How Fractals Make the Best Coffee

[@notarealyoutubeaccount799]

Your channel is going to blow up like mad in the coming months. Absolutely fantastic job. This video was a pleasure to watch.

[@not_David]

Thanks so much, I'm glad you enjoyed the video :)

[@simplykyle]

It indeed blow up!

[@abhyutaichou8322]

And the coming months is officially here. 10k subs under a week! 🎉

[@viv3d]

22k Sub Already! Amazing Channel

[@notarealyoutubeaccount799]

And an extra 3k subs in 5 days. David keep going! 😤

[@ck_cal]

I don't think there has ever been a channel as underrated as yours The videos are incredibly aesthetically pleasing and every single render is on point, the explanations are elegant and simple and as a whole they just make you wanna keep watching! I truly believe the stuff you make is on a whole other level, keep going!

[@not_David]

This is one of those comments that really motivates me to keep working on videos even though its so time consuming. You made my day haha, thank you!

[@Me-0063]

I completely agree. The videos have a very high quality, and I believe are on par with million subscriber channels

[@pilkin5378]

another underated channel that springs to mind is 'lines in motion'. rly rly inciteful commentary about art in manga.

[@not_David]

@@pilkin5378 ooo right up my alley. Thanks for the recommendation!

[@rapidfuryg592]

I completely agree.

[@stevenvroom1041]

Yeah yeah, it's nice to know _why_ fractals make the best coffee, but... HOW DO I MAKE THE PERFECT FRACTAL COFFEE!?

[@lonestarr1490]

Trial and error, unfortunately. The critical density doesn't guarantee you a balanced extraction. So you'll have to dial it in; there simply isn't any way around it. Here's how you do it: Brew a cup. If nothing goes through, grind coarser. Once you get coffee out, taste it. If it is sour, that means the water percolated too quickly and didn't have enough time to extract the sweet components to balance out the acidity. Hence, you need to grind finer for more resistance. If it is bitter, then you extracted too much and thus need to grind coarser. Rinse and repeat (literally) until you get something you're satisfied with. And when you buy different beans the whole process starts anew.

[@gregothy9190]

​@@lonestarr1490Also, with a professional machine, running two ounces through (double espresso) the classic metric is 26 seconds. Finer grinds go slower, coaser grinds go quicker. This "26-second rule" gives you an easy metric without necessarily needing to taste it all. With our professional machine, it actually times it, so you don't even need to have a timer. That said, some people like a 17 second shot with one bean, or a 30 second shot with another bean. All preferences :)

[@not_David]

Hope you enjoyed the video! (post-uhmms video edit) Looking back I have two critisims about this video: -the first is that it is not explicit enough in saying the video is not actually about practical applications of making coffee. I think this is one of those things that im still trying to get better at as a writer and was just a blind spot I missed. I am working on addressing this (I hope my uhmms video is better in this regard). - the second is much bigger in that i never explicitly say what the result is. Like its implied but i just kinda breeze past it. Namely, the result is that you would want to be as close to the fractal without going over it. Of course, this assumes you like a strong coffee. Anyway, I still think the video is good and im proud of it, but im definitly learning a lot from the feedback so thank you everyone!

[@m9l0m6nmelkior7]

It's a really good and interesting one !

[@not_David]

Thank you! I'm glad you enjoyed it :)

[@papycoima]

you deserve a lot more subscribers, the study behind your videos and the dedication are just incredible. Keep it up!!

[@pacificnorthwet]

I really did! You explained the concept of percolation and critical density extremely well and I'm now very excited to find other applications. Thank you very much!

[@tinycatzilla]

I wish it was more in depth, but I liked it

[@Annapaulas]

I don't know how I found my way to your channel, but these videos are amazing! My dad asks me questions about my career (unrelated, but both mathematical), and has always told me I can't really fully understand what I do until I can explain it to him. I think this goes to show you understand your field completely, as you're able to break complicated topics down and relate them into easily understandable and interesting every day scenarios. You mentioned in another video about what your tutor may think about how you're applying your learning - I, for one, think your tutor should be very proud!

[@not_David]

I don't think I understand my field completely, but I do think your dad is very right, and honestly if I could go back and tell my undergrad self what to focus on, it'd be just that because so much of getting a career or grant writing is expressing why your work matters to a group of people that have no idea about physics. Part of making these videos is also for me just to learn to do just that. Thanks so much for the kind words!

