What is the uncertainty principle?

The uncertainty principle was laid down by Heisenberg, and is called Heisenberg’s principle of uncertainty. According to it, it is impossible to measure simultaneously the position and momentum/ velocity of a moving electron. If any attempt is made to measure both at the same instant, there will be uncertainty in measurement of either. This is because to measure the position of electron correctly at a certain instant, we need to use short-wavelength radiations. But, as wavelength and energy are inversely related, the short wavelength radiation imparts high energy to the moving electron. As E =1/2mv2 , where E is the energy of the electron, m is its mass, and v is its velocity, so energy E is directly proportional to velocity v of the electron. Thus the electron will gain velocity and we cannot correctly measure its momentum/ velocity at that instant.