Chapter 12

Building a Shared Language

Measuring mass in zero-g, exponential vocabulary, and loneliness

Grace and Rocky build shared vocabulary at exponential speed. Grace invents a method to measure mass without gravity, and Rocky reveals a devastating truth: his entire crew died from interstellar radiation.

How to measure mass in zero gravity

In the book

Grace ties a string with two containers at the ends and balances water against an iron ball until they spin at the midpoint.

The science behind it

Weight depends on gravity: you weigh less on the Moon, more on Jupiter, nothing in space. But mass is intrinsic: it doesn't change regardless of where you are.

Grace's trick: two objects on the ends of a spinning rope. If both have the same mass, the center of rotation stays in the middle. If one is heavier, the center shifts toward it.

Using water as reference (density = 1 kg/L), Grace measured the water's volume with a syringe (in cubic centimeters = milliliters) and directly got mass in grams. Result: 325 g.

Rocky already knew the answer: the ball was iron (element 26). With the measured diameter and iron's density (7.87 g/cm³), the theoretical mass is 328.25 g. Grace was only off by 1%.

Key terms

Mass vs weight
Mass is the amount of matter (kg). Weight is gravitational force on that mass (newtons). Mass is constant; weight varies with gravity.
Center of mass
Point where all system mass can be considered concentrated. The natural balance point.

Try it yourself

Zero-G Mass Balance

In zero gravity you can't weigh things. But you can compare masses by spinning two objects on a rope.

325g328g
Balanced! Masses are equal

Grace balanced 325 mL of water against Rocky's iron ball (328 g theoretical). Error: ~1%

Language grows exponentially

In the book

Grace and Rocky go from numbers to "yes/no" to abstract concepts. The dictionary grows faster with each new word.

The science behind it

Zipf's law applied: the first words in any language are the most used (numbers, "yes," "no," basic verbs). With each new word, you can define more words using the ones you already have.

It's like compound interest: progress starts slow (10 words → 20 in a day). Then accelerates exponentially (100 → 300 in a day) because you combine existing ones.

Rocky has perfect auditory memory: remembers every chord without notes. In humans, a large brain area is dedicated to vision. In Eridians, that area likely serves sound.

Mathematical base is universal: you don't need a natural language for two intelligent species to start communicating. Numbers + pointing at objects + yes/no is enough to begin.

Key terms

Zipf's law
In any language, a few words are used very frequently and most are used rarely. The most common word is ~2× more frequent than the second.
Exponential growth
Something that grows proportionally to its current size. Each generation is larger than the previous by a constant factor.

Rocky's loneliness: 23 crew members killed by radiation

In the book

Rocky reveals he was the sole survivor. His crew of 23 died from cosmic radiation. Rocky survived because he was surrounded by astrophages.

The science behind it

Erid has a magnetic field 25× stronger than Earth's and 29 atmospheres of protection. Eridians NEVER evolved radiation resistance because their planet protected them 100%.

Leaving Erid's magnetosphere, the crew received lethal doses of galactic cosmic rays (GCRs): protons traveling near light speed, created by supernovae.

Rocky survived because he was in the workshop, surrounded by astrophage containers. Astrophages block all radiation (supertransversality): not even neutrinos pass through them.

When Rocky speaks softly (an octave lower), he expresses sadness. Humans also lower pitch and volume when sad. Emotional expression through sound is a biological universal.

Key terms

Galactic cosmic rays
High-energy protons traveling near light speed. Created by supernovae. Can cause cancer and massive cell damage.
Supertransversality
Fictional property of living astrophages: nothing can pass through them, not even neutrinos.