[@leftysheppey]

Your dad is smart. You can't teach somebody if you don't truly understand. When I used to tutor maths, if I got the feeling the student knew how to do it, but needed practice, I'd make them explain it to me. 90% of the time, it's just confidence they were lacking

[@alejrandom6592]

This makes the statement "coffee people will learn quantum mechanics to make an extraction 0.0001% better" sound a lot less like a joke

[@parrotapocalypse]

This was a great video; it's apparent how much effort goes into these. Please keep making them!

[@not_David]

Thanks so much, the kind words are greatly appreciated :)

[@cqnrad]

i watched two of your videos and then looked at your sub count. i legitimately expected you to have a million subscribers, this has to be one of the most underrated channels on youtube. crazy shit you're doing man keep it up

[@jstrandquist]

A few comments from a coffee-loving physicist: 1. The idea of fractals not strictly repeating as you zoom in or out but merely maintaining the same statistical density is interesting. I'm honestly surprised I hadn't heard about it before. 2. Scale effects are really important in physics-the most significant is probably the quantum-classical transition, in that the further you zoom out from the atomic scale, the less apparent quantum mechanical effects are and the more things behave according to the laws of classical physics. It's also hugely important in trying to describe phenomena such as ferromagnetism and material properties. I also had some personal experience with finite size effects when I worked on synthesizing semiconducting lead sulfide nanoparticles in undergrad. Their cool trick was that while they would absorb visible light and emit infrared as a bulk crystal, once you got them down to a few hundred atoms in size, they would start absorbing and emitting mostly in the visible range due to quantum confinement. 3. Regarding renormalization and gravity, the longstanding issue is that while we have a classical theory of fields that works really well (describing electric fields, gravitational fields, flow fields, etc.) *and* we have a quantum theory of fields that works really well (describing quantum electrodynamics and the nuclear forces), every quantum theory of gravity has proven unrenormalizable. Even worse, because gravity is by far the weakest of the fundamental forces, it's impossible with current technology to test gravitational effects at the quantum scale. (Note: I'm not a professional cosmologist or particle physicist, so I'm neither current with every development in the field, nor can I give much more detail than already given here.) 4. An interesting complication to your model would be to include a range of particle sizes. James Hoffman once put some ground coffee through a laser particle size analyzer, and the results for 3 grinders all showed a slightly skewed Gaussian distribution around 1 mm, along with a long tail rising slightly at 40 μm. 5. Other weird coffee physics topics include the production of foams. Espresso crema is the most well-known foam, but Turkish coffee also produces a foam, which consists of air and water vapor dispersed in a matrix of coffee oils, water, and suspended grounds. I don't actually know what causes it, so I'm starting a research project to figure it out. It's great to do experiments where you can drink the results. I hope you found some of that interesting; I certainly enjoyed your video. Thanks for making it, and best of luck getting your espresso technique down!

[@not_David]

Thanks so much for the comments! Regarding comment 1: A good reference for this would be the book by Christensen And Monloney. They give an excelent overview of the statistical definition of a fractal (e.g., their association with power-law distributions). I addmitedly don't know if this definition is or is not reconsilable with the "traditional" thing we think of when we think of fractal (e.g., mandelbrot, menger sponge, etc.) but I think it should be possible? Regarding comment 4: I did think about this and I think that a distribution of particle sizes wouldn't effect the overall conclusions. If we assume that each grind is impermeable (which is not a great assumption but I think my model implicitely makes) then a distribution of grain sizes would mainly indirectly effect the density. Thats completely conjecture though. I'm reminded of whats apperently called the brazil nut effect, where larger particles rise to the top because smaller particles fill the spaces below. I think it'd be a similar thing where larger particles interfacing with smaller particles would just change the density. Tangentially reagrding 5: In the original version of the script I had a section where I talked about how other coffees relate to this model, or more specifically how they don't. Turkish is actually probably my favourite type of coffee but it is not really modeled by this at all.

