I know what you're thinking: Either Henry is taking some well-deserved time off and I'm just helping to fill in during that vacation, or else he's currently tied up in my basement providing me occasional sound bites for food while I slowly take over the channel for good. To anyone worried about case #2, don't be silly. He's in the attic. Way too many escape routes in the basement.

As Feynman once said "...it takes tremendous strain on the mind to understand certain concepts.." now I know he was right.

"What special curve satisfies the property that the tangency direction for a point theta radians off the horizontal is given by this vector from the special eccentric point from the circle to a point theta degrees around that circle from the vertical? Okay... Is the question clear?" Uhhhhhhhhhh... *infinite intelligence load error*

Ohhhhhh, it all makes sense now. Not to me but I'm sure to someone it does.

“You don’t need calculus to understand this” *3 minutes later* “As you can see, if you keep adding infinitely small sections to this polygon, it trends toward a circle”

I find it fitting that a guest video was used to talk about a guest lecture

Man, this 3b1b guy (grant sanderson) really deserves more recognition and some prestigious awards. He is one of the most influential math guy in present history, so many people like me are everyday getting inspiration to study mathematics from him.

I've seen this video 3 times already. I understand what he's saying everytime I watch it, and then forget how he did it the next time I come around.

ooh this gonna be good

Thank you for the effort that was put into this. Amazing people, teaching millions of anonymous people, you deserve more gratitude that can be offered in a comment!

Once I get into, and then through college, I'm definitely going to build a time machine and yank Feynman out of some class just to show him this video adaptation of his lecture. Beautifully conveyed!!

3blue1brown: *explanations*, Right? Me: Uhhh *brain.exe is not responding* 3Blue1Brown: *continues explaining* Me: *brain.exe crashed*

Minutephysics + 3blue1brown + Feynman? Knowledge-gasm!

Newton - "OMG they don't understand my physics!" Feynman - "Hold my beer."

Grant: "Ok? is the question clear?" Me: Nods in liar liar pants on fire

Thank you for this! Several, "That is so cool!" moments in this video, and...as much as I love learning...I only went as far as Physics 101 in college. Thus, it's not just cool how all of this works out; it's cool that it can be broken down into individual pieces that are each relatively easy to digest. I'm suddenly reminded of Zen Archery. Don't think about the target; just get each individual step right, and your arrow will arrive at its target "on its own".

"Surely you're joking, Mr Feymann !" is one of the best book I have ever read. Its deep, it's mind-boggling, and much more, it's fun !

I admit I'll need to watch this many times before I might have a decent grasp of it. I'm in my 60's & was a high-school dropout. I went on to get a modest amount of formal education & training in a limited variety of subjects. I did okay with electronics algebra & basic trig, but then I hit a plateau. It took me a good decade to recover from that setback, and begin to realize that math can be awesome, beautiful, and even entertaining. I became a person who wished they could have been an astrophysicist. Part of that desire came from finding my way back to a youthful obsession with the nature of the universe, of which I'd all but forgotten. Later, I began to see how impressive were the skill sets of many of the world's physics giants. In the last several years, while I mainly do more-mundane, day-to-day achievements of a kind, I spend a lot of time examining everything I can find on the laws of nature & the stories of science. I can't seem to get enough of it. But I'm too often struggling with concepts that are way over my head, and I've wished to find an easy way to learn some of the fundamentals. Meanwhile, I've tried hard to acquaint myself with every existing variety of fields in which the highest math skills are put to work. I've gotten some great books from the library, and have devoured countless, thrilling stories of the history of science. I've been given or purchased several of my own, too, and have read all the magazines for the last 15 years.. I've learned about the important breakthroughs of Aristotle, Ptolemy, Newton, Brahe, Copernicus, and quite a few others, including Johannes Kepler. I have an awareness of a good number of modern-day achievements, along with today's heavy hitters. too. I can't entirely explain this fascination I've developed. It has a grip on me, and sometimes I think life would just be a lot easier, if I dropped the whole thing, but but just won't go away. Fortunately, like Ron Burgundy once said, that is in no way depressing. For all these reasons, I found a great deal of enjoyment in your fantastic video presentation. It's one of the most helpful demonstrations I've yet come across. You are to be commended, for providing the layman with such a near-intuitive overview of this sort of topic. I'm anxious to see what else you've posted. excellent job!

