courses:ast100:1
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| courses:ast100:1 [2024/10/14 02:34] – [3. Birth of Matter] asad | courses:ast100:1 [2026/02/24 06:33] (current) – asad | ||
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| ====== 1. Particle Age ====== | ====== 1. Particle Age ====== | ||
| - | SOCRATES: The Brahmaputra originates on the northern slopes of the Himalayas from some glaciers like Chemayungdung and Angsi, which are only 71 km east of Manas Sarovar. Many rivers emerge from these glaciers and merge into one stream to form the Tsangpo River. As difficult as it is to find the source of a river, it is at least 24 times more difficult to find the source of the universe. | + | ===== - Event highlights ===== |
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| - | Rabi: I understand that you want to focus only on Angsi to make things easier. But simplifying the description of the particle age of the universe will not be so straightforward. This cannot be understood without understanding the standard model of particle physics mathematically. | + | <div id=" |
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| - | SOCRATES: The ancient Indians said that Brahma is the foundation of the universe, Manas Sarovar is created from the mind of Brahma, and Brahmaputra is the son of Brahma. Since Juno could not understand the mind of Brahma after so many visits to Manas Sarovar, I don't think we can understand the mathematical form of the Standard Model, no matter how much we talk to you. | + | # |
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| - | Juno: With that out of the way, everyone, let's go to the supposed source of the Brahmaputra. Sitting on the ice and talking will hopefully reduce Rabi's fire a bit. | + | # |
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| - | Socrates: Where is this ' | + | /* Timeline Styling */ |
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| - | Hermes: [[https://maps.app.goo.gl/ | + | |
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| - | [Everyone flies to the source of the Angsi River while listening to Hermes' | + | # |
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| - | ===== - Spacetime from the Big Bang ===== | + | #doku-cosmic-light .event-item: |
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| - | SOCRATES: The big bang theory, the standard model of cosmology, says that our universe, meaning all of us, came from an almost infinitely small point. Do you remember the comedy of Borges with two point-dwellers? From a point about fourteen billion years ago, spacetime began to expand, an event called the Big Bang. This expansion is still going on due to the explosive energy of the Big Bang, our universe is still getting bigger day by day. But when I go to tell this to the gods of Olympus, they ask, what was before this big bang or how did this big bang happen? If the gods ask such questions, what will happen to mortals? | + | /* Timeline Dot */ |
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| - | Rabi: If spacetime was born at the time of the Big Bang, then the question of what was before, or beyond, the Big Bang is meaningless. But the question is, can there really be no spacetime except our spacetime created from the Big Bang? Could it even be that nature is actually a multiverse with many or an infinite number of four-dimensional universes? Is there nothing beyond the four dimensions we are thinking of with three dimensions of space and one dimension of time? Could our four dimensions be born from another world of higher dimensions? We still don't know the answer to these, many mathematical theories have been made as an attempt to know, but which theory or model is correct has not yet been proven through observation. It is very common to use many dimensions in string theory. | + | #doku-cosmic-light .time-badge { |
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| - | SOCRATES: I understand that we know what happened after the Big Bang, but the cause or mathematical basis of the Big Bang itself is still unknown. Are mathematical theorems part of the universe, or laws imposed on the universe from outside? | + | # |
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| - | Rabi: Good question. The debate started by your student Plato and his student Aristotle is still going on. This figure made by Roger Penrose can explain the matter. Three worlds can be imagined in nature or reality: mathematical, | + | /* Math Superscripts */ |
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| - | SOCRATES: That means Plato thought that all theories would exist even if there were no universe, because theories exist outside the universe in a separate mathematical world. | + | /* Mobile Optimization */ |
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| - | Rabi: Yes. And according to Aristotle, theory is a human-made model to explain various phenomena of the universe. If there is no universe, there will be no theory. | + | <div class=" |
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| - | SOCRATES: But Aristotle' | + | <!-- Event 2 --> |
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| - | Rabi: That is your own choice. I am a Platonist. One who understands | + | <!-- Event 3 --> |
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| - | Socrates: Well, then these three worlds together what can be said to be the basic structural elements | + | <!-- Event 4 --> |
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| - | Rabi: Definitely STEMIC, meaning space, time, energy, matter, information, and consciousness. | + | <!-- Event 5 --> |
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| - | Socrates: Where is your math? | + | <!-- Event 6 --> |
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| - | Rabi: Everything in math is inside that information. | + | <!-- Event 7 --> |
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| - | SOCRATES: What was the need to separate consciousness? | + | </ |
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| - | Rabi: Many cognitive scientists think that consciousness is another type of thing, not information. But that is another debate. We should first focus on just the ' | + | ===== - Event details ===== |
