Ayad Muhammad
EGEE 101 H
Dr. Semih Esser
Reflective Essay 1: Entropy
Entropy is a concept from Vaclav Smil’s Energy: Beginners Guides I was most
intrigued by due to its importance to the laws of thermodynamics and it’s
implications on the universe.
Rudolph Clausius first introduced the concept of entropy when he
formulated the second law of thermodynamics in 1865. In technical terms, entropy
is the measure of a system’s unusable thermal energy per unit temperature. In other
words, entropy is an indicator of the quality of energy. If a substance has high
entropy, its energy is low quality, whereas the opposite holds true for substances
with low energy. This aspect of entropy is crucial to one’s understanding of the
second law of thermodynamics, which states that heat is naturally transferred from
a warmer substance to a cooler one. In the context of the second law, entropy is a
measure of the disorder within a system. When energy is converted from one form
to another, some energy is lost as heat due to friction or other intermediary
processes that decrease the amount of usable energy exchanged. This waste heat
causes entropy to increase. As a substance is heated, its entropy increases due to the
increase in the random motion of its molecules. Following this procession, heat
flows from a warmer substance to a cooler one, ultimately causing the total entropy
of the system to increase. Therefore, using entropy, the second law of
thermodynamics predicts that the total entropy of an isolated system will always
tend to increase over time.
An important implication of the second law that is still debated today is the
possibility that our universe will ultimately experience a “heat death” when its total
entropy achieves a maximum. According to this theory, which stems from the ideas
of Hermann von Helmholtz in the 1854, as the universe evolves, according to the
second law, it will continue to increase its total entropy until all available heat has
been transferred and there is no usable energy left. In order to transfer heat, a
difference of temperature must exist. Without any temperature differences, the
universe will reach a thermodynamic equilibrium, rendering it incapable of
sustaining any future energy processes. This “heat death” occurs when the universe
moves towards maximum entropy and minimum temperature after which it slowly
fades away, lacking the energy to perform any more work. Proponents of this theory
point to a number of indicators such as stars burning out and the cooling of white
dwarves. It is truly amazing how a seemingly simple concept like entropy could spell
such far-reaching consequences on the future of our entire universe.
It is truly of testament to the inter-connectedness of nature and physics that
the essence of all life could be boiled down to something as simple as heat. This is
essentially what the laws of thermodynamics do. All energy processes require heat
and entropy is a way for us to track the movement of that heat. The possibility that
our universe could run out of heat provokes us to entertain the possibility that
ultimately our world will also run out of usable energy especially as we continue to
deplete its resources for personal and commercial purposes. While the first law of
thermodynamics states that energy is infinite, the second law suggests that usable
energy is not. Regardless of the theory’s accuracy, even the possibility of heat death
only adds to the long list of reasons why we should be responsible with our use of
energy.
Works Cited
1. Smil, V. (2006). Energy in our Minds: Concepts and Measures. In Energy:
Beginners guides (pp. 5-6). Oxford: Oneworld.
2. Entropy. (2015). In Encyclopedia Britannica. Retrieved from
http://www.britannica.com/EBchecked/topic/189035/entropy
3. Entropy. (2009). Retrieved April 29, 2015, Retrieved from
http://science.howstuffworks.com/dictionary/physics-terms/entropy-info.htm
4. Thermodynamics. (2015). In Encyclopedia Britannica. Retrieved from
http://www.britannica.com/EBchecked/topic/591572/thermodynamics/2585
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