Monday, December 03, 2012

Many Scientists have been trying to explain various physical ,or biological phenomenons by citing examples by drawing some analogy. Take an instance of a question , " Why do leaves on a plant appear green?" We answer the question as the attribution of the presence of the pigment called the chlorophyll. To explain questions with why are the most difficult ones to answer.
Famous scientist Albert Einstein also explained his view of  Gravitation with space-time as a thin sheet on a an imaginary 2D plane.
Not only that in the explanation of atomic structure  many analogies were drawn. These explanations have been taken as correct only after its validity by practical experiments. Based on these explanations many applications in real world have been seen.
Sometimes Mathematics have evolved only to explain the phenomenon. And sometimes phenomenons were used to stretch the mathematics further. Mathematics was used as the tool.

Explanation of co-valent bonding, ionic bonds, vaner vaal forces, or hydrogen bonding came into existence after many physical phenomenons didnt have correct explanations. They are  completely on a fictitious plane.
Such explanations often open a new branch of science.

"Hot water freezes faster than normal water" demands a model of explanations. The explanation which can be made a principle. And a principle which can be converted into mathematical explanation. Then using the application of this phenomenon towards our choice of application.
 In a refrigerator the direction of heat flow is reversed by doing some mechanical work. Suppose the rating of the refrigerator is 380 Watts that is 380 joules per second. i.e rate of doing work or it can dispel heat outside at a rate of 380 joules per second.
Temperature of a body is defined as the content of heat. Enthalpy is other measure of  heat content of substance.

The situation at normal room temperature:
If we keep hot water (Water, which has large content of heat)  inside a freezer. Because the temperature of water is higher than the temperature outside there is a natural flow of heat. And thus increasing the rate of discharge of heat. In this process refrigerator might exceed its rating and motor of the refrigerator will fail.
Suppose we make a refrigerator of higher power rating so that it doesn't fail like the previous case. We will see  hot water freezing faster.   



During winters, because of the wind  temperature decreases sharply making the surroundings colder. Making the atmosphere a heat sink or a natural refrigerator of very high power rating, which can be assumed as infinity . When we expose water of 35 degree Celsius it takes longer time to freeze. Whereas the hot water at nearly 90 degree Celsius will freeze faster. Mechanical work of refrigeration is being done by high speed wind accompanied by natural heat flow direction heat discharge is very fast in the case of hot water.  watch the explanation on youtube. http://www.youtube.com/watch?v=JsLEEh9R25c&feature=youtu.be
Please see the experiment   




 

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