Keep up the asking questions out loud stuff with a slight pause. It aids learning and facilitates the drawing together of seemingly unrelated threads within the consciousness of the viewer. Good work.

I think the visuals made it elementary to understand, but I loved the linguistic complexity needed to be able to effectively communicate the concept in the first place. Granted without the visuals I probably would not have understood, nor would I have wanted to understand. Great video!!!

New MinutePhysics video notification: "oh neat, I'll add it to watch it later" Topic is "Feynman's Lost Lecture": "Maybe I'll listen to it in the background" Featuring 3Blue1Brown: **heavy breathing** Video duration is 21 minutes: **drop everything I'm doing and hit the fullscreen button**

Twenty One Minutes Physics

David Goodstein is also the spiritual grandfather of 3B1b videos: he made the landmark “Mechanical Universe” series that aired on PBS. It featured a mix of animated equations and historical re-enactments that brought physics to life for a generation.

"Stay focused" I see what you probably weren't intending to do there.

10:48 *3B1B* : Well, specificly it says that this quantity times the mass of the object stays constant, but, I mean, the mass of the orbiting object isn't gonna be changing. *Michael* : Or is it?

My head hurts a little, but I think I understand most of it. Remembering it on the other hand.....

Everything to know about physics relates to geometry. This was such a pleasure to watch

Thanks for the easy and simple explanation. Every thing is clear now.

The Great Physicists' Road Trip by Ms. Rachel C. Millison Great physicists from the past decide to return to Earth for one last road-trip vacation to the coast together. They all appear on Earth on the appointed evening. Heisenberg pulls up behind the wheel of a gigantic 1930's car, a huge grin on his face. As they're getting in the car, Hubble looks up and says "What a wonderfully dark sky". "Shouldn't be" responds Olbers. "Always has been" says Hoyle. "No, it hasn't" says Lemaitre. "I knew that!" says an embarrassed Einstein. Once they're all in, Teller says "Hey guys, this trip is going to be The Bomb!". "Yeah, but why do I always have to organize?" asks Oppenheimer. "Where exactly will we end up?" asks Kepler. "That's impossible to predict" says Bohr. "I just can't believe that's true" says Einstein. Heisenberg punches the throttle and the old car roars off. "Say - this thing sure accelerates" says Newton. "I don't know, Isaac. It feels like gravity to me" smirks Einstein. Later that night, as they are speeding down a country road, a police car catches up to them and pulls them over.[1] "Do you know how fast you were going?" the cop asks. [1] "No, but I know exactly where I am" Heisenberg replies. [1] The cop says "You were doing 55 in a 35" [1] Heisenberg throws up his hands and shouts "Great! Now I'm lost!" [1] The cop thinks this is suspicious and orders him to pop open the trunk. He checks it out and says "Do you know you have a dead cat back here?" [1] "We do now, asshole!" shouts Schrodinger. [1] "I think it's time to split" says Everett. "Say, how did you manage to spot us on such a dark night?" asks Hubble. "I saw the light from your head lamps" says the cop. "How fast was *it* going?" asks Michelson. "That's simple addition" giggles Galileo. "Not exactly" says Lorentz. "Look here" says Heisenberg, "how do you know I was going that fast?" "I clocked you over a measured distance" says the cop. "How often?" asks Hertz. "I disagree with your measurement, officer" interjects Einstein. "Don't start tonight, Albert" says Bohr, shaking his head. "What Herr Einstein is trying to say" continues Heisenberg, "is that time was running at a different rate for you than for us". "WHAT!!!???" exclaims Newton. "It's true" says Maxwell. "We're all famous scientists and, believe us, Herr Einstein has proved it, though it came as no surprise to me". "Sounds complicated" responds the cop. "I'll draw you a simple diagram" says Feynman. Totally flummoxed, the cop lets them go with a warning. As he drives away, Doppler cocks his head and listens to the sound of the receding police car. "Gotta love that" he says. "Amen" responds Hubble. Returning to their car, Lord Kelvin remarks "Sure is warm tonight" "Yep - lots of disorder" replies Boltzmann. "In places you'd never expect" adds Hawking. "I was lucky to get away with that" says Heisenberg. "Most cops think they're better than everyone else". "Yes - I hate inequality" adds Bell. "Though you *were* speeding" says Faraday to Heisenberg. "I carefully observed the needle creep from 35 to 55". "Actually, it was jumping, Michael" replies Planck. As they pile back into the car, Bohr says "See here - you must fill the seats in order - no empty spaces allowed. And stop interfering with each other!" "Only one of you can sit next to me!" yells an agitated Pauli. "Say, Werner - it's stuffy in here. Be a good chap and crack the window a bit" says Hawking. "Sorry, Stephen. It can be all the way up or all the way down, but nowhere in between" replies Heisenberg. "Hey guys - Albert and I just figured out a great shortcut. Only one bridge" announces Rosen. "It will save us a lot of distance" says Einstein, "but it might get spooky". Arriving at the beach the next morning, they hurry from the car and stand looking out over the ocean. "Look at the wonderful waves" says Schrodinger. "They don't look like waves to me" says Bohr. Looking down at the fine sand, Dirac exclaims "Look at all the particles!" "Now *those* look like waves" says De Broglie. "This is great!" exclaims Feynman, rubbing his hands together. "Now, lets go meet some girls!" "Let's delay" says Wheeler. "We have to be discrete" warns Bohm. "Girls? NEVER!" exclaims Newton. 1 Based on, and including the original, attributed to Rich Granger, engineer, Battelle.

