Alex
>>Einstein is attributed to have said something like: "If you cannot explain something to a 6-year old, then you do not understand it yourself".
How about:
"A physicist's theories are worthless unless he can explain them to the barmaid at the local pub." -- Lord Ernest Rutherford ( a self-described "simple" man who identified alpha/beta/gamma particles while discovering that matter is not immutable; who also performed the first deliberate nuclear reaction in between receiving a Nobel prize and 31 other science medals).
Regards
JR
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
