Why “Thorium” is being discussed
The most recent Hacker News stories and comments contributing to this topic's mentions.
Two teams have independently gotten a new kind of ultra precise clock working based on isomers of the thorium 229 nucleus. Currently not as accurate as atomic clocks but they ha…
by oofbey · Oct 8, 2026
Thorium 229 based nuclear clocks
by oofbey · Oct 8, 2026 · 1 points
Yes that is true, but most of potassium and carbon are not radio isotopes. All of thorium is radioactive. As such it is likely true that all life carries some quantity of radioa…
by austin-cheney · Oct 8, 2026
There are 2 Nature articles, for the 2 independent teams who have built such nuclear clocks with thorium 229. This is the other article, from the Chinese team: https://…
by adrian_b · Oct 8, 2026
Potassium is everywhere, including in every living cell. So the exposure to potassium radiation is constant for any living being on Earth. Exposure to thorium and radon varies g…
by adrian_b · Oct 8, 2026
The hope is that with nuclear clocks there will be no need for the very complex single-ion traps or optical lattices required for clocks that use ionic or atomic energy levels.…
by adrian_b · Oct 8, 2026
Interest
Proportion of Hacker News items mentioning "thorium" over time.
Mentions
Total number of Hacker News items mentioning "thorium" over time.
Thorium is a chemical element; it has symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely divided. Read more on Wikipedia