- Value
- 6.652 458 7051 × 10−29
- Unit
- m²
- Uncertainty
- 0.000 000 0062 × 10⁻²⁹
- Copy-ready
6.6524587051e-29
The Thomson cross section: the effective area an electron presents to low-energy light scattering.
Sets the Eddington luminosity limit of stars and the opacity of ionised gas in cosmology.
NIST, Fundamental Physical Constants — Complete Listing (2022 CODATA adjustment), retrieved 2026-07-26.
Compton wavelengths, radii and cross sections
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UsePhysics. "Thomson cross section — 6.652 458 7051 × 10−29 m²." UsePhysics.com. https://usephysics.com/reference/thomson-cross-section. Value from the 2022 CODATA adjustment (NIST). Accessed [date].