The DNA in our cells holds about the same amount of data as a DVD, but in six feet of DNA that’s packed into a cell a tenth the size of a speck of dust. Together, all the DNA in our body, if laid end to end, would stretch twice the diameter of the solar system. Unlike a simple DVD, though, the DNA in our cells is wet and vibrating in three dimensions. And there aren’t 50 songs, there are more than 20,000.
