Transcript How do you LIGHT Up your world ? Virginia SOL 5.3 Part II-Examining Light with Hands-On Activities Compiled by, Marjorie Anne Wallace Elementary Science Resource Teacher 2002-2005,

How do you LIGHT Up
your world ?
Virginia SOL 5.3
Part II-Examining Light
with Hands-On Activities
Compiled by, Marjorie Anne Wallace
Elementary Science Resource Teacher
2002-2005, NNPS & NSF Coop Agreement
Welcome to a power point
presentation on LIGHT.
• We will investigate the following:
• 1. What is light?
• 2. What makes up the visible spectrum?
• 3.How does a prism work?
• 4.Are there any hands-on/minds-on activities
I can do to learn more?
LIGHT Standards
• National Science
Education Standards
• Physical Science:
Content Standard B
• As a result of the
activities in grades
K-4, all students should
develop an
understanding of light,
heat, electricity, and
magnetism.
• Virginia Standards of
Learning 5.3a-e:
• The student will
investigate and
understand basic
characteristics of
visible light and how
it behaves.
• (*Key concepts,
5.3a-e, are listed in
your teacher
curriculum guide)
A light review:
• Our primary source of light is the sun.
• Light travels in straight lines at a speed of
186,000miles per second.
• Light waves travel faster than sound waves.
• Light energy from the sun travels through
space , reaches earth, and some of it turns to
heat energy and warms the earth’s air.
• Light from the sun also travels to the cells of
green plants (producers) and is stored as
energy.
• When light reaches an object, it is absorbed,
reflected, or passes through it.
Sensing Light
• Humans have two
light detectors.
• Do you know what
they are called?
Did you realize cameras and camcorders are light detectors too?
SOL query
5th grade 2003 Released Test Item#31 / CORE 1
#31 By passing white light through a prism,
you can tell–A
–B
–C
–D
that white light is actually a mixture of
different colors
the mass of the prism
the original source of the light
that blue light is brighter than white
light
What is light really?
Electromagnetic radiation waves
• Light waves are three
dimensional
• Light waves vibrate in all
planes around a center
line.
• The waves have high
points called “crests.”
• Waves also have low
points called “troughs.”
• *The distance from one
crest to the next crest is
called a “wavelength.”
• *The number of waves
passing a given point in
one second is called the
“frequency.”
wavelength
*A Science Museum of VA:
Light Science Activity
*Electromagnetic Radiation
• Electromagnetic radiation can be described in
terms of a stream of photons. Each photon is
traveling in a wave-like pattern, moving at the
speed of light and carrying some amount of
energy.
• The only difference amongst radio waves, visible
light, and gamma-rays is the amount of energy of
the photons. Radio waves have photons with low
energies. Microwaves have a little more energy
than radio waves. Infrared has still more energy.
• As we move down the chart we see visible,
ultraviolet, X-rays, and gamma-rays whose photon
energies gradually increase.
• Gamma and Cosmic rays have the highest
energy waves.
*Slide info from NSTA 2004 conference
Remember radio waves are long…and gamma rays are small
Radio-TV -Microwave- Infrared - VISIBLE -Ultraviolet -X-rays - Gamma- Cosmic
Radio
(Longest electromagnetic waves)
• Emitted by
– Astronomical Objects
– Radio Station
Transmitters
• Detected by
– Ground based radio
telescopes
– *If you turn on a radio,, it
will convert the radio
wave energy into sound
energy.
Television
• Shorter than radio,
also used to carry
messages (pictures
& sound) to our TV
sets.
• *We can sense the
TV waves around us
with our televisions.
Microwave
• Emitted by:
– Gas clouds collapsing
into stars
– Microwave Ovens
– Radar Stations
– Cell Phones
• Detected by
–
–
–
–
Microwave Telescopes
Food (heated)
Cell phones
Radar (systems)
Infrared
(Heat or Thermal)
Are you a source of infrared? YES you are!
• Emitted by
– Sun and stars (Near)
– TV Remote Controls
– Food Warming Lights
(Thermal)
– *Everything at room
temperature or
above,=HEAT
• Detected by
– Infrared Cameras
– TVs, VCRs,
– Your skin
Let’s take a look at
Herschel’s Experiment
• Herschel’s Experiment
– Discovered Invisible
Light
– In 1800, Herschel
places his control
thermometer just
outside the red end of
the spectrum
– Result: The outside
thermometer registered
the highest temperature
Let’s set up Herschel’s Experiment
• Set up of Box Design for Conducting the
Herschel Experiment.
Conducting Hershel’s Experiment
•
•
•
•
Place a sheet of white paper
inside a cardboard box
Tape three thermometers
together and place inside box
Cut a small notch in the top
of the box and position a
glass prism so that the
spectrum is projected inside
the box
Arrange the thermometers so
that one is just outside the
red end of the spectrum, with
no visible light falling on it
Visible
Each color is a different size wave.
Red the longest & violet the shortest
• Emitted by
– The sun and other
astronomical objects
– Laser pointers
– Light bulbs
• Detected by
– Cameras
(film or digital)
– Human eyes
– Plants (red light)
– Telescopes
Prism Power:
Roy G. Biv Activity
*PASCO Probe Activity OR
*AIMS:Primarily Physics:
Prism Power Activity
• *What happens when light shines through prisms?
• Materials :prism, PASCO “wave it,”equipment,
paper, +7 Roy G. Biv crayon colors,
• 1. Give handouts. Darken the room and turn on
light source. What color is the light? If I use a prism
can you predict what will happen to the light?
• 2.Now use the prism. What color is the light?
• 3. Color in your hand out to match the spectrum.
Ultraviolet
Sunburn / black light
• Emitted by
–
–
–
–
Tanning booths (A)
The sun (A)
Black light bulbs (B)
UV lamps
• Detected by
– Space based UV
detectors
– UV Cameras
– Flying insects (flies)
• Emitted by
–
–
–
–
–
–
X-ray
Astronomical objects
X-ray machines
CAT scan machines
Older televisions
Radioactive minerals
Airport luggage
scanners
• Detected by
– Space based X-ray
detectors
– X-ray film
– CCD detectors
Chandra X-ray Observatory
Chandra X-ray
Observatory
*Slide from 2004 NSTA Conference
• Chandra is designed to
observe X-rays from
high energy regions of
the universe, such as
the remnants of
exploded stars.
• The most sophisticated
observatory built to
date.
• Deployed by the Space
Shuttle Columbia on
July 23, 1999,
Gamma Ray
(Short electromagnetic waves but more energetic)
• Emitted by
– Radioactive materials
– Exploding nuclear
weapons
– Gamma-ray bursts
– Solar flares
• Detected by
• --Geiger counters
– Gamma detectors and
astronomical satellites
– Medical imaging detectors
Sources of g-ray Emission
• Black holes
• Active Galaxies
• Pulsars
• Diffuse emission
• Supernovae
• Gamma-ray bursts
• Unidentified
COSMIC Rays
(The highest energy waves and the deadliest)
• Cosmic rays come
from deep space and
can pass through the
Earth.
• A great question!
• Radio waves= (Buildings to
human size);
• Microwaves
(Humans-beetles);
• Infrared waves
(Eye of a needle);
Visible waves
(microscopic size)!
WOW! All the rest are the size
of molecules, atoms, atomic
nuclei and smaller..
Part III looks at: reflection and refraction of LIGHT.
Part I examines: what is light? Waves, opaque, transparent,
& translucent, & sources of light around us.
Special thanks to NSTA Conference 2004 workshops on light!