--- Log opened Fri Sep 23 00:00:27 2022
02:17 -!- mirage3357058 [~mirage335@2a01:4f8:120:2361::1] has joined #hplusroadmap
02:21 -!- mirage33570 [~mirage335@2a01:4f8:120:2361::1] has quit [Ping timeout: 252 seconds]
03:32 -!- darsie [~darsie@84-113-55-200.cable.dynamic.surfer.at] has joined #hplusroadmap
04:56 -!- yashgaroth [~ffffffff@2601:5c4:c780:6aa0::1909] has joined #hplusroadmap
05:32 -!- spaceangel [~spaceange@ip-78-102-216-202.bb.vodafone.cz] has joined #hplusroadmap
06:07 -!- L29Ah [~L29Ah@wikipedia/L29Ah] has joined #hplusroadmap
06:12 -!- L29Ah [~L29Ah@wikipedia/L29Ah] has left #hplusroadmap []
06:14 -!- L29Ah [~L29Ah@wikipedia/L29Ah] has joined #hplusroadmap
06:20 < kanzure> huh, seems to capture roasbeef pretty well https://twitter.com/MatthewZipkin/status/1573288031938875392
06:20 < kanzure> compared to my transcript. i think it's real-time too.
07:33 -!- mirage3357058 [~mirage335@2a01:4f8:120:2361::1] has quit [Quit: Client closed]
07:33 -!- mirage3357058 [~mirage335@2a01:4f8:120:2361::1] has joined #hplusroadmap
08:07 -!- mirage3357058 [~mirage335@2a01:4f8:120:2361::1] has quit [Quit: Client closed]
08:07 -!- mirage3357058 [~mirage335@2a01:4f8:120:2361::1] has joined #hplusroadmap
08:40 < docl> .t https://www.mdpi.com/1099-4300/18/4/132/htm
08:40 < saxo> Entropy  | Free Full-Text | Anti-Icing Superhydrophobic Surfaces: Controlling Entropic Molecular Interactions to Design Novel Icephobic Concrete | HTML
08:40 < docl> "When a hydrophobic molecule (for example, a hydrocarbon immiscible with water, such as decane) is added to water, the water molecules arrange themselves around it to form a “clathrate cage”. This arrangement allows a maximum number of hydrogen bonds between neighboring water molecules, thus achieving a minimum energy state [30]. However, despite the energetic profitability of such a configuration 
08:40 < docl> in terms of the bond energy, the molecules that form the cage are constricted in their motion, thus forming an entropically unfavorable ordered (less random) state. At ambient temperatures, the entropic effect overcomes the energy gain."
09:18 < kanzure> halcyon molecular's patent on "Sequencing nucleic acid polymers with electron microscopy" https://patents.google.com/patent/US8153438B2/en
09:18 < kanzure> says expired
09:43 -!- spaceangel [~spaceange@ip-78-102-216-202.bb.vodafone.cz] has quit [Ping timeout: 265 seconds]
09:45 -!- spaceangel [~spaceange@ip-78-102-216-202.bb.vodafone.cz] has joined #hplusroadmap
10:04 < kanzure> https://www.polytechforum.com/polymers/distinguishing-different-polymer-strips-on-a-flat-surface-1395-.htm  (andregg)
10:23 < muurkha> docl: I think that to answer those questions you will have to go from the level of vague metaphors to the level of mathematical formalization
10:52 -!- catern [~sbaugh@2604:2000:8fc0:b:a9c7:866a:bf36:3407] has quit [Ping timeout: 244 seconds]
11:15 -!- catern [~sbaugh@2604:2000:8fc0:b:a9c7:866a:bf36:3407] has joined #hplusroadmap
11:55 < docl> muurkha: I can almost picture it though :)
11:56 < docl> I still have a strong intuition that deforming diamonds increases their entropy. devil of a job to find anything substantiating it though
14:06 < muurkha> you ought to be able to calculate the entropy change
16:15 -!- spaceangel [~spaceange@ip-78-102-216-202.bb.vodafone.cz] has quit [Remote host closed the connection]
17:41 < muurkha> docl: interestingly, speaking of carboxymethylcellulose, I just mixed up 3% carboxymethylcellulose in just plain water
17:41 < muurkha> and the stuff is damn near solid
17:44 < docl> interesting! at 3%?
17:44 < muurkha> yeah
17:44 < fenn> reducing the degrees of freedom decreases the heat capacity of a substance. compressing a solid seems like it would slightly reduce the degree of freedom in the direction of the compression, maybe?
