What is information

Silvestro Di Pietro

16/03/2023

Definition

Information

Any process that is not completely random, and any observable pattern in any medium can be said to convey some amount of information.

Some Science

Shannon

For Claude Shannon (1948) the information consists

the data what
the channel how
the receiver who

The Surprise

The main idea about the Information theory is the “information value” that depends from the novelty or how much the data is surprising. Shannon introduce the entropy (as is in thermodinamics) formulating the theory.

Enalotto

Data on the first sequence has very little meaning, but the value of the second sequence?

just numbers 58 45 22 51 57 78
winning numbers 23 42 46 54 58 79

Concorso Nº30 del 11 March 2023

A little demon (1867)

Maxwell elaborate this thought experiment in order to confutate his 2nd thermodynamics law trying to avoid entropy with a demon.

Thermo information

62 year later Leo Szilard stated that acquiring information require energy increasing entropy, Léon Brillouin stated that the energy of this action is needed when the demon erase the information.

Quantum wave

Acquiring the information cause the collapsing of the wave function.

Information need energy

the information process generate entropy and need energy
the information is a physical fact.

Binary numbers

Minimal Information

Chings suggested to Gottfried Wilhelm Leibniz the numeration in base 2.

ching symbol	Value
- -	0
—	1

Base 2

Binary is the minimal way to code information, and for this reason are widely used symbols in informatics.

https://www.leibniz-translations.com/binary.htm

Aritmetic

Binary numbers are just numbers

Base 2 exponential

1 kb =2^10

Hexadecimals

Base 16 exponential

Hexadecimals has 16 symbols

0 1 2 3 4 5 6 7 8 9 A B C D F

FFFF = 2^16 = 1111111111111111

HEX On UNIX

Unix (and related) shells, AT&T assembly language and likewise the C programming language (and its syntactic descendants such as C++, C#, Go, D, Java, JavaScript, Python and Windows PowerShell) use the prefix 0x for numeric constants represented in hex: 0x5A3.

HEX On URIs

in URIs (including URLs), character codes are written as hexadecimal pairs prefixed with %: http://www.example.com/name%20with%20spaces where %20 is the code for the space (blank) character, ASCII code point 20 in hex, 32 in decimal.

HEX On XML

In XML and XHTML, characters can be expressed as hexadecimal numeric character references using the notation &#xcode;, for instance &#x2019; represents the character U+2019 (the right single quotation mark). If there is no x the number is decimal (thus ’ is the same character)

On CSS (html)

Color references in HTML, CSS and X Window can be expressed with six hexadecimal digits (two each for the red, green and blue components, in that order) prefixed with #: white, for example, is represented as #FFFFFF.[5] CSS also allows 3-hexdigit abbreviations with one hexdigit per component: #FA3 abbreviates #FFAA33 (a golden orange: ).

storage

R A M

Random Access Memory, Usually we consider this volatile memory that need energy to keep the information stored

R O M

Read Only Memory: is a memory that can just be read and will store permanently the information without need of energy

LOL ROM

Software written by MIT programmers was woven bit by bit into core rope memory by female workers in factories. Some programmers nicknamed the finished product LOL memory, for Little Old Lady memory.

Hard Drive

A magnetic disk partitioned with sectors and block of data with a movable head reading and writing capable.

Flash Memory

Flash memory is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed: is fast and cheap (in your phone the ram is this kind of memory)