We have all spent a lot of hours in front of the mirror getting ready and you can bet that even the apes as well as elephants and other animals would be fascinated by mirrors as well but there is only one dark horse named Peacock who would try to break the mirror at the first sight thinking that it is a rival Peacock. Nevertheless, mirrors are a great object of fascination for all of us because the psychological impact us. This fascination leads to a a lot of questions regarding how do mirrors work.
Conservation of energy:
You might be thinking that in discussing the working principle of mirrors why we are talking about conservation of energy but it is vital that you understand about the principle of conservation of energy before going into the working of the mirrors because the principle of conservation of energy plays a very important role in the working of mirrors.
If you’re somewhat familiar with the principle of conservation of energy then you would understand that energy can neither be created nor be destroyed and therefore it can be only converted from one form to another. No matter which form of energy you use it would have been converted from some form of energy or the other and it cannot be magically created neither can it be magically destroyed.
You might argue that when you’re getting a football where does that energy come from and the answer to that is the potential energy which is stored in your muscles is converted into the dynamic energy and transport into the football and is therefore the football starts moving.
In the same way when you’re using any form of energy like electricity, you have to understand that this particular energy is also converted from some other form of energy and depending on the way in which the energy has been created like the energy can be created from coal when you’re speaking about a normal power plant or it can be converted from water in a hydroelectric power plant or it can be converted from the nuclear reactions in a nuclear power plant. That means that, the electricity which we used is not magically produced but rather it is converted from one form of energy into another. If you look at that form of energy from the electricity originated you would find that, that particular form of energy also got converted from some other energy whether it is coal or nuclear reactions or flowing water.
Thus from this example you can see that the conservation of energy principle works in each and every instance.
Reflections in the mirror:
We all know that the reflection which we see in the mirror is due to the light getting the mirror and light is also a form of energy. When the light is travelling towards the mirror you had to understand that the speed of the light is pretty fast that is 3,00,000 km per second and due to this whenever the light is hurting an object all the energy which is there needs to be converted in one form or the another because it cannot be destroyed according to the law of conservation of energy.
There are three ways in which this energy can get converted or can move forward. The first way is to pass through the object if it is transparent. The second is to sink into the object and go out of sight and this is what happens in opaque object where light disappears. The third option is applicable in the case of mirrors where it gets reflected back. It is a noticeable thing that all the energy might not get reflected back but rather some energy which is a significant part of the energy which was directed towards the mirror does get reflected back whereas the remaining energy might get can be converted into other forms.
How does your reflection appeared in the mirror?
Whenever there is light in the vicinity, in the area where the mirror is placed you would find that light is getting reflected from your body as well as the other objects which are present in the vicinity and this light gets reflected in all directions and not just in a single particular direction and this light which is directed towards the different directions is nothing but packets of light energy known as photons. Due to the random nature of reflection some of the light would also get directed towards the mirror.
When these light photons reach the mirror they go through the first layer to the layer which is behind it which is a silver coating and in case of the more affordable mirrors it is a layer of polished aluminium. Instead of getting reflected from this coating in a haphazard manner, the reflection would or could in a more orderly manner which is known as specular reflection.
When these photons reach the silver coating they transfer the energy to the atoms of the silver coating and therefore these atoms become unstable due to this new energy which they have got from the photons and in order to become stable again they need to give back the energy which is extra. This extra energy is reflected back from the mirror because it is no other way to go because the back of the silver coating is a very dark material to avoid reflection in the opposite direction.
If you looked at all other colours and silver you would realise that it is the shiniest of them all in the pure form and that is because it gives back almost the same amount of energy which it receives that is it reflects back the same amount of photons which come towards it and therefore making it a great option for reflection. That is why the coating be and the first layer of mirror is always that of silver.
This is how a mirror actually works.
Types of mirrors:
Most of us have used to the plane mirror and are accustomed to the plane mirror but that does not mean that the only type of mirror which is present as the plane mirror because if you have been to a hall of mirrors then you would realise that there are many different type of mirrors which are available and these mirrors are nothing but an optical illusion because they distort your image and force your brain to think that the image which is there in the mirror is either taller or shorter or wider or narrower than it actually is and this all depends on the way in which the mirror reflects the light and therefore it is nothing but an optical illusion. Even the normal mirror is an optical illusion because you are not in front of yourself when you’re standing in front of the mirror. Below we would be explaining about the different types of mirrors:
Plane mirror: This is a flat surface to mirror and the only property of this mirror in addition to reflecting the images to invert the mirror.
Concave mirror: This type of mirror is bent inwards and therefore the reflection appears bigger than normal, that is this mirror magnifies the reflection.
Convex mirror: This type of mirror is the exact opposite of concave mirror and since it is bent outwards the image actually appears smaller. The mirrors which are in our cars are a prime example of convex mirrors. Since the image appears smaller you might be thinking that the object which is displayed in the mirror is far away and that is why our vehicle mirrors carry a warning saying “objects in the mirror are closer than they appear”. That is because the image appears smaller than it actually is.
Inversion in the mirror:
Most of the people are confused to to the inversion which is taking place in the mirror because what is on your right seems to be on your left in the mirror and what is on your left seems to be on your right in the mirror and that is what confuses a lot of people and people still think that it is because of the inversion property of the mirror.
Let’s say, you are standing in front of the mirror then arms would seem inverted horizontally. You can get a better understanding of this when you’re standing behind the person who is watching his or her reflection in front of the mirror. What the mirror is actually doing is providing the reflection of what is in front of it and not what is in back of it whereas if the person were to hypothetically walk into the mirror in the exact same place where his reflection is now showing up then you would be able to see the back of the person. That is the reason that the image of the person is coming inverted.
So, the only inversion which is taking place in the mirror is the inversion from front to back.
In order to understand this what you have to do is that you had to write a symmetrical letter on a thin piece of paper like F and then you had to flip the paper to the other side and watch the letter from the back and then you would see it inverted and this is what exactly is happening in the mirror. When you’re turning the paper around you are moving the right inside to the left inside and the other side in the opposite direction as well and that is where from behind you are seeing the letter is horizontally inverted.
These are the factors which influence the working of the mirror and explain how do mirrors work.