Polarimeter

Part of speech: noun

Definitions

1. A device that measures the rotation of polarized light caused by optically active materials is known for quantifying the optical activity of substances
2. This instrument assesses the specific rotation of chiral molecules by evaluating the degree to which polarized light is rotated when traversing these materials
3. An apparatus used to determine the angle of rotation of polarized light as it passes through certain substances

Etymology: A polarimeter is built from two parts that come straight from Greek and 19th-century science. The first is "polar," from the Greek word for axis or pole, which in optics refers to the direction in which light waves are constrained to vibrate. The second is "-meter," from Greek "metron," meaning measure, the same ending found in thermometer or barometer. Put together, the name describes an instrument for measuring polarized light. The device was developed in the early 1800s, after physicists established that light could be polarized and that certain substances, such as sugar solutions, twist the plane of polarized light passing through them. Measuring that twist became a practical way to determine how concentrated a sugar solution was, which is why polarimeters were long standard in sugar refining and in pharmaceutical quality control.