I'm not sure if you're being sarcastic, but I really don't like how they do this extrapolation stuff. Like the universe is currently expanding, and based on the current rate of expansion (or the rate of change of that expansion) we assume it has always been expanding and that 14 billion years ago everything was crammed into something the size of a golf ball. I'm not anti-science, but that seems to be making a pretty big leap.
This is mostly because you apparently don't understand the theory (or the data) very accurately, which is fine. But to take a layman's understanding of something and concluded that "all teh scientists are idiots" is really, really not a good idea.
The evidence that cosmological expansion occurred in the distant past, not just today, is compelling, and direct. We can actually see light that has been traveling unimpeded since the universe was only 300,000 years old, which means that we can directly observe the conditions in the universe at that time. And it was hot, and dense.