Modern chronological clocks

- Discovery-Dr. Vihari shadow

- The method of radio metric dating is used to know the time of an ancient event. Useful for finding the age of antiques

Pu Ratatva Vido says that the earth originated four and a half billion years ago. He also says that the origin of living things settled on the earth three and a half billion years ago. Archaeologists are still struggling to gather enough evidence before reaching the final conclusions about the location of the skeleton. Here we wonder how archaeologists would have known all these ancient times. Do they know how much damage is likely to be done? Which of these methods is the least damaging method? Is. The tribes that had been scattered on the Hawaiian Islands of the United States before 150 came together and became part of a central society. Archaeologists agree that many of the temples built in Maui at that time were similar to each other. It shows that the Hawaiian island was ruled by a single king at that time. But it is not known at what time those temples were built and how quickly their tribal tribes became one.

Radiometric dating is a method of establishing how old an object is - perhaps a wooden artefact, rock or fossil - based on the presence of a radioactive isotope inside it.

The method of radio metric dating is used to know the time of an event in antiquity and antiquity.

The basic rationale behind radiometric dating is that if you compare the presence of radioactive isotopes within a sample with its known abundance on Earth and its known half-life, you can calculate the age of the sample. Radiometric dating is useful for finding the age of antiques.

It is based on a radioactive substance. A radioactive substance is a substance that automatically emits invisible rays from itself. This is because the nucleus of its atoms tends to disintegrate. As a result, the molecule is converted into a molecule of another substance. Eventually it is converted into a substance that does not emit radioactive rays. Thus over time the radioactive substance ceases to emit rays automatically and is converted into a non-radioactive substance. This process is called 'radioactive decay'. It is not possible to say how long a substance will lose its radioactivity. But it can be said that the radioactivity of a substance is reduced by half. This time is called 'half life'. The half-life of uranium (૨૩૮) is 4.5 billion years. The half-life of uranium (૨૩૫) is 3 billion years, and the half-life of thorium (૨૩૨) is 12 billion years. Thus half the amount of all these substances decays in a very long time. Therefore, the time of the sample can be known by calculating the percentage of decay in the quantity found in any antique or antique specimen. This was a straightforward explanation of the radio metric dating method.

Radio metric dating is done in different ways. One of them is the radiocarbon dating method. Thus carbon is not a radioactive substance that emits rays automatically but one type of it i.e. isotopic carbon (12) is radioactive. It's called radiocarbon. Atmospheric nitrogen, in some cases, is converted to radiocarbon. It comes down with rain and falls on buildings, plants and animals. The bones of animals are stabilized by food. It remains in the skeleton even after the animal has died. Its half-life is 215 years. The timing of a sample can be determined from what percentage of the sample has chicks without decay. That way is called carbon dating.

Carbon radio metric dating is an inaccurate method for short periods, according to Patrick Kirch, an archaeologist at the University of California, Berkeley. Radiocarbon dating is not suitable for dating anything that is more than 20,000 years old, as carbon (18) decays rapidly and is therefore not present in significant quantities in older objects. In the case of the above Hawaiian Islands, the inaccuracy of this method can be as high as 20 to 30 years. So they tried the uranium series dating method that geologists use. The question here is what is uranium series dating

We saw that uranium is a radioactive substance. It decays over time and eventually transforms into a non-radioactive substance lead. But this conversion does not take place directly from uranium. Uranium is first converted to other substances. The substances it converts to are also radioactive. And it also decays. So in the second stage it is converted into a third substance and it is also radioactive so it also decays. And it transforms into the fourth substance. Thus a series of radioactive substances are produced during the conversion of radioactive uranium to non-radioactive lead. It also contains substances such as radium, radon and polonium. Substantially converted substances from uranium are called 'uranium series'. Some call it the 'uranium family' while others call it the 'uranium lineage'.

Coral is the ideal material for the uranium series dating method. Corals contain uranium. It gets it from the sea water. This means that by the time the coral was pulled out of the ocean, it would have stopped taking uranium. A type of uranium (૨૩૮) in corals called a isotope of uranium decays and converts to very slowly decaying thorium ()). We know that isotopes of the same substance have the same properties but their atomic weights are different. The figure written in brackets shows the weight of its atom. Coral uranium ૨૩૮ converts to thorium 20 at a fixed rate. As uranium depletes, it decreases and thorium increases. The ratio of coral uranium to thorium is found. In this way, the time of each coral in the temple of the island of Hawaii could be found by calculating 150 to 180. This period of time shows that the same king made great social changes during the same generation.

We know that corals are sea creatures. They are micro-organisms and form rocks in the ocean. There are many coral islands in the ocean.

The uranium series dating method in this coral can be used to know the ratio of the amount of uranium and thorium, the change in the sea level, the formation of the glacier and the time of change in the climate of the world. But these changes can be known over a period of one million years. In the case of the island of Hawaii, it is evident that the period of human development that has taken place in a very deep past can also be accurately known.

Uranium series dating can be used to determine ages ranging from 2.5 billion years to 1 million years. This method is considered to be particularly accurate, with very little inaccuracy

However every dating method has limitations. If we want to determine the time from which the earth's magnetism reverses every three million years, then in the chronological sample there must be some minerals whose magnetism direction has remained the same even after the reversal of the earth's magnetism. This is also a limitation.

Finding time with the help of radiocarbon requires organic matter such as bones and wood in which the time of a non-carbon sample cannot be traced to carbon dating. Similarly the chronology from uranium series should contain a radioactive substance in the sample. If not, potassium-argon dating is also a method used to tell us the age of the rock, or how long ago the rocks were formed. The time can be determined by using the ratio of argon (30) and forward (2) in the sample but for that too the sample should contain potassium and argon. Here we know that argon is an inert gas. It does not chemically bind to anyone. The types of argon (20) and forward (2) are isotopes. Their properties are the same. Only their atomic weights are different.

Argon-Argon is the most powerful and widely used dating method for determining the duration of time. It can determine the sampling time from two thousand years ago to the time of the earliest solar system. From this, the scientists came to know that the Earth originated 2.5 billion years ago. By this method, we know that the earliest human species 'Hominid' roamed the earth 5 million years ago and the genius of today's human being This is how he came to know that he was roaming the earth 40,000 years ago.

The period from 20 million to 25 million years ago is called the Permian epoch and the period from 25 million years to 206 million years ago is called the Triassic epoch. But at the end of the Permian epoch and at the beginning of the Triassic epoch, there was probably a catastrophic asteroid explosion on Earth. In which 80% of the living creatures were destroyed. The timing of this catastrophe has not yet been determined. Is. In 2006, a geochronologist (geologist) determined the time of the catastrophe to be 25 million years ago with the help of small crystal-like fragments of a zircon sample from a volcano found in China. It may fluctuate over 3 million years. Exactly at this time a massive flood of lava from the Earth's crust in Siberia rolled back to the surface. The fact that these two events occurred at the same time is due to the newly modified process of zircon sampling.

Thus there are several methods of chronology. There are other radioactive isotopes whose ratios can be used to measure the duration of rocks, including Samarium-Neodymium, Rubidium-Strontium, and Uranium-Thorium. Each of these has its own advantages and diversity, but they rely on the same logic of radioactivity to work.