Chapter 16 first quarter

Biology, especially paleontology, which I specialize in, is full of specus, omissions, and perfunctory.In fact, the skeleton of this discipline is still incomplete and chaotic, and it is completely unaware of its own status quo, like a sleepwalking patient, fumbling forward.The division of subjects is rough and careless, the blind reliance on and inheritance of precedents is shocking, and the wind of not thinking about making progress prevails. Today, I can relate to those words of Isaac Newton. "The undiscovered truth unfolds in front of me like a vast ocean." Until today, in the 1930s, as a discipline, paleontology clearly lacked the background and talent required for progress.To put it mildly, it needs the efforts of future scholars in order to make a breakthrough.However, as far as the current situation is concerned, this subject may remain lackluster forever, staying at the level of middle school textbooks, and unable to keep pace with other subjects.Obviously, the crux of the problem should be attributed to the laziness of scholars.

If it is ordinary biology, you can use the method of natural history to conduct in-depth observation of the current situation and draw a biological map.However, this is not enough for paleontology, and we should be aware that inquiry in this discipline requires thinking differently than we do in biology or medicine.This is because biology or medicine only deals with the status quo, while for paleontology, the organisms that are its research objects have lived for a very long time, comparable to the age of the planet earth, and the earth itself In the meantime, earth-shaking changes have taken place, and after continuous changes, it has changed beyond recognition.

The surface of the stage carrying the creatures under investigation has gone through vicissitudes and changes, and has already changed into another appearance, but people are only satisfied with piecing together and processing a little bit of bone fossils excavated from the soil, and then relying on imagination Drawing recovery maps, this style is lazy.This is because the biological form is originally the product of adapting to the radically changing living environment, and it is constantly making compromises in the form of thinking about change, which is what we call evolution.It is the causes of these evolutions that researchers must uncover.This is where the soul of the discipline lies.

From this point of view, the history of life should keep pace with geology and astronomy, absorb the latest achievements of these peripheral disciplines one by one, and finally form a set of its own theory.To put it to the extreme, it is not unreasonable to regard paleontology as a part of astronomy, geophysics, or geology.This is because the life that can best describe the environment on a certain planet is the life that has multiplied on this planet for a long time.Conversely, it can also be said that the observation of extraterrestrial life is the core part of astronomy. Like Mars, the planet Earth has a unique environment. For life on other celestial bodies, the environment on Earth is perilous.If a scholar wants to find out what life on Earth looked like 230 million years ago, his search is tantamount to trying to see what life on Mars looked like.At this time, there is no reason for biologists not to work hand in hand with astronomers.

Creatures living in the deserts of Mars survive by constantly adapting their bodies to the unique environment on the planet called Mars.Although it no longer exists, billions of years ago, oceans, beaches, and thin oxygen probably existed on this planet.If any living things have survived to this day, it is the result of their "begging for perfection" to change themselves in the cruel history of evolution and extinction.Likewise, the Earth's surface 230 million years ago may have been much stranger than we imagined, far removed from the present surface.The Earth at that time may have seemed like a completely different planet, and everything was very different from the Earth today.

The creatures living in such an environment are naturally strange.If it can be regarded as a mystery, then the key to decryption should be hidden in the differences between the earth's environment at that time and today and the deep-seated reasons for these differences.If we can understand exactly these differences and why, we may understand that the shape of paleontology is not a mystery, but a unique and inevitable destiny.This is the real way of learning.However, this question has never been raised with confidence in paleontology.It has to be said that this is a kind of self-styled and disgustingly low-level blindness.

The organisms on the earth have evolved from cyanobacteria to the era of higher organisms through the process of evolution. Even from the beginning of the Mesozoic Era when reptiles, mammals and amphibians co-existed, life has a long history of 230 million years .The age of dinosaurs went through the Triassic, Jurassic, and finally the Cretaceous. This period alone lasted a full 160 million years.By comparison, we humans and chimpanzees diverged from our common ancestor only a few million years ago. The emergence of Homo sapiens, the era of clan wars that arose at the same time as farming, and the beginning of the era of religious sacrifices to alleviate bloody conflicts, all of this could not be earlier than 12,000 years ago.It was only four or five thousand years ago that human beings possessed words and symbols, and could write their own history. If we look at the long history of life on earth as a whole, the history of human beings having wisdom is just a snap of the fingers.

