50x50: Science Across America is a national series uncovering exceptional science in all 50 states. It is a production of the Independent Media Initiative in collaboration with HHMI Tangled Bank Studios, Alfred P. Sloan Foundation, and the Winn Family Foundation. See all the states at https://5050science.com In 1656, Christiaan Huygens invented a pendulum clock that, based on the period of its pendulum swings, could measure time down to the second. Today, we have clocks that measure a second out to 19 decimal places. What’s the point of subdividing time into such infinitesimally tiny fractions? LEARN MORE ************** To learn more about this topic, start your googling with these keywords: - Pendulum clock: is a clock that uses a swinging weight known as a pendulum as its timekeeping element - Atomic clock: is a clock that measures time by monitoring the resonant frequency of atoms. - Cesium clock: is an atomic clock that measures time using a precise natural frequency of cesium atoms. 9,192,631,770 cycles of that frequency define one second. - NIST-F3: is an ultra-precise cesium fountain atomic clock, developed to improve U.S. official timekeeping. - Bacteriophage: A virus that infects bacteria. - Cesium: A chemical element (symbol Cs) used in atomic clocks due to its predictable atomic behavior. - Dark Matter: A hypothetical form of matter that does not interact with light and makes up a significant portion of the universe's mass. - Latency: The delay or lag in a system (e.g., in online gaming). - Radiation: Energy that travels in the form of waves or particles; in this case, referring to the energy emitted by atoms. - Supercooled: Cooled below the freezing point without becoming solid. - Ytterbium: A chemical element (symbol Yb) used in more advanced atomic clocks. SUPPORT MINUTEEARTH ************************** If you like what we do, you can help us!: - Become our patron: https://patreon.com/MinuteEarth - Our merch: store.dftba.com/me - Our book: https://minuteearth.com/books - Sign up to our newsletter: http://news.minuteearth.com - Share this video with your friends and family - Leave us a comment (we read them!) CREDITS ********* Cameron Duke | Script Writer, Narrator and Director Arcadi Garcia i Rius | Illustration, Video Editing and Animation Nathaniel Schroeder | Music MinuteEarth is produced by Neptune Studios LLC https://neptunestudios.info OUR STAFF ************ Lizah van der Aart • Sarah Berman • Cameron Duke Arcadi Garcia i Rius • David Goldenberg • Melissa Hayes Henry Reich • Ever Salazar • Leonardo Souza • Kate Yoshida OUR LINKS ************ Youtube | https://youtube.com/MinuteEarth TikTok | https://tiktok.com/@minuteearth Twitter | https://twitter.com/MinuteEarth Instagram | https://instagram.com/minute_earth Facebook | https://facebook.com/Minuteearth Website | https://minuteearth.com Apple Podcasts| https://podcasts.apple.com/us/podcast/minuteearth/id649211176 REFERENCES ************** Boulder Atomic Clock Optical Network (BACON) Collaboration. (2021). Frequency ratio measurements at 18-digit accuracy using an optical clock network. Nature, 591, 564–569. https://doi.org/10.1038/s41586-021-03253-4 Gerginov, V., Hoth, G. W., Heavner, T. P., Parker, T. E., Gibble, K., & Sherman, J. A. (2025). Accuracy evaluation of primary frequency standard NIST-F4. Metrologia, 62(3), Article 035002. https://doi.org/10.1088/1681-7575/adc7bd Hoth, G. W., Sherman, J. A., Radnaev, A. G., Mitchell, P., & Gerginov, V. (2023). NIST-F3, a cesium fountain frequency reference. In Proceedings of the 2023 Precise Time and Time Interval Systems and Applications Meeting (pp. 183–188). Institute of Navigation. https://doi.org/10.33012/2023.18691 Marshall, M., Rodriguez Castillo, D., Dworschack, W. J., Aeppli, A., Kim, K., Lee, D., Warfield, W., Nardelli, N., Fortier, T. M., Ye, J., Leibrandt, D. R., & Hume, D. B. (2025). High-stability single-ion clock with 5.5 × 10^-19 systematic uncertainty. Physical Review Letters, 135, Article 033201. https://doi.org/10.1103/hb3c-dk28 Murdin, B. (2021, March). Scientists are hoping to redefine the second – here's why. The Conversation. https://theconversation.com/scientists-are-hoping-to-redefine-the-second-heres-why-157645 Rowlatt, J. (2014, October 3). Caesium: A brief history of timekeeping. BBC News. https://www.bbc.com/news/magazine-29476893