【TED:二進(jìn)制編碼的原理】

Imagine trying to use words to describe every scene in a film , every note in your favorite song or every street in your town ,now imagine trying to do it with??only the numbers one and zero every time you use the Internet to watch a movie, listen to music, or check directions that’s exactly what your device is doing, using the language of binary code, computers used by Ineri because it’s a reliable way of storing data for example a computer main memory is made of transistors that switch between either high or low voltage levels
Such as five votes or zero V,
?voltage sometimes oscillate but since there are only??two options A value of one vote would still be read as low that reading is down by the computers processor?
Which uses the transistor states to control other computer devices according to software instructions
The genius of this system is set a giving binary sequence doesn’t have a pre-determined meaning on its own , instead each type of data is encoded in binary
According to a separate set of rules.
Let’s take numbers ,in normal decimal notation each digit is multiplied by 10 ,raised to the value of its position?
Starting from the zero on the right ,so 84 in decimal form is 4×10 to the 0+8×10 to the first?
Binary number notation works similarly,
But with each position based on 2 raised to some power so 84 would be written as follows
1010100
Meanwhile letters are interpreted based on standard rules like UTF 8
Which assigns each character to a specific group of eight digits binary strings.
In this case 01010100 corresponds to the letter T , so how can you know whether a given instance of this sequence is supposed to mean t or 84?
Well you can’t from seeing this string alone,
Just as you can’t tell what is the sound DA means from hearing it in isolation.
You need a context to tell whether you are hearing Russian Spanish or English.
And you need a similar context to tell whether you’re looking at binary numbers or binary text.
Binary code is also used for far more complex types of data, each frame of this video for instance:
Is made of hundreds of thousands of pixels
InColor images every pixel is represented by three binary sequences, that corresponds to the primary colors ,Each sequence in codes A number that determines the intensity of that particular color, send a video driver program transmits this information to the millions of liquid crystals in your screen, how to make all the different hues you see now, The sound in this video is also stored in binary, with the help of a technique called pulse code modulation , continuous sound waves are digitized by taking snapshot of their amplitudes every few million seconds?
This are recorded as numbers in the form of binary strings with as many as 44,000s for every seconds of sound, when they’re read by your computer audio software The numbers determine how quickly the coils in your speakers should vibrate, to create sounds of different frequencies, all of this require billions and billions of bits
But that amount could be reduced through clever compression formats for example if a picture has 30 adjacent pixels of green space they can be recorded as 30 green instead of coding each pixel separately, A process known as run- links in coding,
These compressed formats are themselves written in binary code so is binary the end all be all of computing , there’s been research into ternary computers, with circuits in three possible states, and even quantum computers whose circuits can be in multiple states simultaneously, but so far none of this has provided as much physical stability for the storage and transmission so for now everything you see, hear and read on your screen comes to you as the result of a simple true or false choice made billion times over.