breuel@h-sc1.UUCP (thomas breuel) (11/09/85)
Below are the answers to two questions that 'biep@klipper.UUCP' asked. Altogether, you can make many comparisons between the brain and Turing machines, but such comparisons will not tell you much about either theoretical or practical limitations of the human brain. Thomas. ---------- ** Why is time complexity not a useful measure for comparing a Turing machine with a real life architecture? Turing machines are very nice devices for theoretical considerations. In a sense, they give the most believable and strict measure of computational complexity. For real life architectures, the theoretical benefits of a Turing machine are unimportant. You can't, for example do accesses to data on a Turing machine in less than O(n), whereas in real life, even on a serial architecture, you can do them in essentially constant time. ** Can you define 'Turing equivalent'? Something is Turing equivalent if it can simulate a Turing machine. Since a Turing machine does not have a limit on the amount of information that it can store, anything that can simulate a Turing machine can also not have a limit on the amount of information that it can store. The human mind probably has such a limit (judging from its architecture). Therefore, the human mind is probably not Turing equivalent.