String theory began over 50 years ago as a way to understand the strong nuclear force. Since then, it’s grown to become a theory of everything, capable of explaining the nature of every particle, ...

String trimmers get into spots your mower just can’t reach. These tools, sometimes called weed whackers, are also famously tough to start, particularly if they’ve been in storage all winter. Because ...

A string trimmer gets into places that a lawn mower can’t. It’s the ideal tool for keeping the edges of your garden or walkway neat and tidy, and for manicuring around fence poles and tree trunks. It ...

String theory has so far failed to live up to its promise as a way to unite gravity and quantum mechanics. At the same time, it has blossomed into one of the most useful sets of tools in science.