title: Thermal fluctuations in a layer of liquid CS2 subjected to temperature gradients with and without the influence of gravity.
abstract: We report data for nonequilibrium density fluctuations in a layer of liquid CS(2) subjected to temperature gradients on Earth and in a satellite. The structure factor S(q) was measured using a calibrated shadowgraph. Upon removing gravity, S(q) increased dramatically at small wave vector, until the fluctuations generated by thermal noise were limited only by the 3 mm sample thickness. The results agree with theory to within a few percent on Earth and are ∼14% below theory in microgravity, demonstrating that the use of equilibrium Langevin forces is appropriate in this nonequilibrium situation.
authors.affiliation: Department of Physics and ITST, University of California at Santa Barbara, Santa Barbara, California 93106, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Takacs
authors.forename: Alberto
authors.initials: A
authors.lastname: Vailati
authors.forename: Roberto
authors.initials: R
authors.lastname: Cerbino
authors.forename: Stefano
authors.initials: S
authors.lastname: Mazzoni
authors.forename: Marzio
authors.initials: M
authors.lastname: Giglio
authors.forename: David S
authors.initials: DS
authors.lastname: Cannell