sNN = 200 GeV within Landau’s hydrodynamical model. From the measured data on the widths of the pion rapidity spectra, we extract the sound velocity c2s in the early stage of the reactions. It is found that the sound velocity has a local minimum (indicating a softest point in the equation of state, EoS) at Ebeam = 30A GeV. This softening of the EoS is compatible with the assumption of the forma...

Despite the simple design of instruments such as flutes, organs, whistles, and recorders, not all their sound-generation dynamics is understood. The excitation mechanics of these instruments resembles the phenomenon of blowing across the mouth of an empty bottle to induce sound from the bottle. For our experimental setup, such simple resonators were used to probe their sound-generation mechanic...

Our goal is the rapid and accurate measurement of upper-ocean vertical sound velocity (and hence temperature) profiles in the ocean. The objective is to obtain range resolved (»1 m) measurements of temperature and sound velocity over a range of »100 m at an accuracy of 0.1°C and 0.2 m/s, respectively. To this end we are developing an innovative Brillouin LIDAR concept. Present results provide c...

We determine the velocity of sound in the blackbody gas of photons and in the gas of relic photons. Derivation is based on the thermodynamic theory of the photon gas and the Einstein relation between energy and mass. The spectral form for the n-dimensional blackbody is derived. The 1D, 2D and 3D blackbody radiation is specified. It is mentioned the possibility of creation of the Mach cone in ca...

We consider an ideal gas of massive hadrons in thermal and chemical equilibrium. The gas expands longitudinally in an adiabatic way. This evolution for a baryonless gas reduces to a hydrodynamic expansion. Cooling process is parametrized by the sound velocity. The sound velocity is temperature dependent and is strongly influenced by hadron mass spectrum. ∗Work partially supported by the Polish ...