Figure 1: Measured values of ${\text{sin}}^{2}2{\theta }_{13}$. Several experimental collaborations around the world have measured the mixing angle ${\theta }_{13}$, which describes the probability that an electron neutrino will oscillate from one mass state to another, and found it to be much larger than expected. The normalized Gaussians shown here are centered on the measurements of ${\text{sin}}^{2}2{\theta }_{13}$, where the widths of the curves indicate the uncertainty of the measurement.