[@jstrandquist]

@@not_David Thanks for the thoughtful reply. I figured Turkish isn't modeled by this because instead of having a bed of compacted grounds with a fairly high coffee to water ratio, you have a slurry of grounds suspended in 10 times as much water. There I think you're dealing much more with convection currents and bubbles from heating the water, and the grounds are mostly just along for the ride. The other thing I forgot to mention that I was curious about is that your percolation probability vs. density graph around 7:28 looks a lot like the Fermi-Dirac distribution, which describes the average number of fermions (such as electrons) in a given energy state ε as a function of ε, the chemical potential μ, and the temperature T. The functional form is 1/exp((ε-μ)/Τ+1), and as T goes to 0 it looks more and more like a step function. I haven't really encountered it elsewheres. Do you know if there's a theoretical/mathematical connection to your model? Because that would be really cool.

[@not_David]

Interesting question... I'm not actually sure, I'd have to think of it some more... My first instinct would be that if there is a connection it would not be with percolation model itself but rather the Ising model. The ising model also has a phase transition when the external magnetic field is 0 (which is required otherwise it breaks symmetery) and T = T_c (the currie temperature). I think if you plotted the existinace of the order parameter (in this case the net magnetization) against the temperature, you would see the same plot for different grid sizes. The big stretch is making analogy between temperature (in the case of FD) and system size (in the case of percolation and ising model). Maybe the temperature (or more specifically \beta = 1/T) could be thought of some sort of abstract system size, and as \beta goes to infinity is similar to as if the grid size goes to infinity? This is all just early morning pre-coffee guessing by me though, I'd have to think about it, but its a good point, thanks for bringing it up!

[@askyle]

Since we're bringing James Hoffman into the equation 😁, I think it'd be interesting to consider channeling in the model (i.e. the formation of discrete "large" flow channels as opposed to an "even" percolation); he has demonstrated in several occasions (esp. reviews of subpar brewers) that the impact of channeling in extraction quality is definitely non-negligible. One thought would be to maybe consider the number of coffee-water interfaces in the grid, but then I don't know enough about RGT to tell how that would change the subsequent theory (since it's no longer a boolean condition like the existence/nonexistence of a percolation path) 🤔 (Note: I'm neither a physicist nor a barista and I haven't had coffee yet either so all of this may or not be nonsense 😅)

[@MemTMCR]

y'know... I have nothing to say, but commenting helps the algorithm. more people NEED to see this.

[@_XRMissie]

12:24 "Showing everything everywhere all at once would be too intensive for my computer" Folks, I think he's hiding the bagel in his PC 👀 Kinda wild how fractals appear absolutely everywhere. Fascinating video!

[@hamelaman]

so cool! well done! I would like more about the unrealistic societal expectations for fractals please

[@1495978707]

Awesome shit man. Perhaps the best introduction to renormalization I’ve ever seen

[@oceannuclear]

This video felt like it was a lot of fun to make given the amount of jokes and puns in it! I've thoroughly enjoyed it as well as a viewer!

[@not_David]

the video making process has its ups and downs but its worth it for the nice comments like yours, thank you :)

[@SamuelKalkman]

Your ability to take interesting science and math topics and apply them to more 'mundane' topics is really impressive and helps me grasp them more easily than I thought I would. Great video!

[@SupaMario1993]

How are you not one of the most well known science communicators on this platform? It's a terrific melange of informative and entertaining content explained in a easily accessible way. Thank you so much for your efforts. Looking forward to what this channel is going to become.

[@dkf343]

I just discovered your channel, and have to say that videos like this are *amazing*. I’ve long had a penchant for aggregating data that others haven’t and analyzing them in ways that others haven’t, to gain insight and, often, solutions to complex problems that wouldn’t have been possible otherwise. It’s wonderful to find others who take a similar approach, and present the process in such an intuitive manner.

[@not_David]

Thank you! I appriciate the kind words :)

[@okay-oliver]

wow, your channel is such a treasure! I'm usually not very big on maths and physics but your videos really change my perspective, they're really interesting and it's so cool too see how math applies in everyday life! the cherry on top for me is just the Persona 4 and Persona 5 references and visuals. i seriously couldn't ask for more from a channel, great work!

[@not_David]

Thank you! my goal is really to show people who aren't big into maths and physics that there is a lot of creativity in those fields even if thats not how it is usually taught, so your comment means a lot :)

[@defaultnano]

love the subtle references! your humor and writing is on point!

