They have the world's greatest computational capacity, the most expertise in massively distributed processing, the greatest collection of minds interested in and capable of work on AI, the largest store of online data, the largest store of personal data, and the largest library of scanned, computer-readable books. That includes textbooks. Like, all of them.
All they have to do is subscribe to Springer-Verlag's online journals, and they'll have the entire collected knowledge of humanity in computer-readable format.
They almost certainly have the biggest research budget for natural language processing with which to interpret all those things.
They have two of the four smartest executives in Silicon Valley.
Their corporate strategy for the past 15 years can be approximated as 'Win the Singularity.'
If someone gave you a billion dollars today to begin your attempt, you'd still be 15 years and about two-hundred and ninety-nine billion dollars behind Google. If you believe in a circa-2030 Singularity, there isn't enough time left for anybody to catch up with them.
(And I'm okay with that, considering that the other contenders include Microsoft and the NSA. But it alarms me that Google hasn't gone into bioinformatics or neuroscience. Apparently their plans don't include humans.)"