Astronomy

Francois was an exchange student at a school where I taught.  He was originally from France, but moved to Montreal.  He had already taken every math and science course we had to offer, but he had never done any lab work!  So we decided to do lots of labs together. Since I was interested in astronomy, I suggested trying to determine the speed of light by the method first used by Ole Roemer in the 17th century.  Eclipses of Jupiter’s moon Io occur at very regular time intervals, but they seem to occur sooner than expected when the Earth is traveling towards Jupiter, and later than expected when the Earth is traveling away from Jupiter.  The motion of the Earth (and to a smaller extent, the motion of Jupiter) changes the distance between the two planets, thus affecting the amount of time it takes for light to travel from one to the other.  For more info, click  HERE . The Earth travels approximately 1,600,000 miles in its orbit every day, and it takes lig...

Years ago when I was taught how to shoot a rifle, I was told to aim with both eyes open.  Apparently that helps you relax and hold steady.  When I started looking through telescopes, I tried to do the same thing.  I kept both eyes open but concentrated only on what I saw through my dominant (right) eye.  But wouldn't it be better if you kept both eyes open and actually  used them both at the same time?  That's the idea behind binoculars...and binoviewers.  Some thoughts about binoviewers: 1. For many, observing is more "comfortable" with binoviewers, and the view is more 3-D like.  Other people, however, have difficulty merging the images entering each eye into one.  Sometimes I do; sometimes I don’t. 2. Although the total light is obviously split in half, the overall brightness of the image doesn't actually decrease that much.  Maybe a half magnitude is lost?  I don’t notice it much. 3. Because the required light path is lengthened...