[@TheWizardGamez]

least insane coffee bro

[@KyleMielke]

Why did it take me so long to get recommended this channel? I love how you leave this video open, pointing to they myriad potential applications

[@sush1alt]

It's crazy that I was able to understand all of this complex topic that I have never even learned a thing about before just through this video! You have great teaching skills.

[@noahglimcher5445]

This was really a fantastic video, when I started watching your stuff I thought that you must have like a million subscribers or something. All of the effort that you put into your videos is really clear and I love the style. Excited to be in the first 15k when you blow up.

[@greatday19]

I just discovered your channel, this is my second video. I'm surprised the channel is so small! I love how you're able to take random, seemingly mundane topics of every day life and use it as a springboard for introducing a more generalizable scientific principle! I've done some math and physics tutoring and have come to appreciate that it is this exact curiosity, asking the seemingly mundane questions, that sparked my interest in STEM, yet it is something that most high schoolers unfortunately lose... So, having discovered a channel that brings back the fascination and curiosity in the everyday makes me really happy 😊

[@not_David]

Thanks so much! I take a lot of inspiration from the channel Technology Connections if you don't know it already. Alec is the king of making mundane every day objects fascinating (i particularly recommend his video on rice cookers).

[@ThePrimevalVoid]

An absolutely amazing introduction to the topic, thank you so much for making this!

[@not_David]

Thank you! It means a lot to hear that :)

[@zyansheep]

Persona 5 makes me feel nostalgic... never played it myself, but I watched the gameplay walkthough! Favorite persona song is "Road Less Taken" from Q2 :)

[@not_David]

I've had the side games like Q2 on my to-play list for such a long time but haven't had the time to get to them ... one day! I will listen to Road less taken though, my persona playlist needs more. For me it has to be P3's Memories of You or the opening to P3FES. Its such a jam.

[@gradybeckett1777]

Really nice video. Not many people can draw you in with coffee and spring some RG theory when you're not looking! This picked up some of the stuff i learned in my degree, and brought a load of stuff together in an interesting way. There's a lot to enjoy about this video, 10/10

[@microcolonel]

Love the unironic use of the default font in Blender, it is kinda fun.

[@infochan6776]

Usually I'd watch this type of content on the background to fill time and maybe learn something new, but this? This (and much of your other work) is art, I feel like I'm missing out on so much more if I don't pull my full focus to watch. Although it might not mean much from a random person who's not even close to qualified in content making, bravo is all I can say.

[@not_David]

very kind words, thank you :)

[@markm0000]

I get it now. This makes sense why the ice cube doesn’t instantly turn into water once it warms up.

[@Ermude10]

This was such a well done video! And explained from such an interesting angle as well. And yes, as a former physics master student I can relate to just wanting to dig into some everyday thing and ending up at renormalization group theory. XD

[@NathanaelNewton]

0:35 Tim Ho--really diluted watery coffee 😂😂😂😂😂😂😂😂😂

[@fortify505]

This the best physics-related coffee video I've ever seen, good job

[@not_David]

personally I think we need to start conceptually tying more things to coffee. Thank you!

[@skilluber]

Wow simply stunning, you gotta be up there in no time man…

[@Diskowtek]

Brilliant animations and explanations. Thank you!

[@gaurisingh8394]

Spellbound haha. Man, I just took a minute for myself after watching this. Incredibly well done, keep the excellent work coming in! On a different note, Logic at it's Limit: The Grelling-Nelson Paradox is another great video that may be up your alley

[@not_David]

haha thank you for the kind words! I briefly looked into the G-N paradox and it does sound like my thing, I'll have to check it out, thank you for the recommendation!

[@Blubb_Strahl]

You're doing some really awesome videos! Great science explained in a fun and easy way. Keep at it!

[@martensamulowitz347]

the quality of these videos is off the charts

[@koktszfung]

Just learned this in a statistical mechanics course. You explained it very well.

