On the contrary, every single 'thing' in science, has either already been tested or is being tested and changes over time. Atoms space and time are classic examples of 'things' that science has changed its meaning of .. because of new results derived from that testing. These are in fact,
concepts, and
not what we commonly think of as being 'things' (or physical, unchanging objects). If they were 'physical objects' existing completely independently from our concepts, then why would they change at all?
Everything, with no exceptions in science, becomes an
operational definition, otherwise it is neutralised (and bypassed) as being yet another
belief.