Gravitation' by Richard Feynman [1080p HD Video with clear audio]

Transcript Search in video 0:00 he left Cornell in 1950 and went to Caltech where he has been ever since 0:05 before I let him talk I want to tell you just a little bit more about him 3 or four years ago he started teaching a 0:12 beginning Physics course at Caltech and the result has added a new dimension to 0:17 his Fame his lectures are now published in two volumes and they represent a refreshing 0:24 approach to the subject in the preface of the published lectures there's a picture of 0:31 Fineman performing happily on the bongo drums my Cal Tech friends tell me that 0:39 he sometimes drops in on the Los Angeles night spots and takes over the work of the drummer but Professor Fineman tells 0:46 me that that's not so another of his Specialties is safe 0:52 [Music] cracking one Legend says that he once 0:58 opened a lock safe in a secret establishment removed a secret document 1:03 and left a note saying guess [Music] 1:08 who I could tell you about the time that he learned Spanish before he went to give a series of lectures in Brazil but 1:16 I 1:24 won't this this gives me enough this gives you enough background I think so let me let me say that I'm delighted to 1:31 welcome Professor feineman back to Cornell his General topic is the nature 1:38 of physical law and his topic for tonight is the law of gravitation an 1:43 example of physical law professor fin [Applause] 2:05 it's odd but in the infrequent occasions when I've been called upon in a formal place to play the bongo drums the 2:12 introducer never seems to find it necessary to mention that I also do theoretical 2:22 physics I believe that's probably uh that we respect the Arts more than the 2:28 Sciences the artist of the Renaissance said that man's main concern 2:34 should be for man and yet uh there are some other things of interest in the world even the 2:41 artists appreciate sunsets and the ocean waves and the march of the Stars across 2:47 the heavens and there is some reason then to talk of other things 2:55 sometimes as we look into these things we get an aesthetic pleasure pleasure from him directly on observation but 3:02 there's also a rhythm and a pattern between the phenomena of nature which isn't apparent 3:09 to the eye but only to the eye of uh analysis and it's these rhythms and 3:15 patterns which we call physical laws what I want to talk about in this series of 3:20 lectures is the general characteristics of these physical laws that's even another level if you will of higher 3:26 generality over the laws themselves and it's U really what I'm talking about 3:33 is nature as seen as a result of detailed analysis but only the most 3:40 overall General qualities of nature is what I mainly wish to speak about now such a topic has a tendency to become 3:46 too philosophical because it becomes so General that a person talks in such generalities that everybody can 3:52 understand him and it's considered to be some deep philosophy if you however I would like to be very 4:00 rather more special and I would like to be understood in an honest way rather than in a vague way to some extent and 4:06 so if you don't mind I'm going to try to give instead of only the generalities 4:14 in this first lecture an example of physical law so that you have at least one example of the things about which 4:20 I'm speaking generally in this way uh I can use this example again and again to 4:26 give an instance to make a reality out of something which otherwise be too abstract now I've chosen for my special 4:33 example of physical law to tell you about the theory of gravitation or the phenomena of 4:39 gravity why I chose gravity I don't know I had whatever I chose you would have asked the same 4:46 question actually it's uh was one of the first great laws to be discovered and it 4:53 has an interesting history you might say yes but then it's old hat I would like to hear something 4:59 about science more modern science more recent perhaps but not more modern 5:04 modern science is exactly in the same tradition as the discoveries of the law of gravitation it is only more recent 5:10 discoveries that we would be talking about and so I have no I do not feel at all bad about telling you of the law of 5:17 gravitation because I am in describing its history and the methods the character of its Discovery and its 5:22 quality talking about modern science completely 5:28 modern this law has been called the greatest generalization achieved by the human 5:33 mind and you can get already from the my introduction I'm more interested not so much in the human mind 5:41 as in the Marvel of nature who can obey such an elegant and simple law as this 5:46 law of gravitation so our main concentration will not be on how clever we are to have found it all 5:53 out but on how clever she is to pay attention to it 6:01 now uh what is this law of gravitation that we're going to talk about the law 6:06 is that uh two bodies or bodies exert a force upon each other which is inversely 6:13 as the square of the distance between them and varies directly as the product of their masses and the mathemati 6:20 mathematically we can write that great law down and the formula some kind of a constant times a product of the two 6:26 masses divided by the square of the distance now if I add the 6:32 remark that a body reacts to a force by accelerating or by changing its velocity 6:38 every second to an extent inversely as its mass it it reacts uh changes 6:44 velocity more if the mass is lower and so on inversely is the mass then I