As most of us would likely guess, walking is the most popular physical activity in America. But people who walk for exercise do so at wildly varying speeds and intensities. Some stroll at a leisurely 2 miles per hour, which is low-intensity exercise. Others zip along at twice that pace or better, resulting in a sweatier workout.
Mummification is a process in which the skin and flesh of a corpse can be preserved. The process can occur either naturally, or it can be intentional. If it occurs naturally, it is the result of cold (as can be found in a glacier), acid (as can be found in a bog) or dryness.
The Egyptians' encounters with sand-dried corpses might have influenced their particular beliefs and practices regarding the afterlife. Although mummification is the most striking feature of the Egyptian way of death, it draws its meaning from a more encompassing view of the world. Both beliefs and practices continued to evolve over the long span of Egyptian history. The Predynastic period dates from approximately 5,000 years before the Common Era.