Atlas One · Host Biology · Scale 01 — Subatomic

Photon

Quantum of electromagnetic radiation. UV photons (200–400 nm) cause pyrimidine dimers in DNA; ionizing γ/X-ray photons generate double-strand breaks via free radicals. Visible photons (400–700 nm) drive retinal photoisomerization, circadian signalling.

Also known as: γ-ray, X-ray, UV photon, visible light, electromagnetic quantum, hν

Scale 01 — SubatomicScale
draftStatus
2026-06-05Last Reviewed
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photon

Photon

Quantum of electromagnetic radiation. UV photons (200–400 nm) cause pyrimidine dimers in DNA; ionizing γ/X-ray photons generate double-strand breaks via free radicals. Visible photons (400–700 nm) drive retinal photoisomerization, circadian signalling.