light, for grade 5 (teach)

light

WHAT IS LIGHT?

•LIGHT, LIKE SOUND, IS A KIND OF ENERGY

WHAT IS LIGHT?

•ALSO LIKE SOUND, LIGHT CAN TRAVEL IN WAVES

•LIGHT, LIKE SOUND, IS A KIND OF ENERGYWHAT IS LIGHT?

•BUT IT ALSO TRAVELS AS A STREAM OF PARTICLES

•ALSO LIKE SOUND, LIGHT CAN TRAVEL IN WAVES

•LIGHT, LIKE SOUND, IS A KIND OF ENERGYWHAT IS LIGHT?

SCIENTISTS CAME UP WITH THE “PARTICLE” THEORY BECAUSE LIGHT TRAVELS IN A BEAM THAT FOLLOWS A STRAIGHT LINE.

REMEMBER HOW SOUND NEEDED A MEDIUM, LIKE WATER OR AIR, TO TRAVEL. DOES LIGHT NEED A MEDIUM TO TRAVEL THROUGH?

•LIGHT DOESN’T NEED A MEDIUM, IT CAN TRAVEL THROUGH EMPTY SPACE.

REMEMBER HOW SOUND NEEDED A MEDIUM, LIKE WATER OR AIR, TO TRAVEL?

•AND IT TRAVELS IN STRAIGHT LINES. •LIGHT DOESN’T NEED A MEDIUM, IT TRAVELS THROUGH EMPTY SPACE.

REMEMBER HOW SOUND NEEDED A MEDIUM, LIKE WATER OR AIR, TO TRAVEL?

LIGHT COMES TO OUR EYES IN TWO WAYS.•ONE WAY IS FROM A SOURCE OF LIGHT, LIKE THE SUN OR A LIGHT BULB.

LIGHT COMES TO OUR EYES IN TWO WAYS.•THE OTHER WAY IS LIGHT BOUNCING OFF OF AN OBJECT (REFLECTING).

•ONE WAY IS FROM A SOURCE OF LIGHT, LIKE THE SUN OR A LIGHT BULB.

•WE SEE OBJECTS BECAUSE LIGHT HAS REFLECTED OFF OF THEM.

•LIGHT CAN BE SEEN AT ITS SOURCE

•LIGHT CAN BE SEEN WHEN IT IS REFLECTED OFF OF SOMETHING.

•LIGHT CAN BE SEEN AT ITS SOURCE

•LIGHT CAN BE SEEN AT ITS SOURCE•LIGHT CAN BE SEEN WHEN IT BOUNCES OFF OF SOMETHING.

•AND IF THERE IS NOTHING FOR IT TO BOUNCE OFF OF, WE CAN’T SEE IT.

YOU SEE LIGHT HERE AND HEREBUT BETWEEN THE SOURCE AND THE REFLECTION WE SEE NO LIGHT. WHY NOT?

•THE REASON WE DON’T SEE THE LIGHT BETWEEN THE SOURCE AND THE REFLECTION, IS THAT THERE IS NOTHING THERE TO REFLECT THE LIGHT.

• WE DON’T SEE THE LIGHT BETWEEN THE SOURCE AND THE REFLECTION BECAUSE THERE IS NOTHING THERE TO REFLECT THE LIGHT.

•WHEN POWDER IS PLACED BETWEEN THE SOURCE AND THE REFLECTION....

WE SEE THE LIGHT BEAM WHEN THE POWDER IS PRESENT BECAUSE THE LIGHT RAYS ARE REFLECTING OFF THE TINY PARTICLES OF POWDER BACK TO OUR EYES.

• ANOTHER FEATURE OF LIGHT IS THAT IT TRAVELS IN STRAIGHT LINES.

•THIS EXPERIMENT SHOULD HELP US LEARN THAT LIGHT TRAVELS IN STRAIGHT LINES.

OF LIGHT BULBS THROUGH BY LOOKING AT FILAMENTSA PIN HOLE...

WE SEE THE IMAGE TURNED UP-SIDE-DOWN.

• NOTICE THAT THE FILAMENT IN THIS CLEAR LIGHT BULB POINTS UPWARD.

WHEN VIEWED THROUGH A PINHOLE THE FILIMENT NOW POINTS DOWNWARD.

WHY?

BECAUSE LIGHT TRAVELS IN STRAIGHT LINES THROUGH THE PINHOLE CAUSING THE IMAGE TO BE UPSIDE DOWN.

THE SAME THING HAPENS WHEN LIGHT PASSES THROUGH THE SMALL HOLE IN YOUR EYE, YOUR PUPIL.

THINGS DON’T APPEAR UPSIDE DOWN BECAUSE YOU BRAIN TURNS THEM BACK AROUND.

PUPILRETINAEYE

AS WE VIEW THESE BULBS THROUGH A PINHOLE.

•LIGHT HAS OTHER EXCITING PROPERTIES THAT WE WILL DISCOVER LATER.