Light Week 2

Light Week 2Light Week 2Day 1: EM Spectrum

Day 2: Light and ColorDay 3: Property of Light-

Transmission

Day 1: EM SpectrumDay 2: Light and Color

Day 3: Property of Light-Transmission

I Can…I Can…

I Can #3:identify and describe the 7 waves of the electromagnetic spectrum.

I Can #3:identify and describe the 7 waves of the electromagnetic spectrum.

Unlike mechanical waves, EM Waves can travel through empty space.

Light waves are an example of EM waves.

Electromagnetic Waves

Electromagnetic Waves

The Electromagnetic Spectrum


From highest energy to

lowest energy: Gamma Ray

X-Ray UV Light

Visible Light Infrared Microwave

Radio

From highest energy to

lowest energy: Gamma Ray

X-Ray UV Light

Visible Light Infrared Microwave

Radio

Great X-men Use Very Important Mutant Radios

Radio WavesRadio Waves

Longest wavelength (average size=length of football field)

Lowest frequency and energy

Used in radios and can carry signals for cell phones and television.

What do you think the station numbers mean?

Longest wavelength (average size=length of football field)

Lowest frequency and energy

Used in radios and can carry signals for cell phones and television.

What do you think the station numbers mean?

MicrowavesMicrowaves

Longer microwaves (about a foot) used in microwaves to heat our food.

They pass through glass, plastics, and ceramics, but are reflected by thick metal. They are absorbed by water, fats, and sugars--when absorbed they convert directly to heat.

Longer microwaves (about a foot) used in microwaves to heat our food.

They pass through glass, plastics, and ceramics, but are reflected by thick metal. They are absorbed by water, fats, and sugars--when absorbed they convert directly to heat.

InfraredInfrared

Range in size--far infrared light (size of pinhead) to near infrared light (size of a cell).

Far infrared waves are the heat waves we feel from sunlight, a fire, a warm sidewalk, or a heat lamp.

Near infrared are not hot at all--used in remote controls.

Range in size--far infrared light (size of pinhead) to near infrared light (size of a cell).

Far infrared waves are the heat waves we feel from sunlight, a fire, a warm sidewalk, or a heat lamp.

Near infrared are not hot at all--used in remote controls.

QuickTime™ and a decompressor

are needed to see this picture.

Visible LightVisible Light Only a small proportion of the EM spectrum

Only EM wave that humans can see. Humans can see visible light because the eye can only detect frequencies in the middle of the EM spectrum.

Which color has the most energy? Least?

Only a small proportion of the EM spectrum

Only EM wave that humans can see. Humans can see visible light because the eye can only detect frequencies in the middle of the EM spectrum.

Which color has the most energy? Least?



Ultraviolet (UV) Light

Ultraviolet (UV) Light

More energy than visible light and shorter wavelength

Positive Effects: kill bacteria on food and during surgery. Stimulates production of Vitamin D in our skin cells.

Negative Effects: skin cancer, sunburn, and wrinkles,

Where may you have seen UV light before in your life?

More energy than visible light and shorter wavelength

Positive Effects: kill bacteria on food and during surgery. Stimulates production of Vitamin D in our skin cells.

Negative Effects: skin cancer, sunburn, and wrinkles,

Where may you have seen UV light before in your life?

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X-RaysX-Rays X-Rays can go through muscle and tissue but are blocked by bone.

Makes medical and dental X-Ray photographs possible.

Too much exposure to X-Rays can lead to cancer.

X-Rays can go through muscle and tissue but are blocked by bone.

Makes medical and dental X-Ray photographs possible.

Too much exposure to X-Rays can lead to cancer.

Gamma RaysGamma Rays Shortest wavelength-smaller than atoms! Can penetrate most materials.

The highest energy.

Used to kill cancerous cells and released by nuclear weapons.

Shortest wavelength-smaller than atoms! Can penetrate most materials.

The highest energy.

Used to kill cancerous cells and released by nuclear weapons.

Gamma RaysGamma Rays

What are gamma ray bursts?

Do gamma rays have a high or low energy level?

What are gamma ray bursts?

Do gamma rays have a high or low energy level?





From highest energy to lowest energy:

Gamma Ray X-Ray

UV Light Visible Light

Infrared Microwave

Radio

From highest energy to lowest energy:

Gamma Ray X-Ray

UV Light Visible Light

Infrared Microwave

Radio

Great X-men Use Very Important Mutant Radios

Electromagnetic Foldable

Electromagnetic Foldable

Work on your EM foldable. As you work enjoy this short Captain Planet on

UV Radiation! Look/listen for the effects of too much UV Radiation!

Work on your EM foldable. As you work enjoy this short Captain Planet on

UV Radiation! Look/listen for the effects of too much UV Radiation!



