But more than great technology, the real secret to discovery is creativity, because creativity helps you make good use of whatever tools are actually available to you, even if they happen to be, as in the case of Eratosthenes, two sticks on the ground. In the following TEDTalk animated presentation, Myth Buster Adam Savage recounts a few examples (starting with Richard Feynman, moving on to Eratosthenes, Galileo, and Armand Fizeau's toothed wheel to measure the speed of light,) about how small ideas can give rise to mind-blowing ideas and revolutionary discoveries.
And if Carl Sagan is more your style, you might be interested in his take on Eratosthenes.