Sources of Light
Vocabulary
Read the vocabulary terms to understand the reading better.
Artificial Light
Artificial light is light that is made by people.
Bioluminescence
Bioluminescence is when an animal or plant makes their own light.
Natural Light
Natural light is light that comes from nature.
Reflected Light
Reflected light is light that is bounced off of an object.
Reflection
Reflection occurs when light travelling through one material bounces off a different material.
Where does light come from? Light comes from two sources. One source is natural light. This means that the light comes from nature. Light from the Sun is natural because the Sun makes its own light.
The other source of light is artificial. This means that the light is made by people. Light bulbs are artificial because people made them.

Most light sources give off their own light. Our Sun and other stars make their own light. Candles and light bulbs also make their own light. But what about the Moon? We can see light from the Moon, but it does not make light because it is not a star. The light we see from the Moon is reflected sunlight. Reflected light is important in other ways. Reflectors on a bicycle bounce light from car headlights so drivers can see the bicycle.

Unusual Sources of Natural Light
Many animals and plants can make their own light. This is called bioluminescence (buy-oh-loo-muh-NESS-ens). You may have seen a firefly at night. Fireflies produce light at the ends of their bodies. They flash the light to communicate with other fireflies. Some mushrooms can make their own light. If you walk in the forest in the dark, you may see some. Most of the animals that make light live in the oceans and seas. One example is the Anglerfish. This fish has a long, thin fin that grows out of the top of its head. The tip of the fin gives off light to attract prey.

Light Is Important
Both natural and artificial light are very important. Light from the Sun is needed for plants to grow. This light also helps keep animals and people healthy. Most things people do require light. We do many activities during daylight. We can also do many things at night because of artificial light.
Think about how different your life would be if we only had light from the Sun.
To learn more about sources of light, watch the video by NG Science on YouTube.
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