1. The Electromagnetic Spectrum, Visible Light & Us
How do we see what we see??

2. Essential Standard
6.P.1 Understand the properties of waves and the wavelike property of energy in earthquakes, light and sound waves.

3. Clarifying Objective
6.P .1.2Explain the relationship among visible light, the electromagnetic spectrum, and sight.

4. Essential Questions
What part of the Electromagnetic Spectrum is VISIBLE LIGHT?
What causes light to appear as different colors?
What type of WAVE does light energy travel on?
What is the process of light being detected by the human eye?

5. EOG Questions What is the relationship between EYESIGHT & LIGHT?
What is the relationship between the Electromagnetic Spectrum & Eyesight?

6. Light & How we See http://www.youtube.com/watch?v=gtgBHsSzCPE
1:25-4:04

7. Essential Questions Get with a partner and answer…
What causes light to appear as different colors?

8. Waves
Waves are a disturbance or vibration a way of transferring ENERGY from one place to another
They transport ENERGY from on place to another
There are different categories & types of waves
They all have their own characteristics that make them waves

9. Light Waves Light is Photon ENERGY that travels through WAVES
These waves are Electromagnetic Waves
These Electromagnetic Waves create the Electromagnetic Spectrum

10. Photons Photons are particles that have a 0 mass
Electromagnetic waves are carried through the electromagnetic spectrum by photons
These photons can move through mediums but do not need to
They can pass through vacuums

11. How Photons are made Photons occur from atoms
Atoms are made of protons, neutrons & electrons
Electrons orbit around the nucleus

12. How Photons are made
When an electromagnetic charge occurs the electrons of the atom get excited and start moving faster
When they move faster the electrons move out of their regular orbit into an outer orbit
When they stop moving faster they drop back down into their regular orbit
When they drop down they create/make a photon
This is what we see

13. Electromagnetic Waves
Electromagnetic Waves are waves that wave through electromagnetic fields
These are the only waves that do not require a medium to travel through
Transversal Waves
4:00-4:34

14. Electromagnetic Spectrum
The Electromagnetic Spectrum is made up of 6 different kinds of Electromagnetic waves
Radio Waves
Microwaves
Infrared Waves
Ultraviolet Waves
X-Ray Waves
Gamma Waves

15. Electromagnetic Spectrum

16. Electromagnetic Spectrum
Each of these 6 waves has a different frequency
The more to the right on the spectrum you go the higher the frequency of the wave
The higher the frequency the more energy the wave is carrying

17. Wave Frequency
The Frequency of a wave is how many waves are in a given space
The more waves in the given space the higher the frequency
0:55-1:19

18. Essential Questions Get with a partner and answer…
What type of WAVE does light energy travel on?

19. How we See (Reflection)

20. Visible Light
There is a small area in between Infrared waves & Ultraviolet waves that is important to us
This we call VISIBLE LIGHT
These are the only Electromagnetic waves that HUMANS can SEE

21. Visible Light

22. Visible Light Within the small area of visible light are photons
These photons take on the color of that particular spot on the Electromagnetic Spectrum

23. Measuring Waves Visible Light is measured in Nanometers
Each of the waves of visible color has a range of Nanometers
They range from…
380NM to 780NM

24. Visible Light The waves
The waves on the Electromagnetic Spectrum which we can see are
Red (380 NM)
Orange
Yellow
Green
Blue
Violet (780 NM)

25. Essential Questions Get with a partner and answer…
What part of the Electromagnetic Spectrum is VISIBLE LIGHT?

26. Human Eye
Humans can detect the waves/light between Infrared waves and Ultraviolet waves
Humans have RETINAS that are sensitive to Electromagnetic waves between Infrared and Ultraviolet

27. Human Eye
Inside the Retina are
Rods
Cones

28. Rods The human eye has about 100 million rods in its Retina
The cones work with the rods to be miniature sensors of electromagnetic waves or light photons
Rods are responsible for seeing black & white and is why our eyes “adjust to the dark”

29. Cones The human eye has about 6-7 million cones in it’s Retina
The cones work with the rods to be miniature sensors of electromagnetic waves or light photons
Cones are what makes the eye see color. Rods are responsible for detecting
Red
Green
Blue

30. Relationships
Electromagnetic waves make up the Electromagnetic Spectrum
Within the Electromagnetic Spectrum between the Infrared & Ultraviolet waves is “Visible Light”
Visible light shines down as white light. The white light hits an object and reflects a color
The Rods & Cones inside our eyes are able to detect the visible light on the Electromagnetic Spectrum which is what enables us to see

31. Essential Questions Get with a partner and answer…
What is the process of light being detected by the human eye?

32. Important Points
Electromagnetic waves make up the Electromagnetic Spectrum
Within the Electromagnetic Spectrum between the Infrared & Ultraviolet waves is “Visible Light”
Within the Human eye is the Retina
Inside the Retina are the Rods & Cones
Rods help humans detect black & white light as well as see in the dark
Cones let humans see color (rainbow) that is in between Infrared & Ultraviolet waves
Photons are the particles of energy that move on an electromagnetic wave