Laplacian intuition

[@srgkzy1294]

That voice... makes me feel safe with math

[@mitalpattni1977]

Adalberto Rojas you just spoke my mind sir!

[@vijayanandvadhyar7224]

Again voiced my mind!!!

[@DiegoMathemagician]

same

[@mountainc1027]

Go check out 3blue1brown on KZbin, this guy's awesome!

[@Name-jw4sj]

lmfao!! Same dude!

[@ryanthomas9693]

Literally got more intuition from a 5 min video than scouring through a myriad of textbooks back in my college days. It's interesting to note that the Physicists' notation for the Laplacian is nabla^2, which maybe makes it a bit more confusing because it implies it's the second order gradient or could imply the curl of gradient, etc.

[@sumdumbmick]

you do know that multiplication can be rendered in English as 'of', right? 3 * 4 apples = 12 apples -> three groups of 4 apples is 12 apples and thus a second order derivative, which is the derivative of a derivative is validly derivative * derivative, or derivative^2. and the only difference between a generic derivative and the differential is that a nabla indicates is that it's the sum of all n partial derivatives over an n-space. so the second order differential is nabla of nabla, or nabla * nabla, or nabla^2. the reason it appears to be the same as the second order gradient is because it is. it's the sum of the partial derivatives... which is the second order gradient, and the laplacian, they're two names for the same thing, and thus it's actually not confusing. and curl is notated differently, since it's the cross product. if you separate it out as nabla dot nabla, then it might be ambiguous as divergence of the gradient, but with very little effort you can see for yourself that it's actually the same thing anyway, so again... what are you confused about, exactly?

[@sumdumbmick]

see @0:52 he literally shows you that the laplacian is the divergence of the gradient and it remains on screen for the entire rest of the video. how in the world are you confused, and how did anybody like your comment that you're confused? it's not remotely confusing.

[@notstarboard9792]

​@@sumdumbmick 1) Chill out. Just because something isn't confusing to you doesn't mean everyone needs to agree. 2) The Laplacian is not the same as a second-order gradient. The Laplacian is the *divergence* of a gradient, which gives a scalar. The gradient is a vector, so you would expect a second-order gradient to also be a vector / matrix. Ryan is right that the notation obscures the meaning of the term. Leaving it as del dot del would be a lot more clear. 3) The eye-rolling-ness of appealing to English grammar to criticize a benign internet comment aside, multiplication and "of" are not always the same thing in this context. Let's say f(x) = x^3. The derivative of the derivative of f(x) is 6x. The derivative of f(x) times the derivative of f(x) is 9x^4. This line of reasoning is only going to get us into trouble.

[@metheewatchakittikorn4796]

I agree definitely.

[@jlpsinde]

This is heaven on Earth for someone like me that learned this 24 years ago and just now understand!

[@wtflks]

3blue one brown????

[@ANJALISINGH-yp4tr]

yup .....100% sure

[@davidwiedemann9926]

Yes

[@drakefire1800]

ya dude. he is awesome. love his videos. he uses right brain thinking.

[@alial-ansari8815]

Yes that’s him 😂👌🏻❤️

[@lLlILILw]

He did say in an interview that he taught in khan academy or something before youtube

[@e1123581321345589144]

I swear to god, I've been reading various pages for days to understand what this operator does. You made it cristal clear in a few minutes

[@czarlito_]

Welcome, all you travelers, coming from Partial Differential Equations! Praised be 3B1B!

[@lopkobor6916]

I'm from the video "Divergence and Curl" ( also from 3b1b )

[@ummwho8279]

You guys are amazing, thank you for publishing these! Multivariable calc is so much more understandable now!

[@oscarsharkslayer]

I could never understand Laplace operators at school. I hated them. Today, my 7 year old kid looks at this video and says: "it is simple, why did you not understand?". Yes! This is a new wave of learning. Thank you Sal and thank you Blue Brown. You redefine learning!

[@heavennoes]

as a 10 yr old, he makes everything hyper - simple.

[@suveermanj1001]

My son just got out of my wife's womb guys and he also said it's so easy,...thanks Obama.

[@funkdrunk]

​@@suveermanj1001are you mocking? the statement? And Obama at the same time? Kids have a knack to find their own interpretation of stuff presented in visual form. Perhaps they forget in a day, but they comprehend more than adults think

[@DaBestNub]

Dunning Kruger effect go crazy

[@funkdrunk]

@@DaBestNub Dunning Kruger effect MYTH go crazy

[@MattiLargeWorld]

The intuition for the laplacian is exquisite I am very glad that you’re getting a ton of recognition.

