An Ember´s Arc

It began, as these things do
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 From clouds in the aether
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 With untold time, they coalesced
 Their will apart grew weaker
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 This cascade of embers,
 Fused into a star's ignition
 A crucible for their collapse
 Seething crux of its ambition
 The axiom of this expanse
 Unrelenting pressure
 Every moment, in each place
 Collisions beyond measure
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 An ordinary pair that met
 Whilst merging into one
 Heaved and spat a mote of light
 Adrift within the sun
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 Without a bind, it cut away
 Against all else it stood
 As swift as anything that was
 And had, or could, that would
 The axiom when it began
 Unable to elude
 Every moment, in each place
 Destroyed, exchanged, renewed
 At the surface once emerged
 Radiant in birth
 Free at last, its final form
 The photon dashed for earth