You CANNOT juxtapose 'know' with 'think'. They are not synonyms.
For example, I know I am a human being. I have never tested it. I've never had anyone look at my DNA and verified 'yep, that thar be human'. I only have alot of circumstancial evidence. I look like other humans. I have human ailments and tendancies. I was born (or so I'm told. I wasnt actually there to witness it), and have aged like other humans. This may sound silly, but it gets to the heart of our view points. From your perspective you/I dont 'know' anything. May as well get rid of the word because nothing is certain enough to qualify.
But, let us take the advice of Selueceia. You seem to want to call into question particular parts of the 'Big Bang Theory' (which, to be honest isnt any 1 theory. It's a category of science at this point). I am interested to hear what parts you disagree with or find a lack of credibility.
I will now dissect that last post; please feel free to point out specific points you would either like elaboration on or doubt the credibility of.
Maybe the most learned brains on the planet will THINK the 'movement' of the galaxies with in the universe SUGGESTS the universe itself is expanding.....but I don't.
I KNOW their observations of galaxies moving indicates the galaxies are moving.
Ok, maybe my explanation was too brief on this. The galaxies are moving away from each other, and in all directions. To visualize this, imagine dots placed on a balloon that is then inflated. The dots move away from each other in all directions. And just so I'm clear: You can say the galaxies are moving if you so choose (though you would be hard-pressed to explain their motion strictly from this view). You can also say the galaxies are not moving and they appear to move simply because the space between them expanded. Both views are true depending on your point of view.
I also didnt bring up Redshift in my explaination, and I should have. I'm sorry for that. Now, light from very far galaxies has been shifted toward the red end of the spectrum. Red light has a longer wave length. So, the light from these far off galaxies has been 'stretched' to resemble redder light. This directly correlates with the distance to such a galaxy. The light itself has only traversed empty space. Therefore, space has stretched the light as it traveled.
Reverse extrapolation SUGGESTS a 'big bang' but NOTHING more than that.....and certainly not an origin/beginning of a universe...or of time...or of ANYTHING else.
Even your idea that the galaxies are just moving suggests a big bang; it is an extremely simple idea (part of it's beauty). Now as for the final part of that sentence... everything we can see, touch, and measure are, in fact, the logical result of the such a process. Now, I can agree that time isn't necessarily a part of that. The standard big bang models don't touch time. The only thing we know about time for certain is that it is wrapped up with space, and both are heavily affected by the presence of energy/matter. Time slows down, in effect, when there is enough matter. Well, you have all the matter of the universe concentrated in a small area. It's way more than enough to rip a hole in space and stop time. To be frank though, this is an open area of science with lots of competing ideas, and no mathmatically rigorous support. You need quantum mechanics and general relativity in 1 framework, and no one knows how to do that yet.
Why must the Universe NOT be infinite both spatially AND temporally?
Well, it depends on your point of view to some extent, and there is no consensus on whether the universe is infinite or not. We certainly dont see an edge, but it could very well be beyond our ability to see (due to expansion). I also saw a few months back a mathematical theory that started with one dimension, supposed expansion of that dimension, and a stable 4 dimensional world was created as a result. I would guess that the first dimension would be time, but I dont know much more about the idea.
Who is to say there [if there was one] was only ONE 'big bang' ....and NOT a series of them sequentially over time..... FOREVER?
There are certainly theories derived from the Big Bang theory that have such qualities... and some that dont.
Remember ....there once was a time when it was 'known' that if a train exceeded 30 mph all the air would be sucked out of the carriages and people would suffocate.....
What you seem to be implying is that scientists constructed a train and put some sort of rudementry O2 sensor on the train, ran it in an automated way at speeds exceeding 30 mph, and the results showed a lack of sufficient oxygen on the train during the 30+ mph part of the trip. I highly doubt such an experiment was performed. As such, I will claim this 'knowledge' to be superstition, which is the antithesis of science and, really, knowledge.