have said everything about the law of 6:50 gravitation that needs to be said everything else is a consequence a 6:55 mathematical consequence of those two things that I said that's a remarkable enough phenomenon in itself that the 7:01 next lecture will consider this in more detail now I know you're not all here I 7:07 know some of you are but you're not all mathematicians and so you cannot all immediately see all of the consequences 7:12 of these two remarks and so what I would like to do in this lecture is to briefly tell you 7:18 the story of the discovery tell you what some of the consequences are what the effect of this discovery had on the 7:25 history of science what kinds of mysteries such a law entails some something about the refinements made by 7:31 Einstein and uh possibly the relation to other laws of physics the history of the 7:36 thing briefly is this that the Ancients first observed the way the planets seemed to move about in the sky and 7:43 concluded that they all went around along with the Earth went around the Sun this discovery was later made 7:50 independently by cernus after they had forgotten that people have forgotten that it had already been 7:55 made now the next thing question that came up in to 8:02 study was exactly how do they go around the Sun that is exactly what kind of 8:08 motion do they go with the Sun at the center of a circle or do they go in some other kind of a curve how fast do they 8:13 move and so on and this discovery took a longer to make 8:20 the times after cernus were times in which there were great debates about whether the planets 8:27 in fact went around the Sun along with the Earth or whether the Earth was at the center of the universe and so on and 8:33 there were considerable arguments about this when a man named Tao Bri got an 8:39 idea of a a way of answering the question he thought that it might perhaps be a good idea to look very very 8:46 carefully and to record where the planets actually appear in the sky and 8:51 then the alternative theories might be distinguished from one another this is the key of modern science and is the 8:58 beginning of the true understanding of nature this idea that to look at the 9:03 thing to record the M the details and to hope that in the information thus obtained May lie a clue to one or 9:10 another of a possible theoretical interpretations so Tao who was a rich man and owned I believe an island near 9:19 Copenhagen outfitted his island with great brass circles and special 9:24 observing positions situation chairs that you could look through little HS and 9:30 recorded night after night the position of the planets it's only through such 9:35 hard work that we can find out 9:41 anything when these all these data were collected they came into the hands of 9:48 Kepler who then tried to analyze what kinds of motions the the planets made 9:54 around the Sun and he did this by a method of trial and error at one stage he thought he had 10:00 it he ass he figured out that they went around the Sun in circles with the sun off center and noticed that one planet I 10:07 think it was Mars but I don't know uh was 8 minutes of Ark off and he decided this was too big for Tao Brady to have 10:14 made an error and that this was not the right answer so because of the Precision of experiments he was able to proceed 10:21 and find that to go on to another trial and found in fact ultimately this three 10:26 things first that the planets went in ellipses around the sun with the sun of the focus 10:32 an ellipse is a curv you all artists know about because it's a for shorten Circle or children know about because 10:39 somebody told them that if you take a string and tie it to two tacks and put a pencil in there it'll make an ellips 10:46 these two tacks are the fosi and if the Sun is here the shape of the orbit of a planet around the Sun is one of these 10:53 curves the next question is and going around the ellipse How does it go does 10:58 it go faster when it's near the sun slower when it's further from the Sun and so on we take away the other Focus 11:04 we have the sun then and the planet going around and Kepler found the answer 11:09 to this too he found this that if you put the position of the planet down in two at 11:17 two times separated by some definite time let's say uh 3 weeks and then at another place in the 11:23 orbit put the positions of the planets again separated by 3 weeks and draw 11:28 lines from the sun to the planet technically called radius radius vectors 11:33 anyway lines from the Sun to the planet then the area that's enclosed in the 11:41 orbit of the planet and the two lines that are separated by the planet's position 3 weeks apart is the same no 11:47 matter what part of the orbit the thing is on so that it has to go faster when it's closer in order to get the same 11:52 area as it goes slower when it's further away and in this precise 11:57 manner some several years later he found the third 12:03 Rule and uh that had not to do with the exactly motion of a single planet around the Sun but related the various planets 12:10 to each other and it said that the times that took the planet to go all 12:17 the way around was related to the size of the orbit and that the times went as 12:22 the square root of the cube of the size of the orbit and for the size of the orbit is the diameter all the way across 12:28 the biggest distance on the ellipse so uh he has these three laws 12:34 which are summarized by saying it's an ellipse and that equal areas are swept in equal 12:41 times and that the time to go around varies as a