Video Transcript: How exactly does binary code work?

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 using 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 use binary because it's a reliable way  of storing data. For example, a computer's main memory is made of transistors  that switch between either high or low voltage levels, such as five volts and zero volts. Voltages sometimes oscillate, but since there are only two options, a value of one volt would still be read as low that reading is done by the computer's  processor, which uses the transistors states to control other computer devices  according to software instructions. The genius of this system is that a given  binary sequence doesn't have a predetermined 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 zero on the right. So 84 in decimal form is  four times 10 to the zero plus eight times 10 to the first. Binary number notation  works similarly, but with each position based on two raised to some power, so 84 would be written as follows. Meanwhile, letters are interpreted based on  standard rules like UTF eight, which assigns each character to a specific group  of eight digit 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 the string alone, just as you can't tell  what the sound da means from hearing it in isolation. You need context to tell  whether you're hearing Russian, Spanish or English, and you need 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 1000s of pixels in color images. Every pixel  is represented by three binary sequences that correspond to the primary colors.  Each sequence encodes a number that determines the intensity of that  particular color. Then a video driver program transmits this information to the  millions of liquid crystals in your screen 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  snapshots of their amplitudes every few milliseconds. These are recorded as  numbers in the form of binary strings with as many as 44,000 for every second  of sound. When they're read by your computer's audio software, the numbers  determine how quickly the coils in your speakers should vibrate to create  sounds of different frequencies. All of this requires billions and billions of bits, but that amount can 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 length  encoding, these compressed formats are themselves written in binary code. So 

is binary the end all be all of computing, not necessarily. 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 these has provided as much physical stability for data storage and  transmission. So for now, everything you see, hear and read through your  screen comes to you as the result of a simple true or false choice made billions  of times over. Find out more about the mind boggling things happening inside  your computer with this playlist.