But it is a scientific theory based on repeated observations, experiments,measurements and discoveries.

VOA: special.2009.12.01

They're actively engaged in the material, actually seeing the phenomena, by making measurements of real world experiments.

学生们能自主地参与到物质中，看见真切的现象，通过对真实世界实验,做出测量。

麻省理工公开课 - 媒体、教育、市场课程节选

And the measurements from Viking on the biology experiments did not suggest evidence of microbial life or any life on the surface of Mars.

NPR: Revisiting the Viking Missions to Mars

My experiments make use of sophisticated spectroscopy measurements of resonance energy transfer, to help gauge the accuracy of computational simulations of protein dynamics.

WHITEHOUSE: Engage and Connect

As it landed, it made measurements, meteorological measurements, measurements of the surface, and did some very sophisticated biology experiments.

NPR: Revisiting the Viking Missions to Mars