Sample Response: The big bang theory is supported by the observation that the spectrum of nearly all galaxies is red-shifted, implying that the universe is still expanding. It is also supported by the discovery of the cosmic microwave background radiation, which is leftover radiation from the big bang. Finally, the big bang theory is supported by the discovery that the composition of stars is 99% hydrogen and helium, the only two elements that could have existed shortly after the big bang. What