Forty six years ago, scientists announced the discovery of definitive evidence for the expansion of the universe from a hotter, denser, primordial state. They had found the cool afterglow of the big bang: the cosmic microwave background radiation. Since this discovery, the expansion and cooling of the universe has been the unifying theme of cosmology, much as Darwinian evolution is the unifying theme of biology. And so does Darwinian, there are a lot of misconception about Big Bang theory. Foremost, when they meet the Bad science! Here is the summary of common misconception about the Big Bang taken from Scientific American. The Bold is the wrong statement and the right explanation follow it.
1. Matter and energy does not explode from one point and spread out to fill the whole universe! It was space and time. Therefore, there was no explosion in the center of the room and its density almost close same everywhere.
2. Galaxies can not far away each other at the speed greater than light because it was violating special relativity! Yes, Galaxies can far away each other at the speed greater than light. Galaxies move not because the movement inside the space but it is because the space expansion.
3. It is impossible to see galaxy that move away with the speed greater than light because light can not approach us! Yes, we can! Expansion rate can be changed. Hubble limit can grow faster an reach the photons that should not be able to reach us.
4. The red-shift is happen because of Doppler Effect; the light source move away from us because of space expansion! It was happen not only because of Doppler Effect, but mainly because space expansion extend the waves of light.
5. Because the universe ages is approximately 14 billion years old, we can only observe 14 billion light of years! We can observe approximately 46 billion light years. What we observe today has been move away with the increasing speed.
6. All celestial bodies are also expanding! NO! Inter-galactic gravitation always pull each other and against the expansion. The final balance occur in the term of cluster in which the inter-galactic distance become relatively fixed.
Source: Scientific American (click for direct link)