Feynman's Lost Lecture (ft. 3Blue1Brown)

Check out Grant’s channel: 3blue1brown: / 3blue1brown
This video recounts a lecture by Richard Feynman giving an elementary demonstration of why planets orbit in ellipses. See the excellent book by Judith and David Goodstein, "Feynman's lost lecture”, for the full story behind this lecture, and a deeper dive into its content.
Tweet referenced at the start: / 1016936129117937664
Music by Nathaniel Schroeder: / elizabeth-the-mouse
Music by Vincent Rubinetti: / one-two-zeta
Support MinutePhysics on Patreon! / minutephysics
Link to Patreon Supporters: www.minutephysics.com/supporters/
MinutePhysics is on twitter - @minutephysics
And facebook - / minutephysics
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Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!
Created by Henry Reich

[@3blue1brown]

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.

[@sambishara9300]

I love how you could understand that with tenth grade math and eleventh grade physics, and also the satisfaction you get when it all clicks together. Grear job!

[@kadblue2000]

Lmao

[@richardlinsley-hood7149]

3b1b: it is case #3 I'm interested in. Got an answer for the LAG of gravity given its known speed? (see separate question)

[@bigdx5059]

3Blue1Brown loooool🤣🤣🤣🤣

[@blazingkin]

You think of everything.... until you find out he can break through the roof tiles

[@zaheera6899]

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

[@dekippiesip]

I am sure he wasn't even refering to this when saying that. He probably was refering to the crazyness of quantum theory and relativity, things so crazy that this seems like kids play.

[@MrLaptopus]

Unfortunately Feynman never explained some of the simplest concepts, like the ellipse. What is at the other focus?

[@MrLaptopus]

Unfortunately Feynman never explained some of the simplest concepts. What is at the other focus?

[@zephilandevol]

John there is empty space at the other focus (in a real system there might be some dust or another planet passing near the focus though, but it can’t stay there)

[@MrLaptopus]

@@zephilandevol exactly, theres nothing there. so Feynman's analogy is false

[@89macgyver]

"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*

[@leoliu7492]

That has stumped me for a minute :D

[@waiitwhaat]

ngl, i repeated that single sentence at least 5-6 times before i didn't understand it and sucked it up and went on with it

[@erikrindalsholtfredriksen4888]

I am so sorry, but i just liked your comment, even though it had 69 likes. Thankfully, i have the infite intelligence required for this video and i managed to unlike it, not dislike, but unlike, so that it still has 69 likes. Sorry for the inconvenience

[@stevemacbr]

Basically,... we're back to the (constructed) ellipse within the circle, made with the string and two focal points. .

[@weouthere6902]

Basically you need to understand for any point along a curve, its velocity vector has a direction tangent to the path. The bit with constructing a circle by placing the velocity vector tail to tail stumps me tho. Rest of it is easily understood if you think about it.

[@adamkendall997]

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

[@VijayThakurMD]

I'll just stick to god.

[@danielkunigan102]

“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”

[@mannacharya4088]

😂 ∆x v/s dx

[@YaseenKhan-qf8mq]

Daniel Kunigan Caculus

[@robertbrandywine]

@@YaseenKhan-qf8mq The Calculus.

[@simichatterjeemishra1624]

Lmao

[@malou5290]

i was tricked

[@nienke7713]

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

[@twicebittenthasme5545]

Serendipitous, to be honest...

[@stulora3172]

@@mabell01 now rotate that by 90°

[@pragyanpathak9330]

where can you find that "infinate intellegence" lecture can you please tell me?

[@jeffreyleonard7210]

G squared?

[@alfarabi4128]

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.

[@kamiel79]

Coming from Al Farabi, that surely means something :)

[@blueberrypi1021]

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

[@brenttaylordotus]

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

[@scottrackley4457]

@@lorax121323 would agree, if you can't grasp why forming an elipse this way is not the definition of an elispe just worded a different way....you shouldn't be watching this channel

[@MatrixExpress]

@@lorax121323 and that is why he wrote his own encryption ;-)

[@rangerdoc1029]

If anything, Feynman's gift was an ability to put the cookies on the bottom shelf

[@matthewgreen8570]

You're a moron.

[@seremetvlad]

Hold my bonjos

[@tibees]

ooh this gonna be good

[@davidlugarov9685]

Tibees It seems like all my fav science/educational youtubers are on this video or in the comments, incredible, didnt expect to see you here

[@tatvkamdar8976]

Yeah it's great!

