If somebody were to tell you that you could disturb the trajectory of the moon just by looking at it would you believe it?
If somebody else were to share with you that you could alter the direction of the electron just by looking at it, assuming that you can see it, would you believe it?
However the answer is positive for the second question.
So is it really true?
Physics took a whole new meaning with the entry of a great man who is always associated with the falling apple.
He was able to make some quantitative predictions with respect to motion of objects.
He was the one who formulated the three laws of motion which until the very day today stands as the cornerstone of classical physics.
Yet classical physics only reign supreme in the world of large objects and the ones that move at a velocity very much lesser than the speed of light. At microscopic level, which refers to the unseen particles around us and the particles that are zig zagging across the universe without been seen with the naked eye, they behave very differently and are not truly obedient students of the classical laws of motions.
These little unseen particles are under the rule of quantum mechanics, the only one that reign supreme in an unseen microscopic world.
In order to see an object we need light to be shone on that object.
The light will then bounce back and enter our eyes so that the desired image can be formed.
In quantum mechanics, light is a stream of little particles called photons and each photon carries a certain discrete energy proportional to their frequency.
The higher the frequency the greater the energy of the photons this more penetrative.
As such, x-rays are more dangerous as it’s more penetrative than infra red since it has a much greater frequency.
Therefore if we illuminate light onto moving electrons for example, the trajectory will be changed as the particles of light called photons will collide with the electrons as both are tiny by nature.
Altered trajectory means change in momentum, basically a parameter that tells you the velocity of the object combined with the mass of the particle itself.
In short there is a degree of indeterminism in the exact location of the electron and it’s corresponding momentum as the disturbance caused by the collision between the photons and the electrons completely alter the history of its motion.
With quantum mechanics, indeterminism is introduced.
You can no longer know something full of certainty especially in the microscopic world.
This is in contrast to the deterministic world of classical physics.
You can predict many things with the highest possible degree of accuracy.
Quantum mechanics has not only introduced a paradigm shift in how physics should be viewed.
It has open up a new plethora of possibilities that was never evident via the eyes of classical physics.
It only tells us that knowledge is limitless and as we push forward the boundaries of knowledge even more, we are sometimes taken by surprise of what we may find.
Yet perhaps that is why the pursuit of greater understanding of natureis always fascinating.
You never really know what you will find.
Nature is indeed full of surprises.