[@evan7721]

12:00 that process of normalizing and zooming out reminds me of when you're diagonalizing a matrix (say 4x4) and you break it up into clusters of smaller matricies to help you out, but in the opposite way-ish

[@kupa121]

Man, I love your videos, they really remind me of Vihart, I hope your channel is gonna blow up some day

[@Entropy67]

This is the best explanation of fractals that I have ever seen, amazing job dude very underrated channel

[@not_David]

thank you! i was very happy with that video so I am glad it is getting some love now hah

[@nyanbrox5418]

I remember doing a mathsy project at uni where we basically used the spread of a virus through a household, then sort of used recombination group theory (though I had no idea it was called that) to apply the same maths to a system of multiple houses, basically assuming there was a tipping point in each household where everyone gets infected, and this exact same thing happens for cities, and then countries, and that is how to beat plague inc I can't believe I didn't know about maths that was as important as this is until now

[@not_David]

ohh thats interesting, im gonna have to take a look at that. Thanks for sharing!

[@fireclub493]

Wow! What a pleasure to watch. Subscribed!

[@VaraNiN]

How do you only have 20k subs?! This is some extremely high quality content!

[@smithrockford-dv1nb]

Woah! That's some awesome production quality! Keep it up!

[@not_David]

haha the production quality makes making the videos take a long time, but thank you! I will try

[@venskmo5704]

admittably i started watching for your varied and interesting motion graphics but now you have me interested in network science

[@not_David]

my favourite type of comment, a genuine big thank you :)

[@AmazingQuill]

You did an amazing job teaching a really important cool part of math. I've been listening to Choas by James Gleik which dives into how much fractals apear in this world and in science. Great video!

[@not_David]

great book!

[@AmazingQuill]

Do you have any other book suggestions in that genre always looking for a good read.@@not_David

[@rinzhler6922]

Underrated channel, def deserve the top. Subbed ❣ Great content btw

[@heitortremor]

Fantastic content. I'm glad KZbin recommended this to me!

[@not_David]

I'm glad it did as well! Thank you, the kind words are greatly appreciated!

[@TranquilSeaOfMath]

Nice discourse and idea connections. Great animation and editing. 🎞

[@iliapopov2219]

Unrealistic societal expectations for how fractals should like - best line in math KZbin

[@damianvandenhaak]

I watched the latest one now this one and subbed. Please keep it up

[@isobarkley]

cant wait for the part two! great job, not david :)

[@lucota90]

Awesome visualizations man! Keep it up!

[@LeoDaLionEdits]

These videos are such hidden gems! Keep up the great work

[@bruninho12321]

beautiful content. I give it 3 mo for this channel to triple its size! Good work

[@wow-roblox8370]

15:50 why is there one line that starts below the critical point, yet ends up above it, could the inverse happen?

[@not_David]

that's a great question! I have to go back and look at that video (it's been a while) but my guess is that it has to do with what I was talking about at 5:33. The chart at 15:50 is with respect to the grid size and at low grid sizes the critical point is really well defined. Its a quantity that only truly uniquely exists as you have large grid sizes. Phrased differently, its the same thing as flipping a fair coin -- you should expect 50/50 heads/tails, but that's only true in the limit of many many coin flips. If you only flip 10, then you can get any weird ratio of heads and tails. The same thing is happening in that plot. So yes, the reverse could happen as well, but its only a thing that happens at small grid sizes.

[@pedroscoponi4905]

11:06 if quantum gravity is ever resolved, I guarantee it will definitely involve a lot of coffee, so I'd say your priorities are perfectly placed!

[@klamky]

finally the optimal coffee recipe for my spherical cow to get her energised before her long shift in the frictionless plane

[@Boy-os6zu]

yes...I have fallen down the coffee fractal rabbit hole... This video actually came at the perfect time

[@danielrhouck]

I would be quite interested in a follow-up. In particular I bet things get more interesting with the same example but 3d. Maybe the part about 50% being a repelling fixed point holds, but in 3d I’m pretty sure you get a percolating path before 50%.

[@eliascorrea8573]

I am currently studying food engineering, so this was particularly fun :)

[@1PercentPure]

What a great video. Thank you!

[@aksela6912]

To make a cup of coffee… you first have to invent renormalisation group theory.

