Introduction
According to the scientists, the earth is estimated to be about 4.55 billion years in age. This estimation is based on different assumptions and evidence carried out from specific parts of the earth. The scientists used three methods to come up with the actual age of the Earth. This paper will highlight how scientists established the actual age of the earth and all the assumptions that were made.
Methods Used to Estimate the Actual Age of the Earth
Radiometric Dating Method
The scientists also used the knowledge of half-life and the decaying element concentration to estimate the age of the sampled rocks, which translate to the age of the Earth. The age of the rocks obtained gives a lower age of the Earth. This is based on the assumption that the rocks sampled cannot be as old as the Earth itself. Hence, this method provides the most accurate way to know the Earth’s age (Plummer, et al.).
Radioactivity method
This method is a direct method of estimating the Earth’s actual age. The radioactivity method is based on deriving samples from the Earth and meteorites. The method involves measuring three isotopes of lead, which are Pb-206, Pb-207, and Pb-208 or Pb-204. To approximate the age of the Earth, a plot of Pb-206/ Pb-207 versus Pb-208/ Pb-204 is constructed. The scientists argue that if the solar system was formed from a common matter, then the earlier plots for all the objects would fall at a single point. Based on the slope of the line, the scientists computed the amount of time that has passed depending on the separation of matter into single objects. The use of meteorites has limitations because, in order to estimate the actual age of the Earth, the scientist has to acknowledge the constant change of geology. In addition, plate tectonics recycle part of the earth continuously, making it difficult to obtain the oldest regions of the Earth (Morris).
Stratigraphic Superposition method
The Fossil Record
Since the scientists discovered that the fossil organisms are unique as compared to the rock types, it made them focus more on it. The scientists used the intervals of rocks to determine the approximate age of the Earth. Due to the continual study of the early fossils, the scientists broadened their understanding and obtained the history of life on Earth. This method of estimating the age of the Earth is not as accurate to that of the radioactivity method (Plummer, et al.).
Other methods
The other methods that give the upper limits of the age of the Earth include:
Accumulation of helium in the atmosphere
Accumulation of the meteoritic dust on the moon
Decay of the Earth’s magnetic field
Accumulation of metals in the ocean
Conclusion
Based on the methods discussed above, the scientists have managed to estimate the actual age of the Earth to be nearly 4.6 billion years. This estimate has an error of 1%. According to the methods used, it has described in detail how the scientists came to estimate the actual age of the Earth. From the radiometric dating method of estimating the age of the Earth, the scientists studied ancient rocks to discover it. Moreover, the study of the meteorites enabled the scientists to come up with ways to estimate the age of the Earth in years. Another method that the scientists used to approximate the Earth's age is the study of ancient fossils. The methods used by the researchers provide a rough estimate of the age of the Earth.
Works Cited
Plummer, Charles C, Diane H. Carlson, and Lisa Hammersley. Physical Geology. New York, NY: McGraw-Hill/Education, Inc, 2013. Print.
Dalrymple, G B. The Age of the Earth. Stanford, Calif: Stanford Univ. Press, 1994. Print.
Morris, John D. The Young Earth: The Real History of the Earth, Past, Present, and Future. , 2007. Internet resource.