three half power of the size 12:47 the square root of the cube of the size so it's three LS of Kepler which is a very complete 12:54 description of the motion of the planets around the Sun 13:01 the next question was what makes him go around well how can we understand this in more detail or is there anything else 13:08 to say in the meantime Galileo was investigating the laws of 13:14 motion incidentally at the time of uh Kepler the problem of what drove the 13:19 planets around the Sun was answered in some some by some people by saying that 13:24 there were Angels behind here beating their wings and pushing the planet along wrong around the 13:30 orbit as we'll see that that answer is not very far from the truth the only difference is that the Angels sit in a 13:37 different direction and the wings 13:46 going but the point that the Angels sit in a different direction is the one that I must now come to Galileo in studying 13:53 the laws of motion and doing a number of experiments to seeing how balls roll down inclined Plains and pendul swarms 13:59 and so on discovered a idealization a great principle called a principle of inertia which is this that if a thing 14:07 has nothing acting on if an object has nothing acting on and it's going along at a certain velocity in a straight line 14:12 it will go at the same velocity at exactly the same straight line forever unbelievable though that may sound to 14:18 anybody who has tried to make a ball roll forever the idealization did is correct 14:26 and that that there were no influences acting such as a friction on the FL and so on the thing would go at a uniform 14:31 speed forever the next point was made by 14:36 Newton who discussed the next question which is when it doesn't go in a straight line then 14:42 what and they answered this way that a force is needed to change the Velocity 14:49 in any manner first for instance if you're pushing it in a direction that it moves it will speed 14:54 up if you find that it changes Direction then the force have must have been 15:00 sideways and that the force can be measured by the product of two effects 15:05 first how much does the velocity change in the small interval of Time how fast 15:11 is the velocity changing how much is it accelerating in this direction or how much is the velocity changing when it 15:16 changes its Direction that's called the acceleration and when that's multiplied by a coefficient called the mass of an 15:22 object or it's inertia coefficient then that together is a force one can measure the for instance 15:29 if one has a stone on the end of a string and swings it in the circle over his head then one can measure one finds 15:36 one has to pull the reason is that the speed of this the velocity the speed is not changing as it goes around the 15:42 circle but it's changing its direction so there must be perpetually an in pulling force and this uh is 15:49 proportional to the mass so that if we were to take two different objects first swing one and then swing another one at the same speed around the head and 15:56 measure the force in the second one that second one uh the the new force is bigger than the 16:01 other force in the proportion that the masses are different this is a way of measuring the masses by how much how hard it is to change the 16:11 speed now then newon saw I from 16:16 this that for instance to take a simple example if a planet is going in a circle around the 16:22 sun no force is needed to make it go sideways tangentially if there were no 16:28 Force at all on it it would have just keep coasting this way but actually the planet doesn't keep coasting this way 16:35 but finds itself later not out here where it would go if there were no Force 16:40 at all but further down toward the the 16:45 sun in other words its velocity its motion has been deflected toward the Sun 16:51 so what the angels have to do is to beat their wings in toward the sun all the time that the motion to keep it going in 16:59 straight line has no known reason the reason why things Coast forever has 17:05 never been found out the law of inertia is no known origin so the Angels don't 17:12 exist but the continuation of the motion does but in order to obtain the falling 17:17 operation we do need a force so it would became apparent that 17:23 the origin of that the force was toward the Sun as a matter of fact Newton was a 17:28 ble to demonstrate that the statement that equal areas are swept in equal times was a direct consequence of the 17:35 simple idea that all of the changes in velocity are directed exactly to the sun even in the elliptical case and maybe 17:41 I'll have time next time to show you how that works in 17:48 detail so from this law he would confirm the idea that the force is toward the Sun and from knowing how the periods of 17:55 the different planets vary with the distance away from the sun it's possible to to determine how that Force must 18:00 weaken at different distances and he was able to determine that the force must vary inversely as the square of the 18:08 distance now so far he hasn't said anything yes because he only said two 18:14 things which Kepler said in a different language one is exactly equivalent to 18:20 the statement that the forces is toward the sun and the other is exactly equivalent to the statement that the law is inversely is a square of the distance 18:27 but people seen in telescopes the Jupiter's satellites going around Jupiter and it looked like a little 18:32 solar system so the satellites were attracted to Jupiter and the Moon is attracted to the Earth and this