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The age of the earth has been arrived at, slowly and step by step, as scientists refine existing methods and discover new ones.
Charles Lyell is probably the pioneer who first proved that the Earth is millions of years old. Early in the nineteenth century, he examined the great volcano of Etna on Sicily and studied the historical records of frequent eruptions. He noticed that each time it erupted, a new layer of lava would be added, causing the mountain to grow at a measurable rate. By knowing the height of the volcano, its approximate rate of growth and the frequency of eruptions, Lyall determined that the volcano must be several hundred thousand years old. At the edge of the volcano, under the first lava flows, he found fossil shells that were virtually identical to the shells of molluscs still found in the Mediterranean Sea. From this, he deduced that the fossils were geologically recent, that a hundred thousand years was geologically short and that the age of the earth must be immense.
A further important step took place in 1862, when Lord Kelvin, Professor of Natural Philosophy at Glasgow University and regarded by his contemporaries as the greatest physicist of his day, announced that he had calculated the time it would take the world to cool down from its molten state. He calculated that this was between 20 and 400 million years. Later, Kelvin refined his calculations to within the range 20 to 100 million years and, later still, to some 20 to 40 million years. With the discovery of radioactivity, it was soon realised that the uranium present in the earth prolongs its cooling almost indefinitely. So. Kelvin's method only gives a minimum age, but by no means a true estimate.
Samuel Haughton, an Irish geologist, calculated that sediments were deposited on the ocean floor at the rate of "one foot in 8,616 years". He then calculated a minimum duration of around 2000 million years. Unwilling to accept such a long period, he scaled it back, by a factor of 10, to just 200 million years. This may not be an important dating method today, but it does lend confirmation to other dating methods.
These early estimates fell far short of the Earth's real age of more than 4.5 billion years, a figure more recently established by nuclear physicists, but they did show that it was no longer possible to consider the earth to be only a few thousand years old.
What else can I help you with?
When first discoveed the planet earth?
Earth's exact age is indefinite but it is millions of years old. Humans discovered it when they had their first concious thought.
Was Uranus discovered before Earth?
No. The first person to look down discovered Earth.
The Muslims who discovered the world was round?
Muslim scholars such as Al-Farghani and Al-Biruni in the Islamic Golden Age made significant contributions to the understanding of the Earth's shape. They studied various fields including astronomy and mathematics, and their work helped to demonstrate that the Earth is round. The idea that Muslims "discovered" the world was round may be oversimplified, as this knowledge was already present in various civilizations prior to the Islamic Golden Age.
How was Earth's core discovered?
By studying how seismic waves travel through the Earth's interior.
Who discovered imaginary lines on earth?
Equator and AxisThey
How first discovered the planet earth?
No one discovered Earth. Humans have been here since the beginning of our existence. Earth's exact age is indefinite but we know it is millions of years old.
When first discoveed the planet earth?
Earth's exact age is indefinite but it is millions of years old. Humans discovered it when they had their first concious thought.
The year Mars was discovered?
Mars can be seen from the Earth without a telescope, people have known about its existence since the stone age.
WHERE was the moon discovered?
in the earth, people discovered
Was Mars discovered before earth?
No. The first person to look down discovered Earth.
Was Uranus discovered before Earth?
No. The first person to look down discovered Earth.
What was the first planet discovered besides earth?
The first planet discovered besides Earth is Uranus. It was discovered by William Herschel in 1781.
How did they discover earth?
It was not discovered. God made the Earth and and He made Adam and Eve who were the first people on Earth.. It was not discovered. NOTE: Many things exist without being technically "discovered". Earth is one example of many.
The Muslims who discovered the world was round?
Muslim scholars such as Al-Farghani and Al-Biruni in the Islamic Golden Age made significant contributions to the understanding of the Earth's shape. They studied various fields including astronomy and mathematics, and their work helped to demonstrate that the Earth is round. The idea that Muslims "discovered" the world was round may be oversimplified, as this knowledge was already present in various civilizations prior to the Islamic Golden Age.
Helium was discovered in the sun before it was discovered on earth. How?
Helium was discovered in the sun specroscopically
Which element was discovered in space before it was discovered on earth?
helium
What age was Galileo when he discovered the telescope?
Galileo wasn't the first to make a telescope but he discovered the telescope at the age of 46.
