19 Aquarii must be rotating at least that fast. 19 Aquarii 19 Aquarii is a star in the constellation of Aquarius. With an apparent magnitude of about 5.7, the star is barely visible to the naked eye (see Bortle scale). Parallax estimates made by the Hipparcos spacecraft put it at a distance of about 300 light years (92 parsecs) away from the Earth. 19 Aquarii has a spectral type of A8V, meaning it is an A-type main-sequence star. These types of stars are bluish-white colored, and have effective temperatures between 7100 and 11500 K. It rotates fairly fast, as its projected rotational
Wolfram's 2-state 3-symbol Turing machine Wolfram's 2-state 3-symbol Turing machine In his book "A New Kind of Science", Stephen Wolfram described a universal 2-state 5-symbol Turing machine, and conjectured that a particular 2-state 3-symbol Turing machine (hereinafter (2,3) Turing machine) might be universal as well. On May 14, 2007, Wolfram announced a $25,000 prize to be won by the first person to prove or disprove the universality of the (2,3) Turing machine. On 24 October 2007, it was announced that the prize had been won by Alex Smith, a student in electronics and computing at the University of Birmingham, for his proof that it was