goes around the earth is attracted the same 18:39 way so it looks like everything's attracted to everything else and so the next statement was to generalize this and to say that every object attracts 18:45 every other object if so the Earth must be pulling on the moon just as the sun pulls on the 18:52 planet but it's in known that the Earth pulls on things because you're all sitting tightly in your seats in spite 18:58 of your desires to float out of the hall at this time the pull of for objects on the 19:05 Earth was well known in the phenomenon of gravitation and it was Newton's idea 19:10 then that maybe the gravitation which held the moon in the orbit also applied 19:16 was the same gravitation that pulled the objects toward the earth now it is easy 19:22 to figure out how far the Moon Falls in one second because if it went in a straight 19:29 line you know the size of the orbit you know it takes a month to go around and if you figure out how far it goes in 1 19:34 second you can figure out how far the circle of the moon's orbit has fallen below the straight line that it would 19:40 have been in if it didn't go the way it does go and this distance is 19:47 12th of an inch now the Moon is 60 times as far 19:54 away from the Earth's center than we are we're 4,000 mil away from the center in the moon is 240,000 MIL away from the 20:00 center so if the law of inverse square is Right an object that the Earth's surface should fall in 1 second by/ 12th 20:09 of an inch times 3600 being the square of 60 because the force has been weaken 20:14 by 60 * 60 for the inverse Square LW in getting out there to the moon and if you 20:20 multiply a 20th of an inch by 3600 you get about 16 ft and low it is known 20:25 already from Galileo's measurements that fell in 1 second on the Earth's surface by 16 20:31 ft so this mean meant you see that he was on the right track there was no going back 20:37 now because a new fact that was completely independent previously which is the period of the moon's orbit and 20:43 its distance from the Earth was connected to another fact which is how long it takes something to fall in one 20:48 second so this was a grammatic test that everything's all right further he had a lot of other predictions he was able to 20:56 calculate what the shape of the orbit should be if the LA with the inverse square and found indeed that it was an 21:01 ellipse so he got three for two as it were in addition a number of new 21:06 phenomena had their obvious explanations one was the tides the tides 21:12 were due to the pull of the moon on the earth this had sometimes been thought of 21:18 before with the difficulty that if it's the pull of the moon on the earth the 21:23 earth being here the waters being pulled up to the Moon then the would only be 21:28 one tide a day where that bump of water is under the moon but actually you know there are tides every 12 hours roughly 21:35 and that's two Tides a day but you must there was also another school of thought that had a different conclusion their 21:41 theory was that it was the earth that was pulled by the Moon away from the 21:52 water so actually Newton was the first one to realize what actually was going on that the force of the moon on the 21:59 earth and on the water is the same at the same distance and that the water here is 22:05 closer to the moon and the water here is further from the Moon than the earth than the rigid Earth so that the water 22:11 is pulled more toward the moon here and here is less toward the moon than the earth so there's a combination of those 22:17 two pictures that makes a double tide actually the Earth uh does the same trick as the Moon it goes around a 22:25 circle really I mean the force of the moon on the earth is Balan but by what by the fact that just like the moon goes 22:31 in a circle to balance the Earth's Force the Earth is also going in a circle actually the center of the circle is 22:37 somewhere inside the earth it's also going in a circle uh to balance the moon so the two of them go around a Common 22:43 Center here and if you wish this water is thrown off by centrifugal force more than the earth is and this water is 22:49 attracted more than this average of the Earth at any rate the tides were then 22:55 explained and and the fact that they were two a day a lot of other things became quite clear 23:01 why the Earth is round because everything gets pulled in and why it isn't round because it's spinning so 23:08 that the outside gets thrown out a little bit in at balances and why the Sun and Moon around 23:13 and so on now as the science developed and 23:18 measurements were made ever more accurately the tests of Newton's law became much more stringent and the first 23:24 careful tests involved the moons of Jupiter by careful observations of the way they went around over a long period 23:31 of time one could be very careful to check that everything was according to Newton and turned out not to be the case 23:38 the moons of Jupiter appeared to be first to get sometimes to 8 minutes ahead of time and sometimes 8 minutes 23:44 behind schedule where schedule is the calculated values according to Newton's Laws it was noticed that they were ahead 23:51 of schedule when they were close when Jupiter was close to the Earth and behind schedule when it was far away a 23:56 rather odd circumstance and Mr Roma having confidence in the law of gravitation came to an interesting 24:03 conclusion that it takes light some time to travel from the moons to the Earth and that what we're looking at when we 24:08 see the moons and not how they