Exit QuizExit Quiz

1. What are the seven waves of the EM spectrum?

2. Which type of EM wave would you definitely want to stay away from? Why?

1. What are the seven waves of the EM spectrum?

2. Which type of EM wave would you definitely want to stay away from? Why?

I Can…I Can…

I Can #4: describe how light interacts with our eyes to help us see color

I Can #4: describe how light interacts with our eyes to help us see color

The Wonderful World of Color

The Wonderful World of Color

What do we need to see color?

What colors combined made white?

What do we need to see color?

What colors combined made white?



Light and VisionLight and VisionLight and VisionLight and Vision

For you to For you to see an see an object, object, light from light from the object the object has to reach has to reach your eye.your eye.

For you to For you to see an see an object, object, light from light from the object the object has to reach has to reach your eye.your eye.

PrimaryPrimary: gives : gives off its own off its own

lightlight

SecondarySecondary: : reflects reflects light from light from sourcesource

Sources of Sources of LightLight

An object can either be a primary An object can either be a primary source of light or a secondary source.source of light or a secondary source.

COLORCOLOR

Because light is a WAVE, each color we see has a different frequency, energy, and wavelength.

VIOLET has the highest frequency, highest energy, and shortest wavelength.

RED has the lowest frequency, lowest energy, and longest wavelength.

White LightWhite Light

White light consists of all the colors of light.

White light consists of all the colors of light.

Primary Colors of Light

Primary Colors of Light

REDGREENBLUE

REDGREENBLUE

WHITEWHITE

How do we see color?How do we see color?

When we see colors, it is When we see colors, it is because that because that lightlight wave is wave is reflected reflected into our eyes. into our eyes.

All other colors are All other colors are aabbssoorrbbeedd..

When we see colors, it is When we see colors, it is because that because that lightlight wave is wave is reflected reflected into our eyes. into our eyes.

All other colors are All other colors are aabbssoorrbbeedd..

Seeing White ….Seeing White ….Seeing White ….Seeing White ….

When ALL colors are REFLECTED, we see white.

When ALL colors are REFLECTED, we see white.

Seeing Black…Seeing Black… Seeing Black…Seeing Black…

When ALL colors are ABSORBED, we see black.

When ALL colors are ABSORBED, we see black.

Challenge….Challenge….

What color will a YELLOW ball be under BLUE light?

What color will a YELLOW ball be under BLUE light?

Blue – All colors absorbed except blue, which is reflected to eye.

White – No colors absorbed. All colors reflected to eye.

Black – All colors absorbed. No colors reflected to eye.

Blue – All colors absorbed except blue, which is reflected to eye.

White – No colors absorbed. All colors reflected to eye.

Black – All colors absorbed. No colors reflected to eye.

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For this activity, you will be given sticks with different colored squares.

You will see objects of various colors on the screen.

Hold up the colors that are absorbed by the object.

Then, Hold up the color that is reflected by the object.

For this activity, you will be given sticks with different colored squares.

You will see objects of various colors on the screen.

Hold up the colors that are absorbed by the object.

Then, Hold up the color that is reflected by the object.

It’s okay…let’s give it a shot.It’s okay…let’s give it a shot.



What is absorbed? (Hold up colors)What is reflected? (Hold up color)



















I Can#5I Can#5

I Can: define refraction and explain how refraction may be observed in the real world.

I Can: define refraction and explain how refraction may be observed in the real world.

Light Travels in Light Travels in Straight LinesStraight Lines

Light Travels in Light Travels in Straight LinesStraight Lines

Light always Light always travels in travels in straight lines straight lines unless the unless the medium it medium it travels travels through through changes.changes.

Light always Light always travels in travels in straight lines straight lines unless the unless the medium it medium it travels travels through through changes.changes.

Property #1: TransmissionProperty #1: Transmission

Transmission happens when light waves strike something and passes through it.

When you see through glass, it is because light is able to pass through the glass.

Transmission happens when light waves strike something and passes through it.

When you see through glass, it is because light is able to pass through the glass.

Types of objectsTransparent (light transmitted)

Translucent (some light transmitted)

Opaque (no light transmitted)

Types of objectsTransparent (light transmitted)

Translucent (some light transmitted)

Opaque (no light transmitted)

More on TransmissionMore on Transmission

Exploring the Path of Light

Exploring the Path of Light

Experiment #1: “Magic” Penny Experiment #2: “Magic” Pencil Experiment #3: “Magic” Milk “The Hatchet” Observations

Experiment #1: “Magic” Penny Experiment #2: “Magic” Pencil Experiment #3: “Magic” Milk “The Hatchet” Observations

Respond in your notebook to the questions in the BLUE BOXES like this one!

