Light  

The Nature of Light 

I. LIGHT IS ELECTROMAGNETIC RADIATION

 

II. THERE ARE DIFFERENT TYPES OF ELECTROMAGNETIC RADIATION  - LIGHT  8 Types of Electromagnetic Radiation

 
8TypesLightBar.jpg
A. RADIO
~ 3 Hertz by a hand moving a charged tuning fork to battery terminal-- Use tuning fork for 128 or 512  Hz A QUARTZ CRYSTAL VIBRATES at set frequency for each radio station
AM  500-1600 KHz   FM  88-108 Mhz
Radio waves are made in space by moving charged particles
B.  MICROWAVE
RADAR is a kind of microwave
FASTER VIBRATIONS BY TINY quartz CRYSTALS (<.02cm) or resonance of jumping electrons in a magnetron  chamber
YIELD MICROWAVES OF 109 Hz
C. INFRARED
-- FELT AS HEAT ON SKIN  Hotplate left on on teachers desk-volunteer to blindly move toward it
USES: THERMOGRAPH  SATELLITE PHOTOS:  LAVA, MINERALS, VEGET, DISEASED PLANTS, SNAKES, MISSILES, IR SIGNATURE
CAUSED BY VIBRATIONS OF SOMETHING SMALLER THAN CRYSTALS, - MOLECULES  OF MATTER
1013 Hz
ALL MATTER HAS HEAT, VIBRATES, SO GIVES OFF IR
The HIGHER THE TEMP THE HIGHER THE FREQUENCY EMITTED
D. VISIBLE
Our world of beauty, information and action
MOTION BY something still smaller -  OUTER ELECTRONS OF ATOMS Jump & Fall
4 X 1014 TO 7 X 1014   RED TO VIOLET
E. ULTRAVIOLET
Fluorescent light, Used to kill bacteria
ELECTRONS  Jump & Fall To HIGHER LEVELS
  Blacklight  UV causes tan, skin cancer, wrinkles
 THE HIGHER THE FREQUENCY OF LIGHT THE MORE ITS ENERGY (penetrates deeper)
F. X-RAYS
Used to penetrate soft tissue for x-rays;
70kV ACCELERATED ELECTRONS RAPIDLY SMASH TO A STOP - the target gives off x-rays as its inner electrons are knocked off then fall back down.
INNER ELECTRONS Jump & Fall blocked by bones
How x-ray machines work
G. GAMMA RADIATION SPLITTING OF NUCLEI OF ATOMS converts Matter directly to Energy
  part of radioactivity of nuclear blasts or radiation
  Medical treatment of cancer
H. COSMIC RAYS
NUCLEI PARTS AT FASTER RATES STILL  FROM SUN & SUPERNOVAS & OUTER SPACE
  Higher energy than anywhere on earth
Source of mutations on earth
   f  about 1023 Hz  

III. CONCLUSIONS

 Bells.Still001.jpg Bell similie of size and frequency


Light:  Spreads Out - Travels in Straight Lines  - Follows the Inverse Square Law

IllumLaw.jpg

Illumination is Inversely proportional to the square of the Distance the light travels

Reflection

LawofReflection2.jpg
U12L1A1.GIF
AngRefllaw.jpg sunparaboliccollectordiagram.gif

Refraction - bending of light

LaserIntoWater2.jpg RefractedPencil.jpg RefractedThermometer.JPG
RefrPhoton1.jpg Red laser beam refracts upon entering water at an angle.
Light from the pencil bends as it goes into air - spreading out and appearing larger









Lightt behaves as both a particle and a wave - at the same time!  When the "particle" - photon goes through a substance it's slowed down by  repeated absorption and reemission.

Photons thus slowed, when they strike at an angle to the medium are -as a wave- bent.  One side of the wave travels more slowly than the other..
REFRACTION



Different colors of light bend different amounts when refracted in rain drops-so they spread out

Setting Sun rays hit earth at angle and the slower red rays bend more than yellow which bends more than blue.









RAINBOW2.JPG
SKYSPECT.JPG

Convex Lens

Concave Lens

Concave Mirror

Convex Mirror

Light Miscellany

 Rainbows What Causes them?

  About Rainbows

UV  An experiment to detect its presence.  Tonic water responds to UV.  Add a blacklight to this exp for added evidence.


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