Ciro Santilli @cirosantilli 37

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Liquid nitrogen Updated 2025-07-16

77K. Low enough for "high temperature superconductors" such as yttrium barium copper oxide, but for "low temperature superconductors", you need to go much lower, typically with liquid helium, which is likely much more expensive. TODO by how much?

Video 1.

Where Do You Get Liquid Nitrogen? by The King of Random (2016)

Source. He just goes to a medical gases shop in a local industrial estate and buys 20L for 95 dollars and brings it back on his own Dewar marked 35LD.

Video 2.

Making Liquid Nitrogen From Scratch! by Veritasium (2019)

Source. "From scratch" is perhaps a bit clickbaity, but I'll take it.

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LMMS Updated 2025-07-16

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Very easy to use and pretty powerful MIDI creator!!!

One of the rare audio applications actually works with PulseAudio on Ubuntu 20.04 out-of-the-box, so you don't have to turn off every other audio application!!!

Has lot's of plugins built-in just working out of the box, e.g. ZynAddSubFX out-of-the-box without doing a gazillion complex setup connections.

Most plugins are just simple toys however, ZynAddSubFX is the only super powerful one. The others are more LMMS integrate however, and seem to use a more dedicated LMMS GUI style.

TODO can you do liver performance with a virtual instrument?

If you open vmpk, you can then right click on a piano track, and go MIDI, Input and it just shows up there, and it does produce sound as shown at: www.youtube.com/watch?v=NpeP2th08ak

TODO: what about recording the input MIDI? Yes, there is a record button on the piano roll!

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Local symmetry Updated 2025-07-16

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Local symmetries appear to be a synonym to internal symmetry, see description at: Section "Internal and spacetime symmetries".

As mentioned at Quote , local symmetries map to forces in the Standard Model.

Appears to be a synonym for: gauge symmetry.

A local symmetry is a transformation that you apply a different transformation for each point, instead of a single transformation for every point.

TODO what's the point of a local symmetry?

Bibliography:

lecture 3
physics.stackexchange.com/questions/48188/local-and-global-symmetries
www.physics.rutgers.edu/grad/618/lects/localsym.pdf by Joel Shapiro gives one nice high level intuitive idea:
In relativistic physics, global objects are awkward because the finite velocity with which effects can propagate is expressed naturally in terms of local objects. For this reason high energy physics is expressed in terms of a field theory.
Quora:

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Loop-mediated isothermal amplification Updated 2025-07-16

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Like PCR, but does not require thermal cycling. Thus the "isothermal" in the name: iso means same, so "same temperature".

Not needing the thermo cycling means that the equipment needed is much smaller and cheaper it seems.

Trade-offs question: biology.stackexchange.com/questions/92172/what-are-the-trade-offs-between-polymerase-chain-reaction-pcr-vs-loop-mediated

Video 1.

Loop Mediated Isothermal Amplification (LAMP) Tutorial by New England Biolabs (2015)

Source. Explains the basic LAMP concept well.

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Lorentz transform consequence: everyone sees the same speed of light Updated 2025-07-16

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OK, so let's verify the main desired consequence of the Lorentz transformation: that everyone observes the same speed of light.

Observers will measure the speed of light by calculating how long it takes the light going towards

+ x

cross a rod of length

L = x_{2} - x_{1}

laid in the x axis at position

X 1

TODO image.

Each observer will observe two events:

$(t_{1}, x_{1}, y_{1}, z_{1})$ : the light touches the left side of the rod
$(t_{2}, x_{2}, y_{2}, z_{2})$ : the light touches the right side of the rod

Supposing that the standing observer measures the speed of light as

c

and that light hits the left side of the rod at time

T 1

, then he observes the coordinates:

t_{1} x_{1} t_{2} x_{2} = T 1 = X 1 = \frac{L}{c} = X 1 + L

(1)

Now, if we transform for the moving observer:

t_{1}^{'} x_{1}^{'} t_{2}^{'} x_{2}^{'} = γ (t_{1} - \frac{v x _{1}}{c ^{2}}) = γ (x_{1} - v t_{1}) = γ (t_{2} - \frac{v x _{2}}{c ^{2}}) = γ (x_{2} - v t_{2})

