Explore Capsules

GPS accuracy depends on precise clock synchronization between satellites and receivers, and that synchronization requires Einstein’s relativity. Readers will understand how satellite motion, gravitational effects, orbital shape, and Earth’s rotation influence GPS timing, and why correcting for these effects is essential to the location accuracy used every day.

Your daily rhythms are set less by habit and choice than by the natural light-dark cycle, which resets an internal clock deep in the brain. Morning sunlight and dim evenings keep sleep, mood, and metabolism in sync, while artificial light at night throws them off. Align your day with these light cues and you can sleep better and lower your risk of metabolic trouble.