Heisenberg’s uncertainty principle — The WHY we missed in our School’s Science lecture.
You are sitting in your Chemistry/Physics lecture, while your teacher is explaining a concept named as Heisenberg Uncertainty Principle. It’s a lecture just after the lunch break and you are kind of sleepy. (maybe your teacher is as well). The teacher skimmed through while you listened with yawning teary eyes! I bet you didn’t understand the first time, maybe we all crammed up the concept. But did we really care what Heisenberg was trying to explain? I went back in time to understand what he really meant with those scientific terms and boy it was so damn obvious!
According to Wikipedia, here’s the definition -
In quantum mechanics, the uncertainty principle (also known as Heisenberg’s uncertainty principle) is any of a variety of mathematical inequalities asserting a fundamental limit to the accuracy with which the values for certain pairs of physical quantities of a particle, such as position, x, and momentum, p, can be predicted from initial conditions.
Such variable pairs are known as complementary variables or canonically conjugate variables; and, depending on interpretation, the uncertainty principle limits to what extent such conjugate properties maintain their approximate meaning, as the mathematical framework of quantum physics does not support the notion of simultaneously well-defined conjugate properties expressed by a single value. The uncertainty principle implies that it is in general not possible to predict the value of a quantity with arbitrary certainty, even if all initial conditions are specified.
But what does that really scientific explanation imply?
Explaining the above in simpler terms -
In Quantum Mechanics, it’s extremely difficult to figure out the position and momentum of a particle with accuracy, which implies that if you know the position with accuracy, it becomes difficult to calculate the momentum, and if you know the momentum of the particle with greater accuracy, it becomes extremely difficult to calculate its position in space with precision.
Okay, so far so good, that’s what Heisenberg meant with his uncertainty principle. But we never cared to reason Why is that the case? (At least, I didn’t care back in my school days)
So, now, let’s try to explain why!
Why can’t we measure the position and momentum of particles together with higher precisions?
I never cared about this, to be honest, I was just cramming up to pass my exams, but after all these years I realised let’s try to understand the why, and to my surprise, it was really easy. So, let me try to put them in my own words.
How do we figure out the position of a thing in space? (How do you know the position of a car parked in the parking lot) — by looking at it. Does it change the position of the car when you look at it? Probably not. Did it change from the Parking position B1 to B2, or did your act of looking at the car changed the car’s position from the ground floor of the parking lot to the 1st floor? I hope not.
But Quantum mechanics is different, it’s the study of Sub Atomic Particles. It’s the study of those tiny dudes that govern this very fabric of the Cosmos. Things work a little different when we scale down to the level of Electrons, protons, etc.
- Now, how do we observe an electron? Via an electron microscope.
- How do we see things? When the light gets reflected from it.
- So, how do we observe an electron? By bombarding it with photons of light.
Photons of Light carry energy, when a photon interacts with an electron, it passes this energy to the electron. Electron while gaining this energy, changes its position. So when we look at an electron, we give the electron some energy that gets converted to Kinetic energy and hence indirectly changes its position. So while trying to find the position of an electron with accuracy, we changed its position. It’s basically a chase game where the electron always win.
I am not an expert in this field of science, but I tried explaining a concept that I couldn’t understand 16 years ago. Please rectify me if I am wrong somewhere. I hope I did justice to the topic. Why do I do it? I was just inquisitive.
Be inquisitive
Ending this with a hilarious meme I found online.