(2)

and so the moving observer measures the speed of light as:

c^{'} = \frac{x _{2}^{'} - x _{1}^{'}}{t _{2}^{'} - t _{1}^{'}} = \frac{( x _{2} - v t _{2} ) - ( x _{1} - v t _{1} )}{( t _{2} - \frac{v x _{2}}{c ^{2}} ) - ( t _{1} - \frac{v x _{1}}{c ^{2}} )} = \frac{( x _{2} - x _{1} ) - v ( t _{2} - t _{1} )}{( t _{2} - t _{1} ) - \frac{v}{c ^{2}} ( x _{2} - x _{1} )} = \frac{\frac{x _{2} - x _{1}}{t _{2} - t _{1}} - v}{1 - \frac{v}{c ^{2}} \frac{x _{2} - x _{1}}{t _{2} - t _{1}}} = \frac{c - v}{1 - \frac{v}{c ^{2}} c} = \frac{c - v}{\frac{c - v}{c}} = c

(3)

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Lost Horse LLC Updated 2025-07-16

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MacKenzie Bezos's charity instrument.

www.irishtimes.com/life-and-style/people/mackenzie-scott-how-the-former-mrs-bezos-became-a-philanthropist-like-no-other-1.4850049 MacKenzie Scott: How the former Mrs Bezos became a philanthropist like no other (2020) has some good mentions:

But as Scott's fame for giving away money has grown, so too has the deluge of appeals for gifts from strangers and old friends alike. That clamour may have driven Scott's already discreet operation further underground, with recent philanthropic announcements akin to sudden lightning bolts for unsuspecting recipients.

The name of the organization is a reference to the old man lost his horse.

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Lowering and raising Updated 2025-07-16

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Lowering means translating to a lower level representation.

Raising means translating to a higher level representation.

Decompilation is basically a synonym, or subset, of raising.

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lspci Updated 2025-07-16

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lspci is the name of several versions of CLI tools used in UNIX-like systems to query information about PCI devices in the system.

On Ubuntu 23.10, it is provided by the pciutils package, which is so dominant that when we say "lspci" without qualitication, that's what we mean.

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lujakob/nestjs-realworld-example-app SQLite port Updated 2025-07-16

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Tried a quick port to SQLite to get rid of annoying local databases for development, but failed, at c1c2cc4e448b279ff083272df1ac50d20c3304fa

npm install sqlite3 --save-dev

and

{
  "type": "sqlite",
  "database": "db.sqlite3",
  "entities": ["src/**/**.entity{.ts,.js}"],
  "synchronize": true
}

then:

npm start

fails with:

DataTypeNotSupportedError: Data type "timestamp" in "ArticleEntity.created" is not supported by "sqlite" database.

Attempt to hack it:

--- a/src/article/article.entity.ts
+++ b/src/article/article.entity.ts
@@ -20,10 +20,10 @@ export class ArticleEntity {
   @Column({default: ''})
   body: string;

-  @Column({ type: 'timestamp', default: () => "CURRENT_TIMESTAMP"})
+  @Column({ default: () => "CURRENT_TIMESTAMP"})
   created: Date;

-  @Column({ type: 'timestamp', default: () => "CURRENT_TIMESTAMP"})
+  @Column({ default: () => "CURRENT_TIMESTAMP"})
   updated: Date;

and after that it seems to run.

I can signup and login, terrible error reporting as usual, make sure to use long enough usernames/passwords.

However, article creation fails with:

Unhandled Rejection (TypeError): Cannot read property 'slug' of undefined

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Luke Dashjr Updated 2025-07-16

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Accounts:

twitter.com/lukedashjr on Twitter. Status as of January 2024:
father of 10 children
This dude doesn't fuck around. Or perhaps he only fucks around. Either way.
www.linkedin.com/in/lukedashjr/ on LinkedIn
bitcointalk.org/index.php?action=profile;u=3318 on bitcointalk.org
www.reddit.com/user/luke-jr/
github.com/sponsors/luke-jr
freenode username: luke-jr, mentioned e.g. at bitcointalk.org/index.php?topic=38007.0 from Section "Prayer wars"

Author of the prayer side of the Prayer wars.

Creator of Eligius pool Bitcoin mining pool.

According to LinkedIn he studied at the Benedictine College in Kansas.

TODO is his real birthname "Luke Dash Jr."?

