Reverse Turing test subject of the test involves reversing the roles of the real and control subjects. When a Turing test is applied to a mixed group of human and computer subjects, the computers are the nominal subjects. However, the humans are judged in exactly the same way, and so their Turing test scores can also be calculated. This is another way of viewing the situation described in the previous section. The term "reverse Turing test" has also been applied to a Turing test (test of humanity) that is administered by a computer. In other words, a computer administers a test to determine
Turing completeness data is called a Turing oracle. Even a Turing oracle with random data is not computable (with probability 1), since there are only countably many computations but uncountably many oracles. So a computer with a random Turing oracle can compute things that a Turing machine cannot. All known laws of physics have consequences that are computable by a series of approximations on a digital computer. A hypothesis called digital physics states that this is no accident, because the universe itself is computable on a universal Turing machine. This would imply that no computer more powerful than a universal Turing machine