Two siblings of the signal family

A signal is a tool for carrying messages and a carrier of messages. In a broad sense, it includes optical signals, acoustic signals, and electrical signals. For example, the ancient people used to ignite the beacon tower to send messages about enemy infiltration to distant troops.

This is a light signal. When we speak, sound waves are transmitted to the ears of others, so that others can understand our intentions. This is a sound signal; the various radio waves traveling through space, and the current in the telephone network, which can all be used in the distance.

Express various messages, which are electrical signals. Only by receiving light, sound, and electrical signals can people know the messages that the other party wants to express.
In the big family of signals, two siblings are particularly eye-catching, namely "analog" and "number ".

What is "simulation "? "Simulation" is the brother of "number.
"Simulation" is an expression of the entities in our lives.
For example, if you are reading a book and it is black and white, you will have a reaction in your brain. You know something from the book, we say that words printed on paper are a kind of "simulation ". Similarly, you write it down on paper with a pen.

A telephone number or a written poem, and an ancient inscription engraved on the stone, these are "simulation ". In addition to text, we can also see many "Simulated" things in our lives, such as a landscape painting and

It is said that you have heard the laughter and laughter of the children on TV or on the cinema screen, and you have heard the voice of friends on the phone.
"Simulation" requires a carrier or a storage media of information, such as a blank sheet of paper, or a box of film.
A tool is required for "simulation". For example, if you have a TV set, the fluorescent screen and speakers of the TV are all analog devices.
"Simulation" requires communication methods. For example, you can talk to a friend over a dozen meters away, but if your friend is several hundred kilometers away, you have to call the phone, through the "analog signal", the telephone network transmits your voice to several

Hundreds of kilometers or even thousands of kilometers away.

What is "number "?
Similar to "simulation", numbers are also an expression of entities in our lives.
You can write down a phone number on a pen or enter the phone number in your computer's memory. You can read a printed book, you can also watch electronic publications stored in CD-ROM; you can listen to the radio

You can also listen to a CD ).
The minimum unit of measurement for numeric information is bit, which is also called bit. The signal transmitted in the media is electronic in bits to form your data.
Bit is defined as an existing state: ON or OFF, true or false, up or down, in or out, black or white. For practical purposes, we want bitwise to 1 or 0.
It should be said that this definition is quite accurate, but a person with a low degree of knowledge in computer and English still does not understand what "bits" are.
"Bit" is a transliteration of the word "bit" in English. The word bit is compressed by binary and digit, So bit is a "binary number", that is, 0 and 1. The exact meaning of "Digital Age" is

What do 0 and 1 mean in the "binary digital age" or the "Bitcoin age? Let's start with a simple example.
When using a computer, we can adjust the display graphics by using some knob located at the bottom of the display according to our needs and preferences. Under these knob, the center (center) is written separately), size (size ),

Brightness (brightness), contrast (contrast ). These adjustments have a certain adjustable range. We may choose which of them is medium and small within this range. In addition to these knob, there is also an "agency" which is not

In this case, the authorities write 0 and 1 respectively. This is the display switch. It has no adjustment margin. With it, we can only select two statuses: On and off ). The brightness and contrast of the display are both

The "value" between these two poles is multi-value. The switch period has only two values, that is, its two poles. "In" refers to the "value" contained in a period ". For example, a decimal number is a variable.

The conversion cycle contains ten "value" numbers. Similarly, a binary number is a number that contains two values in a change period. What kind of "hexadecimal" is used to count the existence status of a thing? On the surface, it depends on the value of the state of the thing.

In fact, "hexadecimal" is not necessarily and uniquely associated with the state value of a thing. In fact, the computer can use the numbers 0 and 1 to represent or translate the values in the Multi-hexadecimal state. The number is abstract, but the number

Concept is derived from the concrete sensory experience of people. We are used to the decimal counting method. When a person says "12 months in a year", he may think that "12" indicates the number of months in a year. Then

He may think that numbers and the number of things are equally objective-apart from 12 months in a year, how many months in a year can you say?
This is a plausible view of the nature of numbers. To put it bluntly, there are many different "answers" to the question "how many months are there in a year ". In this case, it sounds crazy, but it is not the case if you look at it carefully. When

When we use different mechanisms to represent the number of things, we can say different "answers" to the number of things, and these "answers" are correct. For example, a person is 65 years old or 01000001 years old. Only the last one

It sounds awkward because we are used to expressing the number in decimal digits. If we use a "Six-in-one" number (it seems that no one in the world has used this number), we can say that one year

There are two "six" months. If crabs evolve to a human-like level one day, they are likely to use "Octal numbers" to count, then in their view, there will be an "Eight" and four months in a year.
This is not a joke. I just want to explain that "Numbers" are not as objective as we generally think ". After all, it is a subjective image of the number of objective things.
In addition to "bit", we often encounter several digital information measurement units. A byte is a more abstract or advanced measurement unit than a "bit". Generally, a byte has eight bits, that is, eight bits. And

Three abbreviations: "k", "M", and "G ". 1 k = 1024. In Chinese, we usually call it "thousands". 1 m = 1024 × 1 K. in Chinese, we usually call it "megabytes "; 1G = 1024 × 1 m. in Chinese, we usually call it "Gigabit" or

"Ji ".
BITs are usually used for data transmission over the network. For example, we generally say that this telephone line can transmit 9600 bits of binary streams in one second, rather than 1200 bytes. Bytes are usually used in the data storage system,

For example, the size of this file is 2 MB, which refers to bytes rather than bits. For example, it is a 1.44m floppy disk or 20 GB hard disk, which also refers to bytes.