Russell ES – Saturday Science Adventure –

“Trip the LightFantastic”

WHERE DOES LIGHT COME FROM?

Our major

light source:

the Sun

WHERE ELSE DOES LIGHT COME FROM?

SORTING LIGHT SOURCESNatural vs. Man-made (artificial)

LIGHT SCAVENGER HUNT

How many light sources can you identify on our Russell ES grounds?

ARE THESE LIGHT SOURCES?

moon

watermirror

These items are not light sources, instead they are reflecting light from other sources.

HOW DOES LIGHT TRAVEL?

Light rays travel in straight lines from the light source.

When it hits an opaque object, some light is absorbed and the rest reflects off.

If the object is transparent, light rays pass through it easily.

If the object is translucent, some light can pass through, but the rest of the light will be reflected.

light

source

HOW DO WE SEE?Light coming from, (or reflecting off) objects enters the

eye through the cornea then the pupil.

It is focused clearly by the lens on to the retina.

The light sensitive cells of the retina gather information about patterns of light and dark, colour and movement and send it through the optic nerve.

HOW DO WE SEE?Vision results after light rays are reflected from an object, which in turn activates electro-chemical receptors in the eye allowing us to see. Therefore, the ability of sight would not be possible without the brain and eye working in unison to transform radiant energy.

HOW DO WE SEE? Information entering the brain through the optic nerve, is then

transmitted through more nerve pathways to the visual cortex.

Here the patterns of light and dark, colour and movement are interpreted.

The brain, based on past experience, can then understand what it ‘sees’.

HOW DO WE SEE COLOR?

HOW DO WE SEE COLOR?

Light from most light sources looks white, but actually contains all the colors of the spectrum; also known as the

rainbow.

If an object looks blue, it is absorbing every color except blue, which is reflecting off it and entering your eyes.

If an object looks orange, it is absorbing every color except orange, which, again, is reflecting off and entering your eyes.

If an object looks red... (You get the idea!)

light

source

HOW DOES LIGHT REFLECT?

Angle of incidence

Angle of reflection

The ‘angle of reflection’ is always equal to the ‘angel of incidence’.

LIGHT CAN ONLY BE REFLECTED IN STRAIGHT LINES.

HOW DOES LIGHT FORM SHADOWS?

Light rays travel in straight lines, radiating out from the light source.

If rays are blocked by an opaque object a shadow forms where the light cannot reach.

If the light source is moved closer to the object, more light is blocked and a larger shadow is formed.

light

sourcelight

source

HOW DOES SUNLIGHT CAUSE SHADOWS?

6am

8am

9am

12am2pm 10am

3pm

4pm

7pm

Looking North, the Sun appearsto rise in the East...

...and travel across the sky until it sets in the West.

The position of the Sun effects the position and length of the shadows created.

Thanks to this natural phenomenon a sundial is able to tell us the time, as long as it is a sunny day!

NOW EXPLAIN TO YOUR PARTNER:

What is the difference between light from the Sun and light from the moon?

Why does the Sun rise in the East and set in the West?

Why does an orange look a different colour to a banana?

How does a periscope work?

Why can’t we see anything without a light source?

ACTIVITY – HOW TO MAKE A HOLOGRAM?

hol·o·gram

ˈhäləˌɡram,ˈhōləˌɡram/

noun

a three-dimensional image formed by the interference of light beams from a laser or other coherent light source.

a photograph of an interference pattern that, when suitably illuminated, produces a three-dimensional image.

EVER WONDERED HOW TO MAKE A 3D HOLOGRAM? FOLLOW THESE SIMPLE STEPS TO CREATE A SIMPLE HOLOGRAM USING YOUR SMARTPHONE, VIA YOUTUBE MRWHOSETHEBOSS.

THE VIDEO AUTHOR USED HIS SMARTPHONE AND BASIC HOUSEHOLD MATERIALS TO PROJECT A GHOSTLY 3D IMAGE FLOATING ABOUT THE PHONE'S DISPLAY, THANKS TO A SPECIALIZED FOUR-WAY HOLOGRAPHIC VIDEO.

YOU WILL NEED:* GRAPH PAPER* A CD CASE* A PEN* A PAIR OF SCISSORS* SELL TAPE OR SUPERGLUE* A CRAFT KNIFE OR GLASS CUTTER* YOUR SMARTPHONE

Activity – How to Make a Hologram?

How to make the projector:

1. Sketch out a basic trapezoid shape on the graph paper using the dimensions 1xm x 3.5cm x 6cm.

2. Snap off the shallow sides of the CD case and carefully trace around the paper template to cut the shape into the transparent plastic. Repeat four times.

3. TAPE THE FOUR SHAPES TOGETHER, WITH THE LONGEST SIDES FACING THE TOP OF THE STRUCTURE.

4. SELECT THE HOLOGRAPH-SPECIFIC VIDEO YOU'D LIKE TO PROJECT - THIS IS A GOOD EXAMPLE.

5. PLACE THE SHAPE OVER A VIDEO PLAYING ON YOUR SMARTPHONE TO CREATE A MIRRORED, 3D HOLOGRAM.

HOLOGRAMS HAVE YET TO FULLY MAKE THE LEAP FROM SCIENCE FICTION TO MAINSTREAM CONSUMER USE. AMAZON'S FIRE PHONE WAS TOUTED TO BE THE FIRST SMARTPHONE WITH FULLY HOLOGRAPHIC CAPABILITIES, THANKS TO FOUR ULTRA-LOW POWER SPECIALIZED CAMERAS AND FOUR INFRARED LEDS WITHIN THE DISPLAY. THE RESULTING EFFECT IS MORE OF CREATING THE IMPRESSION THE IMAGE YOU'RE LOOKING AT IS SHIFTING AS YOU MOVE YOUR HEAD, RATHER THAN A PROJECTED IMAGE.

http://www.telegraph.co.uk/technology/mobile-phones/11780393/How-to-turn-your-phone-into-a-3D-hologram-projector.html

JOURNAL ACTIVITY

How is what you learned today relevant to your life?