There have been five mass extinctions since there was life on the earth. The first time happened in the Ordovician period 450 million years ago. Scientists speculate that the main cause of this mass extinction is environmental mutation, which led to 85% species extinction. The second extinction occurred in Devonian 360 million years ago, and marine life suffered heavy losses. The third mass extinction occurred at the end of Permian 250 million years ago, which gave dinosaurs a chance to develop and multiply. The fourth mass extinction occurred in the late Triassic 200 million years ago, and a large number of reptiles suffered heavy losses. The last mass extinction event was the extinction of dinosaurs 65 million years ago.
As can be seen from the above time, the time interval between these five mass extinctions is about 0.5- 1. 1 100 million years. Then according to this law, the extinction of dinosaurs has passed more than 60 million years. Will there be a new mass extinction event on earth?
Scientists have put forward a hypothesis about this matter: First, it is believed that the sun has a companion star named Revenge Star, which will periodically return to perihelion, but Revenge Star may disturb the long-period comet in the outermost layer of the solar system, resulting in a large number of whispers entering the solar system, and the earth may welcome asteroids or other celestial fragments of various sizes. This imaginary sun companion will return to perihelion every 26 million years, which may lead to the extinction of life on earth, but the time interval of 26 million years is inconsistent with many extinction events that have occurred on earth.
The second hypothesis is that some people think that the solar system may have different environments at different points when it orbits the Milky Way. For example, when the earth moves around the sun, there will be four seasons: spring, summer, autumn and winter. The solar system is located on the spiral arm of the Milky Way, about 26,000 light years away from the center of the Milky Way, and it will circle the center of the Milky Way once every 250 million years, but this is not consistent with the extinction events and cycles that have happened on the earth.
These extinction events on the earth are mainly caused by the sudden change of climate and environment and the impact of celestial bodies. Dinosaurs died out in an asteroid impact on the earth. However, after entering the modern society, human development has expanded wantonly, occupying the natural resources of many other animals and accelerating the rate of species extinction. So in the final analysis, human factors have the greatest impact on the earth's environment.
I remember when I was in high school, the physics teacher told such a story. A scientist, through calculation, said that a comet hit the earth at a certain moment in a certain month of a certain year, and people died, but others didn't believe it, but he was very sure that on this day, he fell asleep and waited for death. One day passed and the earth was safe and sound. He was puzzled, rechecked and found a wrong decimal point, with a difference of 108 thousand Li. In the 1980s, it was said that a catastrophe happened on the earth one day in 2000. At that time, someone really believed it and said it was dangerous. They also took out the money from the bank and ate and drank ... Isn't it all right now?
I think large celestial bodies are bound by gravity and cannot be out of orbit. Usually asteroids hit the earth. In the process of hitting the earth, most of them went through the combustion of the atmosphere and just fell to the ground as small meteorites. Even if they cause disasters, they are only local and cannot be global. It is also said that when all nine planets in the solar system run to one side of the sun at the same time and are on the same straight line, derailment will occur. I don't think there is such a possibility, because the time for the earth to revolve around the sun is constant and has never changed. Have they never been on the same side in history? This shows that the law of motion between celestial bodies will not change. What we are really worried about is the environment and resources on the earth. What needs people's efforts is to protect the existing living environment on the earth and develop renewable energy. Today's ecological environment has reached the point where it can no longer be polluted. If the carbon dioxide gas on the earth continues to increase, I am afraid that it is human beings who destroy the earth!
Accidents can happen at any time, but tomorrow or 10 thousand years later, no one looks up and waits for death. Isn't 2O 12' s theory of earth destruction a joke?
Those who go to work tomorrow should go to work, the old people should slip away, the students should go to school, and put their hearts in their stomachs. That's true, no one knows, they will be in another world.
At present, there is no conclusion about this. The last mass extinction occurred in the late Cretaceous, about 67 million years ago. Dinosaurs existed at least 200 million years ago, and dinosaurs existed at least 65.438+0.5 billion years. However, the existence of human beings is only 67 million years, and the history of civilization does not exceed 1 10,000 years. By analogy, mankind will not encounter catastrophe after10 million years. If we are optimistic, there will probably be no geological disasters in 100 million years. Humans have learned to use fire for hundreds of thousands of years, which is almost an instant in the history of the earth. We can't even imagine what human science and technology can achieve in five thousand years, let alone what human beings will look like in half a million years. But I don't think it was difficult for human beings at that time to resist the disasters we can recognize at present.
