Carbon – based life is the only form of life found so far. All living species on earth are carbon – based.
Intellectuals have also raised the conjecture of life on silicon ( for details, I will introduce it in the next article ). However, it has not been proved to exist. If silicon-based life really exists, its natural environment is hotter than the earth’s surface, and each looks like a big stone.
Apart from carbon-based life and silicon-based life, is there any possibility of other life forms in the universe?
Yes. For example, amino life. However, before discussing the possibility of amino life, let’s learn the question of ” why all life needs water”. Knowing this problem, you will know how likely amino life is.
Water, considered by scientists as the most suitable medium for all life on earth, is used to transport nutrients and discharge waste materials.
Water has several advantages.
First, it is easy to form and the materials that make up it are convenient. Because the molecular formula of water is H2O. H is hydrogen, and hydrogen molecules are the most indispensable in the universe. O is oxygen, and oxygen atoms rank first in the universe. Water is easy to generate in the universe, with hydrogen and oxygen atoms, plus a certain temperature.
Second, the temperature difference between the freezing point and boiling point of water is relatively wide, at 100 degrees Celsius. The freezing point of water is 0 degrees Celsius and the boiling point of water is 100 degrees Celsius, so the width of this temperature gap is 100 degrees Celsius. In the earth’s surface environment, the temperature range of most life is 0 ~ 100 degrees celsius, within which any important chemical reactions are allowed to occur. In order to maintain existence, life must include a series of important chemical reactions so that energy and nutrients can be circulated and exchanged.
Third, water has a density reversal before solidification. Water has a high density in a liquid state, but its density decreases when it solidifies, that is, when it is solid ice. After the density is reduced, the ice can float on the water surface. If the density of water does not reverse before solidification, the ice will sink under the water and the rivers, lakes and seas will freeze as a whole. A frozen world is obviously not suitable for life.
Some people suggest that ammonia can also be used as a liquid medium for exchanging nutrients in the body like water. Then, there may be amino organisms.
In the fantastic artistic imagination of some sci-fi works, on a certain planet, its orbit is far away from the stars, resulting in extremely cold temperatures ranging from tens of degrees below zero to 100 degrees below zero. In such a harsh cold environment, there is a strange life called amino life. It is presumed that their metabolism rate is very slow and their skin is very thick. Contrary to silicon-based life, the intelligence of amino life is generally not high, similar to worms. They have a long life, but they are fragile. Perhaps they need to rely on underground radioactive rays to survive.
However, is there a great possibility of amino organisms?
Let’s see, ammonia is different from water. It lacks advantages, that is, it cannot reverse its density around the freezing point like water. When liquid water is cooled, its density decreases. When ammonia is cooled, its density does not decrease but becomes solid. Therefore, the planets where amino life exists are often frozen as a whole and lack liquid that can exchange nutrients.
Therefore, in order to survive the life of amino, we must find ways to stay in a suitable temperature environment to keep ammonia liquid. Life is possible only when there is liquid. However, liquid ammonia must be several tens of degrees lower than the temperature of water. If the temperature of the environment is too low, the metabolic rate is also very slow. If the metabolism is slow, the energy that can provide biochemical reactions will be correspondingly reduced.
Therefore, scientific principles determine that the probability of the existence of amino life in the universe is very small.