Big Bang Evidence
    The first piece of evidence supporting the Big Bang Theory is the Doppler shift,also called the red shift, of other galaxies.  This effect was noted by Edwin Hubble around1930.  The Doppler shift is like the change in sound a train horn makes as the train moves closer or further away.  When viewed using spectral analysis, an object moving toward us at high velocity has a blue shift, due to the contraction of light waves.  When moving away objects shift to red, due to the expansion of light waves.  This indicates that the universe is moving, not static, moving due to the Big Bang.  Any other interpretation require effects that have no experimentation or evidence.
     The second piece of evidence is microwave background radiation.  The Big Bang Theory predicted a much hotter early universe.  In 1964, two reasearchers, Arno Pezias and Robert Wilson accidentally discovered that space was not absolutely cold, but three degrees Kelvin.  The raised temperature is due to the radiation of photons.  The distribution of photons was measured, and, according to Plank's black body radiation curve, equaled the number necessary to achieve a temperature of three degrees Kelvin.  The interpretation of this radiation bath is that it is heat left over from the Big Bang, and again, no other suitable explanation exists.  Let me add that the researchers responsible for this discovered it accidentally.  They worked for a telephone company, and were not attempting to support the Big Bang Theory. 
     The third piece of evidence is something creationists have long said was impossible:  an indirect way to test the theory in a laboratory. 
     The Big Bang Theory predicts that the universe started cooling fractions of a second after the explosion.  Also predicted was that this rapid cooling would produce strings and other topologies in the structure of space-time.  The same mechanisms should produce string like vortices when heated liquid helium cools into a super-fluid state.  This is akin to what happens when water freezes and leaves cracks and lines in the ice cubes.  Two teams of scientists* found just such vortices. 
     Creationists can continue to deny the Big Bang, just as they deny gravity, until they are blue in the face, but just like gravity and evolution, the Big Bang is a fact that they cannot deny away.