2318: Dynamic Entropy

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Dynamic Entropy

Title text: Despite years of effort by my physics professors to normalize it, deep down I remain convinced that 'dynamical' is not really a word.

Explanation

This explanation may be incomplete or incorrect: Created by a PHYSICS PROFESSOR. Explain what "pejorative sense" means. Should briefly explain dynamic programming, information theory, and entropy, and define the word “dynamical”. Do NOT delete this tag too soon. If you can address this issue, please edit the page! Thanks.

This is another one of Randall's 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 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.

The Wikipedia article on Dynamic programming defines it as a mathematical optimization method and computer programming method developed by Richard Bellman in the 1950s. The History section of that 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 that 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).

Merriam-Webster's Dictionary defines dynamic as "marked by usually continuous and productive activity or change" as well as "of or relating to physical force or energy," among other definitions. Additionally, it defines entropy as "the degree of disorder or uncertainty in a system." So while clearly these two words do mean things, the comic provides two quotes from famous scientists saying that "it's impossible to use the word 'dynamic' in a pejorative sense", and "no one knows what entropy really is". The result is a phrase that can mean whatever the concept's originator wishes it to mean, and cannot possibly be heard in a negative light (as has happened with e.g. "cold fusion").

Even though the caption implies that "dynamic entropy" would be available as a new name, it has actually been used in physics, probability, computer science, and even the term "dynamical entropy" in physics and bioscience.

In the title text Randall mentions, that even though his physics professors has 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 "Dynamical system" or as an adjective to name a concept as applied to dynamical systems such as "dynamical entropy".

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.]

Dynamic

"It's impossible to use the word 'dynamic' in the pejorative sense... Thus, I thought 'Dynamic Programming' was a good name."

- Richard Bellman, explaining how he picked a name for his math research to try to protect it from criticism (Eye of the Hurricane, 1984)

Entropy

"You should call it 'Entropy'... No one knows what entropy really is, so in a debate you will always have the advantage."

- John von Neumann, to Claude Shannon, on why he should borrow the physics term in information theory (as told to Myron Tribus)

Dynamic Entropy

[Caption below the panel:]

Science Tip: If you have a cool concept you need a name for, try "Dynamic Entropy."

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Discussion

Can confirm, have never lost an argument. Dynamic Entropy (talk) 00:45, 11 June 2020 (UTC)

You came here for an argument? No, this here is abuse. Argument's next door. Kev (talk) 10:26, 13 June 2020 (UTC)

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.

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

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.

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.

Bugstomper (talk) 01:28, 11 June 2020 (UTC)

Can someone with knowledge of the reference system in a wiki make the reference appear above the discussion, maybe in a section named References?--Kynde (talk) 07:06, 11 June 2020 (UTC)

Done Bugstomper (talk) 09:13, 11 June 2020 (UTC)

Thanks. Could not find the correct way to do it, so nice my call was answered quickly. --Kynde (talk) 11:42, 12 June 2020 (UTC)

Well bugger me (METAPHOR! METAPHOR!) but my current Master thesis in Computer Science could use that term without much shoehorning. (tl;dr: Binary search trees that adapt, =dynamic, can serve a query series faster than static, and the gain depends on the structure of the query series, =entropy. I prefer the good old "instance optimality", though...) 162.158.159.122 08:58, 11 June 2020 (UTC)

This seems to tie in with the recent comic 2315: Eventual Consistency, which is also about entropy (in a thermodynamic(al) sense), but I guess that like the rest of the world I don't know what entropy really is, because if entropy is a measure of how "surprising" a variable is, why is everything being flat and spread out evenly called a state of maximum entropy? Everything being the same doesn't sound very surprising to me... --IByte (talk) 09:08, 11 June 2020 (UTC)

Because entropy is the inverse of how "surprising" or organized or full of information a system is. Bugstomper (talk) 09:27, 11 June 2020 (UTC)

It's not about "surprising" but about an even spread of probability, so for matter a complex molecule has less entropy than a smaller molecule because the atoms are held in place, and if the quarks in the atoms aren't even held together in subatomic particles then that is ultimate entropy. For information having more possible choices for the message or password spreads the probability of any one occurrence around more possibilities. If it is narrowly defined it has low entropy because the probability is concentrated in a few items.162.158.75.104 13:53, 11 June 2020 (UTC)

I can think of a number of cases where "dynamic" would be a bad thing, but not necessarily pejorative. The structure of a building had better not be dynamic (think "sudden energetic disassembly"), and when my (salaried, should be steady) paycheck becomes dynamic, I have to talk to HR. Can someone come up with a pejorative? 162.158.78.212 11:16, 11 June 2020 (UTC)

2050 retro slang: Dynamic, variant of Dienamic, portmanteau of Die and (Viet) Nam + adjectival suffix // Dienam (n): a long, brutal slog with an unsatisfying ending, possibly with unintended consequences arising some time after the conclusion (cv Agent Orange) "Just like the soldiers a century ago, they knew the project was a dienam -- resources would be wasted, careers ended, and goals unmet -- but they couldn't convince the executives to abandon the project." // Some[thing] that is a failure, many years in the making, from which no success can be extricated. "[The development team] was working on a dynamic project for the studio when [the studio] finally was forced to declare bankruptcy and shutter due to literally years of overcomitting and underdelivering." 162.158.75.104 (talk) (please sign your comments with ~~~~)

As there exists such a thing as resilience by explicitness, when it comes to type system discussions in computer programming language design the term 'dynamic' can be pretty condemning. 141.101.76.204 (talk) (please sign your comments with ~~~~)

(Looks like people aren't ~~~~ing. My contribution starts here.) I can just see a reporter, at the scene of some breaking news, saying "It's very much a dynamic situation here", while dodging various rioter/police missiles, hurricane debris, moving away from a wildfire front or in the middle of a rescue situation in post-earthquake aftermath yet still amidst aftershocks. 141.101.107.164 05:28, 12 June 2020 (UTC)

The 'Use “-ic” with nouns ending in “-ics” (usually)' section of that Free Dictionary article is relevant here, since dynamics is a thing. 172.69.62.148 15:28, 12 June 2020 (UTC)

Dynamic gravity, dynamic oxygen level, dynamic surgical compentency, dynamic astronomical unit ... none of these are desireable. These Are Not The Comments You Are Looking For (talk) 20:18, 15 June 2020 (UTC)