Chapter 16
Energy Flow in the Production of Order
The flow of energy through a system acts to organize that system.
— Harold Morowitz
Summary The Earth itself is an open system, with specific sources and sinks
of energy, and a number of continuing ordering processes, including geological
differentiation and life.
16.1 The Flow of Energy Through the Earth System
Much of what the Earth receives as energy comes from sunlight. In addition, the
Earth receives ocean tidal energy from the Moon and Sun, moonlight, starlight,
cosmic rays, extraterrestrial neutrinos, relic microwaves, and even gravitational
waves from exploding supernovae in space. It also has a geothermal heat energy flow
arising predominantly from radioactive material decay in its crust and from tidal
heat. Table 16.1 shows the energy flow (in terawatts) into the Earth from various
sources. In addition, there is energy stored in chemical and nuclear form contained
in deposits, ores, and other materials of the Earth. 1
1 Referring to Table 16.1, the Earth has a mantle and crust containing mostly lithophiles (rocklovers) and a core containing mostly siderophiles (‘iron lovers’). The lithophiles are the oxides,
silicates, and other such compounds, the ‘scum’ and slag that was buoyed toward the surface of
the Earth by being less dense than iron and other unoxidized metals. Uranium and thorium easily
form oxides, and so are mostly found in the lithosphere. Therefore, heat from radioactive decay
comes mostly from the crust and mantle: about 8 TW from Uranium-238, 8 TW from thorium-232,
and 4 TW from Potassium-40. The absorption cross section of neutrinos by neutrons rises linearly
with the neutrino energy to at least 350 GeV: σ ν = 0.68 × 10 −45 m 2 (E ν /MeV), giving the rate
of neutrinos absorbed by the Earth as dN ν /dt = 4πI ν (dσ ν /dE ν )N N . Here, N N is the number
of neutrons in the volume of the Earth. For relic neutrinos, I ν = (7/16)σ T 4
ν is the neutrino total
energy flux. Stefan’s constant σ = 5.67 × 10 −8 W/m 2 /K 4 and T ν = 1.95 K. The peak of the relic
gravitational-wave Planck’s distribution occurs at f ∼ 10 11 Hz, where the stretching parameter h
© Springer Nature Switzerland AG 2020
W. C. Parke, Biophysics, https://doi.org/10.1007/978-3-030-44146-3_16
607
Energy Flow in the Production of Order
The flow of energy through a system acts to organize that system.
— Harold Morowitz
Summary The Earth itself is an open system, with specific sources and sinks
of energy, and a number of continuing ordering processes, including geological
differentiation and life.
16.1 The Flow of Energy Through the Earth System
Much of what the Earth receives as energy comes from sunlight. In addition, the
Earth receives ocean tidal energy from the Moon and Sun, moonlight, starlight,
cosmic rays, extraterrestrial neutrinos, relic microwaves, and even gravitational
waves from exploding supernovae in space. It also has a geothermal heat energy flow
arising predominantly from radioactive material decay in its crust and from tidal
heat. Table 16.1 shows the energy flow (in terawatts) into the Earth from various
sources. In addition, there is energy stored in chemical and nuclear form contained
in deposits, ores, and other materials of the Earth. 1
1 Referring to Table 16.1, the Earth has a mantle and crust containing mostly lithophiles (rocklovers) and a core containing mostly siderophiles (‘iron lovers’). The lithophiles are the oxides,
silicates, and other such compounds, the ‘scum’ and slag that was buoyed toward the surface of
the Earth by being less dense than iron and other unoxidized metals. Uranium and thorium easily
form oxides, and so are mostly found in the lithosphere. Therefore, heat from radioactive decay
comes mostly from the crust and mantle: about 8 TW from Uranium-238, 8 TW from thorium-232,
and 4 TW from Potassium-40. The absorption cross section of neutrinos by neutrons rises linearly
with the neutrino energy to at least 350 GeV: σ ν = 0.68 × 10 −45 m 2 (E ν /MeV), giving the rate
of neutrinos absorbed by the Earth as dN ν /dt = 4πI ν (dσ ν /dE ν )N N . Here, N N is the number
of neutrons in the volume of the Earth. For relic neutrinos, I ν = (7/16)σ T 4
ν is the neutrino total
energy flux. Stefan’s constant σ = 5.67 × 10 −8 W/m 2 /K 4 and T ν = 1.95 K. The peak of the relic
gravitational-wave Planck’s distribution occurs at f ∼ 10 11 Hz, where the stretching parameter h
© Springer Nature Switzerland AG 2020
W. C. Parke, Biophysics, https://doi.org/10.1007/978-3-030-44146-3_16
607