NC
Quantum Mechanics
August 2022
Before we begin, this is a single part of the blog - The Journey of Quantum. Here, we do not go in depth but understand the process in a nutshell. In order to understand the true nature of Quantum Mechanics, one must understand the basic rules that govern the microworld.
In the coming parts, however, we will be discussing these topics in more depth- understanding the particle-antiparticle formation in fluctuations, field fluctuations, etc.
For now, let us simply focus on the basic rules of quantum mechanics.
A short brief on the Uncertainty Principle with Energy
Every particle in this universe tries to remain at the lowest energy state. These particles release energy to be in the neutral state form. When an object is in its lowest energy state, it is considered a stable object. This is why it releases photons/light spectrum when electrons jump from one orbit to another (to be in their stable/lower state). This effect can be observed and is called the hydrogen spectrum.
The Uncertainty with Energy
The Heisenberg Uncertainty principle is the basic foundation of Quantum Physics: many theories and experiments are substantiated by this principle.
It states that the position and velocity of an object cannot be measured at the same time, even in theory.
If we want to measure a velocity of a particle then we must compromise its position and vice versa. But this is not the main thing here, in fact, this relation can be replaced by energy and time.
Just like how velocity is uncertain with position, time is uncertain with energy.
Let's generalize this situation in the real world.
Space is a vacuum and it doesn't have any energy or field, this is what classical physics tells us about the nature of empty space. But according to quantum field theory, there is no free space, there are tiny fluctuations in the field called quantum fluctuations.
Ok, let's elaborate on this concept
Quantum field theory is a theory that says that the particles we see in our daily life are not particles - it's the effect of energy in their respective field.
According to this theory, every particle has its own field. The electron has its own electric field and so do other particles like protons.
When energy is passed in the field it creates a tiny ripple that forms electrons. Every particle is actually generated when sudden energy is given to its respective field. Similarly, like how energy is given through an electric field it produces electrons.
So space has some invisible fields which consist of tiny energies and if quantum field theory is correct, then there must be some particles produced from that field. Well, luckily there is! Scientists have found tiny fluctuations in space-time and they have called them 'Quantum Fluctuations'. These slight fluctuations are the result of small energy present in the quantum field.
Cosmic Microwave Background
To understand the CMB, one must understand its origin- the origin of the universe and time being itself. We must understand the process of the big bang and its effect on our primordial universe.
The big bang theory states that the universe is formed by a single infinitely dense object called a singularity. Other theories disprove the big bang or give other alternatives to our formation of the universe but these theories, however, do not provide enough evidence for our modern physics. The big bang theory is the only strong theory that agrees with both quantum mechanics and general relativity. Hence we are certain that the 'unified theory/ the theory of everything ' must connect general relativity with quantum mechanics.
Since the big bang is considered the beginning of time and the universe, we cannot apply our physics before the beginning of the big bang. In other words, no one can calculate or predict what happened before the big bang. This is why we considered the value of time (t) =0 at the beginning of the big bang.
However, Quantum Physics can explain the physics before the big bang - since it doesn't depend upon any time fluctuations, unlike general relativity. This is still to be proved and it is generally thought that nothing can explain before the big bang.
Inflation
When the singularity exploded, the universe expanded exponentially. The universe had an extremely high temperature after the big bang. At this temperature, there was no formation of any atoms or elements, the electrons and photons would bounce off each other and there was no nuclear nor electrostatic attraction between the particles.
Since the temperature was extremely high, the particles were resistant to the nuclear force. For millions of years, the electrons and photons were bouncing off at each other. After some million years, the temperature was slowly decreasing - this is because of the expanding universe. The universe is expanding regularly and because of that objects are moving very far away, which means that the total temperature of our universe is also decreasing concerning the expansion.
.png)
Our universe started with extremely high temperatures and is cooling rapidly because of the expansion. When the temperature of the universe was stable, the protons and neutrons no longer had enough energy to repel the nuclear force. They combined to produce the first matter: Hydrogen. This stage had a high temperature too, but it was enough to form hydrogen. Similarly, as the universe expanded more, the universe's temperature was slowly decreasing and other particles like helium and nitrogen were also produced.
The gases, which were the remains of the formation of atoms, attracted each other and formed stars and comets.
This is the outlook of the theory of inflation. We are not going in deep into this topic, as it is very complex. But I assure you that the information here is far limited to understanding other aspects of quantum physics.
So let’s go back to Cosmic Microwave Background (CMB)
We discussed that our universe started with an infinitely dense singularity. ( according to general relativity) This point exploded and new matter started to form as the temperature started falling. Well if that is true then we must have evidence of the infinite temperature, right?
Yes, we have!
If you have read my previous blog about the James Webb Telescope then you must know that every object that has a positive temperature must radiate heat ( infrared).
Every object in this universe that has a positive temperature emits heat, which can be detected by telescopes.
Similarly, when the universe was expanding it released an enormous amount of heat with tons of infrared radiation- that is called CMB. The Cosmic Microwave Background is actually the radiation of heat emitted by the big bang. No matter where you look in the universe, you will always find this disturbing radiation which proves the inflation theory. The universe was very hot back in billions of years ago and the radiation (CMB) can be observed.
Awsome theory!! Learned something new today.
❤️