After human beings walked out of the earth, we saw the vast universe. Since then, people have been thinking about: Does extraterrestrial life exist? Are humans alone in the universe?
From the perspective of the universe, it is difficult for us to deny the existence of extraterrestrial life. If extraterrestrial life exists, what are they like? Mankind’s exploration of alien life is mainly based on earth life as a template. It may seem to many people that the existence of life on the earth means that an environment like the earth can give birth to life, which is a condition for the evolution of life.
So is this narrow perception correct? The earth’s environment can give birth to life, which shows that other ecological planets that use the earth as a template are also likely to have life. In fact, we don’t have to doubt this. This is why scientists have been searching for terrestrial planets that are very similar to the Earth.
If we find a planet that is very similar to the Earth in the universe, then this planet is likely to be a living planet, and it has also given birth to its own life and even an intelligent civilization. And more importantly, this kind of life planet is also highly likely to meet the conditions for human habitability.
So are the various life in the universe have the same requirements for the environment as life on earth? It may not be necessary. It is necessary to know that under the environment of the earth, life in different places will be different. Surface creatures, marine creatures and underground creatures will also have different requirements for the surrounding environment.
Of course, regardless of the different needs of life on earth for the ecological environment, their needs in general directions are the same. For example, they are all carbon-based organisms, and life cannot survive without water. Life on earth has a common survival requirement, that is, water. Even the creatures living in the ground cannot survive without water.
In our view, water is the source of life, so does all life in the universe need water for their survival? No one can give this answer at present. Now we only know that oxygen is not necessarily necessary for life. There are also organisms on the earth that do not need oxygen. They live underground.
Different planets have different environments, so the materials needed for the birth of life will also be different. For example, Titan in the solar system also has liquid lakes on it, but it is composed of methane. Scientists believe that there is a high probability that there will be life on the surface of Titan. If there is life, then what they need to survive is methane, not water and oxygen.
It can be seen that water and oxygen are the source of life, but relative to life on earth, there may be countless life planets in the universe, and different life may have different material requirements. Some life needs water and oxygen to survive, but these two substances may be poisons to creatures on other planets.
What we have discussed above is only the needs of life for the environment, so let’s discuss another more interesting topic: that is the size of biological individuals. A friend once asked such an interesting question: Could there be giant creatures larger than planets in the universe?
Maybe in the eyes of many people, no matter how big a creature is, it cannot be bigger than a planet. If so, isn’t the size of this creature hundreds of millions of times that of a human being? In fact, to understand this, the most important thing is to understand the origin of life.
So how does life come? Let’s take the earth as an example. The most primitive life on the earth was born 4 billion years ago. Before that, the earth was inanimate, with only non-living substances, that is, various elemental substances such as carbon and sulfur. It is these non-living substances that formed macromolecules under some special actions, and finally evolved into primitive single-celled organisms.
Life originated from non-biological matter, that is, various elemental matter combined and evolved under a certain mechanism. And what exactly is this evolutionary mechanism? It is still unclear. As for the origin of life on earth, scientists have given the view that non-living matter evolved into the simplest life under the influence of lightning and other factors 4 billion years ago.
Is this interpretation correct? We do not deny that life originated from non-living matter, but how non-living matter is transformed to the level of life may not be as simple as we thought. Scientists have also tried to convert non-living matter into life through artificial creation of various conditions in the laboratory, but none of them succeeded.
The transformation of non-living matter into living matter can only be done by nature at present. What is the operating mechanism of it is still an unsolved mystery. The environment of different living planets may also be different, so the mechanism behind the transformation of non-life into life is believed to be similar. We must know that we are all in the same universe, and the basic laws of physics must be followed together.
Although we do not know what the rules behind the transformation of non-living matter into life are, we all know that life is transformed from non-living matter. In theory, as long as it is an area rich in various material elements, it is satisfied. Given certain conditions, life should be born.
If this is the case, then the environment required for life may not necessarily be the planetary environment. Life may also evolve from some large environments in the universe. For example, in the nebula, each nebula has abundant material elements, especially when supernovae have occurred. The nebula after the eruption has a lot of heavy metal elements.
After having the conditions for the rich elements, as long as there are certain rules, then life can be born. We don’t know what this kind of rule is, but we can make a bold guess, that is, some unknown and mysterious energy. It is a special kind of energy that promotes the transformation of non-living matter into living matter, thereby evolving life.
If this conjecture is true, then it is possible that life can be born not only on the planet, but also in the cosmic nebula. If life is born in a nebula, it is possible that the size of the organism is larger than a planet. We must know that some nebulae are very large, and the range of tens of light-years is not a big deal.
Some people may have said, if there is a giant creature as big as a planet in the universe, what will it eat for food? We must know that the larger the creature, the greater the need for food. It is difficult for us to imagine a creature larger than a planet. What will it feed on?
In fact, this consideration is completely superfluous. What does living beings eat for? It is not that energy is needed for the maintenance of organisms, and energy is the least lacking in the universe. Let alone the various visible substances, the mysterious dark matter and dark energy account for the vast majority.
Therefore, we can make a bold guess: if there are giant creatures larger than planets in the universe, their food may be dark matter or dark energy. Only this powerful energy can satisfy the energy of this star behemoth. demand.
Of course, these are just our guesses. If there are creatures larger than planets in the universe, then humans will be able to see them one day in the future. Perhaps when we see this giant starry sky, it will completely change our understanding of the origin of life.