truly understand it, and all the laws surrounding it, then you will realize that it doesn't clash with scientific theory at all. To propose something came from nothing, which the big bang theory does not suggest in anyway, is faulty theory.
FURTHER READING ON EVIDENCES OF THE BIG BANG:
Evidence for the Big Bang
Frequently Asked Questions in Cosmology
WMAP Cosmology 101: Big Bang Tests
