According to Wikipedia thorium is probably created from neutron stars or supernovae making it one of the rarest elements in the galaxy. But, it’s quite abundant on Earth, maybe 3x as abundant as Uranium on earths crust. Because of this abundance it is, along with Radon, the primary constituent of earths natural background radiation.
fnordpiglet 58 minutes ago [-]
Iron is the last element that can form through a sustaining fusion process. All elements above iron are formed in super nova or neutron star collisions. Specifically gold and platinum are thought to be formed primarily in neutron star collisions
The nuclear clock uses 229Th though which has an 8000 year half life and does not occur in nature at all.
pclowes 27 minutes ago [-]
How do they know the accuracy of the clock? Eg: 2s of drift in 65M years.
Naively, measuring that seems more difficult than the clock. Wouldn’t you need a perfect clock as a baseline? There must be something really clever here.
Reality is amazing!!
Naively, measuring that seems more difficult than the clock. Wouldn’t you need a perfect clock as a baseline? There must be something really clever here.