the electromagnetic spectrum, visible light & us
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The Electromagnetic Spectrum, Visible Light & Us. How do we see what we see??. Essential Standard. 6.P. 1 Understand the properties of waves and the wavelike property of energy in earthquakes, light and sound waves. Clarifying Objective. - PowerPoint PPT PresentationTRANSCRIPT
The Electromagnetic Spectrum, Visible Light & Us
How do we see what we see??
Essential Standard
• 6.P.1 Understand the properties of waves and the wavelike property of energy in earthquakes, light and sound waves.
Clarifying Objective
• 6.P .1.2Explain the relationship among visible light, the electromagnetic spectrum, and sight.
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?
EOG Questions
• What is the relationship between EYESIGHT & LIGHT?
• What is the relationship between the Electromagnetic Spectrum & Eyesight?
Light & How we See
• http://www.youtube.com/watch?v=gtgBHsSzCPE
• 1:25-4:04
Essential Questions
• Get with a partner and answer…
• What causes light to appear as different colors?
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
Light Waves• Light is Photon ENERGY
that travels through WAVES
• These waves are Electromagnetic Waves
• These Electromagnetic Waves create the Electromagnetic Spectrum
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
How Photons are made
• Photons occur from atoms
• Atoms are made of protons, neutrons & electrons
• Electrons orbit around the nucleus
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
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
Electromagnetic Spectrum• The Electromagnetic
Spectrum is made up of 6 different kinds of Electromagnetic waves
① Radio Waves② Microwaves③ Infrared Waves④ Ultraviolet Waves⑤ X-Ray Waves⑥ Gamma Waves
Electromagnetic Spectrum
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
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
Essential Questions
• Get with a partner and answer…
• What type of WAVE does light energy travel on?
How we See (Reflection)
• http://www.youtube.com/watch?v=iletCKDCt_0
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
Visible Light
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
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
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)
Essential Questions
• Get with a partner and answer…
• What part of the Electromagnetic Spectrum is VISIBLE LIGHT?
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
Human Eye
• Inside the Retina are
① Rods② Cones
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”
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
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
Essential Questions
• Get with a partner and answer…
• What is the process of light being detected by the human eye?
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