London-born scientist Stephen Wolfram has built a search engine that apparently can compute answers to factual questions more powerfully than Google.

, Wolfram said he believes that computation, rather than semantic understanding, may be the key to better search.

"A lot of [information] is now on the web -- in billions of pages of text. And with search engines, we can very efficiently search for specific terms and phrases in that text," he wrote on his website.

"But we can't compute from that. And in effect, we can only answer questions that have been literally asked before. We can look things up, but we can't figure anything new out."

Wolfram Alpha is like a giant electronic brain Wolfram is well-known as the inventor of Mathematica, the multi-faceted program that made the computer a useful tool for serious mathematics. He also authored A New Kind of Science (NKS), a 1,200-page report that attempts to explain a vast array of natural phenomena in terms of cellular automata, simple mathematical rules that can lead to complex behaviour.