In 1836, people wanted to communicate with each other across great distances instantly—just like we do today—but technologies such as mobile phones and the Internet were still well over 100 years away.
Telegraphy was the first step toward bridging this communication gap. However, in its infancy, long-distance communication was limited to sending two states— either an electric signal or no electric signal. Samuel Morse developed a code comprised of dots and dashes (or dits anddahs) that could be sent electronically via wires that spanned miles and miles from one city to another. On one end, a telegraph operator would use a key to send a message—and on the other, an operator would hear the Morse Code, and transcribe it into letters, numbers, and punctuation. A skilled operator could instantaneously translate the Morse Code into alphanumeric symbols. It was easily the fastest way to communicate with people across the state, country, or even internationally.
Telegraphy was the first step toward bridging this communication gap. However, in its infancy, long-distance communication was limited to sending two states— either an electric signal or no electric signal. Samuel Morse developed a code comprised of dots and dashes (or dits anddahs) that could be sent electronically via wires that spanned miles and miles from one city to another. On one end, a telegraph operator would use a key to send a message—and on the other, an operator would hear the Morse Code, and transcribe it into letters, numbers, and punctuation. A skilled operator could instantaneously translate the Morse Code into alphanumeric symbols. It was easily the fastest way to communicate with people across the state, country, or even internationally.
Morse code is a variable-widthen coding. This means that each of the characters represented by the dashes and dots of Morse may be different lengths. This was done by design for efficiency. Samuel Morse knew that some characters would be sent much more often than others, and so the information required to send them should be less. For example, 'E' and 'T' each occur often and, as such, are represented respectively by one dot and one dash. 'Z', on the other hand, occurs infrequently, and so requires 4 bits to send (dash dash dot dot).
However, variable-length codes introduce some added complexity—how does one know where one character ends and another begins? In other words, what differentiates two 'E's in a row from one 'I'? Morse used time—the delay between characters— to delimit characters. But, in a way, this sacrifices robustness for efficiency. The sender's perception of time may be different than the receiver's—particularly at high speeds.
However, variable-length codes introduce some added complexity—how does one know where one character ends and another begins? In other words, what differentiates two 'E's in a row from one 'I'? Morse used time—the delay between characters— to delimit characters. But, in a way, this sacrifices robustness for efficiency. The sender's perception of time may be different than the receiver's—particularly at high speeds.
Digital vs Analog Data
Digital data refers to information stored as zeros and ones, while analog data refers to other storage methods. While digital data has largely supplanted analog data, some prefer analog storage techniques. Many analog records have been replaced by digital storage.
Perfect Copies
Common misconception: Digital copies are "perfect."
- Whereas the process of copying does not suffer degradation, the digital copies, like the original digital file, are still only approximations of the natural object. What actually is copied perfectly in a digital file is the binary representation, including any flaws or loss through digitization. This also assumes the process of copying is careful. If not, error can be introduced causing an "imperfect" digital copy.