Yet, the numerical value of the constant has often undergone change in value over the years, as scientists have been able to improve their measuring devices and systems.
(the numerical value of the constant; has undergone; change in value over the years; T:often) (scientists; have been; able to improve their measuring devices and systems) (scientists; to improve; their measuring devices and systems)
the numerical value of the constant scientists scientists
has undergone have been to improve
change in value over the years T:often
able to improve their measuring devices and systems
their measuring devices and systems