Modern science believes that our universe was born 13.8 billion years ago. 13.8 billion years ago, an singularity exploded. The singularity is a point with infinite mass, infinite energy, infinite density, infinite heat, and infinite volume. After this point exploded, the universe quickly expanded to the surroundings. After 13.8 billion years, the universe expanded to what we see now. There are many days in the universe. Bodies, such as stars, planets, comets, asteroids, neutron stars, etc. are all celestial bodies in the universe. Our earth is a planet in the solar system. There are eight major planets in the solar system, namely Mercury, Venus, Earth, Mars , Jupiter , Saturn , Uranus and Neptune. There is also a Pluto outside Neptune.
Pluto once belonged to a planet, but scientists believed that Pluto was too small in size and mass, so they kicked Pluto out of the ranks of planets. Currently, there are only eight planets left in the solar system. Among the eight planets, the Earth is the planet with life. Human beings are the most intelligent life on Earth. Human beings have begun to explore the mystery of the world since their birth. Now human beings are able to go out of the earth to explore the universe, which shows that human technology is still very fast. When human beings walk out of the earth to see the universe, human beings’ curiosity is attracted by the vastness of the universe. Human beings want to know how big the universe is? In addition to life on Earth, is there any alien life in the universe? With these questions in mind, human beings embarked on the road of exploring the universe.
45 years ago, American scientists launched Voyager 1 probe outside the solar system. The purpose of launching this probe was to let it fly out of the solar system and explore the mysteries outside the solar system. At that time, scientists installed a gold record on the Voyager 1 probe. This gold record contains the location of the earth, the sound of humans, the sound of nature, the sound of animals, etc. Scientists believe that if Voyager 1 is captured by aliens in the universe, then aliens may find the earth based on the information above, but now it seems that we are thinking too much, why do you say so? Because the Voyager 1 probe has been flying in the universe for so many years and has not flew out of the solar system, scientists have calculated that according to the flight speed of the Voyager 1 probe, it will take at least tens of thousands of years to completely fly out of the solar system.
Although the Voyager 1 detector has not yet flew out of the solar system, it has sent back many precious photos to humans during its flight. Once, the Voyager 1 detector took a photo 6.4 billion kilometers away from the Earth. After this photo was sent back, many people were very surprised to see it because scientists could hardly find the location of the Earth on this photo. After calculation, scientists found that the pixels of the Earth in the photo were only 0.12 pixels. Many friends who were studying photography should know how big 0.12 pixels are, which is equivalent to a piece of white paper. They gently tapped it with a ballpoint pen. What scientists did not expect was that the Earth we are proud of actually seems so small in the universe.
Later scientists called this point a dull blue dot. Even the famous physicist Carl sighed after seeing this photo: Our mood, our pride, and the feeling of having a special status in the universe are all challenged by this dull blue dot. We are really powerless in the face of the universe. The universe is really too big. The Voyager 1 probe has now flown 23.1 billion kilometers in the universe. For humans, this is already a very long distance, but for the universe, this is negligible. Currently, humans have observed that the range of Milky Way galaxy has reached 200,000 light years, and the Milky Way is just a small galaxy in the universe.
The range of the universe is now 93 billion light years. This is not the entire range of the universe. The universe may be larger than we imagined. How big is the universe? At present, scientists are also actively exploring, but now scientists generally believe that in addition to life on Earth, there must be alien life in the universe, because there are too many celestial bodies in the universe. Take our Milky Way for example, in the Milky Way, there are about 100 billion to 400 billion stars and 40 billion to 100 billion planets. Among so many planets and stars, is it only the planet Earth that gave birth to life? This is obviously impossible. Scientists believe that the earth can give birth to life because the earth meets the three basic conditions for the birth of life.
The three basic conditions are suitable temperature, sufficient air, abundant water resources, thick atmosphere, and powerful magnetic field. If a planet can meet these three basic conditions, then the possibility of this planet giving birth to life is very high. Seeing this, many friends may have a question, that is, why must scientists search for alien life according to the characteristics of life on Earth? According to scientists' research, we can know that the life on the earth is carbon-based life. In addition to carbon-based life, there should be silicon-based life , sulfur-based life, amino- life, etc. However, so far, we only know that life on the earth is carbon-based life. Through research, scientists have found that all known life on the earth have the same basic biochemical tissue and genetic code, and use the same code to form the same amino acid . This shows that all life on the earth comes from the same ancestor, and scientists call this ancestor LUCA.
So why did life on Earth choose carbon-based life instead of other life? After research, scientists have found that carbon elements are stable. In our human body, 97% of the elements are composed of six elements, namely carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur, and a small number of other elements, such as calcium, iron and zinc, etc. Among the organisms on earth, oxygen is the highest proportion. However, oxygen element cannot exist in the form of a single substance. Water has a role in stabilizing cell structure and function, so scientists regard life on Earth as carbon, and carbon atom is the most stable element. I believe many friends should know that in chemistry, the structure that makes up molecules is atom .
. A special chemical bond is needed to influence each other. This chemical bond is a hook. In general, atoms with a large number of hooks have the strongest stability because they can hook other atoms. For example, hydrogen atom has a chemical bond, so it can hook only one atom, and hydrogen atom has two chemical bonds, so it can hook two atoms at the same time, and carbon atoms have four chemical bonds, so it can hook four chemical bonds at the same time. From this point we can see that carbon atoms are the most stable, and life on Earth happens to be carbon-based life, so scientists are currently looking for alien life according to the conditions of the origin of life on Earth.
As of now, scientists have not discovered alien life in the universe, but scientists have discovered planets that are very similar to Earth. Among them, Kepler 452b is called the twin brother of the Earth by scientists. The time for this planet to rotate one circle is about 385 days, while the time for an earth to rotate one circle is about 365 days, which means that the time for this planet to rotate one circle is about 20 days longer than the time for the Earth to rotate one circle is about 20 days. In addition, scientists have also found that the mass, light, etc. of this planet are very similar to that of the Earth.The size of this planet is 1.6 times larger than that of the Earth. There is also a liquid ocean on this planet. We all know that water is the source of life. The earliest life on Earth was born in water. Since there is a large amount of liquid water on the planet Kepler 452b, will there be life on this planet?
Because this planet is very far away from the earth, humans are currently unable to determine whether life has been born on this planet. So far, scientists have not discovered alien life in the universe. Seeing this, many friends may have a question, that is, why we have never found alien life? Some people speculate that the fundamental reason why humans have not found alien life is that human technology is not developed enough. Because we cannot directly log on to other planets, we can only observe through the astronomical telescope , which greatly reduces the chance of discovering alien life. After all, astronomical telescopes can only see the approximate location of celestial bodies and cannot see the real situation on the planets. This is one of the fundamental reasons why humans did not discover alien life.
In addition, our solar system is in a remote area of the Milky Way, and there are not many celestial bodies around it, so there are not many alien life. If we can fly to the central area of the Milky Way, then we may be able to discover alien life. The editor believes that human beings can walk out of the earth to explore the universe in just a few thousand years, which shows that human science and technology are developing very fast. In the future, with the continuous progress of human science and technology, we will definitely be able to find alien life in the universe. The editor hopes that human beings can realize their dreams as soon as possible. Do you have anything to say about this?