| - | SOCRATES: These four together can be explained by relativity, but only on a much larger scale. Relativity does not apply at very small atomic or subatomic scales, where energy and matter have to be explained by quantum theory. If a theory can be made combining general relativity with quantum theory, it is possible to explain STEM at all scales together. Many physicists are still trying to make a Theory of Everything (TOE), aren't you one of them? | + | {{:courses: |
| - | Rabi: I still think some future version | + | The saga of our cosmos began at "time zero" with the Big Bang—a singular event that marked the simultaneous birth of space, time, energy, and matter. Emerging from a state of unimaginable density, the universe was not a traditional explosion bursting into an empty void; rather, it was a sudden eruption of space itself. This " |
| - | SOCRATES: Then tell us what is meant by Everything, and what is meant by unifying. | + | Almost instantly, in the blink of an eye between $10^{-35}$ |
| - | ===== - Birth of Energy ===== | + | As the intense heat of the beginning began to fade within the first fraction |
| - | Rabi: Currently there are four types of energy in our universe. Each energy interacts differently. The interaction | + | |
| - | {{: | + | During the first full second of existence, the universe functioned as a colossal, high-energy furnace where light was constantly transforming into substance. In this era of Particle Creation and Annihilation, |
| - | SOCRATES: Yes, it appears so in this figure | + | By the time the universe was three minutes old, it entered a crucial phase of " |
| - | Rabi: Because, Socrates, after the Big Bang there was only spacetime and energy | + | Following this initial frenzy, the universe expanded |
| - | SOCRATES: Matter doesn' | + | Finally, between 300,000 and 380,000 years after the Big Bang, the universe cooled enough for electrons |
| - | Rabi: We cannot explain something called zero time. At Planck time, all our theories fall apart. Planck time is 1 quattuordecillionth of a second (45 zeros before one), that is $10^{-45}$ seconds. Since Planck time, there has been spacetime, and with it only one unified energy and force. It's called the TOE force, because if a theory of everything is ever discovered, that theory can explain this force. | ||
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| - | Rhea: Wait, I don't understand the time and temperature thing in your figure. Accustomed to the cultural age, I have a hard time digesting such a small number. What was the age and temperature of the universe at the time of this tow force? | ||
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| - | Rabi: Remember, all forces are born in the first picosecond. The TOE force existed much earlier, when the universe was less than 10 trdecillionth of a second. If you go to the [[un: | ||
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| - | Rhea: From what I see in the list, 1 tredecillion means 42 zeros after one, then 10 tredecillion means 43 zeros after one. Just twelve zeros after one makes one trillion, and here we have to put 43. It is impossible for any human being to feel the terrible shortness of time when one second is divided by such a large number. And I don't even want to try to feel the temperature. | ||
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| - | Rabi: It's cool to sit in this ice and wonder what the temperature of the universe was at that time. Think about it. The source of the Brahmaputra is very cold, the temperature increases as you go towards the estuary (Bay of Bengal). The opposite is true of the universe. The temperature was the highest during the Big Bang, and since then, as the universe has expanded, both its density and temperature have decreased, and are still decreasing. | ||
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| - | Rhea: If we look at this figure and the list of numbers, we can say that when the age of the universe is 10 tredecillionths of a second ($10^{-43}$ seconds), and when the temperature is 100 nonillion Kelvin ($10^{32}$ K), then by breaking the TOE force, two separate forces were born, gravity and GUT force. What does ' | ||
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| - | Rhea: On the left side of the name of the four forces, I see the names of some particles, and on the right side some numbers and pictures. What does this mean? | ||
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| - | Rabi: This is a basic introduction to these four forces for the benefit of those who may not understand anything through math. Every force works by exchanging certain particles. The particles of the strong force or interaction are the gluons, the photons for the electromagnetic force, and three types of bosons (for example, Z boson) for the weak force. No such particle has been found for gravity so far, but just as people decide on a name before having a baby, scientists have decided on the name ' | ||
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| - | Rhea: But the most important thing is to understand what the forces really are. | ||
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| - | Rabi: That is shown in the four pictures on the far right. Strong and weak forces act only inside the nucleus of an atom. The strong force binds three quarks together to form a proton. The weak force can convert an up quark of this proton into a down quark by converting the proton into a neutron, thus giving rise to radioactivity. Electromagnetic forces hold atoms together by creating an attraction between electrons and protons. And gravity bends the space around the earth and forces the moon to revolve around it. | ||
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| - | Riya: But you didn't explain one thing. At one picosecond in the middle of your figure it says ' | ||
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| - | Ravi: That is the most important thing. I mentioned the sequence of birth of the four energies or forces, but did not explain why it broke from one into four in this way. The reason is called symmetry breaking in physics. A theory in physics that has symmetry means that the theory applies equally in all space and time. The theory of gravity is as true for the apple tree as it is for the Andromeda galaxy, and is as true today as it was yesterday, and will be as true tomorrow. There is a more extreme form of this symmetry, where even the identity of the particles becomes symmetric, meaning that there is no theoretical difference between one particle and another. For example, there was no difference between photons and Z bosons before the electroweak theory' | ||
