How to measure a second

"The answer to how we measure time may seem obvious."

https://www.nist.gov/how-do-you-measure-it/how-do-you-measure-second?utm_source=1440-st&utm_medium=email&utm_campaign=view-content-pr&user_id=66c4c92f5d78644b3ac5d5b4

Speed of Light

"So, you’re driving a car at half the speed of light."

https://www.wired.com/story/why-time-is-relative/

Space Time

"Theories about space and time have always been the great misunderstood ones for the general public, but one of the great mysteries to work on and investigate for physicists and scholars of these subjects."https://amp-marca-com.cdn.ampproject.org/v/s/amp.marca.com/en/lifestyle/world-news/2025/07/04/6867f0d1ca47416e778b45fa.html?amp_gsa=1&amp_js_v=a9&usqp=mq331AQGsAEggAID#amp_tf=From%20%251%24s&aoh=17519911266752&csi=0&referrer=https%3A%2F%2Fwww.google.com&ampshare=https%3A%2F%2Fwww.marca.com%2Fen%2Flifestyle%2Fworld-news%2F2025%2F07%2F04%2F6867f0d1ca47416e778b45fa.html

Time Dilation

"Time dilation refers to the seemingly odd fact that time passes at different rates for different observers, depending on their relative motion or positions in a gravitational field."https://www.livescience.com/what-is-time-dilation