How to Read the Pillow
500 Million Years
The first panel presents the Earth's changing conditions during its cooling off period. This span displays the three main Ice Ages including that of today, as well as the five mass extinctions, including the latest extinction event (dinosaurs.) The full range of temperatures on Earth are best observed on this long-term horizon.
10 Million Years
The second panel shows the significant human evolution that occurred during a warm period, followed by a dramatic climactic shift - about 2.6 Million years ago, the Earth descended into its current Ice Age, the Quaternary, which presented many challenges. Although currently in an Ice Age, temperatures are near or at their highest levels in the past million years.
This well known climate graph shows the rhythmic nature of temperature change over the last million years. It is a well established record of ice core samples and sea sediment that establish the approximate 100 thousand year cycles of "Glacial" and "Interglacial" periods. During Glacial periods (sometimes erroneously called "ice ages"), glaciers advanced far south into traditionally warmer areas such as the United States and Europe. During Interglacials, ice retreats due to temps that are near the levels when we entered the Ice Age. The temperature regularity during this time period is likely caused by Milankovitch cycles - a result of three aspects of Earth's orbit: the orbit's shape, the Earth's tilt, and the direction of Earth's axis.
During this period, hominids endured difficult conditions ranging from a super volcano to the cold of the latest Glacial period. The colder climate likely contributed to the development of more efficient hunting techniques, as well as new cultural activities, particularly cave painting. The arrival of our current, warmer Interglacial period saw the development of agriculture and other technology.
The "human period" which started approximately 12 thousand years ago upon the end of the latest Glacial period, reached a climax with the emergence of many great ancient civilizations such as the Sumerians, the Egyptians, the Greeks, and the Romans. The relatively warmer period allowed much greater areas of the Earth to be explored and developed.