[@denishtrivedi3071]

can you explain what he said at 15:49 please

[@amarnathck574]

Heeeey... Good to see you here...

[@p.singson3910]

JEE girl.

[@danzerstanley5472]

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 !!!

[@eccentricOrange]

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!!

[@sergeboisse]

"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 !

[@rangerdoc1029]

My favorite work of nonfiction ever.

[@mlmimichaellucasmontereyin6765]

Rite! I especially like the anecdotal story of RF debating 2 post-grad guys in a cafeteria, about his alternative to cosmic expansion. And, despite the last scene of MIB 1, RF's shrinking universe hypothesis is un-disprovable!

[@imranqureshi4299]

My favorite book for sure

[@FelipeFigueroaG]

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**

[@pipodewanto4520]

Felipe Figueroa damn right

[@vaguebrownfox]

This is literally me!

[@AdityaKumar-ij5ok]

damn true

[@studiousboy644]

That true. Just cancelled everything and went full screen. Even though I couldn't follow everything exactly.

[@OmniphonProductions]

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".

[@davidtitanium22]

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

[@elijahjflowers]

David Timothy P yooo for true, I'm just ganna watch Feynman explain it

[@ZeHoSmusician]

*_brain.exe_** has encountered a fatal error. Please try repairing the program before launching it again or contact your support team.*

[@pjcWizard]

Brain better off after the workout!

[@enderallygolem]

Twenty One Minutes Physics

[@MisterAppleEsq]

Isn't that the name of a band?

[@user-yh7dz1bk5y]

Twenty one savage

[@stephenheirtzler]

What an original joke that has never been used on this channel before.

[@zombiesalad2722]

Stephen Heirtzler What an original comment that has never been used on this channel before.

[@osamabillah2069]

Zombie Salad What an original reply that has never been used on this channel before

[@sebastianelytron8450]

Minutephysics + 3blue1brown + Feynman? Knowledge-gasm!

[@littledipper3391]

Sebastian Elytron agree

[@uncleruckus9670]

I consumed so much knowledge that I pooped out an introduction to physics book the next day.

[@Aereto]

Quantum tunneled.

[@danielbenyair300]

Sebastian Elytron Good one...

[@cosimaturing5314]

LOL

[@Tasarran]

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...? 😮

[@schmetterling4477]

Even worse ones. ;-)

[@dakshbadal7522]

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.

[@badgermcbadger1968]

Write it down

[@lancethrustworthy]

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.

[@red-baitingswine8816]

On "watching Feynman 'splain things is just like watching Bobby Fisher play chess"... How true! In both cases, I feel I understand about 20% (to be generous) of what's happening. : ) (I think I'll come back to this video from time to time)

[@MP-cv6if]

You know it think that's what we were born for. To gain infinite intelligence. Like you wil learn to take down walls if you run into them so often, and thus find yourself in always a bigger space, a bigger world, and have more freedom (guaranteed that you don't run into any titans).

[@MP-cv6if]

You know I'm amazed how aot connected here. The linking of two masterpieces, so "mesmerizing?" yet so simple.

[@Crocy]

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

[@ethancheung1676]

BlueKavet you can then always watch it again!

[@Adraria8]

How I feel after every 3b1b video

[@erroneum]

I think this was actually somewhat easier to understand than some of his videos, although it might just be because I've has most of the past week off and am actually caught up on sleep.

[@vladimirshitov2160]

There are three steps in understanding a proof: 1. You can understand the proof 2. You can reproduce the proof 3. You can find a better one

[@LameGeneration91]

Vladimir Shitov true! I ALWAYS skip to number 3

[@osamashoukry399]

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

[@twicebittenthasme5545]

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

[@Hampardo]

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

[@dasaggropop1244]

otherwise you'd be the one reinterpreting newtons mechanics

[@ElusiveTruth]

Trying to visualize this is completely inversely proportional to the methods I was taught throughout all of my education. SAD. We should teach HOW to learn not just regurgitating "facts" and "laws" which, imho, are in "fact" just theories based upon the human's finite perception (real and imagined) ...nevermind...what was I saying? LOL

[@HBC423]

Sebastián that's what I'm saying

[@helperfunction4981]

Very realistic, no joke, answer. An average human brain has ~1500 ccm of brain matter. Mathematicians like Gauss had ~1800 ccm of brain matter, that's 300 ccm or 1 coffee mug of brain matter more than regular people - there is just no way for a regular Joe to deeply understand advanced math, no matter how much effort he puts in, preiod. Your abilities are hard capped by the total number of axons and neurons, it's that simple. Parents, don't lie to your kids that they can be anything they want if they study hard enough, tell them the truth - they can only be what their genetics allow them to be - their abilities in life are predetermined from birth, nothing can change them. Blackpill 101

[@FinBoyXD]

Sebastián I feel soo sorry for you :/

[@charlesmcmillion5118]

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.

