Finding the Eigenvalue of a Mobius Strip (Endgame in the Title)

[@rowanmakesfilms]

You: the WiFi password is on the back of the router The router:

[@shoutz5872]

so you browse r/mathmemes too?

[@emman100]

Lmfaooo

[@UnathiGX]

LOL...My love for this comment will be placed in my Mobius heart..

[@muhammedberkonder7802]

so is the joke that the password is too complicated like the solution in the video or is it that there is no back of the router because it was a mobius strip ? either way you still have my upvote

[@muhammedberkonder7802]

@@Halorocker101 that would be the most fitting i guess

[@latt.qcd9221]

*QM Professor:* "So, today, we're going to go over solving the Schrodinger equation for a 2D square well." *Andrew:* "I've already solved it with Mobius strip boundary conditions." *QM Professor:* "...weird flex, but okay"

[@isidore551]

Rotating trapezoidal charged blackhole

[@brandonklein1]

@@isidore551 ... Trivial.

[@elthomaso10]

@@isidore551 homestucks have no rights.

[@isidore551]

@@elthomaso10 riight2 dont exii2t

[@Adraria8]

Isidore Sévillian 1 TH1NK W3 SHOULD CONT4CT 4 L4WY3R TO R3SOLV3 TH1S

[@sjegannath6295]

Physics professors be like: This question will be asked for 1 mark

[@siquod]

The guy in the video makes it look complicated. The question can actually be solved in the head, if you know your Laplacians.

[@ayanavade3742]

@@siquod I'd like to know how 😲

[@siquod]

@@ayanavade3742 First, you have to know how it's done on a rectangle or cylinder: Use separation of variables so you can solve the problem for each dimension on its own, and simply add the resulting 1D eigenvalues. Then you have to know how to solve it on a line with Neumann, Dirichlet, Periodic or antiperiodic boundary conditions: for each number of standing wave bulges that fit into the line and smoothly obey the boundary condition, there is an eigenvalue of the Laplacian on the line that is inversely proportional to the squared wavelength (A half-wave length of \pi yields an eigenvalue of 1, or if you are doing Quantum mechanics, you have to include another proportionality constant involoving \hbar and the mass). Third, you have to observe than on a Möbius strip, separation of variables is not perfect:, the "across" direction has Dirichlet boundary conditions, so it can carry any nonzero number of half-waves, whereas the "around" direction has effectively periodic or antiperiodic boundary conditions, depending on whether the wave function in the "across" direction is even or odd, which is, whether the number of half-waves in the across direction is odd or even. This is because an odd across wave function is twisted into its own negative when transported around the strip. So let n>1 be the number of half-waves in the across direction, and m>1 the number of half-waves in the around direction, with the condition that m must be even iff n is odd. Let w be the width across and c be the length around. Then (omitting the quantum factors) the part of the eigenvalue for the across direction is (n·\pi / w)² and for the around direction (m·\pi / c)². Get right what is above and below the fraction bar (Think: shorter strings have higher pitch, so eigenvalue increases with shorter half-wave length and length goes under the fraction bar, half-wave length decreases with n resp. m because there are more waves to fit in, and length is measured in units of \pi, so \pi and half-wave count go on the other side of the fraction bar than the length ), then simply add these two. Instead of demanding that m be even resp. odd, you can also use a positive integer l and write 2l resp. 2l+1, which is closer to what is done in the video does and has the advantage that your quantum numbers are consecutive. Edit: I forgot to mention that negative values of m are also okay, but the give the same eigenvalue as the corresponding positive value of m. The two versions of an eigenvalue with m!=0 can be understood as belonging to either two eigenfunctions that are 90° phase-shifted wrt each other, or, if you are more physically minded, as complex eigenstates rotating in opposite directions around the circumference.

[@ayanavade3742]

@@siquod please tell me you were being sarcastic 🙏

[@siquod]

@@ayanavade3742 Sarcastic? About what? About it being easy? I know it sounds complicated, but the line of thinking I described easily fits into a brain trained in these matters. Then again, I might have become blind to the difficulties involved because I spent years writing a doctoral thesis about Laplacian eigenvalues.