are now but how they were the time ago that it took the light to get here now when 24:14 Jupiter's near us it takes less time for the light to come and when Jupiter's further it takes longer time so he had 24:20 to correct the observations for the differences in time and by the fact that they were this much too early or that 24:26 much too late was able to determine the velocity of light this was the first demonstration that light was not an instantaneously 24:33 propagating material I bring this particular matter to your attention because it illustrates something that 24:39 when a law is right it can be used to find another one 24:44 that by having confidence in this law if something is the matter it suggests perhaps some other phenomenon and if we 24:51 had not known the law of gravitation we would have taken much longer to find the speed of light because we would not have 24:57 known what to expect of Jupiter satellites this process has developed 25:02 into an avalanche of discoveries each new discovery permits the tools for much more Discovery and this uh be this the 25:09 beginning of that Avalanche which has gone on now for 400 years in a continuous process and we're still 25:16 avalanching along at high speed at this time another problem came up the planets 25:24 shouldn't really go in ellipses because according to Newton's Laws they're not attracted only by the Sun but also they 25:30 pull on each other a little bit only a little bit but a little bit is something and will alter the motion a little 25:37 bit so Jupiter Saturn and Uranus were big planets that were known and the calculations were made as to how 25:43 slightly different than the perfect ellipses of Kepler the planets ought to be going Jupiter Saturn and Uranus by 25:49 the pull of one on each other and when they were finished the calculations I mean and the observations it was noticed 25:55 that Jupiter and Saturn went according to the calculation but that Uranus was doing something funny another opportunity for Newton's 26:02 laws to be found wanting but courage two uh men both who made these 26:10 calculations Adams and larier independently and almost exactly the same time proposed that the Motions of 26:17 Uranus were due to an unseen as yet new planet and S they wrote letters to their 26:23 respective observatories telling them to look turn your telescope and look there and you'll find a planet how absurd said 26:30 one of the observatories that some guy sitting with pieces of paper and pencils can tell us where we' look to find 26:35 something new planet and the other Observatory was more uh well less uh 26:42 well the administration was different and 26:50 uh they found the 26:55 Neptune more recently in the beginning of the 20th century it became apparent that the motion of the planet Mercury 27:01 was not exactly right and this caused a lot of trouble and had no explanation 27:07 until a modification of Newton's this did show ultimately that Newton's laws were slightly off and that they had to 27:13 be modified I will not discuss the modification in detail it was made by 27:18 Einstein now the question is how far does this law extend does it extend 27:25 outside the solar system and so I show on the first slide evidence that the law of gravitation is on a wider scale than 27:32 just the solar system here is a series of three pictures of a so-called double 27:40 star there's a third star fortunately in the picture so you can see that they're really turning around and that nobody 27:46 just simply turned the frames of the pictures around which is easy to do on astronomical pictures but the stars are 27:51 actually going around and by watching these things and plotting the orbit you see the orbit that they make on the next 27:57 slide it's it's evident that they're attracting each other and that they're going around in the lipse according to 28:03 the way expected these are a succession of pictures uh going for all these different periods of time I think yes it 28:10 goes around this way they didn't see it well when it was too close and here it is in 195 my slide is very old it's gone 28:17 around maybe once more since and you'll be happy except when you notice if you 28:22 have noticed already that this Center is not an a focus of the ellipse but it's quite a bit off so something's a matter 28:29 with the law no it God hasn't presented us with this orbit face on it's tilted at a funny 28:35 angle and if you take an ellipse and Mark its focus and then hold the paper at an odd angle and look at it in projection the the focus doesn't have to 28:42 be at the focus of the projected image so it's uh because it's orbit is tilted in space that it looks that way it looks 28:49 like it's not the right pattern but it's all right and you can figure everything out satisfactory for that how about a 28:55 diff a bigger distance there's forces between the stars does it go any further than these distances which are not more 29:01 than two or three times the Solar System's diameter here's something in the next slide that's 100,000 times as 29:09 big as a solar system in diameter and this is a large number of 29:15 stars tremendous number of stars this white spot is not a solid white spot it's just because of the failure of our 29:20 instruments to resolve it but are very very tiny dots just like the other stars well separated from one another not 29:27 hitting each other each one falling through and back and forth through this great globular cluster it's one of the 29:33 most beautiful things in the sky as good as sea waves and sunsets and the