Light

I am a bulb

Can you imagine how dark this world will be without light? Well, we certainly can't see anything around us without light. 

Do you still remember a fish named cavefish? A type of fish that lives in the dark cave in the bottom of the ocean? This type of fish doesn't have eyes because its habitat is very dark and no light at all. So, if this world has no light we might not need our eyes either. 

So what is light? 

Light is a form of energy that made of photons that enables us to see around. Light has two types of sources which are natural and man-made. The Sun, lightning and the stars are our natural light sources while luminous objects such as candle, lantern, bulb are man-made. 

What about the moon? Is it a light source or not? 

The answer is NOT, because the moon only reflects light from the Sun that's why we can see it from the Earth. 

So, we can see things around us due to the reflection of light. Light travels in a straight line from the light sources then reflected into our eyes. Why then, we can see different colours of objects? The answer to this because light contains all the spectrum of colours (known as rainbow) and once they hit on the object they will absorb all the colours but only reflect the colour of the object. Therefore, we can see it in a certain colour. 

The reason we see colors

Take this blue box as an example, it looks blue because it is absorbing every colour except blue, which reflecting off and entering our eyes. That's why we see it in blue. 

But how does light travel? 

As you know that light comes from light sources. In order to reach objects and enter our eyes, it produces light rays which always travels in straight lines. When it hits an opaque object, some light is absorbed and the rest reflects off. This is the reason why we are unable to see through an opaque object. 

If the object is transparent, light rays pass through it easily. That is why you can see through your window because its made of glass which is transparent. 

However, if the object is translucent, some light can pass through and the rest will be reflected. For instance, when you wear sunglasses at noon, you will be able to see around yet not as clear as when you take off your glasses. Wow, amazing right? Now you understand why we can or can't see through objects. It's all about light.

I'm looking gorgeous today, source

Here is the interesting part,

Have you ever wondered why are you able too see yourself in front of the mirror but not in other objects? Well, this is because of  the surface. The smoother the surface, the clearer you see your reflection. Therefore, you cannot see yourself clearly over a wooden table, paper etc as they have different materials which are actually rough under a microscope. 

Despite that, can we measure the light intensity?   

In order to know how bright something is, you can measure the light intensity using a light meter and a light sensor with a data logger in the unit of lux. The bigger the number in lux, the brighter it is. 

To understand more about light, you may watch this video:

So that's the explanation of light, I hope that it can help you understand about it. 

Now, let's try this!

Now you understand that not all objects can produce light or called as light sources. Can you identify 3 light sources and 3 non-light sources in your home?. Please submit your answer in the following comment box!.

Your loyal Cap. Idaa 

Ciao

Learn Also :

The Solar System
The water cycle

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Magnets 

Bunyi

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