Extraterrestrial civilizations and communication · Chapter 12

Ask what it takes for civilizations to communicate

Chapter 12 of the original book does not simply present the encounter with extraterrestrial civilizations as a matter of hope. Stars, planets, life, and technology, as well as the time to send signals, all constitute conditions for the encounter.

The Drake equation does not promise a certain number. Its strength is in dividing unknowns into questions and showing which assumptions most strongly affect the result.

OBSERVE · Start with evidence

Three pieces of evidence

First, assume the combined civilization generation rate for the remaining conditions.
Multiply the average period for emitting detectable signals.
Changes in the duration of the signal will, in turn, affect the expected number of civilizations that might detect it.

Receiving a message is not the same as understanding it

Commentary extending decipherment and extraterrestrial civilizations in chapter 12 of the original book. The Rosetta Stone is an example of deciphering human writing, not a guarantee that the same method can decode an alien signal.

Sentences that can be read are next to unfamiliar symbols.

The Rosetta Stone records the same decree in three scripts: Egyptian hieroglyphs, Egyptian Demotic, and Greek. The part scholars could already read provided clues for investigating the unfamiliar signs.

Don't immediately reduce this case to a simple cipher story. Decryption is a process that involves accumulating multiple sources and research. If a single symbol consistently corresponds to a specific meaning, it's important to verify that it's consistent across other contexts.

Questions to ConsiderYou hypothesize that a recurring sign represents a particular name. What would you do next?

Extraterrestrial signals may not have a corresponding translation in our language.

For human language decipherment, familiarity with similar objects, bodies, and experiences, as well as pre-existing knowledge of language, can be helpful. When imagining a message from an alien civilization, it's important to first determine the extent of the common ground.

Imagining using mathematical patterns or natural laws as clues is fascinating. However, finding a pattern does not necessarily reveal the sender's intent or meaning. Consider distinguishing between noise and signal, artificial patterns and decipherable messages.

Questions to ConsiderI have encountered a regular signal. What question should I ask first?

Even if they coexist, they cannot communicate.

After calculating the number of civilizations, we must return to the issues of time and distance. The time when one civilization sends a signal may not coincide with the time when another civilization receives it, and the response may require traversing a long distance again.

Therefore, the lifespan of a civilization's signal is more than just a simple input value in a calculator. The conditions for long-term preservation of knowledge and technology are linked to issues of libraries and education, as well as conflict and cooperation. Find the reason why the chapter on extraterrestrial civilizations leads to the final chapter on Earth here.

Questions to ConsiderIf you were to send a record to a distant civilization, what would you prioritize?

Discoveries and their limits

Both small and large expected signal detection numbers are not necessarily accurate reflections of actual detections. In particular, there is significant uncertainty regarding the probabilities of life, intelligence, and technology, as well as the expected lifespan of signals.

Divide the necessary conditions for the message to be transmitted into "arrival," "recognition," and "understanding."

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Evidence and further reading

The question of how long a civilization can transmit signals is not solely a matter for astronomers. How can we extend the lifespan of our own civilization?