Dr. Abdus Salam’s Nobel Prize-winning electroweak theory: What was the theory covering the early stages of the universe, and why is it important?
A scientist from Pakistan named Dr. Abdul Salam, who won the Nobel Prize, put forward electroweak theory in the field of physics almost 50 years ago. Its position in the field of physics is so key that it is still routinely taught in the curriculum today.
His theory of electroweak theory later became known as the Salam-Weinberg model. Its modern form is called the Standard Model. Steven Weinberg is an American scientist who shared the Nobel Prize for this electroweak theory in 1979 with Dr. Abdus Salam and Sheldon Lee Glashaw.
Dr. Abdus Salam first asserted in his electroweak theory that two of the four fundamental forces found in the universe, the wake force or weak nuclear force and electromagnetism, are essentially two forms of the same force.
He combined these two forces and named it Electrovac Force. His discovery led to many results and led to many scientific predictions.
One of them was regarding elementary particles that had not been observed until then.
Professor Pervez Hoodbhoy, a physicist in Pakistan, told the British Broadcasting Corporation (BBC), that the electroweak theory of Dr. Abdus Salam has a key position in the field of physics.
‘Unifying these two forces means that he proved that they have the same structure from a mathematical point of view. It was considered a big task because it has different results.
According to Prof. Pervez Hoodbhoy, one of the most important results that Dr. Salam’s electroweak theory led to was that he predicted that “there are some particles that are of fundamental importance but have not been seen so far.”
These particles were seen 15 years after their discovery when they were tracked by the European Atomic Energy Agency.
What is this game of particles and forces?
Cosmologists think that the universe started out as a particle-filled mass of light and force that was very hot. Then there was a huge expansion that started the journey to the current form of the universe.
According to scientists, this big expansion happened in a moment, and this basic expansion process is called the Big Bang, which explains the existence of the sun, moon, stars, planets, and other celestial bodies.
The basis of this electroweak theory is mostly in the observations of cosmology, and science demands evidence.
What does Dr. Salam’s electroweak theory tell us about the universe?
A branch of physics called particle physics deals with the structure and properties of elementary atomic particles. Its experts look for scientific evidence that can explain the existence of the universe and the creation of matter and life in it.
Dr. Abdus Salam was one of those scientists. According to Prof. Pervez Hoodbhoy, this theory of unity can be applied in the field of cosmology, and thus we can know how the early moments of the universe were spent.
“What kind of particles were in it and what was the temperature, and then why the various elements that formed later formed in the quantities that we observe today.”
What are elementary particles, who give existence?
To understand why Dr. Abdus Salam’s theory holds a key place in physics, it is important to first see what these fundamental particles and fundamental forces are and how they relate to the universe and its creation.
According to science, all the surrounding matter is made up of elementary particles, i.e. these elementary particles are the building blocks of matter. These give weight to other particles.
An example of this can be understood as if you shake a stationary train from its place, you will feel its weight. This is the weight given to it by the fundamental particles that make it up. But now the question was, where did these basic particles get their weight?
We will get the answer to this question in the explanation of Dr. Abdus Salam’s theory. First, let’s see: what are the basic forces?
What are the four fundamental forces in the universe?
Prof. Pervez Hoodbhoy explains it like this: “We see in our world that there are four basic forces, which we can identify separately.” We then plug them into different equations and compare the predictions they make with experience.
These forces are responsible for driving the fundamental particles. One of them you know as gravity.
The other three are known as electromagnetism, strong force, and wake, or weak force. The best way to explain how these three forces affect the fundamental particles is with Drs. Salam and Weinberg’s model and its updated version, the Standard Model.
These three forces arise from the exchange of particles called force carriers. The group to which these particles belong is called “bosons.” Particles of any substance transfer energy to each other by exchanging these bosons.
What happens with the combination of these fundamental forces?
Professor Pervez Hoodbhoy explains that “when the universe was created, at that time these four forces were merged into one force.” As the universe continued to expand, they started to differ.
Each fundamental force has its own boson. We see only two of them here with regard to the doctrine of Dr. Abdus Salam. Electromagnetic energy is carried by photons, while weak forces carried by bosons are called “W” and “Z.”
The weak nuclear force has a very small range, which suggests that it is carried by very large particles. And that means the W and Z bosons had weight, but the photon had none.
How did Dr. Abdus Salam combine these two forces?
Dr. Abdus Salam theorized that if there are four such particles, they are “messenger” or “carrier” particles. If two of them were neutral and two were electrically charged, they could make electrovacuum unity possible.
Thus, it was found that the main balance of this theory was hidden in a scheme that gave weight to particles moving during weak nuclear force exchange but not to photons during electromagnetic exchange.
How important was their prediction?
Dr. Abdus Salam and Weinberg’s theory said that there is an invisible field or fields that extend throughout space and interact with the visible field to give particles their weight.
It also contains the answer to our question as to where the fundamental particles from which other particles are made or carry weight get their weight or how they came to be.
This hitherto unseen field was later known as the Higgs boson, and the particle carrying it was called the Higgs particle, named after Peter Higgs, the scientist who proposed the theory.
What is the Higgs Boson?
According to Prof. Pervez Hoodbhoy, Higgs wrote an article in 1964 that was not related to electrovacuum theory.
‘It was just a miracle in the quantum field theory article that particles could be given weight. Salam and Weinberg applied this work to wake and electromagnetic waves.’
According to Prof. Hoodbhoy, both of them wrote that this boson exists, but their theory did not predict how heavy it would be, so it had to be found experimentally.
The Higgs field was different from the fields of other fundamental particles because it had volume but no direction. Similarly, unlike other particles, its particle, the Higgs boson, had a spin value of zero.
One of its unusual features is that its power is greater when its field value is zero.
What did he explain in the question of the origin of the universe?
According to the Higgs boson theory, all elementary particles gained weight when they interacted with the Higgs field, and this was possible when the universe cooled and the force on it decreased after the initial massive expansion, or Big Bang.
The different masses of elementary material particles are also due to the fact that they interacted with the Higgs field with different force.
This theory also explained Dr. Abdus Salam’s electroweak theory as to why bosons W and Z of the wake force had weight while photons of the electromagnetic force had no weight.
‘It was the work of Dr. Abdul Salam’
In 2012, scientists at the European Atomic Energy Agency conducted a massive experiment to search for the Higgs boson, and scientists at the Large Hadron Collider center claimed to have received a signal consistent with the Higgs boson.
This electroweak theory is important in many ways, and it led to several results, one of which was the explanation of the question of how the universe expanded in an instant and then how it was possible to expand further.
According to Prof. Pervez Hoodbhoy, this is only one of the thousands of things in the story of the existence of the universe. However, it was the work of Dr. Abdus Salam and Dr. Weinberg that saw and discovered the Higgs particle.