The Feynman Lectures on Physics

Inspired by Sigil Wen, I am also reading The Feynman Lectures on Physics, a book Sigil gifted to me. These are my personal notes on the lecture imported from the note taking software I use.

~July 2023: Got the book

Chapter 1 notes: Atoms in Motion

~Mid August 2023

• To prove everything is made of atoms, an idea called Brownian Motion was discovered

• It refers to the motion of particles caused by the bombardment of atoms

• Dispersion refers to the process of evaporation; An accumulation of energy(usually due to the movement of atoms cause by heat) causing atoms to break off

• When water gets too hot, it's atoms accumulate energy from the heat and this can build up to atoms breaking off/evaporating

Chapter 2 notes: Basic Physics

Finished December 29, 2023 at 4:56pm; Edited on December 29, 2023 at 9:33pm

• 2 analogies:

• Physics is like god playing a game of chess, we are observing the game through experiments and observations. Overtime, we will understand the rules of the game through repetition but, rules that appear rarely like castling or En Passant are harder to grasp

• 3 methods of learning the rules:

• The first method of learning the rules is by observing the obvious(32 pieces on a chess board)
• Secondly, observing where rules don't work(a bishop might be confined to black squares only until a pawn gets promoted to a bishop on a white square)
• Finally, testing ideas by approximations of observations(god 1 moved his piece to protect his king from god 2)

• Although we know the rules, we don't fully understand how to play

• We can't fully explain phenomenons(playing moves) based off of the laws of physics(the rules of chess) because of how large these phenomena are

• The electromagnetic field acts as a pool and the different charges/particles act as floats, when 1 float moves, the other is affected by the disturbance in the water(field)

• Question that was pointed out that I found interesting: "Why does carbon attract one oxygen or perhaps two oxygen but not three oxygen?"

• After some research(#chatgpt), I found out that it was due to the fact that when carbon is attracted to 1 or 2 oxygen, that is when it is the most electrically stable

• CO3 can happen but is unstable and will break apart easily

• The universe wants to be in its most stable form

• At an atomic level, many laws don't apply and many laws only apply

• The law of uncertainty(at an atomic level) refers to the fact that we cannot both know where something is and how fast it is going

• This solves the question of why don't electrons fall into the nucleus, because if they do, we'd know it's position and it would need to accumulate a high and unknown speed, breaking off

• Particles with no mass are never at rest and always moving
• Conclusion: We don't know much of anything and we don't know many things

Chapter 3 notes: The Relation of Physics to Other Sciences

Finished on December 30, 2023 at 6:59pm

This chapter was very very long. Although it was around the same length as other chapters, it proposed a lot of very deep ideas, and didn't provide the answer... Which in turn, my monkey brain instinct kicked in and I spent way too long on these questions

• All Science is measuring nature and understanding it

• Math is a Logical Science

• Chemistry:

• Physics and Chemistry share a branch called statistical mechanics, which is the most likely thing to happen based on probabilities

• For example chemical reactions that have thousands of atoms that cannot be tracked

• This also showed how in all field of natural science, it is impossible to be 100% precise with predictions, we can only count on probabilities

• It is also really hard to be precise in measurements with a degree of uncertainty

Biology:

• physics aid in helping understand electrical systems like nerves
• Interesting fact: Biology helped us understand the conservation of energy because of the heat taken and given by living bodies
• A lot of ideas in Biology only take about animals as since Biology is such a large field, we must find the fundamentals of life as a whole, not just one type of it
• Chemical reactions need energy to occur

• Enzymes essentially open up molecules, add atoms, and rearrange molecular structures, allowing reactions to occur easily

• A special chemical reaction that enzymes help is GTP-GDP(Don't worry about the deets, it's bio)

• This reaction is interesting because there is a big energy disparity in this transformation
• BIG QUESTION: The text says "An enzyme, you see, does not care in which direction the reaction goes, for if it did it would violate one of the laws of physics" and then provided no explanation >:( So I went as researched on which law this is and why

• At first I thought it was the conservation of energy as the energy levels cannot increase without external input but then I realized that the enzymes are adding energy. Then, after research, I learned it was the law of entropy that could be violated

• This law states that in a system with no external input or output of energy, the total energy will decrease from its initial value and entropy will increase. Thus, the direction of GTP-GDP reactions occur in a way where the total energy is decreasing, not increasing as that would be impossible. If the enzymes were to make these decisions, then it would violate this law as the direction is self deciding. Also because of the direction deciding itself, it automatically retains balance in this system, preventing any unstablenesses to occur in the body

• I was very confused on how the law of entropy matters as energy is being added by enzymes and I received expert insight from @sana_rfzz on Twitter, confirming this explanation!

• Special experimental techniques are used to make testing and observing easier

• One example would be marking a carbon atom by making it a specific isotope so that we can find it, then put it into a reaction, waiting, then looking for it

• Depending on where it was, we can backtrack to the reactions happening in a chemical reaction that are causing the marked atom to move

• Astronomy:

• Astronomy started physics because of the movement of celestial objects, but this is surprising as back then, we new very little about the cosmos until the 16th century where Copernicus dropped some fire discoveries
• We were able to detect that the atoms inside stars were the same as atoms on Earth by measuring the light they emitted with a spectroscope and then analyze the frequency of light waves to find the atom emitting it

• BIG QUESTION: I realized, I don't know why or how atoms emit light. So my monkey instincts kicked in and I did my research

• The reason is because when atoms go from high to low energy states, they transfer that energy into light, emitting photons

• The most common light creation method would be when electrons are in a high energy state, causing them to be "excited" and unstable, which would result in their energy levels falling back down, releasing photons/light

• Helium was discovered by observing the sun, the god of the sun is Helios..

• Geology:

• Too many bodies to track, too complicated

• These complicated systems mean we cannot 100% predict weather and geologic activity

• Psychology:

• An interesting question that I wont try to solve because no one has solved it yet was that when we learn something, how do the atoms in our brain cells change? What is different?

• In order to create a theory, we must know where things(atoms) are