[@chiralhead7577]

thanks for putting this thing up, its awesome

[@amalantony8594]

Really enjoyed this one.

[@ucid5363]

Most well crafted comment on youtube.

[@akshayv2849]

Thanks for sharing😉

[@NovaWarrior77]

I read one small excerpt from this and it was amazing. I didn't realize it was a full story!

[@johndoh1000]

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!!!

[@TheDalaiLamaCon]

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.

[@babotond]

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?

[@Hexanitrobenzene]

Well, if a comet goes near a Sun, significant part of it will evaporate. So, it does not hold always.

[@pi17]

*Vsauce music intensifies*

[@rachidvanheyningen]

*Michael* : Or is it?.. Change... This word is made up out of 6 roman letters.. *Me* : Wtf.....

[@dekippiesip]

@@Hexanitrobenzene Therefore the trajectory of a comet will involve a more difficult calculation.... Now imagine the rate of evaporation is inversely proportional to the distance to the sun as well as proportional to the surface area of the comet facing the sun, would that be a reasonably solvable situation(without getting into numerical analysis)?

[@topapo3661]

Dun dun dunnnnnn

[@randolphpatterson5061]

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!

[@joetursi4089]

Once again, a wonderful presentation!! Thanks.

[@kelemnamare2535]

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

[@intemister]

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!

[@goharbajwa5676]

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

[@dvd11811]

LOL

[@MohaMMaDiN55]

LOL

[@nischay4760]

LOL

[@AmanSingh-rg7hk]

LOL

[@abdulhaseeb8907]

LOL

[@dejablueguitar]

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

[@sujitmohanty1]

Bravo 3b1b- it's like watching an art and just enjoying the moment without understanding !!

[@adamcummings20]

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

[@the.y.method]

I think Feynman was trolling mathematicians. ;-)

[@RWBHere]

Having heard Susskind's comments about Feynman's massive ego, it would be his kind way of saying, 'Take that, mathematicians; I win!'.

[@BLUEGENE13]

whats the joke

[@sciencemanguy]

@@BLUEGENE13 r/whoosh

[@greatunknown109]

BLUEGENE13 The joke is that mathemathicians sometimes write QED at the their proofs, which is an abreviation of the latin words "quod erat demonstrandum" which means "what had to be demonstrated".

[@godbennett]

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

[@hydropage2855]

So each 3b1b lived for just under 4 years?

[@RobbyBoy167]

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

[@anest-uk]

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.

[@realtan2890]

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

[@common_undead]

I see what you did there

[@alexmatsumura4222]

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

[@actorpus]

Alex Matsumura “so you can see all the parts” 😂

[@JairoCepeda]

NANI

[@yash1152]

timestamps??

[@CapDanAddams]

10:00

[@hervehotot7675]

Just loved this video ! 3Blue1Brown : you are the best at explaining complex concepts step by step with very elaborated (and beautiful !) animations. thank you

[@quietkiller3562]

2 GREAT LEGENDS IN A VIDEO HOPE U BOTH MAKE MORE VIDEOS

[@Pulsar77]

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

[@Pulsar77]

www.reddit.com/r/3Blue1Brown/comments/86e1jw/video_suggestion_a_geometric_proof_of_keplers/

[@columbus8myhw]

Gives me hope that he'll cover my suggestions of RSA and knot theory someday. (Though the latter might be difficult to animate…) To anyone reading this, I highly suggest checking out Pulsar's write-up in the link given. It can help solidify any remaining confusions.

[@discy12345]

O no you di'nt

[@danieljensen2626]

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.

[@psharmacgk]

Physics is a different mindset from math, so yeah this did have a different feel. Orbits are really tough at first encounter but incredibly satisfying once you understand, keep at it!

