The twentieth century was very important for the human race.  Within the first fifty years we saw the development of the automobile, the airplane and nuclear energy.  Not to mention two catastrophic world wars.

The years considered relatively “peaceful” were the years that the fate of life on the entire planet rested on the push of a button, and it still does in a sense.  Clearly, this is a very interesting time for all fields of study and will be for as long as humans are around to study it.