What is entropy? A measure of disorder can seem abstract and somewhat difficult to envision at times. Can I really blame the state of my apartment with unwashed dishes and dirty laundry strewn on the floor on its agency - or does this have to do more with the subjective nature of personality traits? Can one really measure quantitively disorder when colloquially we refer to it in quantitative terms?
I am very fond of the topic of entropy. In high school, I used to tell horror stories about the eventual heat death of the universe ad naseum. Eventually all of the particles would exist in a solid, perfect crystal state, where no energy could rescue them from their eternal plight.
My musician father was fascinated by entropy while listening to CBC radio program Ideas. Many a skype conversation, he will pounce the topic upon me, and question continuously its definition and properties. Once we devised a system of cells in the human body, existing under ideal conditions (eg: no negative effects of the external environment such as a blow to some tissue, or disease), with only the natural aging process as a factor. Applying the statistical explanation of entropy, we were able to determine it was statically unlikely for all of the cells in an common region of the body to spontaneously die, when otherwise undisturbed.
Walking one evening with a someone special, in the crisp fall Montréal air, we discussed how if you have an empty chamber attached to a flask filled with particles of gas, and opened the flask to the empty chamber, the gas particles would distribute themselves so they filled every state in the chamber. The movement of our postulated system of order to one of disorder mirrored that of the Big Bang. We found it disturbing that the transition from order to disorder was mediated by an external event of the person opening the stopcock. Does this part of the analogy translate over to the scenario of the Big Bang as well or not? Where did the initial stimulus for the start of the universe come from?
Entropy can lead to interesting conversations with people of all different backgrounds, and also contribute to an enhanced understanding of the behaviour of the universe. For these reasons, I am going to develop the concept of entropy over a series of posts, discussing both statistical and thermodynamic interpretations of entropy, and employing both qualitative and quantitative means throughout my explanations.
These posts will be dedicated to my dad because I have always promised to explain entropy throughly to him, but we never have sat down properly to discuss it.
Is the word "entropy" the proper term to describe the distribution of items in an apartment or particles within a vessel?
ReplyDeleteI think not...
I believe its correct usage is to describe the change of energy state, that entropy increases as the usefulness of energy decreases. I think that I've got this right.
The slow creep of messiness in our basement is not an increase of entropy because the potential energy level of the items themselves has not changed. No gradient results - it's a flat energy field.
Dad
Perhaps a more direct discussion of energy is required.
ReplyDeleteIn the case of the two vessels connected by a stopcock, the energy of the molecules is degraded when the gas becomes evenly distributed in the larger volume available. This is because the molecules will move more slowly by the Kinetic Molecular Theory and the Ideal Gas Law, as they are less compressed. The greater number of random states available to the molecules of gas, requires for the gas to occupy a statistically greater number of energy levels that are less than the energy levels occupied previously. Therefore, this is a clear example of entropy.
In the case of the apartment, if we define the system to be in respect to the degradation of energy of the arrangement of belongings, the more random state of the strewn out belongings has greater degradation than in their organized locations. This example is not a formal example of entropy, however, it tends to be more intuitive as it applies to everyday life (especially that of a student!).
More generally: order = higher energy, and disorder = degraded energy.
Hope this helps!