In this universe, a magical planet with life appeared, and in a short time, life filled the space, ocean and land of this planet.
We know that everything appears and disappears within the scope of conditions. Beyond this range, everything will change irrevocably, just in another form.
So how long can our planet remain like this?
Humans are afraid of death, especially extinction, but fear is useless. Fear of extinction is the last heartbeat before death. A nervous heartbeat.
Magical universe, and human beings have explored the heartbeat of the universe, groping for the universe, the universe is infinite, and the endless universe is unimaginable to human beings and unimaginable to human beings. Endless little disappointment, also can't imagine.
Then humans also found that the smallest atom is also a universe, endless.
Then the universe has a small universe, a big universe, from small to large, from large to infinite.
Does the universe have an end?
Don't!
There is a big universe outside the big universe, and there is a bigger universe outside the big universe until it is endless.
There is a small universe in the small universe until it is endless.
From the small universe to the big universe, there are countless levels, and our earth, the Milky Way and the stars and clouds in the sky all belong to the same level.
What level of universe does our universe belong to?
Humans also found that the smaller the universe, the faster it changes, and the faster it changes from one process to another.
The frequency from birth to death is also high.
Some tiny electrons have short lifetimes.
The universe changes very slowly, and the changes in billions of years are not significant and can't be detected.
The small universe produces cosmic nebulae, galaxies and the earth, which fill the space inside these planets.
Their respective changes created everything in the universe and created everything in the universe.
The small universe exists in the big universe.
Our universe exists in a big universe.
This bigger universe exists in a bigger universe.
But these universes are not eternal, they are all levels of the universe, and they are the stages of every change of these levels.
But the infinite universe is eternal.
In our universe, we see constant changes.
On our planet earth, we see spring flowers and autumn fruits, spring grows and autumn declines, and vegetation cycles in autumn.
We have witnessed the death and birth of countless small universes.
We are outside their universe and watch them change a lot.
And we can't see the changes in our outer universe, because the life span of our universe is shorter than theirs.
Just as humans can see the death of vegetation, vegetation cannot see the length of human life.
We are in such a cosmic level, how long can our earth survive? It is limited.
As we said, the boundless universe is eternal, but all levels of the universe are constantly changing.
They are all changing in their own form under the conditions of birth, illness, death and internal and external factors.
They may become one way or another.
One day, human beings will disappear in the vast universe, but under certain conditions, in a certain corner of the universe, life forms like the earth will be produced and will flourish in a certain corner of the universe.
How long will life on earth be extinct?
The manpower is incalculable, but the road is long, with Xiu Yuan Xi and Xiu Yuan Xi.
According to the Bible, because the world is far from God, it is extremely sinful. The flood destroyed the world once, leaving only eight people in Norway. There are seven pairs of clean animals and one pair of unclean animals. God put people and animals in the ark.
Now it's the last time,
When will it end? According to the Bible, only God knows. God created everything in the universe for only 1000 years.
The whole earth will never go extinct. What if it's extinct? Human beings are the strongest and unyielding advanced animals, with tenacious vitality in front of nature!
The vast universe, colorful, world science, is this small step, the unknown answer, still have to study. The life universe, the earth is one, the animal earth, the earth environment, the adaptation to animals, the height of animals, the struggle of each site has never stopped. Speaking of the sky, the bright spot at night, the size of the bright spot, and the height, it seems to be very stable. In fact, it is moving, and the whole universe is moving. For example, water is flowing, like the hydrosphere, resulting in today's cosmic black hole. My guess, my opinion, my imaginary statement, the time to play, New Year's Day and Spring Festival are coming!
We have only scratched the surface of the secret of the operation of the universe. We have not deduced the evolution of the universe from the environmental temperature and the three states of objects, nor have we studied the physical properties of vacuum and air pressure. Simply put, air pressure can make an object full of various gases, and vacuum will make the gas suck out the density of the object. The lowest temperature in the universe is-27 1.5 degrees. At this temperature, all gases are solid, and the most living oxygen turns blue when it exceeds 240 degrees. Because of this, the glaciers in the North and South Poles cannot be submerged. The fresh water of the earth becomes gas, ice particles float into space, and carbon dioxide becomes sweet ice. The earth's submerged asteroids collided with the earth, causing changes in the earth's plates, and changes in the earth's magnetic field made things change. It is also evolving now. This is how species extinction and earth evolution happened in the past! Isn't it? Tree jade, tree fossils, the bitter fruit of fish and birds, and a large number of traces left by mountain soil erosion all illustrate this point!