# Comet explained — The End of the World

> Chapter companion for The End of the World by Geoffrey Dennis.

## What happens

This chapter explores the historical and scientific perspectives on comets, from ancient omens of doom to modern astronomical calculations. It examines the dual nature of comets as both feared destroyers and celebrated portents, weaving together medieval beliefs, astrological predictions, and the ongoing debate about the probability of a catastrophic collision with Earth.

## Themes in this chapter

### Uncertainty of Knowledge

The chapter emphasizes that despite scientific calculations, the true risk of a comet collision remains unknown, with conflicting arguments from astronomers.

### Eschatology and Prophecy

Comets are presented as enduring symbols of apocalyptic prophecy, from medieval omens of the end to modern fears of global destruction.

### Optimism vs. Pessimism

Contrasts the optimistic view (comets as harmless or beneficial, e.g., for wine) with the pessimistic view (comets as potential destroyers).

### Nature and the Elements

Explores the elemental forces of comets—fire, water, air—and their potential to cause conflagration, deluge, or poisoning.

## Character check-ins

### Jesus Christ

Referenced in the context of a star at his birth and the millennial comets at his birth and death anniversaries.

### Queen Elizabeth

Cited as a cynic who defied comet fears, opening a window and striding out to see the comet.

### Julius Africanus

Mentioned in the context of early Christian chronology and the end of the world.

### Stoffler

Referenced as a German astrologer who predicted the end of the world based on comets.

### Noah

Implied through the reference to the Deluge as a potential outcome of a comet's tidal effects.

### Satan

Mentioned in the context of the Black Death being heralded by a comet.

## Key lines

> The sum of it all is that nobody knows. If destruction by this mode is not to be expected, it is not to be ruled out.

In the end, we are uncertain: comet-caused destruction is unlikely but not impossible.

_Summarizes the chapter's central theme of epistemic uncertainty regarding cometary threats._

> The only sure nexus the Middle Ages established was that between the fiery visitant and the fate of princes, between comets and lungs; Majesty’s death was announced in the firmament.

Medieval people firmly believed comets signaled the death of rulers, as if the sky itself published a royal obituary.

_Highlights the medieval association between comets and the mortality of monarchs._

> Arago put the chances of crashing with the central kernel of a wanderer at one in two hundred and eighty-one million... Should we take that one chance seriously?

Arago calculated the odds of a comet hitting Earth as extremely low, questioning whether we should worry.

_Illustrates the optimistic statistical argument against comet collision fears._

> There is reason to believe⁠—if one wants to⁠—that long ago a great comet did strike the earth, sinking Atlantis, causing the Great Drift, ushering in the last ice age.

Some believe a massive comet once hit Earth, destroying Atlantis and triggering the last ice age.

_Presents the speculative historical claim of a past comet impact with catastrophic effects._

## Links

- HTML: https://www.betterreads.online/discover/the_end_of_the_world_se/chapters/comet
- Book: https://www.betterreads.online/discover/the_end_of_the_world_se
- All chapters: https://www.betterreads.online/discover/the_end_of_the_world_se/chapters