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How Does Light Travel


You can learn a lot of facts about light in this lesson, specially about how does light travel. Also, know about what light is, examples of sources of light, how we see things, reflection of light and many more.

 

What is light?

 

Light is a type of energy, which is an electromagnetic wave. Light is made up of little packets of energy. We call theses Photons.

 

Sources of Light

 

Objects that give out light are called sources of light.

 
Examples of sources of light
 

Following is a list of light sources;

 

Examples of natural sources of light
 

  • Sun
  • Stars
  • Lightning
  • Fireflies
  • Glowworms
  • Jellyfish
  • Bush fires

 
Examples of artificial sources of light
 

  • Light bulbs
  • Torches
  • Lamps
  • Flame by matches
  • Candle
  • Lasers
  • Fireworks
  • When televisions, computers, mobile phones etc. are turned on

 

 

How does light travel?

 

Light travels in straight lines as transverse waves.

 

Unlike sound waves or water waves, light does not need a medium to travel. Therefore, light can travel through a completely airless space, which is called a vacuum.

 

When light hits a surface its energy can be reflected, or deflected by refraction.

 

 

Reflection of Light and Seeing Objects

 

How does light help us in seeing an object?

 

If  light hits an object on the path that it is travelling, it can reflect and enter our eyes. Then we see the object.

 

Light changes it direction when it is reflected by a surface. As it hits it, it bounces off the surface at the same angle.

 

What can reflect light well?

 

Smooth, shiny surfaces can reflect light well.

E.g. – Mirrors and polished metals

 

What cannot reflect light well?

 
Dull and dark surfaces cannot reflect light well.

E.g. – Dark objects

 

 

Reflective surfaces

 

What are reflective surfaces?

 

Reflective surfaces are surfaces which can reflect light. There are many ways that reflective surfaces can be very helpful.

 
How can mirrors inside cars help drivers?
 

These mirrors inside the car reflect light so that drivers can see objects behind them.

 
How can reflective strips on clothing and bikes help drivers?
 

These things can help cyclists to be extra visible at night.

 
How can ‘Cat’s eyes’ on the road be useful?
 

Cat’s eyes are very useful at night as they reflect light from car headlamps so that the driver see the road at night.

 

Hope you enjoyed learning about how light travels and more other related facts.

 

Also, read the lessons Sources of Light and Shadows