What this work contributes
Analyzes a lateral force between plates at different temperatures and shows that geometric asymmetry alone is insufficient in the studied setup: nonreciprocity is required. The arrangement is a heat engine whose efficiency remains bounded by the Carnot limit.
Where the evidence stops
This is a driven thermal system involving interacting bodies, not proof that a passive hull self-accelerates. The paper does not establish a practical spacecraft propulsion system.
Original source
David Gelbwaser-Klimovsky, Noah Graham, Mehran Kardar, Matthias Krüger. Near Field Propulsion Forces from Nonreciprocal Media. Physical Review Letters 126, 170401 (2021).
DOI: 10.1103/PhysRevLett.126.170401
How we use it
This record belongs to Driven & thermal fields. 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.