distribution of this 29:40 material it's perfectly clear that the thing that holds this together is the gravitational attraction of the stars 29:46 for each other and the distribution of the material in the sense of how the Stars Peter out as you go out in 29:52 distance permits one to find out roughly how what the law is of force between the 29:57 stars and of course it comes out right that it is roughly the inverse Square the accuracy of these calculations and 30:03 measurements is not anywhere near as careful as in the solar system onward 30:09 does gravity extend still further this is a little pinpoint inside of a big Galaxy and the next slide shows a 30:16 typical Galaxy and it's clear that this thing again is held together somehow and the 30:22 only candidate that's reasonable is gravitation but when we get to this this size we haven't any way any longer to 30:29 check the inverse Square law but there seems to be no doubt that these great agglomerations of stars and so these 30:36 galaxies which are 50 to 100,000 light years across the solar system is well 30:42 from the Earth to the Sun is only eight light minutes this is 100,000 light 30:48 years that the gravity is extending even over these distances and in the next slide is evidence that it extends even 30:54 further here is what is called a cluster of galaxies there's a Galaxy here and 30:59 here and here there galaxies here they're all in one lump of galaxies analogous to the cluster of stars but 31:07 this time what's clustered are those big babies that I showed you in this previous 31:14 slide now we uh this is as far as uh it's about 1/10th or 31:20 well 100th maybe of the size of the universe in as far as we have any direct evidence that gravitational forces 31:27 extend so the Earth's gravitation if we take the 31:33 view has no Edge as you may read in the newspapers when the planet gets outside 31:38 the field of the gravitation it keeps on going ever weaker and weaker inversely as the square of the distance dividing 31:45 by four each time you're twice as far away until it mingles with the strong fields and gets lost in the confusion of 31:51 the strong fields of other stars but all together with the Stars in its neighborhood pulls the other stars to 31:57 form the Galaxy and altogether they pull on other galaxies to make a pattern a cluster of galaxies so the Earth's 32:05 gravitational field never ends but Peters out very slowly in a precise and 32:10 careful law probably to the edges of the 32:17 universe the law of gravitation is different than many of the other well is 32:22 is very important in the economy or in the Machinery of the 32:29 universe there are many places where gravity has its practical applications as far as the universe is concerned but 32:36 atypically among all the other laws of physics gravitation has relatively few practical applications I mean the new 32:43 knowledge of the law it has a lot of application it keeps people in their seats and so but it has few the 32:48 knowledge of the law has few practical applications relatively speaking compared to the other laws this is one case in which I picked an atypical 32:55 example it is impossible by the way by picking one example of anything to avoid picking one which is atypical in some 33:01 sense that's the wonder of the world the only application I could think of were first in some geophysical 33:07 prospecting in predicting the tides nowadays more modernly in working out 33:14 the Motions of the satellites and uh and Planet probes and so on that we send up 33:20 and also modernly to calculate the predictions of the planet's position which have great utility for astrologers 33:27 to public their predictions and horoscopes in the 33:32 magazines that's the strange world we live in that all the advances and understanding are used only to continue 33:40 the nonsense which has existed for 2,000 33:46 years now that that shows that gravitation extends to the great distances but 33:53 Newton said that everything attracted everything else do I attract you excuse me I mean do I attract 33:59 I was going to say excuse me do I attract you physically I didn't mean 34:05 know what I mean is to is it really true that two things attract each other D can 34:12 we make a direct test and not just wait for the planets and look at the planets to see if they attract each other and 34:18 this experiment the direct test was made by Cavendish on 34:23 equipment which you'll see indicated on the next slide 34:29 if I got my slides right well I made a 34:35 mistake I was talking about um the the the importance of the gravitation and I 34:41 was overwhelmed by my clever remark about astrologist and forgot to mention the important places where gravitation 34:47 does have some real effect in the behavior of the universe and one of the interesting ones is the formation of new 34:54 stars in this picture which is a gaseous nebula in inside our own Galaxy and 34:59 there not a lot of stars but it's gas there are places where the gas has been compressed or attracted to itself here 35:06 uh it starts perhaps by some kind of shock waves to get collected but the remainder of the phenomenon is that 35:12 gravitation pulls the cloud of gas closer and closer together so big mobs of gas and dust collect and form balls 35:20 which as they fall still further the heat generated by the falling lights them up and they become 35:26 Stars and we have in the next slide some evidence of the creation of new stars it 35:33 is unfortunately harder to see than I thought it was when I looked at it 35:38 before but this is not