Proceedings of the National Academy of Sciences, Volume 122, Issue 52, December 2025. SignificanceWe derive here a group theoretical description of selection rules imposed by symmetries of electromagnetic fields in photoelectron chiral dichroism (PECD). Our theory explains all known PECD selection rules, including the common forward/…
Observations from the Little Bunker
Last updated: December 31, 2025 08:16 AM
Atmospheric CO₂
427.9 ppm
+18.1
ppm/year
Atmospheric CH₄
1930.95 ppb
+-3.5
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year