Most nuclei require X-rays or gamma rays to raise their energy levels, but it can happen to thorium-229 with a far-ultraviolet photon of 8 eV (wavelength 150 nm).
This was predicted in the 1970s, but the precise frequency was only measured recently, and it might eventually be the basis of a vastly more accurate form of clock:
https://www.nature.com/articles/d41586-024-02865-w
Greg Egan /
npub12c…gd38p
2024-09-07 13:07:33
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npub12cuzzqzv8e8y7na77a9zv47mx2v6pec60qs5h7takzmv5p0mw0fsmgd38pPublished at
2024-09-07 13:07:33Event JSON
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