Fossil age
It never ceases to amaze you that archaeologists have rescued dinosaur fossils from the earth, which have dominated the earth for so long, and quickly found out how old they were, how many years ago they were on Earth, and how they did it. I think they recovered their fossils and then put them in the museum. But after all, how many years ago did they find those skeletons or fossils alive on Earth? Yeah Al that sounds pretty crap to me, Looks like BT aint for me either. Then .... one of my older brothers called me the science behind it and broke my mistake.
So I learned it from my older brother.
This time I will go to my elder brother's place. You will go to my place. I will listen to you and how do you determine the age of the fossil?
First of all let me say something about fossils. Fossils are made from the carcasses of animals. When an animal or plant dies, the carcass of that animal begins to mix with the soil under the influence of bacteria for a long time. The soft parts of the animal's body, such as meat, rot quickly. But hard things like bones or shells do not decompose so fast. Occasionally, various soil substances, such as calcium, enter the bones and strengthen them, making them last for thousands of years. These bones then turn into fossils.
Usually archaeologists dig up the soil and find all these fossils, so I assume that I want to find the fossils by digging the soil in the garden behind my house (what else is that happy push). So I found fossils of huge dinosaurs. This time you may think that I will be famous this time, but wait, we are Bengalis, we have tried to become world famous by clapping a lot before. So naturally no one will believe my fossil of this dinosaur so I will not go straight but go a little crooked way to determine the previous age then I will show everyone this time everyone will believe. I said I will determine the age but it is a lot of tough work. But I'm not the one to give up, so I started.
So I now have two methods to determine this age.
1) Seeing the structure of the rock
2) By carbon dating.
First of all, you have said that the age of fossils can be determined by looking at the structure of the rock.
Based on the structure of the rock at the level of the soil I found, scientists initially guessed how many years ago the fossil may have been. This rock layer of our world is actually like an album. It's the same thing to dig one level after another, and flip old photos page after page in an album. Can't believe it! Scientists have divided this leaf or soil and rock layer into several main classes. Some of these layers are Paleozoic, Mesozoic, and Cenozoic layers. By turning the pages of this album, I can go to the earth 500 million years ago in three layers of rock!
I gave the picture at 1 o'clock, now let's see it. I see three levels here. Below this is the Paleozoic layer. This means that the Paleozoic layer is the oldest of these three layers. It gives me a rough idea of what the world was like 500 million years ago. If I somehow find fossils at that level, they will be - reptiles, amphibians, fish and invertebrates. Fossils of this level existed on Earth 500 million years ago. But sadly no dinosaur pub nap at this level. Because dinosaurs have not yet come to earth. I will find dinosaurs at the upper level, the Mesozoic level. This layer is 250 million years old. This means that dinosaurs came about 250 million years ago. However you will not find any mammals at this level. The upper layer of their pub, the Cenozoic layer. We are now living above this level. This layer is only 65 million years old.
Anyway, we can see the memorable album of our world starting from the bottom and going up. I can understand how old the car is. This explains how the earth, along with its children, has evolved over time.
I have said a lot, I think I will be world famous by determining my age in this way, but there is a problem here too. That is, in this method an estimated age is found but the actual age of the fossil cannot be found. Since I could not find out the actual age with the first method, I have to take the second method now. Carbon dating method. It's a little complicated so everyone reads with a little mind.
Age can be determined through this carbon dating method. Which is a perfect method.
We don't know about the atomic structure of carbon before we know what carbon dating is. We know that all matter is made up of 3 basic particles - electrons, protons and neutrons. The number of protons, electrons and neutrons of each element is different. For example, the number of protons in carbon is 6 and the number of protons in nitrogen is 7. The carbon we are familiar with in nature is basically carbon-12. In other words, this carbon has 6 protons and 6 neutrons. But there are also carbon molecules in nature where the number of neutrons is 6. These carbon molecules are called carbon-14. One of the characteristics of carbon-14 is that they are slowly depleted. Through radioactive radiation, the number of protons changes from carbon-14 molecules and at one time carbon-14 molecules become nitrogen atoms. That is, if an object has some amount of carbon-14 molecules, the amount of carbon-14 of that object will gradually decrease.
Every animal has carbon in its body. Plants absorb carbon directly from nature by absorbing carbon dioxide, and those animals absorb nature's carbon by eating that plant. Most of this carbon is carbon-12, but it also contains some carbon-14. Therefore, carbon-14 is also present in the carbon in the fossils of animals. When scientists find a fossil, they examine the amount of carbon-12 and the amount of carbon-14 in that fossil. Earlier, the amount of carbon-14 was determined through beta counting. However, at present, scientists use the accelerator mass spectrometer to determine the ratio of carbon-14 and carbon-12 in fossils.
Since the amount of carbon-14 decreases all the time, the fossils that have less carbon-14 ratio are older. The half-life of carbon-14 is about 5730 years. In other words, if some amount of carbon-14 is taken, it will take about 5630 years for that carbon-14 to be eroded and become half. The time at which exactly half of the total atoms of a radioactive substance is lost is called the half-life of that substance.
When we die, carbon-12 and carbon-14 are in equal proportions. But later carbon-14 gradually decreased. And carbon-12 remains the same as before. If I could figure out the ratio of carbon-12 to carbon-14 in a fossil, I would know the age of the fossil. There is a formula for this.
t = [ln (Nf / No) / (-0.693)] x t1 / 2,
Here,
ln = Natural logarithm
Nf / No = Percentage of Carbon-14
t1 / 2 = Half-life of Carbon-14 = 5730 yrs
Now suppose you find a fossil that contains 10% carbon-14. Then the age of that fossil will be-
t = [ln (0.10) / (-0.693)] x 5,730 years
t = [(-2.303) / (-0.693)] x 5,730 years
t = [3,323] x 5,730 years
t = 19,040 years old
That is 19,040 years old fossil!
Just look at how many values are put in the straightforward just formula to determine the age of the fossil.
I still have no problem being famous ...
References: wikipidiea
I got to learn so much about those time . Thank you so much