Monday, December 20, 2010

Heat Transfer, Pine Needles, Campus Life


The temperature of my living room is 23 C now. My hot cup of tea is 45 C. If I allow my hot cup of tea to cool in this room of 23 C, my cup of tea will quickly reach the temperature of the room.

On the other hand, depending upon the size of my cup of tea and the size of my room, the thermal equilibrium temperature will not be 23 degrees. How do I know? Because the energy of my cup of tea will cause the temperature of the room to increase. The 2nd Law of thermodynamics helps me to understand this concept. So it tells me that entropy tends to increase as defined in its formula:

qqqqqqqS = H / T

S = entropy (kJ/kg K)
H = enthalpy (kJ/kg)
T = absolute temperature (K)

The movement of energy, known as Thermodynamics, is the branch of physics and also basis of understanding the behavior of physical systems. Studied thermodynamics I and II, that were one of my most liked lessons. The "grown-up" life is really amazing, I give my appreciation in every stage of the life that there is always something to look forward to but there is nothing like being "university student". I missed being on the campus, studying thermodynamics, taking dynamics classes from our italian professor Antonio (from Milano), the library,...

If you wonder, right now drinking tea and reading the life story of clothing designer Rachel Riley, (above) Sophisticated English Lady. Boring article.


  1. Haha - thermodynamics I and II, that was my most-hated field during my studies in the last century... took me two attemps to pass the exam. The rest was not that difficult (for me).

    So: How long does it take to increase the temperature of your cup of tea from 296°K to 297°K by stiring it with a tea spoon at a speed of - let's say - 60 RPM??? ;-)

    Wonderful photos you took for your attempt to explain sympathy, err, no, entropy and enthalpy to the rest of the blog community... ;-))


  2. @ Uwe: Hahaaa... so funny:)) You are "great" for being content creator on the comment board:) But wait, they say, SUGAR is CALORIES! I never use sugar in my tea/coffee.

    How were you in advanced math? Shall I bring it later in a new post;)

  3. Great formula, Nihal! To jump from one thing to another, about degrees, I think of the beginning of the universe, when the temperature was more than 100 milliard Kelvin and time and space began to exist. At present, because of the expansion, the medium temperature of the universe is about 3° Kelvin. I find these theories so fascinating!
    Happy Wednesday :-)