Only for us humans, because the evolutionary time is extremely short, we can still ignore the drastic changes in the universe.However, the probability that the entire history of life on the surface, which is tens of thousands of times longer, is not affected by astronomical events is zero.Even if we only take the age of dinosaurs as an example, in the time span of 230 million years after the Mesozoic Era, the probability of life on earth being profoundly affected by the operation of the universe is 100%.The most important part of paleontology is hidden in these deep information of astronomy.

In the vast universe, conflicts are everywhere.After the big bang, the history of the universe is a history of various conflicts.The most domineering element in the universe is gravity.Only gravity can warp space, warp time, and absorb light.Not only that, from the collisions between small meteorites to the collisions between large galaxies, and even the collisions between neutron stars that create cosmic black holes, all objects in the universe are within the influence of gravity. No matter how big or small, all stars in the universe cannot escape this trajectory. They are attracted to each other under the action of gravity, and finally collide head-on when the balance of this wrestling force is broken.Although the vastness of space makes frontal collisions between stars extremely rare, any object has its own gravitational force in the cosmic space, its own gravitational circle and the critical point of "power".

If some other object happens to move to this point, it will affect the path of the other object even if the collision does not happen immediately.Usually, this kind of influence is at best to make the other party change its orbit, but sometimes, it will also push the other party onto a huge elliptical orbit that revolves around itself.And most of these orbits are actually a kind of buffer, that is, it makes the other party fall against itself after the passage of years or hundreds of years. Most of the asteroids that hit the Earth came from the ring-shaped asteroid group between Mars and Jupiter.These stars are just fragments of rocks, they are not big in size, even counting the entire group of asteroids, their volume is not even half that of the moon.But, knowing that their onslaught, night and day, ten times faster than a rifle bullet is a sure-fire threat to any planet.

