A fulgurite is what happens when lightning hits sand hard enough to melt it, leaving a thin tube of glass underground. Dave Bonta's poem starts there, with a geological curiosity, and turns it into an argument about why anything bright, human beings included, might want to go to ground.
The first four lines read like a field note. Lightning "roots deep into the sand, / donning an instant sheath of glass," and the verdict arrives with a pun: "a seemingly pointless exercise in self-glove." The word bends "self-love" into something physical, a glove the lightning makes for itself. The adverb "seemingly" quietly promises that the verdict will be overturned. Then comes the stark fragment "Clap of thunder." It works like a full stop, or a door closing, and the poem begins again from a different angle.
That second movement opens with a question: "Could it be, though, that radiance tires of itself?" The poem's reasoning is playful but consistent. Space is only "alleged" to be black, and it is crowded with "ticking, / pulsing, clusterfucks of stars," with no relief "except on cold planets." The crude word shatters the polite tone, and it makes the cosmos sound like a noisy, overlit party that anyone would want to leave. The poem is also fond of echoes. "Ticking" sets up "tick" a few lines later, when lightning is defended for "burrowing in like a tick." The word first suggests a clock, then a small parasite clinging to a host, and the comparison is deliberately unglamorous.
The speaker then widens the claim to people. We are "full of darkness," the opposite of lightning, yet we behave the same way: we "go on pilgrimage to the ocean," bury ourselves "up to our necks in sand," and dream "of girls with gills." The porpoises, with a "capacity for joy / we suspect of exceeding our own," make the longing sound almost envious. The central image is the poem's most daring: we return to the sea "like adopted children / paying a visit to our birth mother, / hoping that she'll show some sign / she regrets giving us up." The comparison is both funny and painful. It also gives the sea a gender, which the closing lines pick up. The offered signs, "some whelk, some dead star," are small and sad. Judging by the imagery, the "dead star" is likely a starfish, which would bring the vanished stars back down to the beach.
Next comes the sharpest piece of satire. We tell "prospective partners" that we love "long walks on the beach / because it's the deepest thing / we can think to say." The line is a dating-profile cliché, but "deepest" echoes the opening's "roots deep," and the joke softens into sympathy. The cliché, the poem suggests, is a clumsy way of pointing at something real.
The ending shifts to a single figure. Only someone "who knows the shore / well enough to recognize what she doesn't know" will notice the "odd / sandstone lump" and find "black glass" inside. That is a modest definition of expertise, built on knowing where your knowledge stops. The glass is black, which turns lightning's light into darkness, and the last image completes the circle: she sights through the tube and holds it "up to the sun like a sextant," an instrument for navigating by the heavens. The buried flash becomes a tool for looking back at the sky it came from.
Formally the poem is free verse. It has no regular rhythm or rhyme, and its lines run from the clipped "Clap of thunder." to long, sprawling, conversational sentences. Enjambments such as "whose / capacity for joy" and "how / we love" give the speaker an easy, thinking-aloud pace. The ampersand in "& find" adds to that informality.
Its significance lies in how much it holds together: physics, comedy, mythology and longing. It also invites a reading of the poem itself as a kind of fulgurite, a plain-looking object that hides a flash of brightness for the patient reader to find. That last point is my inference, not something the poem states.