Reply to "Comment on 'Precision measurement of the Casimir-Lifshitz force in a fluid'"

TL;DR

This paper defends previous measurements of the Casimir-Lifshitz force against criticisms, providing additional experimental data and analysis to confirm the results align with Lifshitz theory.

Contribution

It offers a detailed response to critiques, including further experiments and calculations, reinforcing the validity of the original force measurements.

Findings

Electrostatic forces are minimal and dominated by trapped charges.

Residual electrostatic forces are small compared to Casimir forces.

Double layer interactions have negligible impact on results.

Abstract

We have reviewed the Comment of Geyer et al. [arXiv:0708.1548] concerning our recent work [Phys. Rev. A 75, 060102 (R) (2007)], and while we disagree with their criticisms, we acknowledge them for giving us the opportunity to add interesting addition material and a more detailed description of our experiment. We describe further our calculation and explain why a more sophisticated model is not warranted. We also present detailed experiments on the effects of electrostatic forces in our measurements and show that the contribution due to work function differences is small and that the residual electrostatic force is dominated by trapped charges and external fields. Finally, we estimate the effect of double layer interactions. These additional calculations and measurements support our original conclusion that the experimental results are consistent with the Lifshitz theory.