Hong et al reply to Canul-Chay et al
  Canul-Chay et al. [1] have conducted the segregation experiment of binary granular mixtures in a bed and subjected the bed to vibration. They report that the reverse Brazil-Nut phenomenon (RBNP) was never observed in their experiments and thus conclude that such does not exist. However, we have clearly demonstrated in [2] by Molecular Dynamics simulations that the reverse Brazil-Nut problem not only exists, but can be determined from the solid-liquid phase boundary by a scaling theory for the crossover from RBNP. Hence, instead of disputing Canul-Chay et al.'s sound experimental results [1], in this reply we want to draw the reader's attention to the experimental set up and the interpretation of the experimental results. 
Daniel C. Hong, Paul V. Quinn, Stefan Luding