[@funkdrunk]

with your young face you risk getting some detractors here. Check some neighboring comments for Dunning or Obama. Hilarious. I agree with the intuition part. First time in my life I understand that stuff! :)

[@Luisgar1234]

I was saying today why doesn’t 3blue have a video on laplace… one trip to the search bar later and I found this hidden gem.

[@quantaali543]

superb ... finally, I understand the concept of gradient, divergence and Laplace's equation.

[@harshchikorde9495]

please make a vedio on LAPLACE TRANSFORM

[@mahsanafisi2937]

Thank you soooo much for amazing illustration and for making it so easy to understand.

[@victorvalencia6466]

3blue1brown should voice all math videos on the internet

[@mcyeetmaster9612]

I second this

[@eduardoandrescontrerasrome6703]

Omg god, this video is sublime. I am currently taking an Electromagnetism class so we constantly use this concepto of the Laplace equation but I never really understood what it meant.

[@othmaneelhanchi4451]

Brilliant explanation !

[@inquisitiverakib5844]

solid concept lucid explanation 😍😍

[@vector8310]

When I click on a Khan Academy video I pray it's a 3B 1B. Ghee was born for this.

[@priyocoutinho]

Nice explanation...it will help us get a picture of what we are doing when we solve laplacians...

[@pavi512k]

Please make a video on laplacian operator in spherical and cylindrical coordinates

[@jh2519]

Awesome, this helps with my electrical prospecting class.

[@vinbo2232]

Thank you, great intuitive explanation

[@mitalpattni1977]

Please do a video on spectral clustering or graph theory!

[@dkoz8321]

I got all that. Tottally understood everything!

[@user-or7ji5hv8y]

What a great explanation. Thank you

[@hanyiliu3332]

This is amazing.

[@BAD_LS]

Well explained, so far! Even for a german, thanks!

[@fahim1943]

Revisiting all of this cause its beena while I didnt touch Multivariable Calc and its still so fascinating and I realised how much I discovred more even if I watched this already time ago

[@BatistaR0X]

Instead of expecting Khan, this guy sounds like 3blue1brown?

[@error.418]

yep, that's 3b1b

[@biggbuck9535]

In fact, it is the same guy 3blue1brown. He decided to do khan just for a bit outside of his patreon channel

[@That_One_Guy...]

@@biggbuck9535 He worked at khan academy before doing his channel

[@Gaming_station93]

No copyright issue from 3blues1brown?

[@dudewhat9329]

this is awesome, thank you :D

[@technosapien330]

this man is getting me through grad school

[@anonymoustraveller2254]

Oh my god! You really exist.

[@chrysostomoschadjiminas6217]

Since we are talking about the direction of steepest descent instead of ascent, shouldn't the gradient vectors point the opposite direction? Shouldn't the sources be sinks and vice versa?

[@williamlee0]

Will the learner notice that you would have to flip the blue blanket inside-out for the water droplet analogy to make sense? Water does not flow uphill to pool at the peak of a hill.

[@ProfeARios]

Great lesson!!!

[@pratikbari1714]

Great explaination

[@bunkerputt]

I just love talking about the Laplacian. It's such an edgy subject.

[@thevegg3275]

Wrt the vectors representing the gradient...are these colored differently to represent magnitude of the vectors? Is it also a convention to use longer vectors to represent vectors with larger magnitudes? I prefer color coding since the smaller and more numerous the vectors are, the better the visualization of what they represent. Changing length of vectors would take up space which could be better used to increase the count of vectors used.

[@EssamSat]

Anybody here from 3blue one brown PDE video ?

[@jv2781]

Me lol

[@ArnabSir]

😀

[@yeungpakming]

I was thinking oh no 3b1b didn't make a video about laplacian, maybe i should just check out this video... nice

[@CGKittenz]

finally understood this!

[@JohnVKaravitis]

Difference between Laplace and Poisson equations? One equals zero, the other does not, right?

[@manojkumar-cb3wf]

i kindly request you to arrange the videos order wise .

[@cory99998]

Ty, im going to try to create a 2D gravity / space-time simulation using this

[@batuskovichuman6886]

All my beloved teacher

[@NEO-z2y]

Grant you're grand❤

[@annashchukina3768]

thank you so much

[@yizhang7027]

Why am I in tears after understanding this

[@richardfeynman7332]

coz u r cutting onions

[@Lonczakt]

Anyone know what software was used to make the graph

[@murphy98969]

Where i can get this software ????

[@BraaiEngineer]

Link so follow-up video, please?

[@OnlyOneesWhoKnow]

Hello, Thank you so much! How would I intuit the Bi-Laplacian ? What's the gradient(3) of the divergence(2) if the divergence(2) of the gradient(1) characterizes already if a point is on a pedestal or in a gap?