[@whatplan4335]

6 seconds in and I already love the video. Persona >>>>>

[@willd2609]

Great video! Also, this is fascinating: This video does what complexity science does, and says "Here is a complex phenomenon with lots of moving parts You guys would benefit from some PHYSICS!" And yes, there are some sort of interesting things that physics can tell us about coffee density. And some of those observations are shared with other phenomena elsewhere in the world. But for coffee, the "best"ness off the coffee comes from source, fermentation, labour conditions, roasting, logistics, and so many other things that are more "not math" than they are "math." And when you do math to that problem, you start to view the world as a "this would be better with math" problem. The primacy of math in the thought process diminishes all the other valid ways of knowing. This is how we get horrible social failures like Effective Altruism and Longtermism and all these other abhorrent ideas that cause huge issues. This was a fascinating video. I would love to see a "why complexity science might be a very bad idea" video. Much love.

[@josephcaouette]

Commenting because this channel is critically underrated.

[@josephcaouette]

Also, for proof that I subbed before 10k once you hit 1mil like a month from now LOL.

[@joshwillson4129]

These videos are so good how do you not have 100k subs already.

[@not_David]

Honestly even the amount that I have now is overwhelming/hard to believe haha. Thank you tho :)

[@joshwillson4129]

@@not_David What you need to do is market these videos. Maybe use streamers? Probably a good way to get a ton of impressions. I'm cheering for you dude. :)

[@pafnutiytheartist]

Very interesting. How doest it apply to practical coffe making though? I hoped for some sort of numerical result.

[@arthuralonso25]

Me 2

[@not_David]

This is a good point. The thing is that the video was more intended as a way to teach phase transitions, fractals, and renormalization groups (which are important in physics but can be difficult to understand) by way of something reltable like coffee making. You could in theory (assuming it does indeed exist) find the critical density by doing successive measurements at various densities, but obviously this is not practicle (or cheap). The issue is that i didn't really make that intention obvious (i kinda assumed it was when clearly it was not). This is largely due to my inexperience with writing still but its something im trying to take into account as i keep making videos (i think and hope the uhmm video is evidence of that? maybe?)

[@SaulKohn]

Incredible video! And incredible that this has fewer than 500 views, it deserves 500K!

[@not_David]

Thank you for the compliment :) I'm glad you enjoyed it!

[@hamzamotara4304]

Nothing like a nice cuppa math and art to start the day.

[@AnHebrewChild]

Very good content. Subscribed.

[@DraconianEmpath]

what a fun rabbit trail of math and life!

[@eliascorrea8573]

Keep the jargon in some of the time, with your footnotes it's super easy to get

[@therandomoneyt8626]

Great video keep making them

[@not_David]

thank you! highly appriciated

[@CampingAvocado]

wtf the qquality of these videos is off the charts holy crap

[@MimoTooThanks]

I didn't realise that this channel has

[@santapacman]

I'm leaving a comment because I want this to blow up, and get lots of publicity.

[@Ravikumar_Sharma]

Very enjoyable presentation. Keep up the good work.

[@not_David]

Thank you :)

[@n0o0b090lv]

Ah yes math behind the substance that is old as time itself or just few centuries back and keeps us awake to make fun litle theories about coffee

[@tristanwegner]

This got more interesting as it went along

[@Jax-ke6jf]

This was so good thank you!

[@jannesvanquaillie9151]

Wow man. No other words. Just great!! I would defenetly wach a follow up video, if the topic has enough interesting things for more.

[@not_David]

Oh definitely there is more. The bigger question is can I do it justice haha. Thank you though!

[@Paul-vi3on]

a few questions: It would've been nice if you said what exactly the grid of coffee+water models: the (top or bottom) *surface* of the, eh, "brewing cup"? Or a cross-section? Does it change the outcome if instead you try to model a 3D cube of coffee grinds and water? Also first you defined density as the ratio of coffee grinds to grid space, saying at density 0 there's only water and at density=1 there's only coffee, and for 0

