Ciro Santilli @cirosantilli 40

As of 2020, Ciro Santilli is getting excited about quantum computing, which is a deep tech field.

He's a bit lazy to explain why here, but Googling will be more than enough.

There is a risk it will fizzle and the bubble pop, like any revolution.

But recent developments are making it too exciting to ignore.

Theory that describes electrons and photons really well, and as Feynman puts it "accounts very precisely for all physical phenomena we have ever observed, except for gravity and nuclear physics" ("including the laughter of the crowd" ;-)).

Learning it is one of Ciro Santilli's main intellectual fetishes.

While Ciro acknowledges that QED is intrinsically challenging due to the wide range or requirements (quantum mechanics, special relativity and electromagnetism), Ciro feels that there is a glaring gap in this moneyless market for a learning material that follows the Middle Way as mentioned at: the missing link between basic and advanced. Richard Feynman Quantum Electrodynamics Lecture at University of Auckland (1979) is one of the best attempts so far, but it falls a bit too close to the superficial side of things, if only Feynman hadn't assumed that the audience doesn't know any mathematics...

The funny thing is that when Ciro Santilli's mother retired, learning it (or as she put it: "how photons and electrons interact") was also one of her retirement plans. She is a pharmacist by training, and doesn't know much mathematics, and her English was somewhat limited. Oh, she also wanted to learn how photosynthesis works (possibly not fully understood by science as that time, 2020). Ambitious old lady!!!

Experiments: quantum electrodynamics experiments.

Combines special relativity with more classical quantum mechanics, but further generalizing the Dirac equation, which also does that: Dirac equation vs quantum electrodynamics. The name "relativistic" likely doesn't need to appear on the title of QED because Maxwell's equations require special relativity, so just having "electro-" in the title is enough.

Before QED, the most advanced theory was that of the Dirac equation, which was already relativistic but TODO what was missing there exactly?

As summarized at: youtube.com/watch?v=_AZdvtf6hPU?t=305 Quantum Field Theory lecture at the African Summer Theory Institute 1 of 4 by Anthony Zee (2004):

That video also mentions the interesting idea that:Therefore, for small timescales, energy can vary a lot. But mass is equivalent to energy. Therefore, for small time scale, particles can appear and disappear wildly.

QED is the first quantum field theory fully developed. That framework was later extended to also include the weak interaction and strong interaction. As a result, it is perhaps easier to just Google for "Quantum Field Theory" if you want to learn QED, since QFT is more general and has more resources available generally.

Like in more general quantum field theory, there is on field for each particle type. In quantum field theory, there are only two fields to worry about:

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: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:

Ciro Santilli's favorites so far:

Bibliography of the biliograpy:

Recommendations by friend P. C.:

Author: en.wikipedia.org/wiki/Anthony_Zee from University of California, Santa Barbara.

ISBN-13: 978-0691140346

Amazon: www.amazon.com/dp/0691140340

lecture 1 mentions that this book is quick and dirty, as one might guess from the title. Ciro Santilli thinks he's gonna like this one.

First edition: from 2003, www.amazon.com/dp/0691010196, ISBN-13: 978-0691010199.

Summary:

Author: David Tong.

Number of pages circa 2021: 155.

It should also be noted that those notes are still being updated circa 2020 much after original publication. But without Git to track the LaTeX, it is hard to be sure how much. We'll get there one day, one day.

Likely used at: David Tong's 2009 Quantum Field Theory lectures at the Perimeter Institute.

Some quotes self describing the work:

A follow up course in the University of Cambridge seems to be the "Advanced QFT course" (AQFT, Quantum field theory II) by David Skinner: www.damtp.cam.ac.uk/user/dbs26/AQFT.html

Man-in-the-middle attack

quantumcomputing.stackexchange.com/questions/142/advantage-of-quantum-key-distribution-over-post-quantum-cryptography/25727#25727 Advantage of quantum key distribution over post-quantum cryptography has Ciro Santilli's comparison to classical encryption.

BB84 is a good first algorithm to look into.

Long story short:

QKD uses quantum mechanics stuff to allow sharing unsnoopable keys: you can detect any snooping and abort communication. Unsnoopability is guaranteed by the known laws of physics, up only to engineering imperfections.

Furthermore, it allows this key distribution without having to physically take a box by car somewhere: once the channel is established, e.g. optical fiber, you can just keep generating perfect keys from it. Otherwise it would be pointless, as you could just drive your one-time pad key every time.

