Atmospheric Distortion of Light (aka “Bubbles in the Air”)
Astronomers can make use of an artificial star by shining a powerful laser to correct for the blurring caused by the atmosphere.Copyright 2015 ESO/B. Tafreshi, Attribution 4.0 International (CC BY 4.0), Wikimedia Commons, https://commons.wikimedia.org/wiki/File:A_Mix_of_Colours_and_Wonder.jpg
Image distortion from the atmosphere accounts for a real-world problem faced by engineers in a range of optical applications. In this activity. students do two kinesthetic activities to model how atmospheric turbulence causes light rays to refract on their way from the Sun or distant stars down to the surface of Earth, resulting in distorted or blurry images. Students then draw conclusions to generalize their observations and apply it to light rays traveling through other media of non-uniform density or temperature.
Atmospheric distortion is a real-world problem that scientists and engineers in a variety of fields must either accept as a source of systematic error or can try to overcome and correct for using adaptive optics (AO) systems. The turbulence in the atmosphere causes issues mainly for people who design astronomical telescopes and laser communication systems.
After this activity, students should be able to:
- Explain physically how temperature fluctuations/differences in the Earth’s atmosphere contribute to the distortion of light in its path.
- Describe the visual appearance or result of atmospheric turbulence and distortion of light (such as the “blurriness” or “fuzziness” of an image on a wall or the human eye).
- Summarize the connection between a macroscopic/human scale model of atmospheric distortion and a smaller scale visualization of the distortion of light through a turbulent medium.