The strange metal phase, characterized by T-linear resistivity, is thought to be related to Planckian dissipation, a fundamental limit on the degree of quantum entanglement possible in a many-body system. The key feature is the universal scattering rate that relies only on fundamental constants, independent of material-specific properties. In this talk, I will share our new measurements of low-energy charge dynamic fluctuations in the strange metal Bi2.1Sr1.9CaCu2O8+x, using momentum-resolved inelastic electron scattering. We find that the dynamics are relaxational, exhibit scale invariance and are independent of momentum, indicating the only relevant energy scale is temperature. Additionally, our data show conformal invariance, suggesting the dynamics live on a circle of radius 1/T in imaginary time.