Apparently he had his coins stolen in January 2023, then worth $3.5m: blog.cryptostars.is/luke-dashjr-an-original-bitcoin-developer-loses-all-his-btc-88421c395ce5p...

www.reddit.com/r/Buttcoin/comments/4936kw/lukejr_is_a_seriously_a_super_crazy_person_quotes/ "Luke-Jr is a seriously a super crazy person quotes gigathread." (2016) on Reddit. Apparently he has some fun views of life.

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Lysozyme structure resolution (1965) Updated 2025-07-16

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With X-ray crystallography by David Chilton Phillips. The second protein to be resolved fter after myoglobin, and the first enzyme.

Published at: Structure of Hen Egg-White Lysozyme: A Three-dimensional Fourier Synthesis at 2 Å Resolution (1965). The work was done while at the Davy Faraday Research Laboratory of the Royal Institution.

Phillips also published a lower resolution (6 angstrom) of the enzyme-inhibitor complexes at about the same time: Structure of Some Crystalline Lysozyme-Inhibitor Complexes Determined by X-Ray Analysis At 6 Å Resolution (1965). The point of doing this is that it points out the active site of the enzyme.

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MakeCode Miro Bit Updated 2025-07-16

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makecode.microbit.org

Microbit simulator using some Microsoft framework.

TODO the Python code from there does not seem to run on the microbit via uflash, because it is not MicroPython.

support.microbit.org/support/solutions/articles/19000111744-makecode-python-and-micropython explains.

forum.makecode.com/t/help-understanding-local-build-options/6130 asks how to compile locally and suggests it is possible. Seems to require Yotta, so presumably compiles?

Presumably this is because Microsoft ported their MakeCode thing to the MicroBit, and the Micro Bit foundation accepted them.

E.g. there toggling a LED:

led.toggle(0, 0)

but the code that works locally is a completely differently named API set_pixel:

microbit.display.set_pixel(0, 0, )

Microsoft going all in on adopt extend extinguish from an early age!

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Making the Cisco connection Updated 2025-07-16

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archive.org/details/makingciscoconne0000bunn on the Internet Archive Open Library.

Nothing phenomenally new on the early days to add on top of Video "Nerds 2.0.1 excerpt about Cisco (1998)", but a few new good points:

Cisco at one point became the largest company by market capitalization. This wore off a bit as of 2020.
They used this overvalued stock in part to buy many other (often also overvalued) up and coming companies. This acquisition spree strategy was apparently not the norm at the time. rohitnair.wordpress.com/2011/12/13/cisco-history-cisco-systems-history-and-trivia-brand-history-and-trivia/ mentions they have bought more than 140 companies since, and that they call this strategy "Build, Buy And Partner"
a big part of what Cisco did was to allow cheap local communication in-campus. At that time, the ARPANET was already up and running, but their "routers", called Interface Message Processors were very expensive at about $100,000, and to send data across the campus you had to go through them, which meant expensive bandwidth. The routers sometimes failed, and the fallback was to send students around with disks: "sneakernet". They needed new local protocols and hardware to efficiently connect different campus networks.
Sandy Lerner nude photo
Cisco was a pioneer in having an Internet support forum. Customers could also help one another. This was fundamental in scaling support, as they grew so fast it would be impossible to hire a support team large enough without the help of the forum.
Cisco gave out source code to some customers who would then implement protocols they cared about, and Cisco would then merge it back

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Mamonas Assassinas Updated 2025-07-16

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This incredibly foul mouthed band was incredibly funny.

Ciro Santilli was a bit young to understand the songs at the time, but the older boys were singing them, and he sang along. So maybe there is a nostalgia factor in play.

But it can't be just that. They are just too funny and brutal, even when Ciro re-listens to it as of 2020.

Many Brazilian religious cranks in were really happy when their plane crashed and killed all of them in 1996.

Official YouTube channel: www.youtube.com/channel/UCPmfP5LNbxYwlN0k6C3F_6w

Best songs:

Pelados Em Santos (1995). Not too amazing, they only try to be funny by making fun of the North-Eastern accent of Brazil, which is considered somewhat funny in São Paulo, and they fail at being funny.
But it talks about Santos, São Paulo, Brazil, Ciro's idolized city, so let's hear it. They didn't live in Santos apparently, but being from São Paulo City, they would have been familiar with that popular local beach location.

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Management Updated 2025-07-16

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Video 1.

DealBook Conference 2015 - Activist Investing by New York Times Events (2015)

Source. At this timestamp, Carl Icahn tells an anecdote of how he found that an entire 12-floor building of the American Car and Foundry Company which he had recently bought was not doing anything useful, and fired the entire building.