[@MegaRaja54321]

Had to take a break from pewdiepie’s complicated red stone so I decided to come watch this

[@mondaynightmood7997]

Raja Choudhary I see you are a fellow intellectual

[@crunchylemon2849]

Yes indeed

[@DhanKOTB]

hahah same

[@forloop7713]

Fellow 9 year olds

[@giovannip8600]

Ahahaha... Funny very... Not

[@charanko2138]

0:00 - 0:02 after he said "what's going on smart people" i closed the video

[@earthinthecomments4944]

But you commented???

[@Sam-pr9rr]

Earth in the comments lol

[@jamesa.646]

Hey dont put yourself down like that, if you pursue a career in math and physics youd be able to understand. Just have patience!!!!

[@corylynn8739]

@@jamesa.646 Engineering major here, still don't understand.

[@ellie_sarabellum]

@@corylynn8739 You survived engineering though 👏 that's hard

[@marakahn24]

This guy: *makes a 38 minute video on a math problem introduced as science jargon in a movie* Also this guy: Thanks for 69,420 subscribers

[@owellwellwell2418]

The duality of man

[@TheTurtleOfGods]

@@owellwellwell2418 underrated comment

[@attilaeckensberger8892]

Is that legit? The guy is a legend then.

[@captainsnake8515]

If you think this is crazy you should see flammable math. Makes videos on college level math problems while calling equations sexy. Think memelord combined with math genius. It’s beautiful

[@victorserras]

ANDREW DOTSON FIGURED OUT TIME TRAVEL OH MY GOD

[@AndrewDotsonvideos]

Victor Serra esketittttt

[@theoneandonlyo5]

Only if you can shrink to the size of a single particle ohh and have the same properties.... Step 2 invent Pym particles and design a suit to mimic the properties of a single particle

[@Chuy4541]

theoneandonlyo5 one step at a time

[@myname-pe2pe]

Watched without even knowing what an Eigen Value is

[@AndrewDotsonvideos]

mad lad

[@snowob]

Same

[@grapeshott]

I have forgotten what that was. Got C grade in my engineering college maths

[@Wolf-yp2qk]

I don't even know what a cartesian coordinate is

[@drinkwater247]

and i still don’t

[@NickyAztec]

Love how you trick the algorithm by including endgame in the title. What a fantastic move

[@samovarmaker9673]

You lost me at "rectangle"

[@mbrusyda9437]

I think it's related to rekt-angel.. I don't know, just my feelings

[@ruatsangawhite7261]

Loooool hahaha

[@Spartan11117777]

What if he said Rectangle Pizza?

[@coolsvilleowner]

oblong

[@sigit2111]

XD

[@emeraldwolf1963]

Friend: Yo man, what's the wifi pass. Me: The first eigenvalue of a Mobius strip in 2D

[@camerondale6529]

Great idea

[@gammarayneutrino8413]

So "The first eigenvalue of a Mobius strip in 2D" is the password? Thanks!

[@duncanw9901]

Imagine knowing how to solve second-order homogeneous differential equations but not knowing what a mobius strip is.

[@AndrewDotsonvideos]

Duncan W lol or an odd/even function

[@JPK314]

@@AndrewDotsonvideos ImAgInE bEiNg A tHeOrIsT aNd NoT hAvInG tAkEn ToPoLoGy

[@johnchristian5027]

my thoughts exactly

[@GAPIntoTheGame]

I know how to solve them(with constant coefficients) but never knew what a mobius strip was ‘till now

[@duncanw9901]

@@GAPIntoTheGame I guess it makes sense, since the math curriculum probably never covers them until topology, but getting to diff eqs without hearing about them from pop-math stuff (matt parker, numberphile, etc.) seems rare.

[@victorserras]

10 minutes in: I thought this was going to be a skit/joke video lol

[@AndrewDotsonvideos]

Victor Serra I’ve never made a joke in my life

[@victorserras]

Andrew Dotson i guess the skit videos in your channel were all made by Jesse Kyle

[@victorserras]

Andrew Dotson oh my god new skit video idea: Jesse Kyle figures out time travel by finding the eigenvalue of a mobious strip

[@sosavelazquez2914]

Everyone: please say sike

[@jrohit1110]

@@AndrewDotsonvideos So, is time travel possible?

[@mehulghosal4017]

that's some epic asmr I fell asleep instantly

[@M4TT4TT4CK]

Flammable maths is my asmr. Something about a German accent and complicated math is just soothing

[@jazminespinoza7932]

Literally Every physics lecture ever.. "There's another layer to this that is much more complicated than what we're going to go into today." And then. There's that small, offhand warning for those thinking of grad school... "Just keep that in mind."

[@casinoroyal93]

Then you understand what you did was just a small fortunate case and the real thing was 10x more complex reeee

[@ResonanceHub]

Excellent, now solve for a particle bounded by a cow

[@AndrewDotsonvideos]

elsupertonga lmao😂

[@Chen19960615]

S P H E R I C A L C O O R D I N A T E S

[@berserker8884]

@@Chen19960615 beat me to it :'D

[@ゾカリクゾ]

Basically deriving the spherical harmonics lol

[@JohmmyN]

@@Chen19960615 smart one

[@bigfly1391]

Invert a Klein bottle and finds its eigenvalue next pls

[@stydras3380]

That would be nice :D You could embedd the cylinder (r*S¹)×(L*Ι) in C×ℝ which then leads to an easy description of the associated gluing (or boundary conditions)! :D

[@stydras3380]

Or you just glue a square directly to get a Klein bottle

[@tomaslopes626]

totally

[@isidore551]

Not general enough.

[@drewm-r7249]

Isidore Sévillian agreed. Do it for an arbitrary n-manifold

[@jakeparker2050]

“Try for yourself and stuff” Me: “I give up”

[@RayWI6]

3:34 Start of the lecture. 14:57 When I doze off for 5 seconds.

[@jackren295]

Exactly! Don't blink or you'll miss it!

[@javiercampoy1707]

Gotta love the humility and dedication you put in this video. You could just leave it like that but instead chose to run through the math again and uploading it a second time. The least I could do was to watch it again (at x2 this time ^^). Now lest hope that my next quantum physics exam is about a particle in a Mobius strip hahaha. Love your content, greetings from Spain ;)

[@AndrewDotsonvideos]

Thanks for the nice comment!

[@ac4740]

"I'm gonna take a sip of coffee, because I've been trying to explain this to myself all morning" - I fucking get this so much goddamnit i love coffee and understanding

[@EthanCanedo]

Even if he made this up I wouldn't question it being wrong lol

[@____-gy5mq]

well others would

[@ethant8368]

Stumbled upon this after filling my search history with "eigenvalue" in preparation for a linear algebra midterm and realized how little I know. wow.

[@cardigran194]

I see your audition for ultimate physics professor of the world, and I approve

[@zamoradecesare1664]

Here’s to the Smart People who are nowhere near this far in physics but watched the whole thing anyway 🥂

[@AndrewDotsonvideos]

here here

[@GeneralPet]

2nd year undergrad. This is easy to follow. We weren't specifically told about separation of variables, but i noticed it when we were doing electron orbitals where the function was described by f(r)*g(θ,φ) and just though "yeah why not"

[@zamoradecesare1664]

GeneralPet yeah, but us high school students have no clue what’s going on and that’s mostly who i was referring to 😂

[@coryellis1877]

GeneralPet I just finished my 2nd year undergrad as well, but I got a D in modern physics 2 (half of which was quantum) I followed this video pretty well, but dang I couldn't have figured this out on my own haha

[@giovannip8600]

Where are you IGCSE students!!!?! lmao

[@Unnjit]

"Try for yourself and stuff" Me: assuming the mobius strip to be spherical

[@SterlingArthur]

As someone who majored in math, but never learned anything about quantum mechanics, this was fascinating. But fix your collar

[@rh7732]

Nobody: Hollywood sci-fi films: *QUANTUM*

[@johnthepancake]

7:46 Sitting in a maths lecturer >Kinda tired, I ll close my eyes for a while >Closes eyes for 5 seconds >Open eyes 36:16

[@earthinthecomments4944]

Lmao

[@kamaltosh]

I watched the whole video except the difficult part 3:00 to 38:00

[@hachat1]

Jump to 5:10 for a change.

[@mbedj1974]

same here

[@ninyoo5926]

When you look away from the board during class for 1 second

[@kamaltosh]

@@ninyoo5926 same thing happens in class but can't skip

[@abelpalmer552]

@Yu Ja This guy is a graduate level Ph.D physics student, and he made a 38 minute video in the form of a lecture. I'm not sure what your definition of a joke video is, but yes he knows exactly what he is talking about, and this is not a joke.

[@harleydelacruz4377]

Teacher : Your Formulas must be on one side of the paper only. Student with bloodline of einstein : (Wrote the formula in a Mobius strip )

[@JustanApple96]

10:00 when the function "g" depends on "g"

[@nlz1]

Red Apple g(g) = g change my mind

[@seanehle8323]

It's the eigenvalue definition. I.e. a vector multiplied by some function equals a constant value multiplied by the same function. The vector is called the eigenvector and the constant value is called the eigenvalue. In this case the function is assumed to be (f*g), and the vector is a matrix of functions (derivatives). It's still saying: [eigenvector] acting on (f*g) = [eigenvalue] times (f*g)

[@reverently]

@@nlz1 g=1 ;)

[@amiss8828]

Hey Andrew, no worries! you only made a mistake in 1 out of 14000000 (14 million) possibilities.

[@manan-543]

14,000,605 to be precise...

[@hasiumcreeper5384]

Andrew: I am inevitable. Mistake: I am Iron Man.

[@tauhid9983]

35:39 "Apparently it was FRIDAY, not JARVIS" and then goes on sayin' "Jarvis should have said...." LOL

[@brycemw]

I remember watching the first version and it was deleted just when I went to share it so I hyped up my friends then never could share it. I’m happy you posted it again so they can see that I’m not crazy

[@AndrewDotsonvideos]

Bryce 😁

[@markl4159]

The Mitochondria is the power house of the cell

[@cinvhetin8054]

There totally is a more consise way of writing the energy. And that form even gets rid of the distinguished cases: The n and l are not the actual quantum numbers. They were only introduced to parametrize an even/odd integer, and it is these even/odd integers that should have been the subscript of E. If you use these integers instead, the eigenvalue just takes the form E = (πħ)²/2m*[(n/W)² + (l/L)²], where n and l are the real quantum numbers now.

[@AndrewDotsonvideos]

Yup that's simpler

[@richardaversa7128]

Pi*hbar, not h/2? That's hardcore

[@35571113]

I think you also need the constraint that n + l is odd.

[@cinvhetin8054]

@@35571113 That's a good point. Either n or l is odd and hence their sum must be.

[@teenx8360]

How are you guys so smart lol

[@Chrizzx3]

"what's going on smart people" 98% of all viewers checks out

[@vodozhaba]

"Finding the Eigenvalue of a Möbius strip" _Now, if you don't know what a Möbius strip is_ I think you've missed something here

[@TurdFurgeson571]

I love that you brought this up to your professor and he actually entertained the idea. This is the kind of professor I had when I realized I loved chemistry. We'd talk after class about things we saw in movies or on TV and discussed how these things might be possible or laugh at the absurdities of artistic conceit in some cases. We all should be so lucky to have profs like these. They see a way to communicate the material in a new way that we as students are already captivated by.

[@lukamitrovic7873]

Why didn't you just use g=10

[@alephnull4044]

Because such accuracy is unnecessary for the purpose of this solution, he's just using an approximation here.

[@taylorwalker2814]

I smell a filthy engineer!

[@ebog4841]

@@alephnull4044 g = pi

[@tedzards509]

@@ebog4841 * = e

[@ebog4841]

@@tedzards509 g = pi = e = e^x = e^ikx so gravitational acceleration is a plane wave. Who knew!

[@bilzebor8457]

that's nice! but in the movie they use it to travel in time, so it's probably a 4d mobius strip (time+3d) and you'd have to solve dirac eqation in curved spacetime (probably nothing right?)

[@KesslerSpaceIndustries]

Actually, you're right.. It's just been using Schrödinger's equation to locate the spin of a quantum particle inside a mobius strip..

[@ayeyobossman6151]

@@KesslerSpaceIndustries duh, of course

[@ex0lezz3]

I didn’t understand anything both of you said but it sounds smart, so I’m interested now

[@adamrod8523]

"4D Mobius strip." Is that a Klein bottle?

[@TheBasikShow]

Adam rod Klein bottles are actually still two dimensional! It’s just that Klein bottles are so twisty that they can only “live” in a four-dimensional space. This is similar to how a Möbius strip is two-dimensional, but the twist means that it can only “live” in a three-dimensional space. As far as I know, there is no four-dimensional analogue of a Möbius strip.

[@BradleyAndrew_TheVexis]

Normal people: "Wow that sounds smart and science, of course, it's Tony Stark!" People who think they understand physics: "Pshhh that's just stupid non-sense to force the plot forward." Real Physicists: "That's an interesting idea!! Why don't we try that!!"

[@FrenchcoreFlava]

I think anyone who think they understand physics would actually understand the problem put forward by stark. Its just the infinite square well, but in an odd shape...

[@thedude633]

Instructions unclear Got my foot stuck in 1969

[@macharstein4329]

The Dude you forgot something

[@nicholaslemosdecarvalho5328]

"Hey, I've seen this one!" - MCFLY, Marty

[@AndrewDotsonvideos]

Nicholas Lemos de Carvalho what do you mean you’ve seen it, it’s brand new

[@wesleyrobinson4532]

Computer Engineer here; I’ve dabbled in quantum computing. I followed you very well. A great explanation. The only recommendation I have is, when you’re doing big algebra, remind your audience why you’re doing the algebra. Like “remember we need this term for this equation”. Keeps them from wandering.

[@abhinovenagarajan.s7237]

I was eating while watching this and I laughed out loud when I saw the Hbar = 1 cap. Love this stuff!

[@AndrewDotsonvideos]

Abhinove Nagarajan.S thanks!

[@ipromaster70]

Love you 3000 Andrew ❤️

[@kcbsuiejd]

alright, alright, alright, alright,...

[@goofballtj]

Personally, even if what you just did is trivial, I still appreciate you talking through all the steps you are doing. Thanks for doing so, you are a great teacher!

[@AndrewDotsonvideos]

Thanks!

[@rhettzkie]

0:00 "what's going on smart people." Me who's new to the channel: this isn't the channel for me.

[@becomepostal]

If you want to understand why separating variables "always work", you can see it as an application of the Stone-Weierstrass theorem. To state it bluntly, this theorem says that functions that are regular enough (continuous, to be precise) can be approximated (up to any given error) by other (more "simple") functions.

[@wolffang21burgers]

28:50 I don't think we can just separate A1 and A2 here, KL = 2λπ is a solution, but for appropriate A1 and A2, we also have KL = arcsin (2A1A2 / (A1²+A2²)) as a solution.

[@wolffang21burgers]

Similarly, case 2: KL = arcsin (-2B1B2 / (B1²+B2²)) = arccos((B2²-B1²)/(B1²+B2²))

[@AndrewDotsonvideos]

Hmm I’d have to graph that out to see what that would correspond to

[@juancruzdelatorre7923]

Was thinking the same thing, I'm not sure but I think all solutions are given by KL = 2λπ or KL = 2(arctan(A2/A1) + λπ)

[@wolffang21burgers]

@@juancruzdelatorre7923 yes, that looks a nicer format. I had arctan( 2A1A2 / (A1²-A2²)) +2λπ which is equivalent. Similarly for case 2 you have: 2arctan(B2/B1) + 2λπ as well,

[@toriknorth3324]

Actually I'm pretty sure that the -KL- Kx has to be independent of the A's and B's. The A's and B's only get determined when you are matching a specific function with a sum of the eigenfunctions.

[@blstuff]

Cinema Sins look at Endgame got a lot more high concept then I expected...

[@12jojimbo]

Imma be real I don't actually understand the math behind what you're doing but it was very fun (for certain definitions of fun) watching you go through it. You did a fine enough job making your case for when you did things so I don't think I got too lost. Thanks for posting this! I really enjoyed it!

[@trevoreguitar]

Words from hell... “Like how do you introduce spin”

[@dennisburgner6237]

I love that analogy for separation of variables. “If the keys aren’t in the light, we weren’t gonna find them anyway” hit me real hard 😂

[@GeorgeVajagich]

I was watching endgame earlier today and was thinking wait what during the mobius strip scene

[@Gregorio416]

* has never taken math over calculus 1 * “ah yes this is quite rudimentary indeed”

[@vladys5238]

tbh if you know derivatives the math is not that hard it's just following all the sines and cosines and knowing about separations of variables

[@rutvikkatkoriya]

As a second year college student I'm surprised how much of this I could follow. I'm a video game design major so my math doesn't go too much farther than calculus, and weirdly enough the majority of this was high school calculus. No idea what an Eigen Value is or what the Schroedinger equation does but the math was not too complicated to follow. Found you through your "Physicis Professors Be Like" video and I just love watching ppl talk about stuff I'll never understand

[@jpa_fasty3997]

9:25 this is a valid step to take so long as the eigenfunctions of the problem form an orthogonal basis. Which you work out via Sturm-Louiville. :)

[@PSNGuyWithHair102]

love you andrew! dont know why youre not uploading much lately but i hope you are happy in whatever you are doing !!!

[@AndrewDotsonvideos]

Christopher Lewis it’s been a busy summer!

[@shubhamghosal9336]

The fact that 2 year ago I didn't understand anything ( almost ) on the white board but now , hell yeah.

[@seanrogers3389]

When you looking for a quick meme and end up learning how to time travel...

[@carlosreyes5139]

This channel is pure gold, Memes, movies references, physics and a lot of mathematics. I love this.

[@AndrewDotsonvideos]

:)

[@deadmandude3152]

I actually can't wait 'till I can understand all of this! It sounds stellar

[@Zeb737]

This is really fun stuff I can tell you. It's like second year undergrad quantum physics, good memories.

[@mossvibes]

i can't believe you just made me enjoy quantum mechanics math when i spend all my time normally trying to AVOID IT LIKE THE PLAGUE. this was super neat, thanks!!! now maybe I'll go finally do the spherical harmonics problems I'm supposed to be practicing

[@Ryan_Perrin]

The Mobius strip (and particle on a ring) is a good exercise for understanding Bloch functions, which are used in solid state

[@Zeb737]

Basically everything with cyclic boundary conditions is a good exercise. I think I once did this for a donut.

[@projecterik1241]

I'm a 14 year old high school student and I understood like max 5% of what you said, but I love how you make it entertaining anyways

[@1Adamrpg]

Separation of variables only works when the Hamiltonian is separable. Essentially, what this means is that the Hamiltonian can be written as sums of Hamiltonians for one variable and for another, which is always trivially the case for the Laplacian. If you like, this is nothing more than a statement of spectral properties of Kronecker sums of matrices. Same with Kronecker (or tensor) products of matrices.

[@ExtremeArcSwag]

Youre a legend for finishing this. I tried to understand it from endgame but couldn't completely

[@thephysicistcuber175]

9:46 you're actually looking for separable solution in the knowledge that any solution can be written as a linear combination of separable solutions

[@jaybhambure5969]

The Physicist Cuber - what you have written is so wrong, plus whoever liked your comment is just mathematically challenged. Linear combination of solutions is a solution, only works if the differential equation is linear, which the schrodingers equation is. But this doesn’t guarantee that separation of variables would work (that’s just dumb). Separation of variables works because of a simple rule of symmetry. If the differential operator and the potential energy are variable separable then the solution must be as well. Think about it for a while

[@thephysicistcuber175]

@@jaybhambure5969 First of all there is absolutely no need to be rude. If you want to make a point against what I've written being rude is basically the worst way to do it. Secondly you first said that linearity is not enough to restrict yourself to searching for separable solution, then you said that if the equation is separable then "its solution has to be". I'm assuming you mean that any solution can be constructed by linear combinations of separable solutions, which is exactly what I wrote in the original comment. So... what are you trying to say? If you're implying that not all linear PDEs are separable then just know that in no way my original comment was trying to claim otherwise. And yes, l do acknowledge the existence of non-separable PDEs. So just to be clear with my original comment: I was claiming that when you have a separable PDE+boundary conditions on a domain that's suitable for separation of variables the reason why you specifically restrict yourself to looking for separable solution is that in the end you can reconstruct any solution as a linear combination of separable solution.

[@Four-S]

Fam the fact that you understand what your doing and how to do it, is better than a majority of the population. Also.. I'm sorry to say that I didn't understand most of it, but hopefully one day in the future I'll watch this video again and comprehend (as well as appreciate) what you've just done.

[@LavenderTown40]

Everybody makes mistakes... We still love you (: *sarcastically* How many mobius strips do I need to invert to get you to be a guest speaker for an sps meeting? I'll throw in a time stone.

[@AndrewDotsonvideos]

Scott throw an engineer off a cliff in vormir and you got yourself a deal

[@LavenderTown40]

@@AndrewDotsonvideos I'm an Mechanical Engineering major and the president. Can I throw myself off, even though I'm not a real engineer yet?

[@baticadavinci3984]

why don't you do a video on some theory of yours about physics and stuff, would be cool to hear what you think about the universe and such

[@coloboquito]

Interesting, that one can go even further and consider string theory with an additional dimension wrapped as a mobius strip and a string wobbling in that dimension That's not real physics, but that will be fun, i guess Anyway really great video, love your channel

[@diarya5573]

That kazoo should've been replaced with Tom Holland playing the avengers theme off key. Apart from that, this is the most me thing i have seen in a video, and I love it.

[@duncanw9901]

32:38 "...so...mine of the sinus is equal to the sinus of the mine..."

[@AndrewDotsonvideos]

Duncan W you made me think I actually said that😂

[@tilmanroeder609]

Really like the analogy with the street light. I remember my maths Prof saying something along the lines of “we hope the solution is separable, and if it’s not, then we prey” 😂

[@ManojKumar-xo7on]

If you're not making mistakes then you certainly not learning... Even the great Einstein did in his time! The only thing mistakes do is just deepens your understanding...keep up the work bro!

[@erik.isomer]

Thank you for this 38 minute video in response to a 37 second clip, this is why I love physics

[@drinksomestew8159]

idk why but whenever I see algebra math written on a board it's so beautiful

[@SirBelchaloT]

Hey just wanted to let you know, I’m still pretty early in my quantum learning and watching this whole thing through helped connect a whole bunch of different simple, but fundamental ideas of solving schrodinger equations. Bringing it all together and following along each step helped me realize that I actually *am* learning something in my quantum course after all! Thanks for the video!

[@HaganeNoGijutsushi]

Tony Stark was talking about time travel though, so my guess is that really the "Moebius strip" referred to some freaky spacetime geometry, so we'd be talking quantum gravity problem. Either that, or the scriptwriters just made some shit up :D.

[@emily-tu1so]

subbed after watching this, this is some mad dedication and skill. Fellow phys student fist bump

[@Joseph125]

So you upload the time travel video twice? Nice.

[@tom_kauf]

I really appreciate you a leaving in the fact that there was an error and explaining your newly found understanding of it.

[@waterflow2324]

The noise from 3:20-3:27 was what my brain was doing for the entirety of this video...

[@rithvikyagnamurthy6560]

It’s crazy that nearly 5 years later as a final year Physics student, I get it.

[@fisikalectures597]

Why does a chicken cross a mobius strip? To get to the same side hahahahaha *ded insied* EDUT since u guyz leiked it, ima tell u another GOLD COMEDY physics joke. Murphy's Ten Laws for String Theorists (1) If you fix a mistake in a mathematical superstring calculation, another one will show up somewhere else. (2) If your results are based on the work of others, then one such work will turn out to be wrong. (3) The longer your article, the more likely your computer hard disk drive will fail while you are typing the references. (4) The better your research result, the more likely it will be rejected by the referee of a journal; on the other hand, if your work is wrong but not obviously so, it will be accepted for publication right away. (5) If a result seems to good to be true, it is unless you are one of the top ten string theorists in the world. (By the way, these theorists refer to their results as "string miracles".) (6) Your most startling string-theoretic theorem will turn out to be valid in only two spatial dimensions or less. (7) When giving a string seminar, nobody will follow anything you say after the first minute, but, if miraculously someone does, then that person will point out a flaw in your reasoning half-way through your talk and what will be worse is that your grant review officer will happen to be in the audience. (8) For years, nobody will ever notice the fudge factors in your calculations, but when you come up for tenure they will surface like fish being tossed fresh breadcrumbs. (9) If you are a graduate student working on string theory, then the field will be dead by the time you get your Ph.D.; Even worse, if you start over with a new thesis topic, the new field will also be dead by the time you get your Ph.D. (10) If you discover an interesting string model, then it will predict at least one low-energy, observable particle not seen in Nature. In summary, anything in string theory that theoretically can go wrong will go wrong, but if nothing does go theoretically wrong, then experimentally it is ruled out. Taken from www.jupiterscientific.org/sciinfo/jokes/physicsjokes.html

[@radwizard]

You win the Internet today. :D

[@tusharpandey6584]

me irl irl

[@haziqthebiohazard3661]

Bazinga

[@JSSTyger]

What was the reason for going all gangster saying "ded insied"?

[@fisikalectures597]

@@JSSTyger idk I'm socially introverted but wanted to come out as a cool physicist. Inevitably i failed due to my lack of "cool" knowledge... I guess the memes didn't help.

[@alexandersanchez9138]

The best way to recombine the cases is to notice that the difference of an even integer and an odd integer is always odd. Thus, you could say: E_(n,k) = (h^2/(2m))((nPI/L)^2+((n-2k+1)PI/W)^2) That is, choose whatever n you’d like, then choose k to get a corresponding (n-2k+1) value.

[@koreboredom4302]

Imagine this alpha dude sliding between you and your girl at the bar and saying "hey gurl, I can find the eigen value for a mobius strip..."

[@StarboyXL9]

This guy is literally the Chad of physics

[@chrisriddell7424]

Quite simply You’re a legend Andrew! This is some of the best content on KZbin. Keep it up mate

[@lennipennanen7644]

Andrew: What’s going on smart people Me: ight imma head out

[@rossboyer2764]

I’m glad I could understand at least a quarter of this. Once I get through more physics courses I hope to understand it all

[@FilosSofo]

Andrew: "So we are going to do just that..." Me: **We are in the endgame now**

[@vru6431]

Doing QM in past made me able to follow and predict your next move in this video. Thanks mate it was like a mental revision. Subbed :)

[@kyakarogenaamjankar898]

Tony - Damn These physicist are too nerdy and smart!

[@anywallsocket]

to simplify your final result, flip the order of one of the summations (case 1 or 2) and distribute the 2 for the first term in case 2, and what you get is case 1: (2lpi/L)^2 + ((2n+1)pi/w)^2, case 2: (2lpi/w)^2 + ((2n+1)pi/L)^2. so you can see length and width do not distinguish between even and odd solutions (since l and n are equivalent). which implies two eigenvalues: odd + even waves in 2D, as one would expect, since the mobius strip cannot in this context differentiate itself from an infinite rectangle.

[@pranav2139]

TIME TRAVEL! I see this as an absolute win

[@Kumurajiva]

My brain is melting. Your hat switch helped clarify my mind. 😂