Can the properties of the quantum vacuum be used to propel a spacecraft? The idea of pushing off the vacuum is not new, in fact the idea of a “quantum ramjet drive” was proposed by Arthur C. Clark (proposer of geosynchronous communications satellites in 1945) in the book Songs of Distant Earth in 1985: “If vacuum fluctuations can be harnessed for propulsion by anyone besides science fiction writers, the purely engineering problems of
interstellar flight would be solved.”. When this question is viewed strictly classically, the answer is clearly no, as there is no reaction mass to be used to conserve momentum. However, Quantum Electrodynamics (QED), which has made predictions verified to 1 part in 10 billion, also predicts that the quantum vacuum (lowest state of the electrodynamic field) is not empty, but rather a sea of virtual particles and photons that pop into and out of existence stemming from the Heisenberg uncertainty principle. The Dirac vacuum, an early vacuum model, predicted the existence of the electron’s antiparticle, the positron in 1928, which was later confirmed in the lab by Carl
Anderson in 1932. Confirmation that the Quantum Vacuum (QV) would directly impact lab observations came inadvertently in 1948 while Willis Lamb was measuring the 2s and 2p energy levels in the hydrogen atom. Willis discovered that the energy levels were slightly different, contrary to prediction, but detailed analysis performed within weeks of the discovery by Bethe at Cornell predicted the observed difference only when factoring in contributions from the QV field The Casimir force, derived in 1948 by Casimir in response to disagreements between experiment and model for precipitation of phosphors used with fluorescent light bulbs, predicts that there will be a force between two nearby surfaces due to fluctuations of the QV. This force has been measured and found to agree with predictions numerous times in multiple laboratories since its derivation.