Wolfram Alpha

It's like a search engine for researchers. No b.s. Pretty helpful on the wards if you ever need hard facts.

http://www.wolframalpha.com/

Examples:

• mortgage 6%, 25 year, $140000 displays, among other things, repayment rates and graphs that represent capital vs. interest over time.
• life expectancy france 25 year old male which gives a survival analysis for a person of the given demographic.
• boiling point of water at 6 atm which returns a phase diagram alongside the result of 432.6 Kelvins.
• lim(x->0) x/sin x yields the expected result, 1, a plot, and the series expansion. The button "show steps" provides a possible derivation of the result using L'Hôpital's rule.^[7]

Wolfram Alpha is also capable of responding to increasingly complex, natural-language fact-based questions such as:

• "Where was Mary Robinson born?"^[8]
• "How old was Queen Elizabeth II in 1974?"^[9]
• "What is the forty-eighth smallest country by GDP per capita?" yields Senegal, $1088 per year.^[10]
• "What is the speed of a swallow?" yields the assumption, "Assuming estimated average cruising airspeed of an unladen African swallow", and the result, "there is unfortunately insufficient data to estimate the velocity of an African swallow (even if you specified which of the 47 species of swallow found in Africa you meant)." This is a reference to a joke from the movie Monty Python and the Holy Grail.^[11]
• When asked "What is the meaning of life?", it replies 42. This is a reference to The Hitchhiker's Guide to the Galaxy novel, in which a supercomputer is told to calculate the meaning of life, and it finds the answer to be 42. These and all other "humorous" queries are individually written by programmers and not "understood" by the software on a deeper cognitive level.