https://mary2point5.tumblr.com/

and what else?...they've been tested with stuff that they really shouldn't have done?...and that's the 'rub', isn't it - dazzlenation...go figure:

 

https://en.wikipedia.org/wiki/Rubidium

 

https://en.wikipedia.org/wiki/Zero_field_NMR

 

 

safer to use etc etc:

 

https://en.wikipedia.org/wiki/Low_field_nuclear_magnetic_resonance

 

P.L. Volegova, A.N. Matlachova and R.H. Kraus, Jr., "Ultra-low field NMR measurements of liquids and gases with short relaxation times."