A few weeks ago, I offered tongue in cheek an image of a traditional roll of the seasons. How we perceive time in itself determines how we generally take in the world. Generally, we view time as a linear process or linear function of distance over space (e.g.: simple relativity). However, these were not the primary means through which people have viewed time in the world. For the majority of the human existence, it appears that humans have considered time to be circular.
The question of the “impending demise of us all” relates to the perception of the time. The Maya, like a large number of native tribes in the Americas, view time as a circular roll of life and death. One baktun died and bore another; one age died and did the same. Sound familiar to Tolkien with the First, Second, Third Ages of Middle Earth? These were inspired by the Norse perception of time, specifically Old Icelandic. Geologically, this is well and easily noticed in the world: there are times in which it is hot (hypsithermal) and times in which the world is cold (the Little Ice Age) and times in which the world is pleasant. Without much surprise or fanfare, times that are colder generally result in more famine, less travel, and a general closing in of the population centers; times that are warm typically see expansion (e.g.: the great migrations and expansions of the Woodland peoples from Ohio, Michigan areas into Tennessee, North Carolina, Kentucky, &c). Even the Anasazi, who’s famous and well noted disappearance in the public consciousness, were most likely broken apart due to increased local heat during a period of climate change that resulted in a large drought that caused the Pueblos to disperse across the landscape as the cultural centers fell apart. These people most likely started or influenced the development of the Zuni, Hopi, Pueblo, and Navajo tribes (note: I am not that abreast of Southwestern Archeology, though I know some of its rougher details).
On a different level, there is a sense of positivism in the means with which Western Culture views time. At its heart positivism argues for a linear course of progression to a more enlightened or improved state. Our lives reflect this very concept: 1.) Stage I: Birth through Two = Baby; 2.) Stage II: Three through Five = Toddler; 3.) Stage III: Six through Ten = Juvenile; 4.) Stage IV: Eleven through Thirteen = Tween; 5.) Stage V: Fourteen through Seventeen = Adolescent; 6.) Stage VI: Eighteen through Twenty = Probationary Adult; and 7.) Stage VII: Twenty-one plus = Adult. This can be extended further out, but the idea is that we progress through different stages of social obligations and concerns because we have “aged” to that point more so than earned that responsibility through our actions. It’s a formulaic means of considering our lives as we age; yet we forget the riddle of the sphinx to Oedipus: “What walks on four legs in the spring, two in the summer, and three in the fall?” Our own existences are essentially cyclical: we are born and learn to crawl, we enjoy our time running in the sun, and then we return to needing assistance to walk. Yet, we arbitrarily define these phases based not only off our physical abilities, appearance, and sexual maturity, but also with time as a function. Because we have achieved X years, we can now do Y social obligation! It is as gifted to us as if a present.
Scientifically, time is a reflection of distance. Everything we perceive is a few moments behind what is occurring when it actually is occurring. Think of the time it takes for the light of the sun to hit the earth versus the time to reach Neptune.