Why does Life Exist?

Most religions explain life as existing because of God’s will. That explanation is fine if it gives comfort to people but it is not a scientific explanation. A scientific explanation is harsher and colder, and leaves us with a displeasing answer as to “Why are we here?” Unlike religion, the purpose of science is not to give comfort.

Gradients

Nature abhors a gradient. Gradients exist when energy or pressure enters one part of a system and is discharged at another. When you suck on a straw inserted in a glass of water, the water rises in the straw because of the pressure gradient caused by a vacuum. Thermodynamic theory says that life exists because nature abhors the energy gradient between solar energy entering the Earth and heat energy reradiating into the atmosphere. On Earth there is an abundance of plant, animal, and microbial life. By converting solar energy into biomass, these organisms reduce the energy gradient between solar energy entering the ecosystem, and heat reradiating out into space. Life is reducing the gradient.  Nature “wants” there to be life on Earth.

Nature “wants” there to be life is a teleological statement. A scientific way to say it is that 4 billion years ago, in geothermal vents there existed both a strong energy gradient and a rich mixture of inorganic chemicals. These chemicals came together in millions of different combinations, but by chance, one combination had the ability to absorb chemical energy and transform it into heat. Thus occurred the first living organism, which incidentally reduced the energy gradient in the vent.  On a lifeless planet such as Mars, there is a strong energy gradient between solar energy hitting the surface and the heat reradiated from the surface. Nature “wants” there to be life on Mars, but is stymied because of lack of water.