Dette er hentet fra kapittel 16 - Mach 9 i boka "Turing's Cathedral: The Origins of the Digital Universe" av George Dyson. Alt som ikke er direkte avskrift fra boka, og mine bemerkninger er satt i trebuchet, mens avskrift er satt i georgia. Alle lenker er naturligvis mine.
By mid-1953, five distinct sets of problems were running on the MANIAC, characterized by different scales of time:
nuclear explosions, over in microseconds
shock and blast waves, ranging from microseconds to minutes
meteorology, ranging from minutes to years
biological evolution, ranging from years to million of years
stellar evolution, ranging from millions to billions of years
All this in 5 kilobytes - enough memory for about one-half second of audio, at the rate we now compress music into MP3s.
These time scales ranged from about 10-8 seconds (the lifetime of a neutron in a nuclear explosion) to 1017 seconds (the lifetime of the sun). The middle of this range falls between 104 and 105 seconds, or about eight hours, exactly in the middle of the range (from the blink of an eye, over in three-tenths of a second, to a lifetime of three billion seconds, or ninety years) that a human being is able to directly comprehend.
Of these five sets of problems, shock waves were von Neumann's first love and remained closest to his heart. He had an intuitive feel for the subject. Calculation was not always enough. "The question as to whether a solution which one has found by mathematical reasoning really occurs in nature ... is a quite difficult and ambigous one," he explained in 1949, concerning the behavior of shock waves produced by the collision of gas clouds in interstellar space. "We have been guided almost wntirely by physical intuition in searching for it ... and it is difficult to say about any solution which have been derived, with any degree of assurance, that it is the one which must exist."