Refracting Telescopes

1. Refracting Telescopes

2. Refracting Telescopes This kind of telescope also has two convex lenses, the objective lens and the eyepiece.

3. Refracting Telescopes In refracting telescopes, the objective lens is much bigger, so the focal length is farther, so the telescope is longer too.

4. Why is it called “refracting”? It refracts here! It refracts here

5. What’s the problem? Refracting telescopes need very large optic lenses. When they get too big it can be hard to move and also the lens can bend because it is too heavy.

6. Reflecting Telescopes concave mirror The light comes in and hits the ___________. The light is ____________ to the ___________ and then to the eyepiece. reflected plane mirror

7. Has this ever happened to you?

8. The best internet is made of optical fibers. Listen to my story…

9. The best internet is made of optical fibers. • The light travels through the cables • Thousands of signals 信号 can go at the same time

10. So, why is the internet slow? • Many wires we use near here are copper, not • optic fibers. • Copper has more resistance and some of the • signal is lost. • The wires might have many turns that slow the • signal down. • The wires might be old and they “leak” 泄漏 • some signal. • Some internet websites are blocked (this slows • everything down)

11. Binoculars

12. Magnifies 会放大

13. Optical Fibers

14. A compound light ____________ uses two ___________ lenses.A microscope ______________ small objects by forming an enlarged image of the object. microscope convex magnifies

15. A _____________ telescope uses a convex lens to collect, refract, and focus light rays from distant objects and a convex eyepiece to magnify the image. refracting

16. A ____________ telescope uses a concave mirror, a ____________ mirror, and a convex lens to collect and focus light from distant objects. reflecting plane

17. ______________ are actually two refracting telescopes put side by side.All the light in __________________ have the same wavelength and moves in the same direction. Binoculars laser light

18. Almost no light is lost or absorbed in______________________ which are transparent glass fibers. optical fibers

19. Refracting Telescopes

20. Refracting Telescopes This kind of telescope also has two convex lenses, the objective lens and the eyepiece.

21. Refracting Telescopes In refracting telescopes, the objective lens is much bigger, so the focal length is farther, so the telescope is longer too.

22. Why is it called “refracting”? It refracts here! It refracts here

23. What’s the problem? Refracting telescopes need very large optic lenses. When they get too big it can be hard to move and also the lens can bend because it is too heavy.

24. Reflecting Telescopes concave mirror The light comes in and hits the ___________. The light is ____________ to the ___________ and then to the eyepiece. reflected plane mirror

25. Has this ever happened to you?

26. The best internet is made of optical fibers. Listen to my story…

27. The best internet is made of optical fibers. • The light travels through the cables • Thousands of signals 信号 can go at the same time

28. So, why is the internet slow? • Many wires we use near here are copper, not • optic fibers. • Copper has more resistance and some of the • signal is lost. • The wires might have many turns that slow the • signal down. • The wires might be old and they “leak” 泄漏 • some signal. • Some internet websites are blocked (this slows • everything down)

29. I think the three most likely reasons your internet is slow are… The wires are copper, not optical fiber. Copper wires can not send signals as fast as optical fibers. Also, the wires are very cheap. Some of the wires the workers used are so cheap. There are many people using it at the same time. China has so many people. That is probably why your internet is so slow.

30. What are the qualitative and quantitative properties of 100ml of white milk if its mass is 50g?

31. Card Prizes!

32. Remember, you can always save your cards for next year if you are coming back.

33. Prize 1 Two Candies!!

34. Prize 2 Four Candies!! One free HW day next year.

35. Prize 3 One no homework day next semester. McDonald's Fries (medium)

36. Prize 4 McDonald’s SMALL Burger

37. Prize 5 And three no HW Days… McDonald’s Burger

38. Microscopes eyepiece lens--------------------- objective lens------------------ stage------------------------- light source-------------------

39. When the picture was clear that means you have the right focal length. Got it! The right focal length!

40. When the picture was clear that means you have the right focal length. Focal length is the distance between Two convex lenses to make an object bigger.

41. How does it work?

42. How does it work? The object is on the stage

43. How does it work? The picture goes through the objective lens and is magnified.

44. How does it work? Then the bigger picture goes through The eyepiece lens and is magnified again.

45. Which brand of gum is the most delicious? BAD TEST!! - There is no way to test it, it is an opinion

46. Who is the tallest in the class? BAD TEST!! - It is easy to see, there is no test here.

47. Which brand of gum lasts the longest? (Which brand of gum has the longest life)? GOOD TEST! • We don’t know the answer and it is something • we can test.

48. The Diaper Test!

49. Three kinds of mirrors!

50. Plane Mirror - A plane mirror is totally flat • Rays that hit the mirror come back • following the law of reflection - Most mirrors are plane mirrors