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: \( \triangle x Ã \triangle v_x \geq \frac{h}{4\pi m}\)
You can say where the stool was, but not where it is now. What's more, you could calculate the velocity of the stool after you hit it with the ball, but you have no idea what its velocity was before you hit it. Â­This is the problem revealed by Heisenberg's Uncertainty Principle. To know the velocity of a quark we must measure it, and to measure it, we are forced to affect it. The same goes for observing an object's position.