Until Dr Agrawal's discovery, even these indirect methods were slow.

ECONOMIST: Number theory

To find out how warm the earth was before that, climatologists have had to resort to indirect methods, such as measuring tree-rings, or counting the different isotopes of oxygen in layers of polar ice.

ECONOMIST: The hole story of global warming

De Beers has been selling its diamonds and diamond jewelry through indirect methods to the U.S. For example, through a separate entity with luxury retail conglomerate, LVMH, it sells diamond jewelry on the retail level in the U.S. through the De Beers Diamond Jewellers brand.

FORBES: De Beers Seeks A Return to the U.S., Moves Diamond Operations To Botswana

Instead, mathematicians turn to other, indirect, methods that can test for primality without factorisation.

ECONOMIST: Number theory

With the suitably mysterious name of "Project 1640, " the new instrument is the first of its kind that's able to directly spot planets orbiting distant suns -- as opposed to existing systems that use indirect detection methods to determine the orbit of exoplanets.

ENGADGET: Project 1640 offers new way to search for planets beyond our solar system