magnets ! not defined by ’ old fashioned ’ classical physics ! still , only first year college math , string theory not needed at this level , slight familiarity with quantum mechanics basics is recommended , but only a little bit !!
of course , a deeper dive will take much more math and quantum weirdness comfortability ;
https://www.feynmanlectures.caltech.edu/II_34.html
( did i post this 20 times yesterday ?? or was it 42 times ? )
( are whippets magnetic ?? i do seem drawn to them ! )
< edit > ( seems like maybe it was 2 days ago when i posted this feynman lecture many , many , many times https://bbs.boingboing.net/t/watch-anti-vaccine-crank-tells-public-meeting-that-vaccines-cause-cutlery-to-stick-to-your-head/ )
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