Even though it is the bedrock of modern measurements, the International System of Units (SI) is not set in stone. As science ...

SI Unit: Every measurement we make, be it for length, time, temperature, or electric current, needs a standard unit so that results are understood universally. To maintain uniformity worldwide, ...

Scales aren't changing and the weather won't be noticeably different, but on May 20 the definitions that underlie what your scale and thermometer report—along with standard definitions used in ...