Ciro Santilli @cirosantilli 37 

TODO

Rockefeller family by

Ciro Santilli 37 Updated 2025-07-16

They were basically a Microsoft of their century. A little less monopolistic perhaps as countries believed they should own they natural resources, unlike their data.

Quantum field theory by

Ciro Santilli 37 Updated 2025-07-16

Theoretical framework on which quantum field theories are based, theories based on framework include:

so basically the entire Standard Model

The basic idea is that there is a field for each particle particle type.

E.g. in QED, one for the electron and one for the photon: physics.stackexchange.com/questions/166709/are-electron-fields-and-photon-fields-part-of-the-same-field-in-qed.

And then those fields interact with some Lagrangian.

One way to look at QFT is to split it into two parts:

deriving the Lagrangians of the Standard Model: S. This is the easier part, since the lagrangians themselves can be understood with not very advanced mathematics, and derived beautifully from symmetry constraints
the qantization of fields. This is the hard part Ciro Santilli is unable to understand, TODO mathematical formulation of quantum field theory.

Then interwined with those two is the part "OK, how to solve the equations, if they are solvable at all", which is an open problem: Yang-Mills existence and mass gap.

There appear to be two main equivalent formulations of quantum field theory:

Quantum Field Theory visualized by ScienceClic English (2020)

Source. Gives one piece of possibly OK intuition: quantum theories kind of model all possible evolutions of the system at the same time, but with different probabilities. QFT is no different in that aspect.

youtu.be/MmG2ah5Df4g?t=209 describes how the spin number of a field is directly related to how much you have to rotate an element to reach the original position
youtu.be/MmG2ah5Df4g?t=480 explains which particles are modelled by which spin number

Video 2.

Quantum Fields: The Real Building Blocks of the Universe by David Tong (2017)

Source. Boring, does not give anything except the usual blabla everyone knows from Googling:

youtu.be/zNVQfWC_evg?t=1335 shows www.youtube.com/watch?v=9TJe1Pr5c9Q from quantum field theory simulations
youtu.be/zNVQfWC_evg?t=1522 alludes to the Birch and Swinnerton-Dyer conjecture

Video 3.

Quantum Field Theory: What is a particle? by Physics Explained (2021)

Source. Gives some high level analogies between high level principles of non-relativistic quantum mechanics and special relativity in to suggest that there is a minimum quanta of a relativistic quantum field.

Octagon by

Ciro Santilli 37 Updated 2025-07-16

Received Pronunciation by

Ciro Santilli 37 Updated 2025-07-16

Hard Attack: How English is getting more "choppy" by Dr Geoff Lindsey (2023)

Source. Goodness this dude is a master of it.

Age of Empires by

Ciro Santilli 37 Updated 2025-07-16

Raising and lowering indices by

Ciro Santilli 37 Updated 2025-07-16

History of radio by

Ciro Santilli 37 Updated 2025-07-16

Bose-Einstein statistics by

Ciro Santilli 37 Updated 2025-07-16

Start by looking at: Maxwell-Boltzmann vs Bose-Einstein vs Fermi-Dirac statistics.

Quantum Hall effect by

Ciro Santilli 37 Updated 2025-07-16

Quantum version of the Hall effect.

As you increase the magnetic field, you can see the Hall resistance increase, but it does so in discrete steps.

Figure 1.
Hall resistance as a function of the applied magnetic field showing the Quantum Hall effect
. Source. As we can see, the blue line of the Hall resistance TODO material, temperature, etc. It is unclear if this is just

Gotta understand this because the name sounds cool. Maybe also because it is used to define the fucking ampere in the 2019 redefinition of the SI base units.

At least the experiment description itself is easy to understand. The hard part is the physical theory behind.

TODO experiment video.

The effect can be separated into two modes:

Integer quantum Hall effect: easier to explain from first principles
Fractional quantum Hall effect: harder to explain from first principles
- Fractional quantum Hall effect for $ν = 1/ m$ : 1998 Nobel Prize in Physics
- Fractional quantum Hall effect for $ν \neq = 1/ m$ : one of the most important unsolved physics problems as of 2023

Integer and fractional quantum Hall effects by Matthew A. Grayson

. Source. Presented 2015. This dude did good.

Applications of Quantum Mechanics by David Tong (2017) by

Ciro Santilli 37 Updated 2025-07-16

Author: David Tong.

Summary:

Chapter 2 "Band Structure" covers electronic band theory

Bell's theorem by

Ciro Santilli 37 Updated 2025-07-16

Basically a precise statement of "quantum entanglement is spooky".

Quantum computing player by

Ciro Santilli 37 Updated 2025-07-16

It is hard to beat the list present at Quantum computing report: quantumcomputingreport.com/players/.

The much less-complete Wikipedia page is also of interest: en.wikipedia.org/wiki/List_of_companies_involved_in_quantum_computing_or_communication It has the merit of having a few extra columns compared to Quantum computing report.

