Editing 2318: Dynamic Entropy

{{comic
| number    = 2318
| date      = June 11, 2020
| title     = Dynamic Entropy
| image     = dynamic_entropy.png
| titletext = Despite years of effort by my physics professors to normalize it, deep down I remain convinced that 'dynamical' is not really a word.
}}

==Explanation==
{{incomplete|Do NOT delete this tag too soon.}}
This is another one of [[Randall|Randall's]] [[:Category:Tips|Tips]], this time a Science Tip. This time it is a bit special since it came less than three weeks after another Science Tip: [[2311: Confidence Interval]]. This thus became the first time a type of tip, that was not a [[:Category:Protip|Protip]], has been used more than once, and it was even for two "tips comics" in a row.

This Science Tip suggests that if you have a cool new concept, you should call it ''Dynamic entropy'', hence the title. 

{{w|Dynamic programming}} is a mathematical optimization method and computer programming method developed by Richard Bellman in the 1950s. The [https://en.wikipedia.org/wiki/Dynamic_programming&oldid=960681597#History History section] of the Wikipedia article contains the full paragraph from Bellman's autobiography that contains the quote that is in the comic strip. Bellman describes how he was doing mathematical research funded by the military at a time when the Secretary of Defense had a literal pathological fear of the word "research", and by extension, "mathematical". Bellman borrowed the word "dynamic" from physics as being both accurate for his work and as a word that in plain English has positive connotations and is never used in a pejorative sense (expressing contempt or disapproval).

{{w|Entropy}} is a term from physics, specifically statistical mechanics, describing a property of a thermodynamic system. When Claude Shannon developed a mathematical framework for studying signal processing and communications systems, which became known as {{w|Information theory}}, he struggled to come up with a proper name for one mathematical concept in his theory that quantified amount of noise or uncertainty in a signal. Computer scientist John von Neumann noticed the similarity of the equations with some in thermodynamics and suggested, "You should call it entropy, for two reasons. In the first place your uncertainty function has been used in statistical mechanics under that name, so it already has a name. In the second place, and more important, no one really knows what entropy really is, so in a debate you will always have the advantage." (see [https://en.wikipedia.org/w/index.php?title=History_of_information_theory&oldid=917334152#Entropy_in_statistical_mechanics History of information theory])

The naming of dynamic programming and of entropy in Information Theory are both examples of scientists choosing a name for what were at least partially very non-scientific seeming reasons. In the one cased because it has only positive and no negative connotations in plain English. In other case because there is much confusion over the meaning of the word so Shannon would be free to adopt it in a new context. [[Randall|Randall]] is claiming that would make them great to put together to name some new concept, contributing toward it becoming as famous as dynamic programming and information theoretic entropy.

Even though the caption implies that "dynamic entropy" would be available as a new name, it has actually been used in physics<ref>Allegrini, P., Douglas, J. F., & Glotzer, S. C. (1999). Dynamic entropy as a measure of caging and persistent particle motion in supercooled liquids. Physical Review E, 60(5), 5714, doi: 10.1103/physreve.60.5714.</ref>, probability<ref>Asadi, M., Ebrahimi, N., Hamedani, G., & Soofi, E. (2004). Maximum Dynamic Entropy Models. Journal of Applied Probability, 41(2), 379-390. Retrieved June 11, 2020, from www.jstor.org/stable/3216023</ref>, computer science<ref>S. Satpathy et al., "An All-Digital Unified Static/Dynamic Entropy Generator Featuring Self-Calibrating Hierarchical Von Neumann Extraction for Secure Privacy-Preserving Mutual Authentication in IoT Mote Platforms," 2018 IEEE Symposium on VLSI Circuits, Honolulu, HI, 2018, pp. 169-170, doi: 10.1109/VLSIC.2018.8502369.</ref>, and even the term "dynamical entropy" in physics<ref>Green, J. R., Costa, A. B., Grzybowski, B. A., & Szleifer, I. (2013). Relationship between dynamical entropy and energy dissipation far from thermodynamic equilibrium. Proceedings of the National Academy of Sciences, 110(41), 16339-16343.</ref><ref>Słomczyński, W., & Szczepanek, A. (2017). Quantum dynamical entropy, chaotic unitaries and complex Hadamard matrices. IEEE Transactions on Information Theory, 63(12), 7821-7831, doi: 10.1109/TIT.2017.2751507.</ref> and bioscience<ref>Chakrabarti, C. G., & Ghosh, K. (2013). Dynamical entropy via entropy of non-random matrices: Application to stability and complexity in modelling ecosystems. Mathematical biosciences, 245(2), 278-281, doi: 10.1016/j.mbs.2013.07.016.</ref>.

In the title text Randall mentions that, even though his physics professors have continued to use the word "dynamical", "trying to normalize it" by repetitive usage, he remains convinced that it is not really a word. I.e. it would just be something they use, like in this comic, where putting "Dynamic" in front of another word can give it a positive meaning.

The term "dynamical" in physics generally is used in "{{w|Dynamical system}}" or as an adjective to name a concept as applied to dynamical systems such as "dynamical entropy"<ref>Atmanspacher, H. (1997). Dynamical entropy in dynamical systems. In Time, temporality, now (pp. 327-346). Springer, Berlin, Heidelberg, doi: /10.1007/978-3-642-60707-3_22</ref>.

==References==
<references />

==Transcript==
:[One panel only with text and a few lines and arrows. There are two columns each with a heading. Beneath each heading is a quote written on four lines. Below the quote, in grey font, and indented, starting with a hyphen, with the text aligned to the right of this are five lines of text. This explains who the quote belongs too and where it was stated (in brackets at the end). From the bottom of each of these two gray text paragraphs gray curved arrows goes down to two gray lines. Below each of these two lines are one large word per line. They are again in black text.]
:<big>Dynamic</big>
:"It's impossible to use the word 'dynamic' in the pejorative sense... Thus, I thought 'Dynamic Programming' was a good name."
::<font color="gray">- Richard Bellman, explaining how he picked a name for his math research to try to protect it from criticism (''Eye of the Hurricane'', 1984)</font>

:<big>Entropy</big>
:"You should call it 'Entropy'... No one knows what entropy really is, so in a debate you will always have the advantage."
::<font color="gray">- John von Neumann, to Claude Shannon, on why he should borrow the physics term in information theory (as told to Myron Tribus)</font>

:::<big><big>'''''Dynamic Entropy'''''</big></big>

:[Caption below the panel:]
:Science Tip: If you have a cool concept you need a name for, try "Dynamic Entropy."

{{comic discussion}}

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