He discovered that a system's entropy can be given by the natural logarithm of the number of microstates times his namesake constant, equal to the gas constant over Avogadro's number.  
This man names an equation whose lattice method can be used to solve the Navier-Stokes equation and which is used to find the distribution function of a fluid.  The fraction of particles at a specific temperature is given as inversely proportional to the partition function by a distribution named for this man, and with Maxwell he names a distribution of molecular velocities in a gas.  He discovered that a system's entropy can be given by the natural logarithm of the number of microstates times his namesake constant, equal to the gas constant over Avogadro's number.  For 10 points, identify this physicist who names a law governing blackbody radiation with Stefan.
This man names an equation whose lattice method can be used to solve the Navier-Stokes equation and which is used to find the distribution function of a fluid.  
Ludwig Boltzmann