The world is full of light and darkness. But what does the word darkness mean? We often regard darkness with a "black" color, don't we? But in the real world, darkness is something different than we think. In English, we learn certain words called antonyms, which basically mean "opposite words". By this we know that the opposite word for the word "light" is "dark", isn't it? So what is darkness exactly? What is silence? What is nothing?
All these words, darkness, silence and nothing, have something in common. What is that? It's the absence of something in each case. Just think about it. What is darkness? The absence of light. What is silence? The absence of sound. What is nothing? The absence of something. This means that darkness is not a quantity by itself, but rather, it exists because of the absence of light. Darkness doesn't exist as a physical quantity. When there is no light, it simply means there is darkness. It's just the same way of telling "the absence of light or no light".
In the above image you can see a ball is blocking the light. This creates a shadow. And we all know that all shadows are black. That is why we often refer darkness to as blackness which is in one sense correct as well.
Now, we know what darkness really is. In fact we also know the relation between light and darkness. They're just the two sides of the same coin. So we know that light has the fastest speed in the universe. We also know it why. It's because light photons are massless and according to Einstein's theory of special relativity, light was proved to be the fastest. A detailed explanation is given in our series of Special Relativity Theory here:
Coming back on the speed of darkness, we know that darkness exists because of light. And its not like when you turn off the light, it takes some time and then darkness comes, no. The thing is, the moment you try to block light, darkness is created instantaneously. Does that spark something in your mind? All this simply means that the speed of darkness is always equal to the speed of light! Yes and that's the fact! We all know the speed of light is 299,792,458 m/s. Therefore, the speed of darkness will also be the same 299,792,458 m/s.
As you turn off the light, the last bit of light, or the last photon of light travels at the speed of light. Then naturally, the state right after it should also travel at the speed of light. That is why darkness has the same speed as that of light.
An amazing fact: If the sun suddenly disappeared, it would stop shining light on the earth and the earth would go dark. But it takes 8 minutes and 19 seconds for the light from the sun to reach earth. The last bit of light given off by the sun right before it disappeared would take 8 minutes and 19 seconds to reach us, and the darkness that comes right after the last bit of light would also take 8 minutes and 19 seconds to reach us. We on earth would not see the sun disappear from the sky until 8 minutes and 19 seconds after it had vanished.
So, that's it for today! I hope you learned something new and amazing today! As always thank you for reading and we'll see you in our next article. Explore more deeper.
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