Notes on Seven Brief Lessons on Physics - Carlo Rovelli

Physics used to be the most scary subject for me, as I couldn't bring myself to decipher its logics despite my relentless efforts during high school. 

At university, I rekindled back with physics as my professor taught it from the philosophical point of view, rather than just shoving theorems and calculations straight away. Thus, I started to read more physics book- and this one was my first try! I stumbled upon this copy at a local library in Bucharest, and I had to borrow it after reading the reviews.

This is not meant to be a review, but rather a compilations of key points and excerpts I extracted from reading this book back in summer '2022 (:

Seven Brief Lessons on Physics - Carlo Rovelli

• the fabric of space, origins of the cosmos, nature of time, phenomenon of black holes, working of our own thought processes

Lesson 1 - The most beautiful theory

🪐 Riemann’s mathematic

• space and gravitational field are the same thing
• Space keeps expanding
• Remnants of universe explosion 💥  (Einteon’s theory)

🪐 General Relativity

“Spacetime tells matter how to move and matter tells spacetime how to curve”

• John Wheeler (American Physicist)

Lesson 2 - Quanta

🪐 Quantum Mechanics

• Max Planck: father of the theory
• Einstein: the parent who nurtured it
• Niels Bohr: pioneered it’s development 

• quanta - packet of energy
• Photon for light (proved by Einstein)
• quantum leap- by Niels; in which electrons only take certain amount of energy to excite -> discrete

🪐 Heisenberg Uncertainty Principle

“the uncertainty principle states that we cannot know both the position and speed of a particle, such as a photon or electron, with perfect accuracy; the more we nail down the particle's position, the less we know about its speed and vice” - Caltech

h - Planck’s constant 

• it’s not possible to predict where an electron will appear, but rather, by its probability
• ‘quantum mechanics does not describe what happens to physical system, but rather, only hope a physical system affects another physical system’

 

Lesson 4 - Particles

⚛️ Higg’s bosons

• quanta 

⚛️ Standard Models 

Lesson 5 - Grain of Space

General relativity and Quantum mechanics can’t both be right!

• Newton: universal gravity by combining Galileo parabolas and ellipses of Kepler 
• Maxwell: equation of electromagnetic by combining theories of electricity and magnetism 
• Einstein: relativity by resolving an apparent conflict between electromagnetism and mechanics

☄️ Loop quantum gravity

• an endeavour to combine general relativity and quantum mechanics

☄️ Plank’s star

-> the entire matter of sun is condensed into the space of an atom

• Not stable: condensed and rebound again: expansion of universe-> explosion of black hole 

Lesson 6 - Probability, time and the heart of black holes

🛰️ Heat

• previously thought of some sort of liquid ‘caloric’ from 1 or 2 liquids (hot and cold)
• Decided by James Maxwell and Ludwig Boltzmann
• the difference between the post and the future exist only when there’s heat

: pendulum swinging forever (momentum shall be initiated by every obtained from stationery point- not from stationary position

🛰️ Boltzmann

• movement of heat from hot too cold is due to sheer chance! - large degree of probability 

Thermodynamics- The Science of heat 

Statistical mechanics- the science of the probability of different motions

What is a hot gravitational field ? -> what is a vibrating time? ->  what exactly is the flow of time? 

‘To trust immediate intuitions rather than collective examination that is rational, careful and intelligent is not wisdom: it is the presumption of an old man who refuses to believe the great works outside his village is any different from the one which he has always known’ - p59

1. Quantum
2. Gravitational
3. Thermodynamic

In Closing - Ourselves

Mesocospic - 2014; details mapping of the brain structure of a mammal has been achieved

• scientists and philosophers are discussing about special ideas on how the mathematical form of the structures can correspond to the subjective experience of consciousness.

Giulio Tononi - Integrated Information Theory 

• an attempt to characterise quantitatively the structure that a system must have in order to be conscious
• When we are awake (conscious) VS asleep (unconscious)

‘Our appetite for life is voracious, our thirst for life insatiable’ - Lucretius (De rerum natura, III, 1084)