Question

What is the significance of the Heisenberg uncertainty principle?

Answer 1

Hint: Heisenberg’s principle states that more precisely we measure the position of a particle, less precisely you can know its velocity and vice versa. It also states that the product of uncertainty in measurement of velocity and uncertainty in measurement of position.

Complete step by step answer:
Let us just get straight into Heisenberg’s Uncertainty Principle and its sheer significance in the field of quantum mechanics.
> The Heisenberg uncertainty principle is a physical law that forms part of quantum mechanics. It says that the more precisely you measure the position of a particle, the less precisely you can know its motion (momentum or velocity). And the more precisely you measure a particle's motion, the less precisely you can know its position. This is contrary to our everyday experience of life, where these measurements are independent of each other, and can be measured as precisely as we'd like. The mathematical expression of the law is given below:
                                               \[\Delta x\times \Delta y\ge \dfrac{h}{4\pi }\]

Here, $\Delta x$ is the change in position of the particle and $\Delta y$ is the change in momentum of the particle and h is something known as the “Planck's constant” which is equal to the energy of a photon released in one electromagnetic radiation.
> This principle rules out the existence of definite paths of electrons or other similar particles. In other words we can say that the position of an object and its velocity fix its trajectory.
> The effect of the Heisenberg uncertainty principle is significant only for motion of microscopic particles and for macroscopic objects, it is negligible. We can say that when we calculate uncertainty of an object which has a mass of a milligram or more, it has hardly any consequence.
> The precise statements of the position and momentum of electrons need to be replaced by the statements of probability that the given electron has a given position and momentum.

Note: Uncertainty principle holds good for all the objects but this principle is significant for only microscopic particles. The energy of a photon is insufficient to make change in velocity or momentum of bigger particles when collision occurs between them.