The Electromagnetic Spectrum, Visible Light & Us

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 • http://www.youtube.com/watch?v=d50avTf0OLw • 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 • http://brianleewhite.com/2012/01/14/understanding-sound-waves-frequency-and-amplitude-video/ • 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) • http://www.youtube.com/watch?v=iletCKDCt_0

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