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Storgy

The Annotated Edition

242, 243:— by Percy Bysshe Shelley

Summary, meaning, line-by-line analysis & FAQ.

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This is a two-line poem accompanied by Shelley's scientific footnote that describes the true appearance of the sky and sun from outside Earth's atmosphere.

Poet
Percy Bysshe Shelley
Themes
beauty, doubt, nature
The PoemFull text

242, 243:—

Percy Bysshe Shelley

The sun’s unclouded orb Rolled through the black concave. Beyond our atmosphere the sun would appear a rayless orb of fire in the midst of a black concave. The equal diffusion of its light on earth is owing to the refraction of the rays by the atmosphere, and their reflection from other bodies. Light consists either of vibrations propagated through a subtle medium, or of numerous minute particles repelled in all directions from the luminous body. Its velocity greatly exceeds that of any substance with which we are acquainted: observations on the eclipses of Jupiter’s satellites have demonstrated that light takes up no more than 8 minutes 7 seconds in passing from the sun to the earth, a distance of 95,000,000 miles.—Some idea may be gained of the immense distance of the fixed stars when it is computed that many years would elapse before light could reach this earth from the nearest of them; yet in one year light travels 5,422,400,000,000 miles, which is a distance 5,707,600 times greater than that of the sun from the earth.

Public domain

Sourced from Project Gutenberg

§01Quick summary

What this poem is about

This is a two-line poem accompanied by Shelley's scientific footnote that describes the true appearance of the sky and sun from outside Earth's atmosphere. The poem vividly portrays the sun as a fierce sphere set against complete darkness, while the note explains the physics that prevent us from perceiving it that way from the surface. Together, they reveal Shelley's deep interest in science as a means to gain a clearer understanding of the universe.

§02Themes

Recurring themes

§03Line by line

Stanza by stanza, with notes

  1. The sun's unclouded orb / Rolled through the black concave.

    Editor's note

    These two lines make up the entire poem. "Unclouded orb" takes away the gentle, diffused glow we typically see from Earth and shows the sun as a hard, flawless sphere of fire. "Black concave" refers to the expanse of space — devoid of blue sky or scattered light, just pure darkness curving around the sun. The term "rolled" suggests the sun moves slowly and indifferently, as if it drifts through the void without any awareness of us. Shelley then adds a lengthy scientific note, which reads almost like a second poem in prose: it clarifies that the blue sky arises from atmospheric refraction, that light can behave as either a wave or a particle (a debate still relevant in his time), and that it travels 95 million miles from the sun to Earth in a little over eight minutes. He concludes by pointing to the fixed stars, mentioning that light from the closest one takes *years* to reach us — a fact intended to impress upon the reader the true vastness of the cosmos.

§04Tone & mood

How this poem feels

Cool and precise. There's no sentimentality here — Shelley isn't romanticizing the sun; he's making it feel unfamiliar. The two-line poem carries the sharp authority of a scientific observation, and the prose note aligns perfectly with that tone. The overall impression is one of awe kept at a distance, with wonder conveyed through data instead of emotion.

§05Symbols & metaphors

Symbols & metaphors

The unclouded orb
The sun, when viewed without the softening effects of the atmosphere, represents an unfiltered truth — reality in its purest form, untainted by the way we perceive it on Earth. Shelley aims to peel away those comforting illusions.
The black concave
The void of space isn't merely a backdrop; it reflects the universe's indifference to human existence. There's no warmth or color out there — those come from our atmosphere, not from the cosmos itself.
Light and its velocity
The speed of light in the prose note serves as a reminder of humility. By measuring how far light travels in a year and how long it takes to move between stars, Shelley uses light as a symbol to illustrate the unfathomable scale of existence.

§06Historical context

Historical context

Shelley wrote this note for *Queen Mab* (1813), his early radical poem-epic. The numbered references (242, 243) refer to specific lines in that work. He was deeply interested in the science of his time — he read Lucretius, followed the debates between wave and particle theorists about the nature of light, and admired William Herschel's astronomical findings. The early nineteenth century was a time when the universe's scale was becoming more measurable: since the 1670s, the speed of light had been estimated through observations of Jupiter's moons, and discussions about stellar distances were gaining traction. Shelley's note captures that excitement. He was also making a philosophical argument: if the blue sky results from refraction, then our usual view of the world is somewhat of an optical illusion, suggesting that reason — rather than our senses — leads us to the truth.

§07FAQ

Questions readers ask

Yes and no. It began as a footnote to *Queen Mab*, referring to lines 242 and 243 of that longer poem. Shelley's notes to *Queen Mab* are well-known for being nearly as extensive and ambitious as the poem itself—they delve into topics like atheism, vegetarianism, political economy, and science. This specific note was eventually taken out and regarded as a standalone piece because the two-line verse at its beginning stands strong on its own.

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Themes in this poem

Poems about beautyPoems about doubtPoems about naturePoems about time