“From Atom to the Quantum Ordeal”
- Binod Bhattarai
Sweet is by convention, bitter by convention, hot by convention, cold by convention, color by convention; in truth there are but atoms and the void.
– Democritus
Hello. Yes you, let’s schmooze for a while. How is the weather today? It’s sunny or cloudy? No? Ok so it is dark already. But how can you read something in dark? Lights are on? Oh, so you are lucky that the Maxwell’s Equations worked fine for you. Do not get surprised but there are few mega-cities in the world that celebrate darkness; electric. Oh you’re already in one? See I can predict at least few things. It’s really obvious that there is no proper way of telling the current state of your mind neither the time of the day nor the weather outside while you are here reading this. I won’t even surprise you if I say that I never knew you were going to read this article. (I hope you won’t take it as some task or challenge and run away closing this book…). It is outlandish to think about but it really did happen; a beautiful work of science and mathematics to get you here right now reading this article. Here, Science and Math just does not mean numbers and physical laws that govern but a wonderful combination of phenomenon and figures that worked beautifully together to get you here.
The piece of paper you are holding, the ink in which this very text you are reading, you and everything that exists around your surrounding are made up of some fundamental particles called electrons, protons and neutrons. Make a little twist in their numbers and they work together to create something else somewhere or even to destroy things. Every drop of water out there or the cool air we breathe, the sun and the stars that shine in the sky and everything else that exists; they all have things in common if we look into their very fundamental part.
That is again the small fundamental particles called electrons, protons and neutrons, which you can visualize after taking out 10,00,00,00,000 slices from this single paper of this magazine. Together they can form different atoms by varying their number in their combination. In addition, those atoms finally become elements and compounds and on a large scale when they combine, we begin to see things around us the way they are right now. This combination of atoms of different elements taking account to their current position and state around you as a whole never happened before and would only exist like this once. Moreover, those particles never had any plan of creating things the way they are around us. The best example is you, yourself. The atoms inside you of various elements exist like this for now and it will only exist like this once for the age of this universe. When we die, those atoms and molecules transform into other compounds. Electrons, which are negatively charged particles, are in continuous motion in an atom. They are moving around the nucleus and are very good at one thing id est never stopping. It does not care where it is, what it is going to make up in macroscopic level through other such combinations but it is interesting how it can create such a beautiful world around us.
Whatever now, let us mull over to your previous night. Sorry for a dark beginning but let us do it anyway. Here I’m taking you to a lonely night ride away from your home. You are reading a science article so without any delay let’s get scientific here. How about starting up with a gentle thought experiment? Do you remember your bed you slept on last night? Yes your bed, hammock, truckle, trundle or whatever.
All right, let us focus now. Imagine you woke up suddenly in the middle of a night and you find darkness all around you. No it’s not the NEA doing power cuts. Here I mean serious darkness, nothing but only emptiness all around you. Yes even your bed is gone. You can’t even see where you are standing. Now if you tend to move, can you tell where you were moving and how far have you gone? Sounds eldritch? Nothing is creepy here so no worries. You moved your feet but still can you tell where you are going? Ok let’s make it easier now. How about adding the bed in our earlier thought experiment? Ok now start with the presence of bed and you but nothing else in our experiment, if you move you can always tell whether you moved away from the bed, towards left or towards right. Or even up and down if you had wings. See as soon as we add a reference point all the things start making sense at a sudden.
The world is made of tangible things that we can observe and recognize. Thanks to electrons, protons and neutrons (If you still remember them…). All the things around us that are made of nothing but different atoms and molecules, exert forces, or bump into one another, and their motion change in response to those influences. If we could fix a reference point and know all the positions and momentum of every particle in the universe, we could predict the future and the past with perfect accuracy. However, unfortunately, there is something wrong with our world where uncertainties start counting and leads us to a very different world called the quantum world.
According to quantum mechanics, what we can observe about the world is only a tiny subset of what actually exists. That is whatever we have right now is just one subset of the many many many possible outcomes. When we talk about predicting where the particle would be after noting their position and momentum, we would be talking about what Physicists usually refer to, as “Classical Mechanics” also known as Newtonian Mechanics as it relies on the rules laid down by Newton. Nevertheless, classical mechanics is not correct now. We know better. It does not matter even if Classical Mechanics worked fine with Einstein’s general relativity but we needed something else to explain the behavior of those microscopic particles like electrons, protons and neutrons that is quantum mechanics.
In quantum mechanics, there is no exact fact of where a matter is located. In our earlier thought experiment when we saw nothing, there was still a probability that our bed was somewhere. In classical mechanics, where the state of a particle is a specification of its position and its momentum, we can think of that state as specified by a collection of numbers. For one particle in ordinary 3-Dimensional space, there are six numbers, the position in each of the three directions and the momentum in each of the three directions. In quantum mechanics the state is specified by a wave function, which can also be thought of as a collection of numbers. The job of these numbers is to tell us the probability of getting a certain result for any observation or measurement we could imagine doing. The complete wave function consists of some value of amplitude for every possible observational outcome that specifies the state in quantum mechanics, just as the positions and momentum specify the state of the object in classical mechanics. Thus there is amplitude that your bed is somewhere and your whole house could be somewhere in the universe. So no worries you’ll get back there soon. And tonight be certain no matter what happens your bed is going to be there somewhere here or somewhere else.
“It is not that modern physics has rediscovered ancient Buddhist wisdom or something but the quantum world is leading us to brilliant future possibilities and is arguably the greatest triumph of human intelligence and imagination in all of history.” – Sean Caroll
