---
title: "Unweaving the Rainbow"
chunk: 2/3
source: "https://en.wikipedia.org/wiki/Unweaving_the_Rainbow"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:34:56.704083+00:00"
instance: "kb-cron"
---

=== Huge cloudy symbols of a high romance ===
Unlike "magisterial poetry" (where metaphors and pretty language are used to describe the familiar), "pupillary poetry" uses poetic imagery to assist a scientist's thinking about the exotic (e.g. consider "being" an electron temporarily). Although it is useful, some authors take pupillary poetry too far, and, "drunk on metaphor", they produce "bad science"; i.e. postulate faulty theories. This is powered by humanity's natural tendency to look for representations.

=== The selfish cooperator ===
Genes compete with each other, but this occurs within the context of collaboration, as is shown with examples involving mitochondria, bacteria, and termites. Two types of collaboration are co-adaptation (tailoring simultaneously the different parts of an organism, such as flower colour and flower markings), and co-evolution (two species changing together; e.g. predator and prey running speeds may increase together in a sort of arms race).

=== The Genetic Book of the Dead ===
The body of any organism provides clues about its habitat. The genes allow one to reconstruct a picture of the range of ways of life that the species has experienced; in this sense DNA would act as a palimpsestic "digital archive" if only its language of encoding history could be fully understood. Finally, the curious genetics of cuckoos is discussed.

=== Reweaving the world ===
The brain is akin to a powerful computer, which creates a sort of virtual reality to model economically the environment. Neural circuitry is discussed, and a comparison is made between brains and genes: albeit over different time scales, both record the environment's past to help the organism make the optimal actions in the (predicted) future.

=== The balloon of the mind ===
The simultaneous explosions in hardware and software of the 20th century are together an example of what Dawkins calls "self-feeding co-evolution".
A similar event occurred over a longer time scale (millions of years) when the minds and brains of our ancestors simultaneously improved very rapidly. Five possible triggers of this improvement were: language, map reading, ballistics, memes, and metaphors/analogies.

==== Conclusion ====
The final two paragraphs of The balloon of the mind conclude by saying that human beings are the only animal with a sense of purpose in life, and that that purpose should be to construct a comprehensive model of how the universe works.

== Petwhac ==
The book coins the acronymical term, petwhac, short for "Population of Events That Would Have Appeared Coincidental". Dawkins suggests that when one encounters an extremely unlikely coincidence, it should be considered in the broader context of other, similar events which would also have seemed coincidental.
An example would be a person on a foreign holiday encountering a friend they had not seen for years. In isolation this may feel like an impossible coincidence, but considering the wider petwhac (meeting any friend from around the same period, or meeting an acquaintance, or not meeting them but being told weeks later that they had been in the same city at that time) the true odds are more likely. In short, the bigger the petwhac, the stronger case you have to avoid ascribing something to fate or coincidence.
Dawkins offers several examples of petwhacs in the book, two of which are the bedside clock of a woman (Richard Feynman's wife) stopping exactly when she died, and a psychic who stops the watches of his television audience.
The first is explained by the fact that the clock had a mechanical defect which made it stop when tilted off the horizontal, which is what a nurse did to read the time of death in poor lighting conditions. The matter of the watches, in Dawkins's own words, is explained thus —

If somebody's watch stopped three weeks after the spell was cast, even the most credulous would prefer to put it down to chance. We need to decide how large a delay would have been judged by the audience as sufficiently simultaneous with the psychic's announcement to impress. About five minutes is certainly safe, especially since he can keep talking to each caller for a few minutes before the next call ceases to seem roughly simultaneous. There are about 100,000 five-minute periods in a year. The probability that any given watch, say mine, will stop in a designated five-minute period is about 1 in 100,000. Low odds, but there are 10 million people watching the show. If only half of them are wearing watches, we could expect about 25 of those watches to stop in any given minute. If only a quarter of these ring into the studio, that is 6 calls, more than enough to dumbfound a naïve audience. Especially when you add in the calls from people whose watches stopped the day before, people whose watches didn't stop but whose grandfather clocks did, people who died of heart attacks and their bereaved relatives phoned in to say that their 'ticker' gave out, and so on.

== Notes ==

== External links ==