observable

/əbˈzɜrvəbəl/
adjective
  1. Able to be seen, noticed, or detected.
    • The effects of the new policy were observable within a few months.
    • The observable universe contains billions of galaxies.
    • There was no observable change in the patient's condition after the treatment.
noun
  1. A physical quantity or phenomenon that can be measured or detected, especially in science.
    • The scientists recorded several observables during the experiment.
    • In quantum mechanics, an observable is something like position or momentum that can be measured.
    • Temperature is a key observable in weather forecasting.
What does "observable" mean? | whatsthatwordmean | whatsthatwordmean