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Maxwell's equations Updated 2025-07-16

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Unified all previous electro-magnetism theories into one equation.

Explains the propagation of light as a wave, and matches the previously known relationship between the speed of light and electromagnetic constants.

The equations are a limit case of the more complete quantum electrodynamics, and unlike that more general theory account for the quantization of photon.

The equations are a system of partial differential equation.

The system consists of 6 unknown functions that map 4 variables: time t and the x, y and z positions in space, to a real number:

$E_{x} (t, x, y, z)$ , $E_{y} (t, x, y, z)$ , $E_{z} (t, x, y, z)$ : directions of the electric field $E : R^{4} \to R^{3}$
$B_{x} (t, x, y, z)$ , $B_{y} (t, x, y, z)$ , $B_{z} (t, x, y, z)$ : directions of the magnetic field $B : R^{4} \to R^{3}$

and two known input functions:

$ρ : R^{3} t o R$ : density of charges in space
$J : R^{3} \to R^{3}$ : current vector in space. This represents the strength of moving charges in space.

Due to the conservation of charge however, those input functions have the following restriction:

\frac{\partial ρ}{\partial t} + \nabla \cdot J = 0

(1)

Equation 1.

Charge conservation

Also consider the following cases:

if a spherical charge is moving, then this of course means that $ρ$ is changing with time, and at the same time that a current exists
in an ideal infinite cylindrical wire however, we can have constant $ρ$ in the wire, but there can still be a current because those charges are moving
Such infinite cylindrical wire is of course an ideal case, but one which is a good approximation to the huge number of electrons that travel in a actual wire.

The goal of finding

E

and

B

is that those fields allow us to determine the force that gets applied to a charge via the Equation "Lorentz force", and then to find the force we just need to integrate over the entire body.

Finally, now that we have defined all terms involved in the Maxwell equations, let's see the equations:

d i v E = \frac{ρ}{ε _{0}}

(2)

Equation 2.

Gauss' law

d i v B = 0

(3)

Equation 3.

Gauss's law for magnetism

\nabla \times E = - \frac{\partial B}{\partial t}

(4)

Equation 4.

Faraday's law

\nabla \times B = μ_{0} (J + ε_{0} \frac{\partial E}{\partial t})

(5)

Equation 5.

Ampere's circuital law

You should also review the intuitive interpretation of divergence and curl.

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Maxwell's equations are Lorentz invariant Updated 2025-07-16

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Subtle is the Lord by Abraham Pais (1982) chapter III "Relativity, the special theory" mentions that this fact and its importance (we want the laws of physics to look the same on all inertial frames, AKA Lorentz covariance) was first fully relized by poincaré in 1905.

And at that same time poincaré also immediately started to think about the other fundamental force then known: gravity, and off the bat realized that gravitational waves must exist. general relativities is probably just "the simplest way to make gravity Lorentz covariant".

Bibliography:

physics.stackexchange.com/questions/219474/proof-that-maxwell-equations-are-lorentz-invariant

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Maxwell's equations require special relativity Updated 2025-07-16

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The following aspects of Maxwell's equations make no sense without special relativity:

the Lorentz force would be different observers have different speeds, see e.g.: charged particle moving at the same speed of electrons thought experiment
Maxwell's equations imply that the speed of light is the same for all inertial reference frames

When charged particle though experiment are seen from the point of view of special relativity, it becomes clear that magnetism is just a direct side effect of charges being viewed in special relativity. One is philosophically reminded of how spin is the consequence of quantum mechanics + special relativity.

Bibliography:

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Measure theory Updated 2025-07-16

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Main motivation: Lebesgue integral.

The Bright Side Of Mathematics 2019 playlist: www.youtube.com/watch?v=xZ69KEg7ccU&list=PLBh2i93oe2qvMVqAzsX1Kuv6-4fjazZ8j

The key idea, is that we can't define a measure for the power set of R. Rather, we must select a large measurable subset, and the Borel sigma algebra is a good choice that matches intuitions.

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Medium (website) Updated 2025-07-16

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While this has some of the metrics features that Ciro Santilli wants to implement for OurBigBook.com, it limits the number of articles your readeres can read.

How the fuck can you publish on a website that limits the number of views for your articles?!?! When all it has is static pages + some metrics?!?!

Evil. Just learn to use GitHub Pages for God's sake.

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