What this work contributes
Demonstrates measuring optical power through the mechanical force exerted by laser radiation. Photon momentum is a real force source and an essential calibration and background term for proposed field-propulsion experiments.
Where the evidence stops
A reflected external beam can transfer about 2P/c at normal incidence; an onboard ideal one-way photon exhaust yields P/c. These different system boundaries must not be conflated.
Original source
Paul A. Williams, Joshua A. Hadler, Robert Lee, Frank C. Maring, John H. Lehman. Use of radiation pressure for measurement of high-power laser emission. Optics Letters 38(20), 4248–4251 (2013).
DOI: 10.1364/OL.38.004248
How we use it
This record belongs to Photon momentum. Its evidence label describes the cited work, not the maturity of a Metric Flight device. Follow the original methods, corrections and conditions before transferring a result to a different geometry or scale.
Editorial note reviewed 19 October 2026. AI assisted research discovery and synthesis. Citation metadata and claims were checked against primary publication or institutional records; full-text access varies. Read the source for the complete method.