3.1 Life on Earth

Life on Earth can be generally divided into the life of organisms living in the soil, water or air, in other words on the land and above it. Each of those organisms has some characteristic features restricted by the environment in which it lives, and simply cannot survive in some other environment without additional means. We can hardly imagine a dolphin leaping on the ground and learning to drive, or a human swimming and surviving for a long time in water, catching fish with bare hands and sleeping on waves. With the help of additional technical achievements, such as diving suits or submarines, humans manage well in the water. Thus, they have become acquainted with hard-to- reach depths of the sea and found there specific organisms that are accustomed to the high pressure ruling in the ocean depths.

Human discoveries and knowledge gained on Earth led to explorations beyond our planet. Humans transited from the air into the space. Beyond the living conditions on Earth, they must have special technical equipment that enables them to leave the atmosphere, as well as be protected from unpleasant and very dangerous influence of the universe. The achievement is magnificent: human travels through the universe, lives in it and develops technical means up to the level of providing tourist tours around space stations and watching the Earth from above. The transit from the earthly living conditions into the space conditions represents a difficult and problematic step, where people must have such protection that enables them the exact conditions of life as on Earth. They perform the actions and operations necessary in those conditions by means of various aids and special protection suits.

The dolphin has not succeed to create aids in order to move on the ground, because it is handless and could not attain technical development like human, and therefore it stayed on the present level of development and may only live in water, also doing the activities it learned, such as playing with children. It is easier to come out of the water and live on the land, than transit from the earthly conditions to the universe, due to completely different and unpleasant living conditions.