Loading in 5 sec....

Light: Geometric OpticsPowerPoint Presentation

Light: Geometric Optics

- 131 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about ' Light: Geometric Optics' - abdalla

**An Image/Link below is provided (as is) to download presentation**

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

### Light: Geometric Optics

Introduction – 23-1, 23-4, 23-5, 24-10

Light

- Electromagnetic Spectrum

Light

- Light is the Part of the EM spectrum that stimulates the retina of the human eye
- ROY G BIV

Ray Model of Light

- Light travels in straight line in vacuum or uniform media
- Ray model assumes straight line travel for light
- Ray Optics – ray diagrams to study travel of light; ignores wave nature of light

Speed of Light

- Before 1700, thought to be instantaneous
- Galileo worked on speed of light
- Couldn’t believe that it was that fast!

- Ole Roemer – first to determine light traveled with measureable speed
- A.A. Michelson – measured light between two mountaintops in California
- 2.997996 x 108 +/- .00004 x 108 m/s

- 1960’s Lasers found to measure speed of light better than atomic clocks v = λf = c

Sources of Light

- luminous--body emits light
- illuminated--body reflects light
- incandescent--glows HOT; luminous; W wire is heated by electricity and glows inside a light bulb
- luminous flux, P--rate at which light is emitted from a source
- Lumen – lm – unit of flux

- illuminance, E--lm/m2 or lux, lx

Illumination

- 100W light bulb – 1750 lm
- If 1m sphere: 1750 lm / (4π(1)2) = 1750/4π lx
- If 2m sphere: 1750 lm / (4π(2)2) = 1750/16πlx
- Candela cd – measures luminous intensity
- 1750/4π lx = 139 cd

Illumination

- To increase illumination
- increase flux of alternate source
- decrease distance between source and surface

- Illuminance= E = P/4πd2
- perpendicular line between source and surface
- point sources

Light and Matter

- Transparent – light through; transmitted
- Translucent — light sort of through; transmits and diffuses light
- Opaque – light not through; absorbs reflects all light; no transmission

Dual Polarizers

Download Presentation

Connecting to Server..