Outline
 1. What you need to know:
 a. X-rays from the Sun -
 magnetic activity, x-ray spectra
 b. Hot stars
 c. Radiation-driven winds and
 the Doppler shift
 d. The holy grail
 of science: a measurement that can discriminate between two contradictory theories
 2. What we have observed/measured with the new
 generation of
 high-resolution x-ray telescopes
 3. Our empirical model and fits to the data
 4. An answer…and more questions