jim bell recommends the following story from Science X: New measurement of nucleus of thorium-229 moves scientists step closer to a nuclear clock https://phys.org/news/2020-10-nucleus-thorium-scientists-closer-nuclear.html jim bell's comment: No, this is not an "atomic clock". This is a NUCLEAR clock! -------------------------------------------------- NOTE: This e-mail was sent by jim bell by filling e-mail form at https://sciencex.com/. If you do not know this person you may choose to disregard this e-mail or report it to info@sciencex.com