more-ang_size.html - learned about what is angular size
more-rltnshp.html - learned about the relationship between angular size
	and actual size
ang_prac1.html - practice using angular size (everyday situation)
parallax-movie.html - saw a movie demonstrating stellar parallax
betelgeuse.html - practice using angular size in astrophysical
	situation
parallax-size.html - using parallax to fins the distance to HT Cas
psf.html - learned about point-spread functions and why any telescope is
	limited in what it can image
strength.html - learned about the 1/r^2 effect of decrease in strength of
	signals with distance
time.html - learned about the size scale of the Universe and how long a
	radar signal would take to travel to HT Cas and back
lightcurve_match.html - practice matching points in the binary's orbit to
	points in the lightcurve
htcas-xray.html - learned how to use the relationship distance = dt * v
	and X-ray lightcurves to calculate the size of the central star