The tools of astronomy, hmmm, what could that be. So the show talks about the types of telescopes used in astronomy. Galileo invented the first telescope. It was a REFLECTING telescope. It had two lenses, one at each end. REFLECTING telescopes are like over grown pirate's spy glasses. There is a limit as to how big the objective lens, the business end, can be made. That is about 36 inches. After that you have trouble. A more modern telescope, within the last 150 years, is the REFRACTING telescope. Here, a MIRROR replaces the OBJECTIVE LENS and shoots light into another mirror and finally into an eyepiece. These can be made up to about 10 meters which is about 400 inches. Now, these telescopes only deal with visible light. There is more to the ELECTROMAGNETic SPECTRUM then just the light that we can see. There is, Ultraviolet, Infrared, Radio waves, X-Rays, Gamma Rays and Charles Ray. Today, astronomers have instruments that can sense all of these forms of non-ionizing magnetic radiation. One problem astronomers have is our atmosphere. Water vapor bends the light. The ionisphere filters out some wave lengths. In general, our atmosphere makes telescope work difficult. That is why most descent telescopes are way up on a mountain top. And it also why we launched the HUBBLE SPACE TELESCOPE. Ok, so that's what the show was about. This is what the book said. --Astronomers employ various telescopes to observe the heavens. Now, this is what you should know for the test. Define ELECTROMAGNETIC RADIATION Define WAVE LENGTH What is a PHOTON What is CCD What is a RADIO INTERFEROMETER Know what the OBJECTIVE LENS is Know what a REFRACTING TELESCOPE is Know what a REFLECTING telescope is Define CHORMATIC ABERRATION What is an ATMOSPHERIC WINDOW What is the FOCAL LENGTH What is PRIME FOCUS, NEWTONIAN FOCUS, CASSESGRAIN FOCUS What is ACTIVE OPTICS What is a PHOTMETER What are the types of mountings Hey, down at Case they have a real observatory with a real telescope. rather than killing us with words, why can't we do a field trip and actually learn how to use one of these things?