Astronomers use the phrase "surface of last scattering" for the point, long ago, when the young universe cooled enough to let light travel freely. Before it, the cosmos was an opaque glow, and light was knocked about too often to carry any image across space. Nothing earlier can be seen. Mary F. C. Pratt takes that wall of fog as her title and sets it beside other things we cannot see past: our own beginnings, our dreams, and the moment another person dies.
The first stanza states the limit bluntly. "As for the beginning, / you will be forever blind." The reasons given, "the speed too great, / and you too far away," are simpler than the physics of the title, as if the speaker were explaining to a child. The comparison that closes the stanza is the strangest. You will "sooner comprehend / the minds of stones, / the music in the hearts of suns." Both are impossible, and both are personified, so that rocks think and stars sing. Even those absurdities are easier than knowing the origin. The near-echo of "stones" and "suns" makes the two images feel like a matched pair, a small music of the kind the stanza says we will never hear.
The second stanza turns inward with a question: "Do you even remember, do you / understand your dreams?" The dream images are vivid and unexplained: a "white-robed, / hooded figure," a rabbit that dies and revives to hide "beneath your bed," and a "silver cup that held the deep-red / souls of all your friends." Judging by the imagery, the dream mixes death, resurrection and something like a chalice, but the poem offers no key. Our own minds, it suggests, are another surface we cannot see through. The cup's "deep-red" is also the only strong colour in the poem, and it flares up just before the pale, cold language of the ending.
The third stanza is the hinge, and it is the hardest to read. Pronouns slide between "you" and "I." The father's last words come "the night that you were born," while he says nothing about "the night I was conceived." I read this as a death and a birth falling on the same night, though the poem never says so. What is clear is that origins stay silent. The three dying relatives are reported only in fragments. The sister says, "how good of them to come," which suggests she sees visitors the living cannot. The great-aunt sings "universe revealed." The father's actual words are withheld altogether, so we learn when he spoke but not what he said. The stanza ends on a dash, with the great-aunt's line cut off like a breath.
The last stanza answers that interruption. "Nothing beyond the primal opacity, / that background of heavy light" fuses the cosmic and the bodily. "Heavy light" is an oxymoron, light so trapped it has weight. The poem then jumps to the far future, where "every stellar furnace" is out and "each black hole dissipated." Then, with surprising tenderness, comes "every / molecule of breath accounted." That line is both cosmic bookkeeping and a deathbed's last exhale. The great-aunt's phrase returns as a standalone cry, "Oh, universe. / Revealed." It now ends in a full stop where before there was a dash. Whether this is awe or a final settling of accounts is left open. The universe may be revealed only at the end, when no one is left to see it.
Formally, the poem is free verse in four eight-line stanzas, with no rhyme and short, plain lines. Enjambments such as "do you / understand" and "every / molecule" leave the reader hanging, as the speaker hangs between knowing and not knowing. The scientific vocabulary arrives late and lightly, so the physics never overwhelms the family scenes.
Its significance lies in how it joins the largest scale to the smallest. A cosmologist's limit on observation and a family's memory of deathbed words turn out to be the same kind of limit. The poem offers neither comfort nor despair. It stays at the edge of what can be known and listens, and the great-aunt's song is the one sound it finds there.