"This 100-second simulation represents the first 760 thousand years of evolution of the Universe, as vast sound waves rippled through the hot matter that filled the expanding Universe. As this expansion takes place the Universe becomes more of a bass instrument and the pitch drops. The sound frequencies used in the simulation had to be boosted by a huge factor (about 10 to the power of 26) to be audible to the human ear because the actual Big Bang frequencies, which had wavelengths on the order of a fraction of the size of the Universe, were far too low to be heard by humans."

Credit: John G Cramer; NASA/WMAP Science Team