As an undergrad I helped with research on quasars, where reasonable precision was solar mass orders of magnitude and tens of parsecs, and the periodic table was

As an undergrad I helped with research on quasars, where reasonable precision was solar mass orders of magnitude and tens of parsecs, and the periodic table was Hydrogen, Helium, and "metals". Then I switched to condensed matter physics for grad school, where "bulk" meant "a scale visible to the naked eye under very good conditions". The dichotomy makes me laugh.