Post on 21-Jan-2016
The Wonder of Light
a study of theelectromagnetic
spectrumMrs. Parker
4th Grade
Put on yourPut on your rraaiinnbbooww glasses!glasses!
Look around for a few minutes with Look around for a few minutes with your special glasses on. Can you see your special glasses on. Can you see the light separating? the light separating?
What is light?What is light?
How does light travel?How does light travel?A) perfectly straight lineA) perfectly straight lineB) bends around objectsB) bends around objects
C) in a circleC) in a circle
Let’s Make Shadow Animals
Electromagnetic SpectrumElectromagnetic Spectrum
We can only see a very small portion (the We can only see a very small portion (the visible waves) of the visible waves) of the
Electromagnetic Spectrum.Electromagnetic Spectrum.
• InfraredInfrared waves are felt
as heat.
• Microwave
Where have we heard about Infrared Waves?
ReflectionReflection
Reflection occurs Reflection occurs when light when light strikes a surface strikes a surface and bounces off. and bounces off. Light changes Light changes direction when it direction when it is reflected off a is reflected off a surface.surface.
PRISMSPRISMS• Take out your prism and try to Take out your prism and try to
separate the light.separate the light.
• What are you creating?What are you creating?
• Why?Why?
•What is a rWhat is a raaiinnbbooww??
•What shape is a rWhat shape is a raaiinnbbooww??
The Visible Waves
On the other side of the visible spectrum…….
UV X Ray Gamma Ray
Why are sunscreen and sunglasses important?
X rays have many uses in medicine.
High-energy gamma waves are found in radioactive materials used
in nuclear power plants.
Electromagnetic Spectrum
Light can travel through fiber optics.
Where do we use fiber optics?
Fiber Optics
Have you ever used a laser?
How do we use lasers?
Surgeries (LASIK)Price Scanning
CD PlayersDVD PlayersDental Drills
Heavy Duty/Accurate CuttingRadiation
PrinterLaser Speed Gun
Let’s Play Tag! 5 hand held mirrors 1 laser pointer
Light travels in a straight line, but it can reflect!
The rays bounce off the mirrors and travel in a new direction.
Create a bracelet made from UV beads
What do you think would happen to the beads if you put sunscreen on them?
Why?
Go outside and try it!