Perhaps the greatest legacy of Alan Turing lies in his Turing machine. It’s a concept that defines the abilities of a hypothetical machine. Turing believed that a machine is capable of simulating the logic of any computer algorithm.
The Turing machine was never intended to have a physical construction. It is merely a concept which Turing believed would help mathematicians and computer scientists understand the full capabilities of computation. It was the time when distinguished individuals in the field are trying to perfect the formal arithmetic language of computation to be used in machines. But what many fail to see is that in doing so, they are limiting computation to a finite set of instructions. Turing saw this pitfall and aimed to correct it by establishing the hypothetical device that is the Turning machine.
Established in 1936, the Turning machine defines that any machine is capable of diverse mechanical computations. This machine operates on a tape wherein numerous symbols are included. These are the symbols that the machine can read and write with using a tape head. To better understand this, there is a need to be familiar with the components of the Turing machine. There are four parts – the tape, the tape head, the state register and the table of instructions.
The tape acts like a data storage or in modern day, it represents the memory. It looks like a cluster of square cells which resembles an empty one-line crossword puzzle. The tape head has three functions. It reads the symbol for instructions. It writes its output and edits the symbols either by erasing them or by replacing it with a new one. And lastly, it moves the tape horizontally to enable reading and writing multiple instructions. The state register, on the other hand, stores the states of the machine from the start state to the many operational states and finally back to the start state. Instructions are stored in a finite table which takes into consideration the symbols that are currently being read by the tape head to the state of the machine. It enables the machine to interpret the symbols and translate them into a specific set of instructions.
Through this hypothetical device, Turing was able to capture the essence of logic and mathematics in algorithms. The machine provided the foundation for many scientists which led to countless breakthroughs in computer science and mathematics.