Casimir forces
What does a boundary change?
Material boundaries change electromagnetic fluctuation interactions. Compare attraction, repulsion and measured geometry dependence without treating a force on one boundary as vehicle thrust.
Which material, separation and geometry actually enter the force prediction?
On the attraction between two perfectly conducting plates
Derives an attractive interaction for ideal parallel conducting plates from the change in electromagnetic zero-point energy. The ideal zero-temperature pressure scales as the inverse fourth power of separation.
Demonstration of the Casimir Force in the 0.6 to 6 μm Range
Uses a torsion-pendulum apparatus to measure the interaction between conducting surfaces. The reported range extends into micrometers, correcting the claim that Casimir forces are measurable only at nanometer separations.
Measured long-range repulsive Casimir–Lifshitz forces
Demonstrates repulsive interactions between a gold-coated sphere and silica separated by bromobenzene. Carefully selected material responses can change the sign of a fluctuation-mediated interaction.
Measurement of the Casimir torque
Measures the alignment torque between an anisotropic solid crystal and a separated liquid crystal using the liquid crystal's twist. Material choice changes the sign and magnitude, and measured angular and separation dependences agree with calculations within reported uncertainties.