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一般说,地球年龄有50亿年左右。地球科学家给出更准确的数字是46亿年。这么久远的过去,不仅人类没有出现,生命也没有出现,自然环境与现在也大不相同。要推算地球年龄,首先要有一个准确的时间尺度作衡量标准。另外,地球作为太阳系中的一个行星,在其形成球体前有较长期的演化阶段。那时,地球形成前可能是一团旋转的“云”,逐渐凝聚成球。凝聚到什么程度才称它是地球,这个问题也影响到地球的准确年龄。目前,地质学家普遍接受这样的认识:由与现今地球的
In general, Earth’s age is about 5 billion years. Earth scientists give a more accurate figure is 4.6 billion years. In such a distant past, not only did humankind not appear, nor did life appear, nor was the natural environment quite the same now. To calculate the age of the earth, we must first have an accurate time scale as a measure. In addition, as a planet in the solar system, the Earth has a longer-term evolutionary stage before its formation. At that time, before the formation of the Earth may be a rotating “cloud”, gradually condensed into a ball. The extent to which it has been condensed has called it Earth, and this issue has also affected the exact age of the Earth. At present, geologists universally accept this recognition: from Earth with the present