Like other planets, the rocky chunks that make up the asteroid swarm orbit the sun, but their orbits are slightly different.Therefore, although the distance between each other is wide enough, they sometimes collide and kick each other out of the orbit.If the kicked out guys are traveling in a direction that inappropriately overlaps with the earth's orbit, they will pose a threat to life on the earth. Among the major planets in the solar system, Venus is the most worthy of special mention.The second-closest star to the Sun is quite the maverick.Except for Venus, other planets in the solar system, including the sun, all rotate in the same direction, but Venus rotates in the opposite direction.This puzzle has long puzzled astronomers. In my opinion, the reason why Venus is like this is because it has been hit by an unusually violent asteroid.In the distant past, countless asteroids collided with Venus, and the impact angles were all small angles opposite to the direction of rotation. Therefore, the impact may first force Venus to stop its rotation, and then make its rotation The direction is reversed. This kind of imagination may belong to the imagination, but other than that, there is no other way to explain it.The impact of stars is what can have such a strong impact on planets.Due to the impact of the collision, the planets can easily change the angle of the axis of rotation, causing the poles to shift, and even the direction of rotation has changed.Still, it's better than being knocked apart and reduced to being part of a group of little stars.The so-called universe is such a world, which creates such "sensation" all the time. An astronomer once said that, in fact, our earth has also faced a hail of bullets from countless asteroids, large and small, since its birth.It is said that only medium-sized asteroids with a diameter of more than 200 kilometers have hit the earth 30 to 40 times, and large celestial bodies with a diameter of more than 500 kilometers have also hit the earth at least five times. The language description sounds mediocre, but every impact of this scale is enough to put the earth in jeopardy.At least one of them shattered the earth, and a small piece of it flew into space, where it began to circle around the satellite orbit, attracting debris and dust from its surroundings, and after gathering together, it formed the moon. The planet that collided with the earth at that time belonged to such a situation: it was about the size of Mars. Running on a trajectory to collide with the Earth.At this time, if there are living organisms on the earth, they will naturally be wiped out, and after the earth cools down and the dust settles, the evolution process will be restarted from the origin of life. The earth continues to suffer countless damages caused by falling rocks with a diameter of about 100 meters.According to surveys by geologists, the most recent giant rock fall occurred in Siberia in 1908, an event known as the Tunguska explosion.At that time, a rock with a diameter of about 90 meters fell from the sky, causing a big explosion and fire in the Siberian forest.Fortunately, the place where it fell was uninhabited, so there was no danger. If it fell in a city, the residents in the city would not survive. The frequency of meteorite falls of this size is about once in a hundred years.Fortunately, 70% of the earth's surface is ocean, and most meteorites are buried under the sea.Even if it falls on land, it is often a sparsely populated mountainous wasteland.But what is worrisome is that there are fewer and fewer mountains and wastelands. Once this happens in the future, the consequences will be unimaginable. Falls of small meteorites are an almost daily occurrence.Although most of them burn up after friction with the atmosphere and do not fall to the ground, there are always a few times a year when rocks about the size of a car rush into the Earth's atmosphere, burning what remains Parts of it fell to the ground as meteorites. Moreover, about every 100 million years, an asteroid with a diameter of about ten kilometers will collide with the earth.Every time a collision of this scale would cause earth-shattering changes on the surface.The raging fire spread around the center of the crash site, turning the earth into a fiery purgatory, and the surface fragments that were bounced into the stratosphere or even space by the impact force gradually fell back and re-injected into the sea of ​​flames on the surface. Due to the fire and high temperature, all the plants in a large area around the crash site died, resulting in the reduction of oxygen on the earth, changes in the composition of the atmosphere, and a devastating blow to life forms.The temperature is getting lower and lower. Even if the dust on the surface has settled, the dust caused by the impact of the meteorite will cover the earth's atmosphere and keep the sunlight out.As a result, the surface cooled abruptly after reaching the appropriate temperature, and the ice age came as expected.The cycle of life being wiped out like this, and then starting all over again has happened more than once on the earth. However, the frequency of such disasters can be said to be a kind of luck among misfortunes for the earth.Some astronomers believe that even if the planets anywhere outside the solar system have conditions suitable for the existence of life similar to the earth, as mentioned above, due to the extremely intensive attack of asteroids, the organisms on them are still in the form of cyanobacteria. , or at most the stages of amphibians are all dead, and have to return to the origin of life again and again. In this way, it becomes an impossible task to reach the stage of higher organisms like human beings.In the solar system, the frequency of the earth being attacked by asteroids is extremely low. Thanks to it, the earth has obtained a long and stable evolution time, making it possible for human beings to appear on the stage. A big reason why the earth is so blessed is that, on the outer side of the earth, closer to the sun, it guards a large planet with a strong gravitational field-Jupiter.Jupiter's gravitational field can affect its surrounding range of 400 million kilometers.The massive planet interfered with the rogue molecules that bored into its gravitational field, changing their orbits and either kicking them out of the solar system or crashing them on its own surface. Even if these invading wandering molecules can break through Jupiter's gravitational field, they cannot escape the fate of turning in circles along a flat elliptical orbit under the action of the sun's gravitational field.In this way, because they have to pass by the sun many times, the probability of them being captured by the gravitational field of the large planets in the relatively inner position of the solar system will definitely not be too low. The gravitational field of Jupiter is a protective umbrella, which can intercept the asteroids that break away from the orbit of the asteroid group and go straight to the earth or the planets that invade from outside the solar system, reducing the frequency of asteroids falling to the earth.If Jupiter does not exist, the earth will suffer the impact and fall of large asteroids once every fifty years, and creatures will not even dream of obtaining advanced intelligence.