As my eyeballs glazed, I realized fully that I do not have 'infinite intelligence'. I guess it's good for us to run into a wall now and then. Wow.

Can you imagine what sort of lectures and presentations Feynman would have produced if he had access to the same animation software used to make this video...? 😮

If KZfaq channels like minutephysics or 3Blue1Brown existed when I was in high school I probably would have become a physicist or mathematician instead of a biologist.

Holy crap, I suggested this topic to Grant on his subreddit. I can't believe you guys are actually doing this! Awesome!

I'm afraid I only have a finite amount of intelligence.

Feynman was an artist who had shown us some ultimate beauties of universe through the colours of physics.... This is a gem.... 💎💎

This is AWESOME ~ Thanks for sharing this!! Love 3Blue1Brown! You summed this up awesome!!

The video currently has 467,294 views including my 467,200 views to understand it That too at 0.5X speed

That's a pretty *_normal_* way of constructing an ellipse!

Thanks a lot for the video Grant...You really tried your best to keep it simple...even though I had to occasionally pause and ponder. I wish 3blue1brown makes a collection of all the lectures of Feyman !!!

0:54 - Notice that the endpoints of all those many line segments form two other circles. Is there a significance to that?

2000 years later: The physics/maths behind creating level II universes. Animated and taught by 3b1b the 500th.

This is the most satisfying maths/physics video I've ever watched period.

Wow!! I'm a mathematician, and as my colleagues will, I think, agree, this video gives a lot more intuition and insight than the standard analytical mechanics-differential equation proof which has hardly any geometry and only blind calculation. Thank you!!!

I was a math major for 1 year before I switched to mechanical engineering. I'm now retied and can indulge my first passion. I simply loved this video. I do believe, though that the constructs are merely consequences of natural laws without any useful knowledge.

I am fully convinced that the term 'Quantum Electrodynamics' was coined solely to make the 'QED' joke

I thought it was 3blue1brown who uploaded video

I personally Love Feynman's work... His brilliance wasn't in just discovering new things, but being able to explain them at an elementary level. It is almost like watching Monet paint, or Bach compose music... if we could, that is. My only problem with the video is... how does one pronounce "Principia" correctly, but not "Foci?" They are both Latin words, in which the c is always pronounced hard, like a k. Everything else in the video made perfect sense, but it was like hearing nails across a chalkboard every single time he said it. On a side note, speaking of the relation of Kepler and Newton... Kepler spent over 30 years to develop his laws of planetary motion. There is a museum to him that actually still holds thousands of notes on his work. This is actually motivated Newton to try and find an easier way to solve the "Tangent Line Problem." But, don't be fooled... what Newton wrote about in The Principia was not The Calculus we regularly learn. He discusses it in the third part of the book, and it mostly deals with differential equations. Libenitz really was the one who developed most of The Calculus we learn in school. Newton took the claim solely because he was the head of the Royal Society at the time. The same position Stephen Hawking held until he passed away.

Fantastic video. Grant does a good job of graphically summarizing Feynam’s lost lecture.

I just found this video ... BEAUTIFUL ... Richard Feynman is who I want to be when I grow up ... what an Alchemist ... I believe everything he touched turned to gold ...!!! and Grant, you should win some sort of video award for content (I know they give Creator Rewards for subscriber count) ... Hey KZfaq, this guy's content, production and presentation values are nonpareil ... this is a magnificent presentation and should be the standard for all other content on the web ... BRAVO Sir! Also, thank you for pointing me to the free online Feynman Lectures ... Thumbs Up...WAY Up!!!

Was I the only one that forgot this was a minute physics video?

I'm impressed with the accuracy Grant can predict each moment my is brain is about to melt

When 3B1B hosts this channel: *Bravo Six, going dark.*

A guest lecture about a guest lecture! Excellent! Hopefully this will never become known as "3Blue1Brown's Lost Lecture"

“So I’m gonna draw it nice and thiccc” *12 year olds have entered the chat

I am not a mathematician but I love it! I once took a physics class called Physics for Poets and this is exactly what it was like. You and of course Feynman deconstructed this concept so that even a guy like me could appreciate its beauty. Thanks!

Anyone noticed that at 1:00 we have full plan of that video, and exatly second frame on it is this plan. Mind blowing

Somehow this seemed even denser than most of 3blue1brown's other material. I feel like I could probably get it all if I spent a couple hours working it out for myself, but right now my head just kinda hurts.

Grant not only is a genius but he is also a fantastic teacher. Honestly, every time i didn't understand a specific part of the proof he addressed it right away, almost as if he could read my mind! That is, in essence, teaching, and he's brilliant at that!

thank you for making this !!! love you !!!

its beautiful. When i first learned about the focal length constancy in ellipses it drew all my attention. Maybe should have looked deeper. Maybe thats what makes a Feynmann

Latin focō (as in the video) is the ablative of focus, which means at the fireplace. the form focus derives from the nominative which is focus not foco.

Newton started off with a bet to prove this (the ellipse being a consequence of the inverse square law) and produced a series of publications, eventually compiling the principia mathematica out of this seed. However, although he never states this clearly, I'm sure he realized that the proof he gave was for the converse: that given an elliptic orbit, an inverse square force law follows. This was much easier at the time because so much was known about the geometric properties of the ellipse than was about F=m a. In fact, Newton couldn't really mathematically use velocities because they compare two quantities with unequal units (distance, time). Also of course algebraic notations and vectors weren't invented yet. But still Newton claimed to have won his bet, and the Principia avoids any clarity about proving the inverse square law vs. the converse (proving the elliptic shape). I'm sure Newton would have LOVED this type of proof, and this proof in particular! Although I'm sure he'd appreciate how much more powerful modern mathematical notation and ideas such as vector or Lagrangian calculus are. And that's where Feynman and 3blue1brown comes in: Elementary proofs just are the next level of understanding: being able to explain something seemingly complicated in simple terms. With intuitive concepts, but with methods not more complicated that what was available to Newton.

I feel like I understood from the very beginning and then it got more and more complicated, looking at it a million different ways, for no apparent reason. The fundamental thing that's missing in EVERY ONE of your videos (I'm talking about Grant) is the question "why" at EVERY stage of explanation and obviously a clear answer to it. Why we're analyzing a given thing and what it corresponds with in the nature of the problem is essential to making something intuitive. Otherwise, you're just doing an infinite series of whatever math problems for seemingly no apparent reason. While your explanation for HOW things work are very good (assuming every single reference is COMPLETELY familiarized and ENTIRELY able to be followed as you string a multitude of technical terms together and grow them in succession) and the visual presentations are of course stellar, all of that is completely undermined by the purpose being completely lost. People still don't seem to understand that math, if taught to human beings, shouldn't be fed like to a computer program, simply explaining whatever concepts/functions through whatever form of (believed) simplification.

"All you need to follow along, is infinite intelligence " got it lol

20 minute Physics Even better!

I am definitely gonna have to rewatch this several times but I look forward to it

The incredible nature of the rubber band. Think like Feynman. He amazed me when I found his lectures on you tube. I love this man

I just wanna thank you I did not completely grasp it but I do have some insights on it Thank you very much to Grant Anderson and Richard Feynman And of course Newton

Didn't think it was serious until he said Go full screen.

"So the question is: What special curve satisfies the property that the tangency direction of the slope for any point theta-radians off the horizontal is given by /this vector/ from a special eccentric point on the circle to a point theta-degrees around that circle from the vertical? Okay, so is the question clear?" XD

It would be amazing for you guys to remake the feynman lectures on physics videos. They are wonderful, but hard to see and hear

I find it simply amazing we can know so much and yet understand so little. Thanks for sharing!

