1 Chapter 16 Objectives: 1) Be able to identify the parts of the electromagnetic spectrum including the wavelengths of visible light. Explain R.O.Y.G.B.I.V. 2) Develop a ray model for the path light takes from the source, to an object, to our eye. 3) Describe luminous and illuminated. 4) Differentiate between opaque, transparent, and translucent. 5) How was the speed of light first accurately measured? Be able to solve calculations involving the speed of light. 6) Describe how diffraction demonstrates that light is a wave.

2 7) Predict the effect of mixing colors of light (addition and subtraction). 8) Explain polarization of light and how it is achieved.

3 What do all of these have in common?

4 Ch.16 Fundamentals of Light *Light waves are just a small part of the _________________ spectrum: Visible light: = 700 nm to ____ nm. All electromagnetic waves: v = ___________ m/s.

5 I) Illumination A) Ray Model of Light Light’s Path:

6 1) Classification of Matter by Light: a) _________ Object: an object that emits light. Ex: b) _____________ Object: an object that becomes visible as a result of light reflecting off it. Ex. b1) _______: a material that ________ some light and _________ the remaining light (cannot be seen through).

7 b2) ____________: a material that _________ light (can be seen through clearly). b3) ___________: a material that transmits a fraction of incoming light and reflects the remaining light (can be seen through with much distortion).

8 B) The Speed of Light *Velocity = (_________) / (_____). 1)First accurate measurement of light by Danish astronomer Olaus Roemer, 1675.

9 *It took light sixteen minutes longer to reach the earth from Io when the earth was farthest away from Io while in its orbit around the sun.

10 II) The Wave Nature of Light A) Diffraction and the Wave Model of Light 1) _____________: the bending of a wave around a barrier. Ex:

11 B) Color 1) Light Addition a) ________ _______: three colors that combine to form white light; b) Two primary colors are added to form a __________ _______:

12 c) _______________ _______: two colors that combine to form white light.

13 2) Light Subtraction a) ____________________: (the primary colors of light subtraction) they subtract (_bs_rb) one primary color and reflect the other two primary colors.

14 b) The Color Things Appear:

15 C) Polarization of Light *_____________: light whose waves oscillate (move back-and-forth) in only a single plane. 1) Polarization by Filters:

16 a) Two Polarizing Sheets??

17 2) Polarization by Reflection: “Think of how you skip a stone on water.” a) Sunglasses are polarized: