The Wave Equation simplified

[@Parth-i2n]

Man do I understand anything at this point?

[@alithedazzling]

haha did the video help you understand it more?

[@Oraki_salamat]

Yes, Ali I understand it a bit, but thank you for taking your time teaching us 😊

[@Parth-i2n]

@@alithedazzling did help thanks

[@sphakamisozondi]

I was asking myself the same thing bro 😅

[@treeross]

I have found the deeper you dive into research on a subject the more you understand how little you understand. In a good way, if that makes sense.

[@endmercy]

Thanks Ali, I'm a high school student and I've been watching your videos for a while now. I used to want to be a network technician but I've always enjoyed playing with physics, so watching your videos basically influenced me into becoming a electrical engineer 💪💪

[@endmercy]

love from Honduras brother♥

[@carguy8902]

I love this. I started learning this when I was a kid. And I’m still learning. Keep going like that Ali, I’m also an Arabic fellow. Greetings from Morocco

[@mateuszkosinski7162]

Yo! I am EE student from Wrocław Poland. I started same as you doing Mechanical degree but then I switched for EE engineering and rn going into microwaves topic. Not regretting it at all. You are doing great job, love your videos and wishes you best for your carrer!

[@madeleininspace]

Super, że inni Polacy też tu są!

[@Delan1994]

Thanks Dr Ali . Keep posting the videos. I Truly enjoy these videos

[@Romain-wh9jd]

Many thanks from France, I'm a student in "classe prépa" and your videos are very interesting.

[@alithedazzling]

Glad you like them!

[@Mahamations]

why do u look older after every single vid u do btw thanks i understood the wave equation tdy :)

[@alithedazzling]

im gaining more wisdom

[@Mahamations]

@@alithedazzling kool

[@fuzailkhan9701]

Hi Ali, When you press the button the circuit is completed and current flows due to which the electrons in LED or in screen gets into excited state and emit radiation/photons(which are alsoEM waves) of specific wavelength and frequency and corresponding to that frequency We see light of different colours More specifically we can see only visible region so all the light which we see we can say its wavelength and freq lie in visible region.

[@dean532]

14:05 this sounded like a good teacher having the cocky knack of preventing students who try heading out disrespectfully “…and just before you get lost..these are way more interesting than what you normally do to pass your time” 😅

[@tobiahbower1951]

yes! please talk about the harmonic equation! i am a BS-MS electrical engineering student from UCF, and these videos are really helpful!

[@glenmarkdublin5081]

I don't have broad knowledge about the topic, so I'll just answer based on what I understand from your lesson. I see the problem as a system. In the pond analogy, the source of the force is the act of letting go of the object from a higher position, so the object becomes the source of the force. In the watch problem, I see the watch and the button-clicking as a system. Initially, the watch isn't lit but has the potential to light up. By clicking the button, that potential is released, so I would say the source for the light is the clicking of the button.

[@wdujsub7902]

Good video, but I think the video does not give justice to the title . When somebody does not intuitively understand the wave equation this video just teaches him that not only displacement or mechanical waves for example in solid bodies, but also electric and magnetic fields propagate the same way being described with the same equation. But it adds nothing to the understanding of the wave equation itself. Okay, change in time and space, but why second derivative and not first? first derivatives describe changes too. Okay you have to describe curvature so you need at least the second spatial derivative, but why not the third? Why is the velocity term in them squared? An explanation like hey, a very high second time derivative means that the function changes a lot through time and it is equal to its curvature basically. Just like an example drawing of radio waves being long and slowly varying and not that curvy and xrays next to them by being way faster varying and way squigglier. squigglines is the curvature and their frequency is connected to their time variation. I think this approach would give more intuition to the average viewer.

[@cooterhead_jones]

Paragraphs.

[@exo-580]

im a chemist and grateful for you my favourite creator Ali.My answer to your quesion is that the action of pressing the button completes the circuit in the watch and current flows i.e electrons and energises or gives the right amount of quantized or discrete amount of energy hf which causes excitation of the electrons in the different spectra where it emits light through release of the photons of corresponding amount of wavelength in the visible spectrum,ir or uv.but in our case it's visible spectrum.

[@alithedazzling]

you are a great chemist!

[@exo-580]

@@alithedazzling thank your ,it's my pleasure to have you too

[@crazychallenger6796]

Hey ali! Thanks for your videos . I am currently completing my astrophysics from iisc india. Your videos are very very interesting.

[@shuvro6358]

I need this right now . u saved me...

[@aidanvogel3757]

Potentially projecting here, but as someone who’s never intuitively understood calculus until lately, here’s my $.02. Math is a language that corresponds to the abstract nature of what it describes. So my $.02 is be sure to really highlight what EACH aspect of the equations mean in terms of the picture. It’s practically a story(this is where most teachers seriously fail) and that story must be told in a way that gives the reader the image in their head. So for example: the C2 just recently made sense why the squared was there. To me(maybe I’m a bit slow..) the squared just meant the speed times its speed, which makes no sense. Now I understand it’s pointing to curvature. Hope this helps, coming from someone who’s smart enough to comprehend it, but too dumb to see how it all connects intuitively.

[@amaabed]

No wonder you're called the dazzling. Great video, keep it going brother.

[@alithedazzling]

haha thank you! what did you like about the video?

[@MatthewSuffidy]

I'm not an expert on the topic of LEDS, but my understanding is there is a excitation of silicon and then dropping through a junction so the electrical potential loss emits as light and heat.

[@smostars]

The cause of an electromagnetic wave is an oscillating charge source, or an accelerating source of charge

[@JeffreyNColeman]

The cause of the emission of light is the acceleration of charges.

[@sirtajali5841]

Plz continue making such vedio this is what most students need

[@syed_zaid7]

The cause is in pressing the button .... which sends signal to the led which is in the form of electric charges. Basically a whole electric circuit is completed.

[@jalsiddharth]

Mate NASA post doc buddy, people are struggling with equations in general and most people will live their lives without hearing about the wave equation because apparently we have all failed everyone but the zeroth and first order students with basic mathematics lol. (globally speaking) But thank you so much for the video. 😊subbed.

[@adeltorjmen7508]

Really like your videos making complex physical phenomena intuitive to understand ! Please carry on… As per your watch, the initial cause was triggering an electrical change in the LED circuit causing a electromagnetic wave (4th Maxwell equation) which was a visible light wave; which when it hits your retina will cause an electric current in the optical nerf going to your brain and interpreted as such … All is a matter of causes causing effects . Time is of essence of course… otherwise all would be frozen and static 😂

[@alithedazzling]

I'm glad you enjoyed the explanation. It's all about those cause-and-effect chains!

[@alreadyghosts7727]

Thank you for the terrific video! May I suggest that whenever you create a video, you post in the comments two additional resources. One would be a set of at least five textbook problems per concept for the curious to work through that you think would help to achieve a more thorough understanding (please be sure to include solutions). The other would be any lab experiments that you think really gave you a better feel for understanding the concepts. I know it is a big ask, but you seem to have a knack for actually being able to teach this stuff so I'd like to also see what problems and experiments you'd suggest to gain a greater mastery of this subject.

[@wyvern4597]

Ali my bro im doing computer science but i love physics... Im lowkey binging your videos

[@marcocardinale7800]

I have wave exam next week, thank you ;)

[@jimbritt8175]

Question, I have not used my EE degree in 20 yrs. Very much enjoyed the video. So, if instead of a rock dropping in a pond, what if I call it a packet of energy. When that packet of energy interacts with the medium, the pond, or space time through Maxwells equations we can derive the wave function of that packet of energy. I assume we could go backwards too, and from the wave function, do the process in reverse and come up with a force, or a mass, point particle with acceleration. It seems like a linked duality, just depending on how we look at it, or observe it, is my theoretical packet of energy a particle or a wave? Is that a way to look at it as well, the duality of light, depending on the observation or am I stretching my thought too much?

[@chisomobi1308]

I lovd the way you teach....i really appreciate!

[@Rogertheripper07]

Hey can you please talk about the theory of relativity and explain us how things work i just love your videos if possible ❤️

[@Rogertheripper07]

Btw this video was fantastic this led me thinking more into this topic the thing is I don't know how time passes by soo fast that's the reason I can't study things in depth 😅😂

[@lowersaxon]

What is interesting and seldom discussed is: where did epsilon and mu ( permittivity ….) come from and what does it mean exactly. The speed of light c can be derived from it like Maxwell did. So what determines both those values?

[@Mushemkap]

Yeah ... A videos please on harmonic waves thank you for your sharing

[@lupino652]

It is a special type of equation that models a type of process where a local perturbation (partial derivative of the perturbed field in time) spreads in space (partial derivative of the perturbed field in space). Other type of equation like transport phenomena, models that spatial spreqd in a different, but similar way (transient steady process generally) until it stabilizes Wave: acceleration of the perturbation related to the concavity of the spatial spreqd Tranport phenomena: acceleration of the perturbation to the steepness of the spatual spread (the steepness finally gets stabilized) and the phenomen is sustained

[@haryr_]

Great video man, this really recalled my vector calculus knowledge! Do you think you could one day make a video on how to derive the Maxwell Equations? (Mathematically)

[@pcdeveloper9154]

Great video btw, I did see that you quickly skimmed through the curl on curl at 14:15 and it wasn't explained clearly. You did not show what ∇ = Del , Nabla or upside down Delta does or represents. - The Grad operator will turn scaler into a vector field. While ∇· = Div or divergence defined as Dot Product - returns a scaler field. The rule for taking the curl of a curl in mathematics is that the curl of the curl of a vector field is essentially equivalent to applying the Laplacian operator to each component of the vector field, with a slight adjustment to account for the vector nature of the operation; mathematically, it can be written as: curl(curl(F)) = ∇(∇ · F) - ∇²F where ∇ is the gradient operator, ∇· is the divergence operator, and ∇² is the Laplacian operator.

[@fardinshaan6957]

Loved it. Pls make a video about Laplacian operator and its meaning and intuitive

[@JeffreyNColeman]

Thanks very much for this explanation, and for putting it together so quickly! I have a related question. Physicists generally seem to believe that gravitational waves also propagate at C, which has been supported by recent observations of gravitational waves and EM radiation from the same stellar event arriving at approximately the same time. Looking at it without a background in General Relativity, it would seem a curious coincidence that both electromagnetic waves and gravitational waves propagate at the same velocity, especially considering that for EM waves, the values of the constants of permittivity and permeability determine C. But those are electrical and magnetic constants seemingly unrelated to the spacetime curvature of General Relativity. Why do disturbances in spacetime curvature propagate at exactly the same speed as disturbances in the electromagnetic field?

[@Abhimanyukushwahamp2uo]

The cause of EMW is the jump of electrons from higher energy levels to lower energy levels in atoms and this radiates energy in form of EMWs. 👍

[@shadmanbinalamshimanto2917]

Plz make a video about freelancing as an Electrical and electronics engineering graduate.

[@OneLine122]

If I follow your methodology, the cause would be the electro-magnetic fields moving through empty space, c2 being the reverse of empty space. I would suggest something else though. Look at what you did to derive this, you took out electric charges, so it can't create a magnetic field anymore. However, you did not change the magnetic field equations. So maybe your watch can be seen as a magnetic charge that you said previously could not be caused and did not exist. It's the only way to start the system. So you could consider "c2" as an magnetic field that is at rest, which is the case in empty space. Then you cause a disturbance in the force by dropping a magnetic charge in it. So now it ripples in every direction through the same medium that offers no resistance to it because there are no particles of magnetism. It just propagates it locally. The equations only describe the mechanism of that propagation, the electric component feeding the magnetic one, and vice versa, which creates inertia that conserves the original charge's energy, just like in an electric field which needs particles to propagate. Now what causes that magnetic charge, is the electricity running in your watch. If it goes around the watch, it should create a magnetic current, but since it can't go out of the watch, it creates a charge that kind of explodes. Light bulbs are like that. The energy goes through a circuit that can't go back to the source, so it needs to go somewhere and I would suggest it creates a magnetic charge that creates light. No reason you can't conceptualize it this way, the result is compatible with experience. It's also interesting in explaining the curvature of space time. Consider a ray of light, it has the magnetic wave on a 2d plane, so that ray of light isn't going anywhere except on that plane. It's why when it comes near a mass, which also has a c2 factor when converted to mass, it will curve a ray of light, just like if it were a resistance. Gravity is just another wave that may interfere with the one of the light and maybe could be seen as another magnetic charge but caused by something else than electricity. Maybe they act like electric dipoles, just with no need for positive and negative charges, just the space-time distortion.

[@POLYNIKEGMAXOUT]

can you make a video explaining what an electrical engineer actually does in all the different subfields at the bachelor's, masters, and then PhD level. I'm interested in knowing how much of the stuff that they learn in school is actually used at the job, and also just what it is each on actually does. Thank you so much!

[@EmmanuelMatabaro]

Answer: It is the force of the finger pressing on the button that closes the electrical circuit and the lamp is lit in the watch🤷 No electromagnetic courant without an external force or energie🤓.

[@bikeros77]

you are speeding on chalk bro :) , great video , thanks

[@2122届-罗睿喆]

yes do more of these please and thank you

[@pimpilikaa]

Cuteness, cuteness, cuteness ❤❤

[@JustQoutes26]

Thankyu allot man fro your efforts now i am confident that i can might become a physics professor in future or maybe a quantum physicist wow such big term 😂 well thankyu lets see where the wind takes me

[@inferno9378]

Wtachong you from France

[@rahulsinghmahar9480]

Brother can you please please explain the meaning of wave form Y=aSin(wt-kx) Intuitively please

[@rumatalukder7220]

Bro can you make a detailed video on coding and programming languages also it would be better if you talk about a bit of python and c++ as well

[@Cirwlos]

This is incorrect because x represents a position, while u represents a shape. You cannot treat d²u/dt² as if it were d²x/dt² and equate d²u/dt² to a force. Also, you are confusing x(t), the function with x, the parameter. Although you have named both as x, they represent different concepts.

[@alithedazzling]

which part of the video are you referring to? when describing force?

[@Phoenix-rb4bf]

Make videos on mechanics and multivariable calculus

[@MrTNT49]

Yay! Wave equation!

[@fingeroffang]

But what is u? is it a single point on a wave? Is it the wavefront moving in the x direction? And what does taking its second differential with respect to t mean? Does that mean just considering what is going on at a fixed x point i.e up and down movement? Otherwise x is changing as well.

[@alithedazzling]

u is the displacement of the medium in Y axis for a wave travelling in X axis in this example

[@fingeroffang]

@@alithedazzling Thanks for replying. So the time derivative is d**2y/dt**2 at a fixed position in x?

[@alithedazzling]

@@fingeroffang yes you can replace u with y if that is easier to get it in the 2d form

[@ergo6450]

Love from 🇧🇷 brazil

[@theosky7162]

17:33 HOW do we know identity of ( c ) ? Thanks and Regards !

[@sidstam]

The cause of the EM wave to start propagating? An energy source: be it a cell in a watch or nuclear fusion in a star causing the emission of photons.

[@EmmanuelMatabaro]

Thanks dear

[@alex79suited]

Preach, what ya got. Peace ✌️ 😎.

[@ee-036g.raghuveer2]

Hey bro I'm an a eletrical student.I also want to became as you.But i think i have a problem.That i can understand and imagine all the laws of Eletromagnetic laws and analyse also..i cant put all this imagined concepts into a mathematical equations. Could you help me out from this problem 🦋

[@vanditseksaria5897]

hey ali, can you make a vid proving that earth's axis can be assumed to be approximate inertial frame of reference for objects in its orbit.

[@LilDoubleMo]

Do you have a discord where we can ask questions?

[@lupino652]

5:02 you are wrong. The wave does not varies in time (if it follows the wave equation, other wise is another phenomena like damping or transport phenomena like mass transport or viscocity) the time term discribes the chabge in velocity of the perturbation at its source or origin. In that example it should be analyzed only the point where the drop falls. And the displacement in that point is what is propagated, so linkinh the acceleration of that displacement, and the capacity of repeating that movement in the medium (space)

[@lachlanrob1511]

allegedly?

[@RobertoCarlos-tn1iq]

So many places when you apply the Laplacian you don't have a second order derivative in the denominator. confusing. 17:05 and 19:05

[@saidctbb]

can you do the same for the Navier-Stokes equations?

[@foxbat888]

But an electromagnetic wave doesn't propagate in a medium, also the light from the LED in your watch is modelled as a particle, a photon, not a continuous wave so Quantum mechanics and Maxwells equations don't really mix

[@ThugginGame-sb3du]

Hardly give any intuitive examples.

[@shibdassarkar9357]

Sir how much a postdoctoral fellow at your position earns a year? Plz reply. Thanks a lot.

[@AdityaChabukswar-i5w]

Hey brother please can you solve jee advance exam paper physic 2016

[@Manoj-w7c4y]

I think The cause of light in the watch ⌚ is the electron jump to Higher energy State and go back to lower energy state and the difference in energy is emitted a photon in the LED , did i got it right 👍

[@Manoj-w7c4y]

The cause is electron jumps in different energy level

[@polarkerr]

I love you Ali, now I know I'm not stupid, just had bad physics teachers hhhhh

[@ezkil1759]

R u originally iraqi?

[@atandritabhattacharyya3882]

Hurting your ego is how he earns views

[@Stan_Castan]

5:25 those who know 💀

[@Mushemkap]

Bro looks changed ... maybe is the shaved beard that gives me this impression

[@jacoboribilik3253]

I like the videos but I don't like the cocky titles to them.

[@pascal2745]

Only valid in linear homogeneous media.

[@lumpyspaceprincess6335]

Okay i can understand why you hate greece but why th you also hate the greek alphabet common man it's just an innocent alphabet

[@lumpyspaceprincess6335]

They're so cool man, common

[@MilosVuksanovic-sj8kj]

in my opinion this video is very superficial. you didn't even mentioned general solution for wave equation ie if you have: c (d^2/dx^2)u = d^2/dt^2 u general solution is u(x,t) = F(x-ct) + G(x+ct). F is sometimes called "retarded" solution and G is "advanced". 2: you explanation of light propagation. it is true that E, B and c-"direction of light propagation" are all mutually perpendicular, that came for poynting theorem. wave equation doesn't implies this. 3: be very very careful when you change dimensions in wave equation, because this equation have quite different behavior in odd versus even dimensions. in spatial odd dimensions 1,3,.. after disturbance passes you location you don't "see" any disturbance. however in even dimensions 2,4,.. after disturbance reaches your location you will see/fell some disturbance from that wave to infinite time. if you are floating on water after leading edge of wave reaches your location, after that you will go up and down to infinity! but amplitude shrinks. (that is mathematically correct description for solution of wave equation)

[@albertomontecarlo6231]

I’ve been watching your video lately, like you don’t’ understand Maxwell equations , now you don’t understand the wave function… honestly , and you are not alone this is the worst method to give people interest in watching your physic. First the way you explain physics it doesn’t add to something we already know and saying things like “ think as a Nasa engineer think “ it’s even worse in promoting your science.. nothing personal,

[@alithedazzling]

thanks for the feedback -- at which point in the video do I say think as a nasa engineer?

[@RSingh_26]

I disagree

[@albertomontecarlo6231]

@@alithedazzling Hi Alithedazzling… I don’t want to get misunderstood. I like your videos,,, I like also the way you explain things, mine it’s just a suggestion. Those topics are already not very accessible for most people because not everyone knows calculus and stuff like that, not talking about a subject like quantum mechanics where things are mostly explained by probabilities.. I will try to capture people interest not making they feel they don’t understand but somehow in a different way because it could be intimidating. Ps…the way Nasa engineers think was regarded a couple of video you posted days ago…

[@fuzailkhan9701]

Bro i think you have not understood what Ali said in this video i think you have little knowledge of physics. First go and study.

[@EmmanuelMatabaro]

I think here the teacher gives the essential for us to have the intuition. It's supposed that those who watch his videos know already enough maths and physics basics notions.🤷