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| - | Rhea: I understand, but don't you think, Socrates, that Robbie' | ||
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| - | SOCRATES: Right. | ||
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| - | Ravi: Time for a metaphor then. The reason for symmetry breaking at a certain point is actually phase change. For example, water is a gas at 200 degrees Celsius. Lowering the temperature won't do much until 100 degrees, but at 100 degrees the water will actually turn from a gas to a liquid. Not at any other temperature, | ||
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| - | Rhea: Now I understand better. But the inflation you wrote down at an octillion degree age needs a little explanation. | ||
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| - | Ravi: Just as heat or energy is required to boil liquid water into steam, energy is released when steam is converted into liquid water. Similarly, every phase transition or symmetry breaking in the universe releases a lot of energy. At one octillion degrees, the energy release was so high that the universe suddenly became very large. This phenomenon is called inflation, but its definite proof is not yet available. | ||
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| - | Rhea: We need to get to know these phase-changing, | ||
| - | ===== - Birth of Matter ===== | ||
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| - | Rabi: That's why we have to keep an eye on the figure below. The seventeen particles that have so far held their place of honor in the Standard Model of particle physics are shown below in two ways: on the left is the mass, charge, and spin of each particle, and on the right are the same particles arranged differently to show the beauty of the model. | ||
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| - | Rhea: Here we also see four particles known as carriers of the three forces: gluons, photons, Z bosons, and W bosons, each with spin 1. Strong and electromagnetic forces are similar in that their particles have no mass and no charge. Two particles of the Wick force are very heavy, one has a mass of 91 and the other has a mass of 80 GeV, but what is the meaning of this unit of mass? I understand that GeV stands for giga electron-volt, | ||
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| - | Rabi: I have already said that energy and matter (mass) are the same thing with Einstein' | ||
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| - | Rhea: Let's look at the left figure first. Here on the left are 12 particles of matter whose common name is fermion, named after Enrico Fermi of Italy, and on the right are 5 particles of energy whose common name is boson, named after Satyendranath Bose of Dhaka University. Energy particles have spin 1, matter particles have spin 1/2. Particles of energy are called carriers of interaction or force. The Higgs boson is called a scalar boson, and the other four are called gauge bosons, or vector bosons. Even if I understand scalar and vector, I don't need to understand the meaning of these names. The Higgs is the heaviest of the bosons, while the gluon and photon are massless. Matter particles are of two types: six quarks and six leptons. The six quark names are pretty cool: Up, Charm, Top, Down, Strange, Bottom. The charge of the first three is 2/3, the charge of the next three is -1/3. The names of the six leptons are electron, muon, tau, electron neutrino, muon neutrino, tau neutrino. The first three have a charge of -1, and the three neutrinos have a charge of 0, making them neutral. The heaviest quark is top, and the lightest is up. The heaviest lepton is the tau, and the lightest is the electron, our most beloved object. | ||
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| - | Rabi: Great description, | ||
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| - | Rhea: But you told Socrates in the beginning that you would ' | ||
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| - | Rabi: Good question. Since energy and matter are equivalent, one was created from the other after the Big Bang all the time. This phenomenon is called 'pair production' | ||
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| - | Rhea: So can matter and antimatter be created from energy even now? | ||
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| - | Rabi: No. Because it takes a lot of energy to create matter through pair production, it requires temperatures much higher than today which does not exist even in the center of stars, but the Universe was hot enough just after the Big Bang. Antiparticle of electron is called positron. The temperature required to form an electron-positron pair is 10 billion Kelvin, the temperature required to form a proton-antiproton pair is 10 trillion Kelvin, and the various quark-antiquark pairs require about 1 quadrillion Kelvin. Since the temperature of the universe was one quadrillion kelvin at an age of 1 picosecond, quarks were first born between 1 picosecond and 1 nanosecond. Then at the age of 1 microsecond, | ||
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| - | Rhea: Interesting. But you only talked about particles of matter. In each of these cases, don't we also get antiparticles of antimatter? | ||
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| - | Rabi: Yes, antimatter has always been created along with matter. But the interesting thing is that from the very beginning, for some unknown reason, there was a little more matter than antimatter in the universe. Now you see in the figure that just as matter-antimatter can be formed from energy, so also matter-antimatter can completely annihilate each other and return to energy. This destruction, | ||
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| - | Rhea: Where did the energy created from all these annihilations go? For example, where are the photons produced in all electron-positron annihilations? | ||
| - | ===== - Background of Photons ===== | ||
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| - | ===== - Light, Color, Telescope ===== | ||
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