1. Lloyd, Seth. “Ultimate Limits to Computation”, Nature, August 31, 2000. » Current laptop: speed: ~10 9 operations per sec. memory: ~10 10 bits » Analysis based on quantum theory » Theoretical limit: ~10 32 operations per sec. on 10 16 bits » Experimental quantum computers based on NMR to store one bit per spin of a nuclei.

2. Some algorithms are not feasible because they take too long to execute. Recall from a previous lecture... password lengthexecution time 2 chars 3 chars 4 chars 5 chars 6 chars 8 chars 15 chars Password cracking by testing all possibilities:

3. Q: What kind of algorithms are infeasible? play cards by considering all possible hands A: Algorithms that consider all possible _________ or _________ for a significant number of values. A: Algorithms that consider all possible _________ or _________ for a significant number of values. play chess by analyzing all possible games test every possible DNA gene sequence Examples -- Consider algorithms to...

4. Are computers intelligent? Alan Turing Turing Test (1950) respondent?

5. More about the Turing Test Criticisms: Sometimes humans are not intelligent. Some intelligent behavior is not human behavior. Turing test