Many cultural relics discovered by human beings have a very long time span. From today's excavation and discovery of various prehistoric human civilization remains, from a very long time ago, there has been human beings on the earth, and developed a highly developed civilization. For example, it is hard to imagine that the footprints of human beings wearing shoes found on trilobite fossils 600 million to 250 million years ago, the large chain nuclear reactor found 2 billion years ago in today's Gabon Republic of Africa, the metal ball found 2.8 billion years ago in South Africa, and many stone tools of different periods belong to the same human civilization period. Therefore, scientists put forward the theoretical conjecture of many times of prehistoric civilization, believing that there have been many times of prehistoric human civilization on the earth, and that human civilization is cyclical.

Modern science has realized that all things develop periodically. Human beings are born, aged and dead; plants and animals are also born, aged and dead; social development is cyclical, and human development is likely to be cyclical. Clues can be found from various prehistoric human civilization relics and tools left by different prehistoric human stone age that are excavated and discovered today.

In his book encounter of the Milky way, Apollo object and Atlantis: discontinuous mutation in human history, Emilio, a scholar, made an in-depth analysis of the causes of prehistoric human destruction. He believed that objects from outer space (comets, meteorites, etc.) caused abnormal earth climate, which may lead to the destruction of human civilization.

However, it is extremely obvious that different prehistoric human civilizations eventually disappeared from the earth. The earth's catastrophes in different periods destroyed the civilization at that time, even the vast majority of the living things at that time, leaving only a very small number of survivors.

人类发现的许多文明古迹时间跨度非常久远。从当今发掘和发现的各种不同史前 人类文明遗迹，从非常久远的远古时代开始，在地球上一直存在人类，并发展出高度发达的文明。如在 三叶虫化石上发现的6亿年前至2.5亿年前穿着鞋的人类脚印，在今天的非洲 加蓬共和国发现的20亿年前的大型 链式核反应堆， 现今 南非发现的28亿年前的 金属球，及多次不同时期的石器等，很难想象其属于同一人类文明时期。因此，科学家提出多次史前文明的理论猜想，认为地球上曾经有过多次史前人类文明，人类文明是 周期性的。

现代科学已认识到一切事物发展皆有周期性。人有生老病死；植物、动物也有生老病死；社会的发展有周期性，人类的发展极有可能有周期性，可以从当今发掘出和发现的各种不同 史前人类文明遗迹和不同史前人类石器时代留下的工具找到线索。

学者 埃米利奥（Emilio）在其著作《 银河的遭遇， 阿波罗对象和 亚特兰蒂斯：在人类历史上不连续的突变情况》中对史前人类毁灭的原因作了深入分析，认为来自外 星际空间的物体（ 彗星、陨石等）造成地球气候异常，可能导致人类文明的毁灭。

然而，极其明显的是不同史前 人类文明最终从地球上消失。不同时期地球的 大灾难毁灭了当时的文明，甚至灭绝了当时的绝大多数生物，只存留极其少量的幸存者。