[@trip_on_earth]

please make a video on your channel 3b1b of Laplace transform

[@AmeerulIslam]

is there any relationship between laplacian and laplace transform?

[@amandhakal8939]

So, to conclude, "At lowest point of any field, laplacian gives maximum value and at highest point of any field, lapacian gives minimum value", am I right?

[@leguminosa9]

but why is the gradient is toward the top of hill? shouldn't it converge to the goalie instead?

[@robitybopity]

Martin Johnsons I believe the gradient points toward the steepest point, or the greatest rate of spacial change

[@tahaabujrad7806]

What this has to do with L(f(t))=integral from 0 to inf of e^-st*f(t)

[@sergiolucas38]

great video, yhanks :)

[@AssassinGrudge]

is this difference from the laplace transform because i was trying to understand the spherical harmonic. but instead of searching for Laplacian function i searched the laplace transform and i spend like 2 days learning it is it a waist ?

[@Raptured_and_back]

Not kind of. It is a minimum if f '' > 0 and maximum if f '' < 0, be it a local or extreme.

[@benjaminbrady2385]

I recognise Grants voice anywhere!

[@mithsaradasanayake3211]

Yup

[@अण्वायुवरीवर्त]

I'll be really greedy this time, What is the software that u used Plzz seems like a fun way to learn things (intuitively)

[@Pogosoke]

Lawliet L i think he Programms it himself, same with the animations on his channel

[@reemashrestha9718]

In 3B1B, he uses Manim: an open-source code that he created himself.

[@jobhiojkp]

Does anyone say del anymore, instead of nabla? Or is that from another generation?

[@kvamshi4561]

Those who're wondering whether this guy is 3Blue1Brown guy.. Hell yes! He is the same guy left khan academy and doing his own videos

[@axelmeramas976]

he didn't left khan academy, is still working

[@kvamshi4561]

@@axelmeramas976 OK

[@dastran2731]

what about f(x,y,z) intuition?

[@nomanruhani5626]

oh, look who I got, mr grant

[@michaelhaggerty569]

what program did you use to make this?

[@robertwilsoniii2048]

Michael Haggerty He wrote his own software from scratch. If you want to learn the skills to build something like this, you can take Stanford’s cs106ab and cs107 via KZbin.

[@MoeSalamaIbrahim]

POV: you've stayed here because of 3Blue1Brown's very own Grant Sanderson and his soothing voice.

[@mingxi1055]

heat equation intuition

[@arjunmenonkandanat6328]

Is this Grant Sanderson ?

[@joluju2375]

As intuitive as expected. Was it on purpose you didn't use the word "concavity" ?

[@murphy98969]

When laplacian of function is zero what it mean???

[@richardwborge]

I recognize this voice :)

[@marcosviniciusrodriguescos8118]

thank's man!

[@stevewhitt9109]

3Bu1Bn miss you at Khan

[@Graywolf116]

So the laplacian is the divergence of a gradient? It'd be so much easier if they just said *that* instead of slapping someone's name onto it.

[@weeborghini4016]

are u bluebrown?? u sounds similar

[@nautiyogi8386]

Amazing ! Amazing !

[@MP-cv6if]

3 blue 1 brown???

[@Revan176]

You haven't plot the laplacian too :'(

[@subtlethingsinlife]

3 blue1 brown , I know the voice ... Happy

[@kossanmoo9931]

why wouldn't the water flow downwards following the gravity (:

[@vectracris1]

Because the water example was just an analogy so that he could explain and make us visualise better, with the help of the blue lines, not an actual example of how gravity works

[@masterj2245]

Good

[@rio_agustian_]

Blanket of nightmare

[@NSLikeableHuman]

3b1b army reporting!

[@rawlayer999]

Voice is same as of 3blue 1brown

[@ManojKumar-cj7oj]

Oh my goodness

[@DracoRenaissance]

idea: Sal does the audio, another the animations and graphs and prettiness, a third the math

[@drewm-r7249]

Omg is this the 3blue1brown guy!?!??!

[@jasonpapadopoulos7732]

3BLUE1BROWN YEAHHHHHH

[@seandafny]

Wait a minute !! I know you !! And you are no sal khan !!!

[@seandafny]

Lol 1 year to forget not bad

[@victorserras]

3Blue1Brown in da house

[@Originalimoc]

Wait... Who is taking 😂

[@ConstructionGuy]

1st?

[@DracoRenaissance]

calligraphy hurts my eyes

[@That_One_Guy...]

what ?

[@akhilan1]

TEACH ME

[@rat_king-]

No Pi people? What? 3 Blue 1 Brown....

[@neallucas]

I guess.

[@prabalsrivastava4945]

@3:44 it looks like a calculus monster at the origin with one eye. Calcaaasur. 🤢