Chapter 14

Erid

An alien planet, steam-powered muscles, and nukes to save Earth

Grace reconstructs Erid's biology: a super-Earth with 25× stronger magnetic field, where Eridians run on biological steam engines and mercury blood. On Earth, a desperate plan: detonate nuclear bombs under Antarctica to release methane.

Planet Erid: a super-Earth without radiation

In the book

Erid has 8.5× Earth's mass, double the diameter, 5.1-hour days, and a 25× stronger magnetic field.

The science behind it

Earth's geomagnetic field is generated by the rotating molten iron core (dynamo effect). Erid: larger core + closer to its star + spins 17× faster = 25× stronger field.

Erid's magnetopause (magnetic field boundary) is much farther than Earth's. Eridian ships orbited WITHIN the magnetic protection. They never needed radiation shielding.

With xenonite (extraordinary tensile strength), Eridians built a space elevator: a cable from the equator to geostationary orbit. Earth can't do this because no known material is strong enough.

Without radiation in their world, Eridian DNA has no damage repair mechanisms. Human DNA DOES (because we're constantly exposed to solar UV radiation). Eridians simply die when exposed.

Key terms

Dynamo effect
Magnetic field generation by rotational movement of a conducting fluid (like Earth's molten iron core).
Space elevator
Cable anchored at the equator reaching geostationary orbit. Would allow sending cargo to space without rockets.
Magnetopause
A planet's magnetic field boundary. Beyond it, radiation protection drops dramatically.

Eridian physiology: biological steam engines

In the book

Eridians have mercury blood, metal bones, muscles that work by vapor pressure, and two circulatory systems at 210°C and 305°C.

The science behind it

Eridian muscles are literally steam piston engines: receptacles with water at 210°C (under pressure, still liquid). Hot blood at 305°C heats the muscle → water expands as steam → contraction. Ambient blood (210°C) cools → relaxation.

Mercury is liquid from -39°C to 357°C, perfect for an organism operating between 210°C and 305°C. It's dense and conductive, ideal as a transport fluid.

Eridians produce their own oxygen (internal photosynthetic cells) and recycle CO₂. They're a walking closed biosphere. They only need food (energy) and heat dissipation.

Eridian sleep is "forced maintenance": the hot circulatory system (305°C) cools so specialized cells can repair the ducts. During this time, all muscles are paralyzed. Rocky can't wake up while sleeping.

Key terms

Biological steam engine
Muscle working by water vapor expansion/contraction under pressure. Mechanical analog to a steam engine's pistons.
Closed biosphere
System recycling all its waste internally. The ISS tries to be one; Eridians ARE one biologically.

Nuclear bombs in Antarctica: methane to buy time

In the book

Dr. Leclerc orders detonation of 241 fusion bombs under Antarctica. Released methane will act as temporary greenhouse effect.

The science behind it

Fusion bombs (thermonuclear) use a fission explosion (uranium) to trigger fusion (hydrogen → helium). Fusion is cleaner: produces helium, not heavy radioactive waste.

Methane (CH₄) is ~80× more potent as a greenhouse gas than CO₂ in the first 20 years. But it naturally decomposes to CO₂ + H₂O in ~10 years, making it "reversible."

Under Antarctic ice are fossil jungle remains from when Antarctica was tropical (millions of years ago). Methane (swamp gas) was trapped under the ice.

Without this intervention: 3.5 billion dead in 19 years from famine. With methane: the window extends to ~27 years. Extra time for the Hail Mary to find a solution.

Key terms

Fusion bomb
Nuclear weapon using hydrogen fusion. More powerful and "cleaner" than fission. Also called H-bomb or thermonuclear.
Methane (CH₄)
Greenhouse gas ~80× more potent than CO₂ short-term. Naturally decomposes in ~10 years.
Greenhouse gas
Gas trapping heat in the atmosphere. CO₂, CH₄, N₂O, and water vapor are the main ones.

Try it yourself

Greenhouse Gas Comparison

Methane (CH₄) is ~80× more potent than CO₂ short-term. It's the option chosen to buy time in the novel.

Potency relative to CO₂ (20 years)
CO₂
1×
CH₄
80×
N₂O
273×
SF₆
17400×
CH₄ decomposes naturally in ~10 years → "reversible" effect. CO₂ persists for centuries.