I LOVE ANYTHING AND EVERYTHING FEYNMAN!!! This was a great video, and I love seeing the cooperation between math/physics/science channels.

minute physics+3b1b+Feynman what could i want more, best day of this month

At 6:13, I love the animation of the focus acting like a sprinkler! I played it 10 times.

this was a strange experience for me and i dont know what to make of it- but despite never seeing this idea before, almost as soon as i heard the introduction i knew almost every step we were going to use to get there (of course it wasnt a full proof in my head using theories and all, but like the vectors making a circle and the rotations and some of the perpendicular bisector stuff, really all the visual ideas). it just... came to me at the start. never had that happen before.

This channel is amazing. Minute physics, your channel is one of the best out there. Keep it up!

*Yes, I'm going to pretend like my brain has enough computing power to fully comprehend every single word in this video and instantly apply it to every subject previous brought up, and watch the video a ×1 speed without pauses.*

One of my physics Profs, was a student for Feynman’s lectures. He had Feynman for a junior level class. One of the students completely bombed the midterm. He had mistakenly been attending the wrong class. But Feynman made it seem so easy, he just stayed there thinking he understood.

Stop at 5:06 and look at the calculation at the top right corner

I've commented this in many 3blue1brown videos but not enough times. This was BEAUTIFUL.

That black dot on the screen from 1:43 to 1:48 got me! I was pawing at my screen trying to remove the 'spec'. How dare you! :3

Feynman explaining the basics of orbital celestial mechanics. Tasty.

every time i see a video like this i curse the educational system that did not make the connection between slope, velocity, calculus in high school math. what i learned is the biggest obstacle to understanding what i am watching!

The PCA explanation by 3blue1brown got me a job ❤️

Goddammit grant. You couldn't just be a teaching god on one channel, you gotta invade minute physics too? Jk, love you both. Henry, you got me into physics when I was in middle school (going into uni in 2 months) and Grant, recently you made linear algebra make sense. Which was strange for me, because my teacher did an absolutely awful job. Thank you both, you've helped me and many others immensely.

Had a fallout with math in highschool. Then after twelve years I found 3blue1brown. Had to watch this video multiple times, some sections over and over but finally got it . My OCD can be a boon sometime. Without OCD no way I would have continued watching it. Now I lay satisfied after spending two hours on this video. Don't know how I will use it in my life but I feel good to make friends with a old friend again.

We must really marvel at the intelligence of feynman who came up with this elegant method.just wow and the guy who explained is really in some league of his own.wow

Loved this collab. Thanks for this video! Knowledge just blasting off from this video, like water sprinkler.I don't think I managed to catch all the water.

1:00 top row 2nd square *GRID-CEPTION*

I never thought about the origin of the word "eccentric," but "out of center" makes prefect sense both mathematically and socially ;)

I. understood. I have watched this video in high school in 2018 and I'm an university student now. Today I finally understood Feynman's Lost Lecture.

The best thing about this is that I understand very little of it but it still manages to amaze me :)

I appreciate your through discussion of this. It really reminds me of my grandfathers explanation. I was looking forward to your method of explanation, and was quite entertained

Great video. It's a bit like the classic Cambridge natsci/physics interview question "describe how you might approach proving the following or what laws you would need to invoke'. Thankfully mine was simpler however. We had a first edition of Newton's Opticks in the college library and I was kind of thrilled to request it and read a chapter... in a long-gone innocent age where there was no door security on the college or the reading room.

The video that introduced me to 3Blue1Brown last year. I was so obsessed with Feynman and his works and I landed here.

Woah 3blue1brown! :)

"...approaches a Perfect Circle. Isn't that neat?" - "indeed it is!" (Walks away and puts Lateralus by Tool on play)

Professor Feynman said that you MUST do the groundwork to understand the higher. He went on to say that most people don't want to do the basics, which MUST be known well

Thanks to "Minutephysics" aka Henry Reich, for making this video - and thanks to "3Blue1Brown" for the geometric mathematic elliptical gymnastics - which unfortunately didn´t explain the causes of such planetary motions. As 3Blue1Brown are the lecturer in this video, I´ll post an elaborated reply about the cause of the elliptic motion to him below.