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Language:English 英文
【Maintaining Energy Balance - Part 2: Earth and Life 维持能量的平衡下编-地球生命编】
What is the meaning of the universe's arrangement of all this? Perhaps the continuation of life and civilization is the answer. As human beings, we should take on the guardianship of Earth's civilization and protect the continuation of the myriad lives on Earth — that is the best gratitude.
The initial Earth: the energy game between lava and cooling (4.6–4.0 billion years ago); in the solar system's protoplanetary disk, planetesimals accreted through collisions to form proto-Earth, converting kinetic energy into heat, with surface temperatures exceeding 1200°C, forming a global magma ocean. Dense iron and nickel sank to the center, releasing gravitational potential energy — the total gravitational potential energy released during Earth's complete accretion process is about 2.24×10³² joules, further heating the interior. Lighter silicates rose and gradually cooled to form the primitive crust. Long-lived isotopes such as uranium-238, thorium-232, and potassium-40 decayed, providing a long-term heat source (still contributing about 50% of geothermal heat today). Mantle convection transferred internal heat to the surface, and volcanic eruptions released excess energy to avoid overheating and melting. Earth achieved dynamic balance through radiative cooling (Stefan-Boltzmann law) and internal heat production (radioactive decay), avoiding becoming a dead rock. Volcanic eruptions released H₂O, CO₂, N₂, CH₄, NH₃, etc., forming a reducing atmosphere. Some water may have been delivered by water-rich meteorites (such as carbonaceous chondrites). High concentrations of CO₂ and CH₄ maintained surface temperatures, preventing the ocean from freezing (early solar luminosity was only 70% of today's) and maintaining greenhouse balance. Seawater dissolved ions from volcanic rocks (such as Na⁺, Cl⁻), initiating geochemical cycles.
About 4.5 billion years ago, a Mars-sized body struck Earth obliquely, ejecting material to form the Moon, and the axial tilt caused seasonal changes. The Theia impact released 10³² joules of energy, reshaping the mantle structure and accelerating core differentiation. After the Hadean magma ocean cooled, basaltic and granitic crusts gradually differentiated. Local mantle convection triggered early tectonic activity, but did not form a modern plate system. Liquid water, the atmosphere, and chemical gradients constituted an "energy ladder," providing a reaction medium for subsequent molecular evolution. Volcanic vents and deep-sea hydrothermal vents became arenas for abiogenic synthesis (such as iron-nickel sulfides catalyzing the formation of organic compounds). The lava and cooling of the initial Earth set the stage for the next step of "chemical reactions" — in the boiling oceans and lightning-filled atmosphere, energy would give rise to more complex molecules, ultimately leading to
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