Also of interest: quantumzeitgeist.com/interactive-map-of-quantum-computing-companies-from-around-the-globe/

Quantum computer simulator by

Ciro Santilli 37 Updated 2025-07-16

Other good lists:

quantumcomputingreport.com/resources/tools/ is hard to beat as usual.
www.quantiki.org/wiki/list-qc-simulators

JavaScript
- algassert.com/quirk demo: github.com/Strilanc/Quirk drag-and-drop, by a 2019-quantum-computing-Googler, impressive. You can create gates. State store in URL.
- github.com/stewdio/q.js/ demo: quantumjavascript.app/

Bibliography:

www.epcc.ed.ac.uk/whats-happening/articles/energy-efficient-quantum-computing-simulations mentions two types of quantum computer simulation:
- The most common approach to quantum simulations is to store the whole state in memory and to modify it with gates in a given order
- However, there is a completely different approach that can sometimes eliminate this issue - tensor networks

ZX-calculus by

Ciro Santilli 37 Updated 2025-07-16

As en.wikipedia.org/w/index.php?title=ZX-calculus&oldid=1071329204#Diagram_rewriting tries to explain but fails to deliver as usual consider the GHZ state represented as a quantum circuit.

How can we easily prove that that quantum circuit equals the state:

\frac{∣000 > + ∣111 >}{2}

(1)

The naive way would be to just do the matrix multiplication as explained at Section "Quantum computing is just matrix multiplication".

However, ZX-calculus provides a simpler way.

And even more importantly, sometimes it is the only way, because in a real circuit, we would not be able to do the matrix multiplication

What we do in ZX-calculus is we first transform the original quantum circuit into a ZX graph.

This is always possible, because we can describe how to do the conversion simply for any of the Clifford plus T gates, which is a set of universal quantum gates.

Then, after we do this transformation, we can start applying further transformations that simplify the circuit.

It has already been proven that there is no efficient algorithm for this (TODO source, someone said P-sharp complete best case)

But it has been proven in 2017 that any possible equivalence between quantum circuits can be reached by modifying ZX-calculus circuits.

There are only 7 transformation rules that we need, and all others can be derived from those, universality.

So, we can apply those rules to do the transformation shown in Wikipedia:

Figure 1.
GHZ circuit as ZX-diagram
. Source.

and one of those rules finally tells us that that last graph means our desired state:

\frac{∣000 > + ∣111 >}{2}

(2)

because it is a Z spider with

m = 3

and

n = 1

Working with PyZX by Aleks Kissinger (2019)

Source. This video appears to give amazing motivation on why you should care about ZX-calculus, it mentions

Bibliography:

Qubit by

Ciro Santilli 37 Updated 2025-07-16

Saylor Academy by

Ciro Santilli 37 Updated 2025-07-16

This is an interesting initiative which has some similarities to Ciro Santilli's OurBigBook project.

The fatal flaw of the initiative in Ciro Santilli's opinion is the lack of user-generated content. We will never get there without UGC and algorithms, never.

Also as of 2021, it mostly useless business courses: learn.saylor.org unfortunately.

But it has several redeeming factors which Ciro Santilli aproves of:

exam as a service-like
they have a GitHub: github.com/saylordotorgo

Licensing appears to be a mixed mess between the dreaded CC BY-NC-SA and the good CC BY, e.g.:

The founder Michael J. Saylor looks a bit crooked, Rich people who create charitable prizes are often crooked comes to mind. But maybe he's just weird.

Michael Saylor interview by Lex Fridman (2022)

Source.

At the timestamp:

When I go, all my assets will flow into a foundation, and the foundation's mission is to make education free for everybody forever.

What statement... maybe he's actually not crooked, maybe it was just an accounting mistake... God, why.

If only Ciro Santilli knew how to contact him and convince him that his current approach is innefective and that Ciro has something better! Michael, please Google into this page some day, Ciro Santilli needs funding for OurBigBook.com. A hopeless Tweet at: twitter.com/cirosantilli/status/1548350114623660035. Also tried to hit his saylor@strategy.com.

Single particle double slit experiment by

Ciro Santilli 37 Updated 2025-07-16

electron experiments: single electron double slit experiment.

This experiment seems to be really hard to do, and so there aren't many super clear demonstration videos with full experimental setup description out there unfortunately.

Wikipedia has a good summary at: en.wikipedia.org/wiki/Double-slit_experiment#Overview

For single-photon non-double-slit experiments see: single photon production and detection experiments. Those are basically a pre-requisite to this.

photon experiments:

aapt.scitation.org/doi/full/10.1119/1.4955173 "Video recording true single-photon double-slit interference" by Aspden and Padgetta (2016). Abstract says using spontaneous parametric down-conversion detection of the second photon to know when to turn the camera on

Non-elementary particle:

2019-10-08: 25,000 Daltons
interactive.quantumnano.at/letsgo/ awesome interactive demo that allows you to control many parameters on a lab. Written in Flash unfortunately, in 2015... what a lack of future proofing!

Single Photon Interference by Veritasium (2013)

Source. Claims to do exactly what we want, but does not describe the setup precisely well enough. Notably, does not justify how he knows that single photons are being produced.

Metagenomics by

Ciro Santilli 37 Updated 2025-07-16

Experiments that involve sequencing bulk DNA found in a sample to determine what species are present, as opposed to sequencing just a single specific specimen. Examples of samples that are often used:

river water to determine which bacteria are present, notably to determine if the water is free of dangerous bacteria. A concrete example is shown at: Section "How to use an Oxford Nanopore MinION to extract DNA from river water and determine which bacteria live in it".
sea water biodiversity: ocean-microbiome.embl.de/companion.html
food, including searching for desirable microorganisms such as in cheese or bread yeast
poo, e.g. to study how the human microbiome influences health. There are companies actively working on this, e.g.: www.microbiotica.com/

One related application which most people would not consider metagenomics, is that of finding circulating tumor DNA in blood to detect tumors.

Variable number tandem repeat by

Ciro Santilli 37 Updated 2025-07-16

Caused by slipped strand mispairing.