“Magic” Penny

“Magic” Penny

1. Decide who will be the EXPERIMENTER and who will be the OBSERVER.

2. The EXPERIMENTER should place the coin in the middle of the white cup so that the OBSERVER can see.

3. The EXPERIMENTER should pull the cup away from the observer until the OBSERVER can no longer see the coin.

4. The EXPERIMENTER should carefully add water to the white cup until the OBSERVER can see the coin again.

1. Decide who will be the EXPERIMENTER and who will be the OBSERVER.

2. The EXPERIMENTER should place the coin in the middle of the white cup so that the OBSERVER can see.

3. The EXPERIMENTER should pull the cup away from the observer until the OBSERVER can no longer see the coin.

4. The EXPERIMENTER should carefully add water to the white cup until the OBSERVER can see the coin again.

Respond in your notebook (complete sentences):

1. Describe what happened.

2. Why do you think this happened?

“Magic” Pencil“Magic” Pencil

1. Pour the water from the white cup back into the beaker.

2. Now, place the colored pencil in the beaker of water.

3. Observe from the side of the beaker .

1. Pour the water from the white cup back into the beaker.

2. Now, place the colored pencil in the beaker of water.

3. Observe from the side of the beaker .

Respond in your notebook


4. Draw a diagram of what you see.

DO NOT SHINE THE LASER IN ANYONES EYES!!!! It will

CAUSE PERMANENT EYE DAMAGE!!

DO NOT SHINE THE LASER IN ANYONES EYES!!!! It will

CAUSE PERMANENT EYE DAMAGE!!

“Magic” Milk“Magic” Milk

1. Place a 1 dropper full of milk in the beaker.

2. One person should point the laser pointer DOWN into the beaker.

3. Observe what you see from the side of the beaker.

1. Place a 1 dropper full of milk in the beaker.

2. One person should point the laser pointer DOWN into the beaker.

3. Observe what you see from the side of the beaker.

Respond in your notebook


6. Draw a diagram of what you see.

The HatchetThe Hatchet

So what happens when the medium changes?So what happens when the medium changes?

If the light wave enters

perpendicular to the medium, it

transmits straight through

medium.

If the light wave enters the medium at an angle--the light

wave bends.





REFRACTIONREFRACTIONREFRACTIONREFRACTION

The changing of The changing of DIRECTION and DIRECTION and SPEED of light SPEED of light when it goes from when it goes from one medium to one medium to another.another.

REFRACTION= REFRACTION= the BENDING the BENDING of lightof light

RefractionRefraction

Similar to a sound wave, a light Similar to a sound wave, a light wave changes SPEED when it enters wave changes SPEED when it enters a different a different MEDIUM..

Similar to a sound wave, a light Similar to a sound wave, a light wave changes SPEED when it enters wave changes SPEED when it enters a different a different MEDIUM.. SLOWER…

Light, as it moves through air, travels 186,000 miles per second.

RefractioRefractionn

RefractioRefractionn

The change in the speed of light causes the rays of light to BEND.

The greater the difference between the speeds of light, the more the light will bend.

SO, the MORE DENSE MEDIUM = MORE BEND

The change in the speed of light causes the rays of light to BEND.

The greater the difference between the speeds of light, the more the light will bend.

SO, the MORE DENSE MEDIUM = MORE BEND

Labeling the Refraction

Labeling the Refraction

A. Incident Ray

D. Refracted Ray

B. Air

C. Water

NORMAL

““Magic “ PencilMagic “ Pencil““Magic “ PencilMagic “ Pencil

Why does Why does the the pencil pencil appear appear broken? broken? Is it Is it broken?broken?

Why does Why does the the pencil pencil appear appear broken? broken? Is it Is it broken?broken?It’s

REFRACTION!!

RefractionRefractionRefractionRefractionWhat are the 3 mediums that What are the 3 mediums that

light travels through in light travels through in the picture?the picture?

What are the 3 mediums that What are the 3 mediums that light travels through in light travels through in the picture?the picture?

1.1. AirAir

2. Water2. Water

3. 3. GlassGlass

Why does the pencil appear broken?

Why does the pencil appear broken?

When light travels from air to water, it SLOWS DOWN.

When light travels from water to glass it SLOWS DOWN.

MORE DENSE = SLOWER = MORE “BEND”

Prisms: Why do we see colors?

Prisms: Why do we see colors?

White light is bent into all its different wavelengths.

This allows us to see all the colors of the rainbow.

A prism is an example of refraction!

Rainbows: Why do we see Rainbows: Why do we see colors?colors?

Rainbows: Why do we see Rainbows: Why do we see colors?colors?

Raindrops = a new medium= bending of white light into its colors!

Raindrops = a new medium= bending of white light into its colors!

It’s REFRACTION!

It’s

REFRACTION!

Magic Penny ExplainedMagic Penny Explained

Exit QuizExit Quiz

A. _________

D. __________

B.

_________C. _______

1. Label the diagram

2. Why does light bend?

3. What do we call the “bending of light”?

4. T/F: Light will bend more in water than glass.

1. Label the diagram

2. Why does light bend?

3. What do we call the “bending of light”?

4. T/F: Light will bend more in water than glass.

Light Week 2

Documents

light waves

property of light

light week

sourcecolorbecause light

lowest energy

primary source of light

near infrared light

infrared waves