If you take care of your own lawn and landscaping, you’re going to need a string trimmer. These powerful machines and their rotating string allow you to quickly and easily trim and slice through ...

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 ...

Covariance and contravariance are precise terms that describe which conversions are safe on parameters and return types. Learn practical definitions for those terms, what new constructs will be ...

When you shop through retailer links on our site, we may earn affiliate commissions. 100% of the fees we collect are used to support our nonprofit mission. Learn more. String trimmers (also called ...

String theory is an attempt to unite the two pillars of 20th century physics — quantum mechanics and Albert Einstein's theory of relativity — with an overarching framework that can explain all of ...

Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute, host of Ask a Spaceman and Space Radio, and author of "Your Place in the Universe." Sutter contributed this article ...

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, ...