Amazing facts about the neutron EDM experiment

  • This experiment is said in the literature probably to have disproved more theories than any other experiment in the history of physics (url).
  • The structural asymmetry we are sensitive to is so small that, if the neutron were expanded to the size of the Earth, the distortion would be less than a tenth of the thickness of a human hair.
  • If the structural asymmetry we're sensitive to were expanded to the size of, e.g., a football, then a football expanded by the same factor would be the size of the visible Universe.
hubble big bang-football.jpg
  • The neutron "clock" runs at 30 Hz, or 1800 rpm; about the same as a car engine. We can measure the frequency so precisely that we'd be sensitive to an extra one turn per year on top of it.
  • We can sense energy changes of 10-21 eV, or 10-42 J; that's something like a million million million million million million million millionth of the amount of energy you need to boil water for a cup of tea.
  • The developments in precision frequency measurements needed for the first nEDM experiment, back in 1950, led ultimately to atomic clocks, NMR and MRI, GPS...