Original version With This story appeared in How much warehouse.
Ask a question to Magic 8 Ball, and answer yes, no, or something annoying. We consider it a toy for children, but theoretical IT specialists employ a similar tool. They often imagine that they can get acquainted with hypothetical devices called Wybniki, which can immediately and correctly answer specific questions. These fancy thought experiments inspired novel algorithms and helped researchers to map the calculation landscape.
Scientists who recall the oracles work on the subfly of computer science called the theory of computational complexity. He is worried about the inseparable difficulty of problems, such as determining whether the number is the first or finding the shortest path between two points on the web. Some problems are basic to solve, others seem much more challenging, but they have solutions that are basic to check, and others are basic Quantum computers But seemingly challenging for ordinary ones.
The theorists of complexity want to understand whether these apparent differences in difficulties are fundamental. Is there anything challenging by nature in some problems, or are we just not intelligent enough to come up with a good solution? Scientists deal with such questions, sorting problems in “Complement classes“-For example, basic problems go in one class, and all basic to check problems go in another-and prove the claims regarding the relationship between these classes.
Unfortunately, the map of the landscape of computing difficulties turned out, well, well, challenging. So in the mid -seventies some researchers began to examine what would happen if the calculation rules were different. There they enter the oracles.
Like Magic 8 Balls, oracles are devices that immediately answer questions yes, not revealing anything about their internal actions. Unlike Magic 8 Balls, they always say yes or no, and they are always correct – the advantage of being fictitious. In addition, each Dana Oracle will only answer a specific type of question, for example “Is this number primary?”
What makes these fictitious devices useful to understand the real world? In brief, they can reveal hidden connections between different complexity classes.
Take the two best -known complexity classes. There is a class of problems that are basic to solve, which scientists call “P”, and a class of problems that are basic to check which scientists call “e.g.”. Are all basic to check problems also basic to solve? If so, it would mean that, for example, it would be equal to P, and all encryption would be Easy to break (among other consequences). The theorists of complexity suspect that, for example, it is not equal to, but they cannot prove it, even though they tried to establish a relationship between two classes Over 50 years.
Oracles helped them better understand what they were working with. Scientists invented oracles that answer questions that facilitate solve many different problems. In a world where each computer had a helpline of one of these oracles, all basic to check problems would also be basic to solve, and P equal, e.g. But other, less helpful oracles have the opposite effect. In the world of those inhabited by these judge P and, for example, they would be different.