Experimental physics is one of the crucial ingredients of physics. There are at least two major tasks within its realm. The first is to examine nature through observation. These observations can then be extrapolated into systematic measurements that can be quantified. The second aspect is that experimental physics serves as a platform to test hypotheses that are already formulated by theory. In this way, it acts as a conduit connecting theory to real-world situations. Additionally, it reveals the limitations of any theory, thereby serving as a valuable test bed.
These two tasks are essentially intertwined: an observation can lead to new hypotheses, and, conversely, a well-formulated hypothesis can lead to systematic measurements.
For example, while hunting for astronomical radio sources, an important discovery was made: the observation of the cosmic microwave background. This finding turned out to be one of the crucial ones in physics, providing vital insights into the Big Bang theory and becoming a foundational aspect of observational cosmology. Another example is the special theory of relativity, where the Michelson-Morley experiment ruled out ether, which enabled Einstein to formulate his theory with greater confidence.
These two examples offer a snapshot of the possibilities within experimental physics and highlight its essential role in the duality between theory and experiment in physics. In a way, experiments and theory complement each other, and are like two sides of a coin.
VISMAYA - History & Philosophy of Science 