Chapter 6- Telescopes Flashcards
two types of telescopes
- refracting
- reflecting
refraction
bending of light as it passes one transparent medium to another
bending
change of direction
what was the first type of telescope
refraction
why does light refract
- speed of light is different in different materials
- change in speed= change in direction
index of refraction
speed of light in vacuum/ speed of light if given material
what can a lens do
- focus light down to a point
- curved piece of glass
focal length
-distance from lens to local point
long focal point equals what
large image, small field of view
short focal length equals what
small image, large field of view
what are the main purposes of telescope
1) gather light
2) improve resolution
3) magnify
reflecting telescope
- bending or change of direction as it bounces off a surface
- developed by newton
what is the problem with reflecting telescope
focal point is on the same side as the object being viewed
differences between refraction and reflectors
- mirrors in reflectors are cheaper to produce
- mirrors can be made much lighter than lenses
- biggest refractor is 1 meter and biggest reflector is 10 meter
what is the rule about bigger telescopes
doubling the size of the object is quadrupling light gathering power
