Media rationale of Ciro Santilli's website Updated 2025-07-16
Meritocracy Updated 2025-07-16
Regular expression Updated 2025-07-16
Steve Jobs quote on saving lives with a faster boot Updated 2025-07-16
This idea also comes up in other sources of course.
The truth will set you free Updated 2025-07-16
Zermelo-Fraenkel set theory Updated 2025-10-14
One of the first formal proof systems. This is actually understandable!
This is Ciro Santilli-2020 definition of the foundation of mathematics (and the only one he had any patience to study at all).
TODO what are its limitations? Why were other systems created?
ELF Hello World Tutorial Generate the example Updated 2025-07-16
hello_world.asm
section .data
hello_world db "Hello world!", 10
hello_world_len equ $ - hello_world
section .text
global _start
_start:
mov rax, 1
mov rdi, 1
mov rsi, hello_world
mov rdx, hello_world_len
syscall
mov rax, 60
mov rdi, 0
syscallCompiled with:
nasm -w+all -f elf64 -o 'hello_world.o' 'hello_world.asm'
ld -o 'hello_world.out' 'hello_world.o' Yeast artificial chromosome Updated 2025-07-16
ELF Hello World Tutorial How to learn Updated 2025-07-16
Spin like mad between:
- standards
- high level generators. We use the assembler
asand linkerld. - hexdumps
- file decompilers. We use
readelf. It makes it faster to read the ELF file by turning it into human readable output. But you must have seen one byte-by-byte example first, and think howreadelfoutput maps to the standard. - low-level generators: stand-alone libraries that let you control every field of the ELF files you generated. github.com/BR903/ELFkickers, github.com/sqall01/ZwoELF and many more on GitHub.
- consumer: the
execsystem call of the Linux kernel can parse ELF files to starts processes: github.com/torvalds/linux/blob/v4.11/fs/binfmt_elf.c, stackoverflow.com/questions/8352535/how-does-kernel-get-an-executable-binary-file-running-under-linux/31394861#31394861
ELF Hello World Tutorial Index 0 section Updated 2025-07-16
Contained in bytes 0x40 to 0x7F.
The first section is always magic: www.sco.com/developers/gabi/2003-12-17/ch4.sheader.html says:
If the number of sections is greater than or equal to SHN_LORESERVE (0xff00), e_shnum has the value SHN_UNDEF (0) and the actual number of section header table entries is contained in the sh_size field of the section header at index 0 (otherwise, the sh_size member of the initial entry contains 0).
There are also other magic sections detailed in
Figure 4-7: Special Section Indexes. Skew-symmetric form Updated 2025-07-16
CAIDA/commoncrawl-host-ip-mapper Updated 2025-07-16
Human spinal cord Updated 2025-07-16
Particle in a box Updated 2025-07-16
Quantum tunnelling Updated 2025-07-16
Examples:
- flash memory uses quantum tunneling as the basis for setting and resetting bits
- alpha decay is understood as a quantum tunneling effect in the nucleus
Supercomputer by owner Updated 2025-07-16
Potassium Updated 2025-07-16
BB84 Updated 2025-07-16
Does not require entangled particles, unlike E91 which does.
en.wikipedia.org/w/index.php?title=Quantum_key_distribution&oldid=1079513227#BB84_protocol:_Charles_H._Bennett_and_Gilles_Brassard_(1984) explains it well. Basically:
- Alice and Bob randomly select a measurement basis of either 90 degrees and 45 degrees for each photon
- Alice measures each photon. There are two possible results to either measurement basis: parallel or perpendicular, representing values 0 or 1. TODO understand better: weren't the possible results supposed to be pass or non-pass? She writes down the results, and sends the (now collapsed) photons forward to Bob.
- Bob measures the photons and writes down the results
- Alice and Bob communicate to one another their randomly chosen measurement bases over the unencrypted classic channel.This channel must be authenticated to prevent man-in-the-middle. The only way to do this authentication that makes sense is to use a pre-shared key to create message authentication codes. Using public-key cryptography for a digital signature would be pointless, since the only advantage of QKD is to avoid using public-key cryptography in the first place.
- they drop all photons for which they picked different basis. The measurements of those which were in the same basis are the key. Because they are in the same basis, their results must always be the same in an ideal system.
- if there is an eavesdropper on the line, the results of measurements on the same basis can differ.Unfortunately, this can also happen due to imperfections in the system.Alice and Bob must decide what level of error is above the system's imperfections and implies that an attacker is listening.
Bell's theorem Updated 2025-07-16
Basically a precise statement of "quantum entanglement is spooky".
Spinor Updated 2025-07-16
- Physics from Symmetry by Jakob Schwichtenberg (2015) page 72
- physics.stackexchange.com/questions/172385/what-is-a-spinor
- physics.stackexchange.com/questions/41211/what-is-the-difference-between-a-spinor-and-a-vector-or-a-tensor
- physics.stackexchange.com/questions/74682/introduction-to-spinors-in-physics-and-their-relation-to-representations
- www.weylmann.com/spinor.pdf
There are unlisted articles, also show them or only show them.