The Astonishing Science behind the working of a Thermometer

 The Astonishing Science behind the working of a Thermometer

You might be wondering after reading that statement(astonishing science behind the working of thermometer) that what science would lurk behind a normal mercury thermometer that we would have not known and this is what I am going to explain in this post. So fasten up your seat belt readers because it's gonna get hot here. (Pun intended ;)

So for explaining the science We will have to first understand the concept of heat energy transfer between bodies of two different temperatures and how it takes place.

Explanation: So let's assume you have two bodies, one is hot(maybe a cup of coffee) at 60 degrees Celsius and the other one is cool( a glass of cola)  at 2 degrees Celsius and let's also assume that both bodies are made up of same metal( I will tell later why we chose it) and you took both the bodies and kept them in contact with each other. Now after some time what will happen is the cold cola will become slightly less cool and the coffee will cool off a little bit and finally both the bodies will be at 29 degrees Celsius. So actually what has happened is the heat energy from the hot cup of coffee has transferred over to the glass of cola until both the bodies are of the same temperature( 29 degrees Celsius). This is the key concept we have to understand and the rest of the article revolves around it.

Heat energy always travels from a hot body to a cold body until they acquire equilibrium(both bodies have an equal temperature) if the bodies are kept in contact with each other. 

Now let's talk about our thermometer again.

So let's assume you are feeling fever and you try to measure the temperature of your body using the thermometer and you find out your body is steaming at 103 degrees Fahrenheit. So actually what has happened is that the moment you use the thermometer, the thermometer acquires heat energy from your body( since your body is hotter than the thermometer)and it happens until both the thermometer and your body are of equal temperature(which is 103 degrees Fahrenheit).

So the moment you started measuring your body's temperature your body was not exactly at 103 degrees Fahrenheit it was a bit hotter than that and the extra heat that was there was transferred to the thermometer to make it the same temperature. ( the thermometer will acquire a very low amount of heat energy from you to reach the same temperature since its volume is very less as well as its heat capacity)

So now you would ask what is astonishing about all this and which is that the temperature the thermometer is measuring is not yours's and it was never meant to do that but it was always measuring its own temperature. The moment you start using it the temperature rapidly moves up as it acquires heat from your body and the final reading that it gives is actually the temperature it is at itself.