This paper takes part in the series essay competition of “great science” of Recordunkown.
Four billion years ago, the earth, an ordinary blue planet, gave birth to early life. Since then, the earth has become a beautiful life planet. After a long evolution and continuous growth, simple life finally gave birth to intelligent human beings millions of years ago.
It can be seen that the birth of human beings is not easy. After billions of years of long evolution and suffering, life on earth finally sublimates and gives birth to intelligent life. In the long history of life evolution, mass extinction is definitely the biggest disaster for life. If we are not careful, the earth may lose the breath of life completely and become a desolate planet like Mars.
Fortunately, the earth itself has a very strong ecological recovery ability. Every mass extinction will leave the seeds of life to the earth, and then these seeds will continue to evolve and grow to the present. Among the five mass extinctions experienced by the earth, the fifth mass extinction, also known as the dinosaur extinction, is the most concerned by scientists.
The reason why scientists are very concerned about the extinction of dinosaurs is that before the birth of human beings, there was a very powerful race dominating the earth for 160 million years. They were tall and domineering dinosaurs. From the dinosaur fossils found by scientists all over the world, we can see how huge the dinosaurs were at that time. They were not only tall and powerful, but also had a large number, with a conservative estimate of more than 10 million.
What’s more, dinosaurs were all over the world at that time. If it wasn’t for the subsequent mass extinction, dinosaurs might have been able to become intelligent life after some time of evolution. In that case, there might have been no human birth. You know, in the biological world at that time, dinosaurs were the absolute overlord. Once they had wisdom, they would never allow the birth of a second intelligent race.
Unfortunately, maybe God doesn’t want to see dinosaurs become intelligent life. 65 million years ago, an asteroid hit the earth and killed the dinosaurs. Maybe many people think that after the asteroid hit the earth, the time of dinosaur extinction is very short. Some people think that dinosaurs will be extinct in a year. Is that true?
The power of asteroid impact is very great. If a planet level celestial body hits the earth, it is possible for dinosaurs to die out instantly. The impact power of that level is beyond our imagination. However, if the earth really encounters the impact of celestial bodies that instantly destroy dinosaurs, then the earth’s ecology will be completely destroyed and there will be no possibility of recovery. Naturally, there will be no subsequent life recovery and no human birth.
Since the earth’s ecology can still recover after the dinosaur mass extinction, the diameter of the asteroid that hit the earth at that time was not too large. Scientists estimated that it was an asteroid with a diameter of 10 km. An asteroid impact of this level will release the explosive power of 50 million tons of hydrogen bombs equivalent to two million pieces.
The shock produced by this impact will reach deep into the earth’s crust, causing global volcanic eruption. After the asteroid hit the ground, the huge energy generated instantly can make the surrounding materials instantly turn into ashes. If there were dinosaurs around at that time, they would surely go up in smoke. Most of the dinosaurs will not be greatly affected in a period of time after the impact, so how did the dinosaurs die out? How long did it last?
In fact, the real cause of dinosaur extinction is the volcanic eruption after the asteroid hit the ground. As we all know, volcanic eruption will produce a lot of volcanic ash, the volcanic ash, gas and dust material will cover the sky, making the earth into a gray. If it’s just a small volcano eruption, naturally it won’t have much impact.
However, the impact of an asteroid with a diameter of 10 km will produce a very large crustal vibration, which may lead to a global volcanic eruption. At this time, a large number of high-temperature debris, gas and dust will completely block the sun.
As we all know, the sun is very important to the life of the earth. It can be said that it is the mother of the life of the earth. If the earth does not see the sun for a long time, the photosynthesis of plants will not be able to proceed, and a large number of plants will die at that time. Without plants, herbivores will continue to die out, and herbivorous dinosaurs will be the first to die out.
Carnivorous dinosaurs will also lose their food supply because of the mass extinction of animals, and then they will gradually become extinct. Of course, carnivorous dinosaurs lasted longer than herbivorous dinosaurs, because dead animals were still edible. Therefore, the cause of dinosaur extinction is asteroid impact, and the final real extinction of dinosaurs is actually food.
Any life without food will be extinct, just like dinosaurs, so will human beings. In particular, dinosaurs, a large animal, have a huge demand for food. The larger the animal, the less hungry it is. A month’s food shortage can make many dinosaurs die. Of course, this state of slow starvation will last for a long time, not as people think it will be extinct in a very short time.
Scientists speculate that after the asteroid hit the earth, dinosaurs may continue to persist for at least several decades before extinction. The reason for this is that there is a certain basis, which is the shielding time of the dust produced by volcanic eruption to the sky. According to the research of scientists, if it is a global volcanic ash shelter, it will last at least several decades before it can completely dissipate and see the sun.
Of course, some people think that dinosaurs were extinct by freezing. After the asteroid hit the earth and triggered a volcanic eruption, the temperature of the earth dropped sharply without the sun’s irradiation, thus ushering in the ice age. A large number of creatures were frozen to death. Dinosaurs were completely extinct without freezing because they were not blocked by thick hair. So is this perception right? It’s not exactly true.
Volcanic eruptions block the sky, and will indeed make the earth’s temperature drop sharply for a period of time, but this decline will not last. And then it will slowly rise, which may be much higher than the ambient temperature before the eruption. The reason is that volcanic eruptions will bring a lot of carbon dioxide, which will cause a serious greenhouse effect, so that the temperature of the earth will rise.
Therefore, 65 million years ago, after the asteroid impact, the temperature of the earth may have dropped first and then increased. We can see this by looking at the sister planet Venus. Venus is a purgatory planet with a surface temperature of more than 460 degrees Celsius. The reason why it has such a high temperature is that 95% of the atmosphere is carbon dioxide.
And now the global temperature is rising year by year, which is also caused by the rising concentration of carbon dioxide in the atmosphere, but the carbon dioxide comes from a large number of industrial production. If the emission of greenhouse gases is not effectively controlled, the temperature of the earth may rise to a point that we fear in a few decades. At that time, the earth may usher in a new crisis of mass extinction.
Guys, what do you think of this? Welcome to leave a message below to discuss and express your opinions.