exactly the same as this this bump here is further out 35:44 than here and that this also has a new DOT here there are I have found better 35:51 examples but we're unable to produce a slide there is one example of a star patch A Light That Grew GRE in a place 35:58 in 200 within 200 days so that when this it was in in the same kind of condition 36:03 of a gas cloud when the gas collects too much together by gravitation Stars Are Born and this is the beginning of new 36:10 stars so the Stars belch out dirt and gases when they explode sometimes and 36:16 the dirt and gases then collect back again and make new stars sounds like perpetual 36:21 motion I now uh turned to the subject I meant to introduce which was the experiments on the small scale to see 36:28 whether things really attract each other and I hope now that the next slide does indicate this is a second try yeah Cav 36:34 Dish's experiment the idea was to hang by a very very fine quartz fiber a rod 36:41 with two balls and then put two large lead balls in the positions indicated here next to 36:48 it on the side then because of the attraction of the balls there would be a slight Twist of 36:53 the fiber it had to be done so delicately because the gravitational force between ordinary things is very 37:00 very tiny indeed and there it was and it was possible then to measure the force 37:05 between these two balls Cavendish called his experiment weighing the 37:11 Earth We're pedantic and careful today we wouldn't let our students say that we 37:17 would have to say they measuring the mass of the Earth you know but the reason he say that said that is the 37:23 following by a direct experiment he was able to measure the force and the two masses and the distance and thus 37:29 determine the gravitational constant you say yes but we have the same situation on the earth we know what the pull is 37:35 and we know what the mass of the object pulled is and we know how far away we are but we don't know the either the mass of the Earth or the constant but 37:42 only the combination so by measuring the constant and knowing the facts about the pull of 37:47 the Earth the mass of the Earth could be determined so indirectly this experiment was the first determination of how heavy 37:54 or how massive is the ball on which we stand I it's a kind of an amazing achievement 38:01 to find that out and I think that's why Cavendish named his experiment that way instead of determining the constant in 38:06 the gravitational equation weighing the 38:12 Earth he incidentally was weighing the Sun and everything else at the same time because the pull of the sun is 38:19 known in the same manner now one one other test of the law 38:25 of gravitation is very interesting and that is the question as to 38:31 whether the uh the pull is exactly proportional to 38:36 the mass if the pull is exactly proportional to the mass and the reaction to forces the Motions induced 38:42 by forces the changes in velocity are inversely proportional to the mass that means that two objects of different mass 38:49 will change their velocity in the same manner in a gravitational field or two 38:54 different things no matter what their mass in a vacuum will fall the same way toward the Earth and that's Galileo's old 39:01 experiment from the Leaning Tower I took my young son of two and a half to the Leaning Tower of Pisa and 39:07 now he every time a guest comes he says Leaning Tower so anyhow it means for example 39:16 that in a satellite uh I mean a a man-made satellite an object inside will go 39:23 around the Earth in the same kind of an orbit as a satellite on the outside and thus float in the middle apparently so 39:29 that this fact that the force is exactly proportional to the mass and that the reactions are inversely proportional 39:35 Mass has this very interesting Consequence the question is how accurate is it and it has been measured by an 39:43 experiment by a man named OS in 199 and very much more recently 39:49 and more accurately by Dicky and it is known to one part in 10,000 million the 39:56 mass is exactly proportional I mean the forces are exactly proportional to the 40:03 mass how it's possible to measure with that accuracy I wish I had the time to 40:09 explain but I'm afraid I I cannot it's a remarkably clever I'll give a hint how I 40:14 give one hint there it suppose that you wanted to measure whether it's true for the pull of the sun you know the sun is 40:20 pulling us all it pulls the Earth too but suppose you wanted to know whether you had a piece of lead here and the 40:27 piece of of copper here or polyethylene and Lead it was first done with sandal wood 40:34 now it's done with polyethylene whether the pull is exactly proportional to the to the inertia the 40:41 Earth is going around the Sun so these things are thrown out by inertia and they're thrown out to the extent that 40:47 these two objects have inertia but they're attracted to the Sun to the extent that they have mass in the 40:53 attraction law so if they're attracted to the sun in a different prop and they're thrown out by inertia one will 40:59 be pulled toward the sun and the other away and so hanging on another one of those Cavendish quartz fibers the thing will twist toward the sun it doesn't 41:06 twist to this accuracy so we know that the sun's attraction for these two objects is exactly proportional to the 41:13 centrifical effect which is inertia so the force of attraction on an object is exactly proportional to its coefficient 41:18 of inertia in other words its mass I should say something about the 41:24 