17:45 < fenn> or maybe it has no effect at all
17:45 < fenn> just changes the speed of sound or something
17:45 < muurkha> I think it still has the same number of degrees of freedom per atom, fenn :)
17:45 < docl> .wik Boltzmann's_entropy_formula
17:45 < saxo> "In statistical mechanics, Boltzmann's equation (also known as the Boltzmann–Planck equation) is a probability equation relating the entropy  /    /      /        /         S /        /      /     {\displaystyle S} /    / , also written as  /    /      /        /          / [...]" - https://en.wikipedia.org/wiki/Boltzmann's_entropy_formula
17:45 < fenn> ok i'm not discussing quantum mechanics or thermodynamics today. good luck
17:46 < docl> lol
17:46 < muurkha> if it changes the speed of sound, that would mean that different sound waves traveling through the same crystal interact nonlinearly
17:46 < fenn> most things become nonlinear at extreme values
17:46 < muurkha> indeed
17:47 < muurkha> it would be pretty cool if you could get that to happen with diamond at stresses well below its yield stress
17:47 < muurkha> because phononic computing
17:47 < fenn> 2028-12-23
17:47 < fenn> Adjusted expiration
17:47 < fenn> on the halcyon patent
17:47 < muurkha> hm
17:49 < fenn> maybe that just means when it would have expired if they had paid the fees, adjusting for the time it took for the slow patent office to process the patent
17:50 -!- darsie [~darsie@84-113-55-200.cable.dynamic.surfer.at] has quit [Ping timeout: 252 seconds]
17:56 < docl> so the equation says the entropy is boltzmann's constant (tiny number of joules per kelvin) times the natural log of the number of possible microstates (in a system where the microstates are all equal probability, which they aren't in real life)
17:58 < docl> more equivalent probability microstates is then more entropy, all else equal (as is more kelvins)
18:02 < muurkha> I don't think it's just "all else equal"
18:02 < muurkha> but I'm not that confident in my understanding of thermodynamics
18:04 < docl> well you could increase the number of microstates and decrease kelvins to keep it constant, like when the rubber band shrinks
18:05 < muurkha> I don't think you can do that, no
18:05 < muurkha> I think decreasing kelvins decreases the number of microstates
18:21 < docl> cooling without increasing the number of microstates is also possible, but that involves reducing entropy. like if you have a canister of helium, you can increase its microstates, thereby decreasing kelvins, or you could stick it in the fridge
18:22 < docl> if I'm understanding correctly anyway
18:31 < docl> I'm thinking microstates is a catch-all for things that describe a particle like its velocity/momentum, direction, position, charge, spin, etc. changing a gas's volume would have a huge effect on the number of equivalently probable positions. lower temps would be fewer equivalently probable velocities (although low velocities become less likely at high temps so this might balance out)
18:55 < muurkha> well, you can increase the number of microstates in one way while decreasing the temperature, keeping the number of microstates and thus the entropy constant
18:56 < muurkha> but Boltzmann's entropy formula doesn't have one term computed from the temperature and another one computed from the number of microstates
18:56 < muurkha> if decreasing the temperature affects the result of Boltzmann's entropy formula at all, it must do so by changing the number of microstates
18:58 < docl> well, boltzmann's constant is in terms of joules per kelvin
19:07 -!- yashgaroth [~ffffffff@2601:5c4:c780:6aa0::1909] has quit [Quit: Leaving]
19:31 < muurkha> that's right
19:33 < muurkha> because those are the units of entropy, you see, and the logarithm is dimensionless
19:36 < muurkha> are you comfortable with Shannon entropy?  I think the analogy with Shannon entropy is illuminating
19:43 < docl> I should read up, but I have the impression it's akin to noise or random numbers, i.e. information you can't compress further
19:44 < muurkha> hmm, then it probably won't help you understand Boltzmann (or Gibbs or von Neumann) entropy
19:44 < muurkha> I was asking in case it was something you were very familiar with
19:50 < docl> I mean, that might be underselling my level of familiarity a little, but I'm no expert
19:54 < docl> if you flip a fair coin you get bits with equal probability, whereas a biased coin yields bits that are unequal in probability implying you could compress them. so we can say the former has maximum entropy
19:57 < docl> which if you're translating to the momentum vectors of atoms is like the difference between the kinetic energy of a moving gas (biased in a given direction) vs the kinetic motion of atoms that makes heat (which sort of averages out to equally in all directions)
20:41 -!- codaraxis__ [~codaraxis@user/codaraxis] has quit [Ping timeout: 260 seconds]
20:44 < muurkha> neat, you can get an insoluble hydrogel with 7% carboxymethylcellulose and 2% calcium chloride: https://core.ac.uk/download/pdf/188194092.pdf
20:45 < docl> woah cool
20:52 < muurkha> this paper is not very well written
20:53 < muurkha> in particular it's not clear if the calcium chloride they're using is anhydrous or hydrated
20:54 < docl> I'm familiar with CaCl, it's commonly used as a desiccant. the hexahydrate form is liquid at room temperature. you can get little containers of it for putting in a closet to keep it from getting musty. also used as ice melter for sidewalks and such
20:55 < muurkha> aye
20:55 < muurkha> but it also has monohydrate, dihydrate, and tetrahydrate forms
20:56 < muurkha> also I usually keep my rooms lower than the melting point of the hexahydrate
20:56 < muurkha> there are a surprising number of salts you can precipitate with CaCl₂
20:57 < muurkha> sulfates, phosphates, oxalates, carbonates, bicarbonates, and so on
20:58 < docl> I wonder if the hydrogel is stable if you bake the water out to make an aerogel? maybe not since you'd lose the hydrogen bonds
20:59 < muurkha> they mention that people have done that
21:00 < docl> ahh neat
21:01 < muurkha> in https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8167666/ they instead used Fe⁺⁺⁺ salts
21:03 < muurkha> I wonder if someone has tried using aluminum salts; that would probably be just as effective and safer for medical applications
21:03 < muurkha> borate is another obvious candidate
21:05 < muurkha> I guess the earlier paper also neglected to describe the degree of (hydroxyl) substitution in the CMC they were using
21:06 < muurkha> oh hey, this paper says aluminum salts also work
21:48 -!- Malvolio [~Malvolio@idlerpg/player/Malvolio] has quit [Read error: Connection reset by peer]
21:50 -!- Malvolio [~Malvolio@idlerpg/player/Malvolio] has joined #hplusroadmap
23:06 -!- Malvolio [~Malvolio@idlerpg/player/Malvolio] has quit [Quit: ?sel LNGshor dist PLNHRZ rsmngt dy loc autoptmp-- cuniculoria in lapidariae; TRVVNZLV 23922 2565 01234567890/qWe333]
--- Log closed Sat Sep 24 00:00:28 2022