Light is something we experience constantly. From the moment we wake up to the moment we sleep, we rarely feel the effects of total darkness. It’s just something so conventional that we often forget to consider the science behind it. On a Physics note, light can be described both as a wave and a particle that the naked eye can see. But even with modern physics being what it is, and despite the fact that we’ve learnt more than ever before, no one is exactly sure how to define it. Let’s delve deeper into what we know.
Sources of Light
Humans have always relied on light and its sources for survival and our collective sanity. There are various sources of light. The sun or a candle both emit light because they’re hot; this type of light is called incandescence. Sources like a cellphone or a flashlight are not hot, but still, they emit light. The light they produce is called luminescence.
The speed of light
There is nothing that travels faster than light. The speed of light is estimated to be roughly 300 000 kilometres per second; this means it would only take eight minutes for light to travel the vast distance from the sun to reach Earth. The light bouncing off the moon would take only one second to get to us. So, until it is blocked by something, this racing light will always move in a straight line. The speed of light varies with the material it traverses, leading us to three light behaviours on different surfaces.
The law of reflection states that the angle of reflection will always be equivalent to the angle of incidence; this means that a wave’s property will be thrown back from a surface, reflecting an image. One great example of this is a mirror when you see an image being reflected.
When light moves from one medium to another, such as from air to water, it slows down and changes direction slightly; this is called the refraction of light. This phenomenon can be observed in a glass of water with a spoon. You may perceive the spoon as being bent or bigger or smaller than it is because light refracts when it travels at an angle.
When light bends around an edge or passes through a slit, it causes waves to propagate around barriers. Water waves bending around a fixed object is an excellent example of this. Showing that light has wavelike qualities, as demonstrated by the pattern of darkness and light generated when it bends around an edge.
Light has always played a vital role in our daily lives; It has existed from the beginning and will continue for longer than we can contemplate. Even armed with the knowledge of modern Physics, light is still a huge mystery. But we have to admit that we have come a long way in understanding light and its nature. Light’s importance in our daily lives is evidenced by the fact that we rarely notice it. So, it’s only fair that we try.
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