reflection & refraction of electromagnetic radiation by emin menachekanian, phd
TRANSCRIPT
![Page 1: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/1.jpg)
Reflection & Refractionof
Electromagnetic Radiation
ByEmin Menachekanian, PhD
![Page 2: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/2.jpg)
What Is Light?
Wave Particle
ɤ
![Page 3: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/3.jpg)
Electromagnetic Spectrum
![Page 4: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/4.jpg)
The Speed of Light Is Finite, But Fast!
Consider the round-trip distance from here to UCLA and back: 30 mi ≈ 60 km
How much time is involved in the blink of an eye?
≈ 0.3 seconds!In that time, light would have made
an astonishing 1500 round trips!!
![Page 5: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/5.jpg)
The Speed of Light Is Finite, But Fast!
Voyager 1, launched in 1977, took about 30 years to reach the edge of our solar system.
Light would take about 12 hours to do the same thing!!
![Page 6: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/6.jpg)
Understanding How Light Reflects & Transmits
Use:Fermat’s Principle of Least Time
![Page 7: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/7.jpg)
Pierre de Fermat
![Page 8: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/8.jpg)
Fermat’s Principle of Least Time
Light will always take the path from one point to another that minimizes the
time of its journey.
In Empty Space:
![Page 9: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/9.jpg)
What About for Reflecting from a Mirror?
Mirror
![Page 10: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/10.jpg)
Mirror Image
![Page 11: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/11.jpg)
What’s the Correct Reflection?
Mirror
A
B
Equidistant to Mirror
B’
This path not only minimizes the distance, but it also minimizes the time!
Because speed of incident ray is the same as the speed of reflected ray.
![Page 12: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/12.jpg)
Law of Reflection
Mirror
A
BNormal to
Mirror
θi θr
θi = θr
![Page 13: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/13.jpg)
Why Does He Look Like This?
![Page 14: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/14.jpg)
Simple Example
Mirror
![Page 15: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/15.jpg)
Simple Example
Mirror
![Page 16: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/16.jpg)
Simple Example
Mirror
![Page 17: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/17.jpg)
Transmission of Light
It takes time for the light to be re-emitted when captured → Slows down!
Speed of light in medium Speed of light in empty space
Index of Refraction
![Page 18: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/18.jpg)
Indices of Refraction for Various Materials
![Page 19: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/19.jpg)
Which One Is The Shortest Distance?
ABC
50 m
50 m
85 m
25 m
![Page 20: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/20.jpg)
Which One Takes The Least Time?
ABC
Running Speed Is 10 m/s
Swimming Speed Is 2.5 m/s
5 s
20 s
8.5 s
10 s
![Page 21: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/21.jpg)
Which One Takes The Least Time?
ABC
Fast
Slow
![Page 22: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/22.jpg)
Light Behaves the Same Way!
•As light enters from a medium with a LOW index of refraction to one with a HIGH index of refraction, the ray bends TOWARDS the normal.
•As light enters from a medium with a HIGH index of refraction to one with a LOW index of refraction, the ray bends AWAY FROM the normal.
![Page 23: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/23.jpg)
Refraction Simulator
http://interactagram.com/physics/optics/refraction/
![Page 24: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/24.jpg)
The “Bent” Pencil
![Page 25: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/25.jpg)
The “Bent” Pencil
Water
Actual Straw
Image of Straw
![Page 26: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/26.jpg)
Full Reflection from Medium Interface!
![Page 27: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/27.jpg)
Total Internal Reflection
Only occurs when light is going FROM a medium with a HIGHER index of refraction INTO a medium with a
LOWER index of refraction
http://interactagram.com/physics/optics/refraction/
![Page 28: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/28.jpg)
The Critical Angle
The angle (with respect to the normal) at which the light totally internally
reflects is known as the critical angle.
The larger the index of refraction of the medium in which the light totally internally reflects, the smaller the
critical angle.
![Page 29: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/29.jpg)
Critical Angles (Surrounding Medium: Air)
Internal Medium Refractive Index (n) Critical Angle [Deg.]
Water 1.33 48.8
Ethyl Alcohol 1.36 47.3
Quartz, Fused 1.46 43.2
Lucite 1.50 41.8
Glass, Crown 1.52 41.1
Glass, Flint 1.66 37.0
Zircon 1.92 31.4
Diamond 2.42 24.4
![Page 30: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/30.jpg)
45° Glass Prisms> 41° (TIR)
![Page 31: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/31.jpg)
Binoculars
![Page 32: Reflection & Refraction of Electromagnetic Radiation By Emin Menachekanian, PhD](https://reader031.vdocuments.net/reader031/viewer/2022012916/56649d205503460f949f4f39/html5/thumbnails/32.jpg)
Fiber-Optic Cables