[@danieljensen2626]

P Sharma I think it's actually the math perspective that's throwing me here. I have a pretty good intuitive understanding of orbits from physics in terms of angular momentum and potential energy (and let's be honest, most of my intuition for orbital dynamics comes from playing Kerbal Space Program) so this sorta abstract mathematical approach is throwing me off. I often find that math is very dense though, so it's not too surprising. The people who came up with our mathematical language did a very good job of distilling complicated ideas into concise and precise language.

[@psharmacgk]

I suggest checking orbits out in a college level classical mechanics text, there's way more math involved but it may help you reconcile everything here. The actual derivation of elliptical orbits from Newton's second law is truly awesome and it was a lecture I don't think I'll forget, hopefully you'll enjoy that too.

[@psharmacgk]

pyropulse your comment made me laugh so much... If you think physics and math are the same thing then you're either just barely through your majors and trying to talk big or you've been taught rather poorly. This was a wonderful video but it was very noticeably done from a mathematician's perspective, he didn't hit on physical intuition very much because he used math proofs instead which (I'm guessing) is why OP felt like something was different, you with your double major should've recognized that.

[@discy12345]

That escalated quickly

[@TheCyberHippie]

Love the conceptual simplicity of this.

[@ShaneAck]

Amazing video. This channel is so impressive. Thank you!

[@jimandaubz]

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

[@harrystuart7455]

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

[@Rudenich911]

Gorgeous collaboration!

[@Fabsurf101]

A beautiful geometric expression of this interesting orbital relationship with mathematical proofs how it derives into such fascinating vectors from the gravitational pull.

[@kushagraverma9452]

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

[@dragoncurveenthusiast]

It's the only way to watch a 3blue1brown video imo!

[@beattoedtli1040]

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.

[@fanimeproductionst.v.3735]

Wow! What a trickster!!!

[@nightowl19god25]

Beat Toedtli I didn’t even read the comment because I knew I wouldn’t understand it but I’m acting like I do understand it so I seem smart.

[@gunsandkithes6900]

wait Newton didnt have vector????

[@SharonOnTheNet]

I think he proved it both ways.

[@SharonOnTheNet]

@Simon Tracer The velocity doesnt matter, onlt the acceleration of the sun would matter.

[@wilhelmtaylor9863]

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.

[@PotPoet]

I highly recommend this excellent presentation. Bravo.

[@dvd11811]

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 KZbin, 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!!!

[@kanavdwevedi826]

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

[@hughbarton775]

Tremendously clear!!!! Great job.

[@debjitdas583]

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

[@micayahritchie7158]

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

[@joselinares4888]

No

[@kindlin]

'No,' sarcastically or literally? It can _go either way!_

[@joselinares4888]

Literally, it’s just like a 3b1b video: long and interesting af.

[@micayahritchie7158]

kindlin I had just taken it literally but now I'm curious

[@shahinaa7425]

Nah

[@tiresias3342]

20 minute Physics Even better!

[@brianjohnson2905]

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

[@flwi]

Wow, this is mind blowing. Very well explained - one thing you and Feynman have in common.

[@althealligator1467]

*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.*

[@fanimeproductionst.v.3735]

I too, shall do this.

[@althealligator1467]

@@fanimeproductionst.v.3735 Wonderful, truly wonderful!

[@red-baitingswine8816]

An energizing idea!

[@chris-tg6ki]

Think of operating a cnc machine when carving out, the chips fly in those directions, if the tool breaks it also flys in that direction, just have the infinite intelligence to have the guards shut when it dose!

[@ishworshrestha3559]

Ok

[@dnzssrl]

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

[@user-qj7qq6lw2n]

LOLL'I579 Welcome to the 3blue1brown land.

[@dnzssrl]

I'm already a citizen of that place :D

[@zapkagerrit6951]

go have a look on fractal geometry ;)

[@MyBiPolarBearMax]

fierce competition? =p

[@zapkagerrit6951]

urgh

[@TheVikrant997]

This is really challenging stuff to conceive. Appreciated .

[@ChandravijayAgrawal]

I thought it was 3blue1brown who uploaded video

[@temp_name_change_later]

Chandravijay Agrawal I did too lol

[@cucginel1941]

Chandravijay Agrawal me too

[@zeronothinghere9334]

Same

[@N00B283]

tru

[@sanzhang5892]

me too

[@hiddeneagle1408]

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

[@JochemKuijpers]

This video came from 3blue1brown. See the video description for more videos like this.

[@sandyz1000]

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

[@tranquoclan5043]

thanks so much for the knowledge

[@realityChemist]

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

[@hasiumcreeper5384]

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

[@Evan490BC]

Everything except the accent...

[@craigmatthews4517]

Appreciate the explanation as I know there are a lot of proofs of Kepler's laws, but I have found very few videos explaining Newtons conclusion on why orbits must be ellipses. That part of the story where Halley requested his analysis has always fascinated me. Thanks

[@MichaelRWolf]

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

[@useit97]

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!

[@anywallsocket]

"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

[@Amar061]

With each new replay of the video, the question becomes clearer by 1 word. All in all, 41-43 concentrated plays of this video are required for the question to be clear. If you want proof... well, you have this line that shows it if you just turn it 90 degrees into your brain. Good luck & have fun!

[@rumfordc]

+Amar Are you telling me the answer is 42?

[@yashpandey5416]

the answer is an ellipse. which is a curve that satisfies the above property

[@vvanderer]

@@yashpandey5416 that's an elliptical way to say 42

[@ElusiveTruth]

This is EXACTLY what I have pondered for many years! Now it is time to take it to the next step: The algorithm is quite simple actually, all mathematics can be defined with only a couple of variables. My computer science professor would look at me cross-eyed every time is suggested that digital and analog were not meant to be separated and thus the constant battle for accuracy with "smaller and smaller slices" so to speak....

[@turkishmaid]

Grant has for sure the most awesome voice on KZbin. I catch myself drifting away when he speaks all the time. O how I would love he would read bedtime stories for us (albeit probably in a separate channel)...

[@zoltantoth1566]

fantastic presentation of a difficult but interesting subject

[@semiawesomatic6064]

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.

[@luhadiagarvit]

Every bit of this statement is true...... Everytime I watch one of your videos, you take my breath away......just as talented as the honorable Christopher Nolan.

[@theflaggeddragon9472]

I had almost the exact same experience. Henry got me into physics, Sal Khan got me into calculus, I'm now going to second year math studies in uni with Grant inspiring me with every upload! These people are gifts to humanity!

[@semiawesomatic6064]

There's always that one guy.

[@semiawesomatic6064]

pyropulse dude, everyone is different. I just took my differential equations course and my first nuclear physics course, maybe half an hour of studying a week per class. Aced it. Not all of us have inferiority complexes like you, and not everyone has to study like you.

[@ishworshrestha3559]

Ok

[@triggerhappyhippie]

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

[@ishworshrestha3559]

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

[@onlyme0349]

Props for all the effort that went into this, I kind of expected a more intuitive overview with some examples of why this is useful, but we can't really expect you to be Feynman

[@johannesschutz780]

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.

[@shahidnabi010]

Wow...loved this one...

[@themuslimview]

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

[@sushruttadwalkar7701]

This is probably my favorite video on youtube.

[@quahntasy]

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.

[@fingernailclipper2152]

Woah 3blue1brown! :)

[@gee-haoddmuhamanana-jones4859]

Fingernail Clipper I believe it was supposed to say, G's up ho's down

[@alejrandom6592]

omg please more physics videos you are great!

[@eddiemorrone870]

That was great! I'll have to watch it again.

[@huhneat1076]

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

[@jm309767]

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

[@huwpickrell1209]

Beautifully explained thanks

[@twoduece]

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.

[@ROHAN0APK]

The PCA explanation by 3blue1brown got me a job ❤️

[@mkali56]

Rohan Damodar could you link to the video?

[@ROHAN0APK]

Not exactly a video on PCA. But understanding the eigen values and eigen vectors helped me a lot.

[@SatvikPlays23]

@@ROHAN0APK to q,2

[@SatvikPlays23]

I accidentally replied

[@Noname-nk5kv]

you know its good when minutephysics realeses a vid with Feynman in the title

[@robertocfaguiar]

Wall...so nice and not complicated at all. I think would be so hard to come with concept but once it is done is not that hard at all. He is basically using some calculus and geometry concepts. It is unbelievable how the graphics help the understanding of these things. Imagine Newton doing this from scratch with no visual aid. Also we need to congratulate Blue Brown, the way he explain it is so clear. It is like he sees inside your brain and trace the path to make your neurons flow. I didn't even had to focus that much, I just laid back and let the lines do the work for me. Awesome.....

[@irodionzaytsev]

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!!!

[@toomanyhobbies2011]

I don't think a Mathematician would ever say "blind calculation".

[@priyanshupradhan4388]

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