Dopplerin

Dopplerin is a fictional chemical compound commonly used in textbooks and simulations to demonstrate the Doppler effect in spectroscopic and fluid-dynamic contexts. The name combines the Doppler principle with a conventional chemical suffix, signaling a tracer-like substance.

In typical educational depictions, Dopplerin is described as a stable, colorless liquid that can be introduced into a flowing medium. It is said to fluoresce under excitation at a specific wavelength, with the emitted light undergoing a frequency shift proportional to the velocity of the surrounding medium, providing a visible representation of Doppler shifts.

In real science and engineering, velocity measurement relies on techniques such as Doppler ultrasound, laser Doppler velocimetry, or MRI-based methods. Dopplerin, as presented in teaching materials, does not correspond to an actual synthesized compound and has no regulatory status or experimental use outside fictional or didactic contexts.

See also Doppler effect, Doppler ultrasound, laser Doppler velocimetry.