In normal temperature, most water molecules don’t have enough kinetic energy to escape from surrounding molecules. So water remains liquid. But a very small percentage of water molecules do have high enough kinetic energy to escape the pull of surrounding molecules and become water vapor. Some of these water vapor rise to the sky and fall down as rain or snow. Rain and snow wet the land, supply water at higher places so water can flow down along rivers. Rain and snow, as distilled water free of minerals, resupply fresh water on the ground. Without a very small percentage of water molecules escaping from the liquid water, most of the land will be barren, devoid of life. Inside the sun, there is a very small percentage of protons with high enough speed to collide each other to generate fusion. That is the source of energy that brightens the sky and provides energy for most life on the earth. That percentage of proton with high energy is so small that even after several billion years, there are still abundant amount of protons in the sun. But without that tiny percentage of high speed protons, the sun will not shine. We cannot write off ourselves simply because we are very different from most others.
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