However, the keys likely have a limited rate of generation, so you can't just one-time pad the entire message, except for small text messages. What you would then do is to use the shared key with symmetric encryption.

Therefore, this setup usually ultimately relies on the idea that we believe that symmetric encryption is safer than , even though there aren't mathematical safety proofs of either as of 2020.

Quantum mechanics is quite a broad term. Perhaps it is best to start approaching it from the division into:

Key experiments that could not work without quantum mechanics: Section "Quantum mechanics experiment".

Mathematics: there are a few models of increasing precision which could all be called "quantum mechanics":

Ciro Santilli feels that the largest technological revolutions since the 1950's have been quantum related, and will continue to be for a while, from deeper understanding of chemistry and materials to quantum computing, understanding and controlling quantum systems is where the most interesting frontier of technology lies.

This is a cool project that attempts to make it easy to emulate any of the three operating systems on QEMU.

Homepage: github.com/quickemu-project/quickemu

Introductor tutorial by Ciro Santilli: askubuntu.com/questions/884534/how-to-run-ubuntu-desktop-on-qemu/1545712#1545712 intro

Unofrtunately as of 2025 the project was falling a bit back on support, and the latest versions of the two closed source systems were buggy, tested as of quickemu 4.9.7 on Ubuntu 25.04:

Tutorial by Ciro Santilli: www.reddit.com/r/commandline/comments/v85fmx/comment/mpsvd25/

Ciro Santilli finds it interesting that radioactive decay basically kickstarted the domain of nuclear physics by essentially providing a natural particle accelerator from a chunk of radioactive element.

The discovery process was particularly interesting, including Henri Becquerel's luck while observing phosphorescence, and Marie Curie's observation that the uranium ore were more radioactive than pure uranium, and must therefore contain other even more radioactive substances, which lead to the discovery of polonium (half-life 138 days) and radium (half-life 1600 years).

Ciro Santilli appreciates this concept of "remembering the suffering of others" a lot due to Ciro Santilli's self perceived compassionate personality and Ciro Santilli's cheapness.

Ciro Santilli considered it before he stopped using file managers altogether, it is not bad.

Has Serial wire debug debug pre-soldered. Why would you ever get one without unless you are a clueless newbie like Ciro Santilli?!?!

It is however possible to solder it yourself on Raspberry Pi Pico W.

For some reason, Ciro Santilli is mildly obsessed with understanding and visualizing the real projective plane.

To see why this is called a plane, move he center of the sphere to $z=1$, and project each line passing on the center of the sphere on the x-y plane. This works for all points of the sphere, except those at the equator $z=1$. Those are the points at infinity. Note that there is one such point at infinity for each direction in the x-y plane.

A non-tool-assisted speedrun.

Ciro Santilli views humans as biological robots, and therefore RTA videos can be thought of as probabilistic TAS with human achievable reflex constraints.

This aspect is especially highlighted in "speed run record evolution videos", which can be quite fun, e.g. www.youtube.com/watch?v=pmS9e7kzgS4 Ocarina of Time - World Record History and Progression (Any% Speedrun, 1990s-2017) by retro (2017)

From a similar point of view, Ciro also sometimes watches/learns a bit about competitive PvP games from a "could a computer play this better than a human" point of view.

Ciro also likes to watch commented manual speedruns of games as a way of experiencing the game at a high level without spending too much time on it, often from Games Done Quick. Their format is good because it generally showcases one player focusing more on the gameplay, and three couch commentators to give context, that's a good setup.

It is a

Ciro Santilli's experience: www.quora.com/Is-it-legal-for-billionaires-to-make-anonymous-charitable-donations-How-can-it-be-determined-if-a-large-sum-of-money-was-donated-anonymously-or-not/answer/Ciro-Santilli

Ciro Santilli's account is www.reddit.com/user/cirosantilli/, see also: accounts controlled by Ciro Accounts.

Ciro Santilli had to see this in a few separate places, until he underestood: that little pictur emust be a thing! Examples:

It should be illegal to give someone money to advertise your product.

We should just use tags and upvote-based algorithms.

Advertisement is a form of brainwashing.

TODO find Sergey Brin quote bout advertising being a form of perverting search engine ranking neutrality. In other words, there are neutral metrics to what people find good, like links and upvotes. And then advertising is a way to pervert that to someone's profit.

Sometimes Ciro Santilli thinks advertising should be on-subscription only, but that is too restrictive, e.g. imagine the local business owner who wears a t-shirt of their business.