Curated OER
WAVES AND PHOTONS
Learners examine the many types of electromagnetic waves, the concept of an EM wave, how James Clerk Maxwell proposed a slight modification of the equations of electricity, Heinrich Hertz and his radio-frequency, wavelengths, and light...
University Corporation for Atmospheric Research
Ucar: Coronal Holes in the Sun's Atmosphere
Coronal holes are areas in the Sun's atmosphere that appear dark in X-ray and ultraviolet images of the Sun. View a picture and read a description of coronal holes in this article.