However, a terminological difference arises in the expression mean squared error (MSE). The mean squared error of a regression is a number computed from the sum of squares of the computed residuals, and not of the unobservable errors. If that sum of squares is divided by n, the number of observations, the result is the mean of the squared residuals.
Heisenberg Uncertainty Principle. Heisenberg, a German scientist stated the principle of uncertainty which is a consequence of dual nature of matter and waves. The Heisenberg uncertainty principle states that it is impossible to find the position and momentum (velocity) of an electron at the same moment. Mathematical representation of this is as follows: \( \triangle x Ã \triangle v_x \geq \frac{h}{4\pi m}\)
(Ä§ is the reduced Planck constant, h / 2Ï). Historically, the uncertainty principle has been confused with a somewhat similar effect in physics, called the observer effect, which notes that measurements of certain systems cannot be made without affecting the systems.n fact, the Robertson uncertainty relation is false if is an angle variable and is the derivative with respect to this variable. In this example, the commutator is a nonzero constantâjust as in the Heisenberg uncertainty relationâand yet there are states where the product of the uncertainties is zero.