[@not_David]

great questions, I'll try to do them in order. This is would be more of an "abstract" 2d coffee in this case, I don't think it could work as a layer or something like that. 3D would still work and be more interpretable, the only reason I didn't use it is just its harder to visualize. Everything remains true in 3d, the only thing that changes is the value of the critical density. Whenever you talk about density, we have to assume like a nominal density. if i tell you the density of air in the room and then you take a cube and calculate the actual density within that cube, it will deviate from that true density, and the smaller that cube becomes the more it will deviate. Here the nominal density is fixed, but because the grid is so small when you pick random values the measured density in any given trial will vary, but averaged over all the individual trials you'll get the nominal density. Thats what the discussion around 4:43 is about. Of course as we increase the grid size the measured density will approach the nominal density as it does later in the video. I would say this point is my biggest self-critisism of the video looking back. The idea is that, in theory, you should try to get the density as close to the critical point without going over it for the "perfect coffee". And the clsoer you get to that critical density the more the grinds will resemble a fractal. This of course assumes you like a strong coffee and does not take into account that some people would like a weaker coffee. In this case, you'd want to back away from the critical density instead. Of course in practice finding what this critical density is from a real espresso basket is not easy, but conceptually it would follow these same rules. I just wanted to use the idea of making coffee to motivate phase transitions, fractals, and RG theory, which are some of the most important tools in physics.

[@kleinebre]

Dure, you need a machine with an overpressure valve so that the coffee doesn't get too densely packed by the pressure.

[@lc9245]

I learn about PID in control theory the first time on coffee forum. Espresso world is full of engineers and nerds.

[@redblacktech]

You missed your chance to say "Critical Moistness" ha! Pardon the childishness but amazing video! I'm actually shocked at the definition of fractals that you just laid out. Not only that but you definitely frightened me about the implications of universality. Really cool.

[@not_David]

Not gonna lie at one point it was that but when it came to recording I couldn't bring myself to do it haha Admittedly I did kinda handwave the definition of fractal there but thats largely because I wanted to save it for the next video. The 3blue1brown video on the topic I think does it pretty but obviously I wanted to present it very differently and if I recall correctly he doesn't go into unversality. Thanks as always!

[@robertdeckard2136]

I clicked on this thinking it was a blender tutorial on how to make a more convincing 3d render of a cup of coffee.

[@Sagitarria]

content: amazing and this is so good and i learned a ton. graphic feedback: having the text pop up word for word on top of the images makes it almost impossible to watch the screen - I had to look away to keep my attention on what you were staying. Your graphics were interesting and then flashed with text on top. easily remadied by designating space for images OR text and giving us time to look at graphics OR text without them being chopped up discontinuously. In addition I really encourage you to only use orthographic images when it's needed- they are used in architecture to preserve measurements, but when you present a 2d graph orthographic it's impossible to make sense of it. If you are going to show a graph, there is an assumption that it is something to try to make sense of. For example 6:19 is challenging because it requires us to project it in our minds while listening to you.

[@phillipneal8194]

Excellent ! Thank you.

[@uumuu]

great bg music choices

[@not_David]

great taste in bg music

[@maxg6581]

11:37 I distinctly remember doing this in my nuclear engineering class. We called it “homogenization” or something similar

[@archiepeffers6986]

This guy is criminally underrated

[@not_David]

haha thank you :)

[@Schaddn]

I'd appreciate it if you'd master the audio closer to 0dB. This video is stunning, but I wish it were a bit louder.

[@mRhea]

i wish id had this video when i was doing my dissertation on traffic simulation physics 10 years ago

[@not_David]

haha i think this video is a bit too hand wavy for a dissertation. Ive been really interested in traffic simulation problems recently, if you have a go-to reference material that you felt was well written I'd genuinely appricate it!

[@mRhea]

@@not_David sorry for late reply this paper was the bible: The physics of traffic jams Takashi Nagatani 2002

[@not_David]

@@mRhea Amazing, thank you!

[@mRhea]

@@not_David years after my dissertation, i was in Edinburgh studying HPC. and as a example one of the lecturers used traffic simulation to demonstrate various methods of making the algorithm multithreaded. unfortunately i cannot remember which lecturer or which course that was. but it was super eye opening, and i wish i had seen it years earlier. if youre intererested in using the GPU to make it multithreaded, i suggest using a contact email and asking about it, i think they'd point you to the slides which should be public

[@russmack11]

Subbed for the Tim Hor.. i mean diluted coffee joke 😆

[@fluorina6355]

i love this channel and how you take a random Topic of normal Human life and make it sience

[@tuxino]

At 1:50 you describe the square as "orange-y". Was that a reference to the Technology Connections video about brown being weird?

[@not_David]

cannot confirm or deny but lets just say im a big fan of the refridgeration cycle

[@shivk6660]

Ok now we need a James Hoffman collab