by Robert Quigley Mar 28th
functionalist philosophers use to present their theory of mind as a series of inputs and outputs. At that, Turing machines, as Alan Turing proposed them in 1936, have quite a bit in common with modern computers, whose elegant, thought-experiment cousins they might be considered to be:
In non-technical terms, a Turing machine can be visualized as an indefinitely and infinitely long tape divided into rectangles (the memory) with a box-shaped scanning device that sits over and scans one component of the memory at a time. Each unit is either blank (B) or has a 1 written on it. These are the inputs to the machine. The possible outputs are:Remarkably, Mike Davey recently made theory into reality when he built a working Turing machine using a felt-tip pen, a Parallax propeller, motors, and 1000 feet of white film leader. Video after the jump: Read More
- Halt: do nothing.
- R: move one square to the right.
- L: move one square to the left.
- B: erase whatever is on the square.
- 1: erase whatever is on the square and print a '1.