Comment on "Phase transition in a one-dimensional Ising ferromagnet at   zero temperature using Glauber dynamics with a synchronous updating mode"
  Sznajd-Weron in [Phys. Rev. E {\bf 82}, 031120 (2010)] suggested that the one-dimensional Ising model subject to the zero temperature synchronous Glauber dynamics exhibits a discontinuous phase transition. We show here instead that the phase transition is of a continuous nature and identify critical exponents: $\beta \approx 0$, $\nu \approx 1$, and $z \approx 2$, via a systematic finite-size scaling analysis. 
Il Gu Yi and Beom Jun Kim
cond-mat.stat-mech