relation of gravitation to other forces to other parts of nature other phenomena 41:30 in nature and I'll have more to say of a general quality later but there is one 41:36 thing that's particularly interesting and that is that the inverse Square law appears again it appears in the electrical laws for instance that 41:42 electricity also exerts forces inversely as a square of the distance this time between charges and one thinks perhaps 41:51 inverse square of the distance has some deep significance maybe gravity and electricity are different aspects of the 41:56 same thing no one has ever succeeded in making gravity and electricity different aspects of the same thing today our 42:03 theories of physics the laws of physics are a multitude of different parts and pieces that don't fit together very well 42:09 we don't understand the one exactly in terms of the other we don't have one structure from which all is deduced we 42:15 have several pieces that don't quite fit exactly yet and that's the reason why in these lectures instead of having the 42:21 ability to tell you what the law of physics is I asked talk about the things that are common to the various laws 42:28 because we don't know we don't understand uh the connection between them but what's very strange is that 42:33 there are certain things that are the same in both but now let's look again at the law of electricity the law goes inversely as 42:40 the square of the distance but the thing that is remarkable is the tremendous difference in the strength of the 42:46 electrical and gravitational laws people who want to make electricity and gravitation out of the same thing will 42:52 find that electricity is so much more powerful than gravity that it's hard to believe they could both have the same origin now how can I say one thing is 42:59 more powerful than another it depends upon how much charge you have and how much mass you have I'm certainly uh well 43:07 the you can't talk about how strong gravity is by saying I take a lump of such and such a size because you chose 43:13 the size if we try to get something that nature produces her own pure number that 43:19 has nothing to do with inches or years or anything to do with our own Dimensions we can do it this way if we 43:25 take the fundamental particles such as which is an electron any different ones will give different numbers but to get 43:31 an idea of a number take electrons two electrons a fundamental particle that's an object it's not something I can't I 43:37 don't have to tell you what units I measure in it's two particles the fundamental particles and they repel each other inversely as a square of the 43:43 distance due to electricity and they attract each other inversely as a square of the distance due to gravitation question what is the ratio of the 43:50 gravitational force to the electrical force and that is Illustrated on the next slide 43:57 the ratio of the gravitational attraction to the electrical repulsion is given by a number with 42 44:04 digits and goes off here it's all this is written very carefully out so has 42 digits now there in lies a very deep 44:12 mystery where could such a tremendous number come from that means if you ever 44:17 had a theory from which both of these things are to come how could they come in such disproportion from one equation has a 44:24 solution which has for one two kinds of an attraction and a repulsion with that fantastic 44:31 ratio people have looked for such a large ratio in other places they're looking for a large 44:38 number they hope for example that there's another large number and if you want a large number why not take the 44:43 diameter of the universe to the diameter of a proton amazingly enough it also is 44:49 a number with 42 digits and so an interesting proposal is made that this ratio depends is the same 44:57 is a ratio of the size of the universe to the diameter of a proton but the universe is expanding with time and that 45:04 would mean the gravitational constant is changing with time and although that's a possibility there's no evidence to 45:10 indicate that it's in fact true and there are several difficulties where I mean partial indications that it doesn't 45:15 that the gravitational constant has not changed in that way so this tremendous number remains a 45:22 mystery I must say to finish about the theory of gravitation two more things one is that Einstein had to modify the 45:30 laws of gravitation in accordance to his princip with his principles of Relativity the first was one of the 45:36 principles was that effect effects cannot occur instantaneously while Newton's Theory said that the force was 45:41 instantaneous he has to modify Newton's Laws they have very small effects these modifications one of them is all masses 45:48 fall light has energy and energy is equivalent to mass so light should fall 45:54 and it should mean that light going near the sun is deflected it is and also the force of gravitation is slightly 46:00 modified in his theory so that the laws slightly changed very very slightly and it is just the right amount to account 46:07 for the slight discrepancy that was found in the movement of mercury finally with Rec connection to 46:14 the laws of physics on a small scale we have found that the behavior of matter on a small scale obeys laws so different 46:21 very different than things on a large scale and so the question is well does gravity how does gravity look on a small 46:27 scale what is what is called the quantum theory of gravity there is no quantum 46:33 theory of gravity today people have not succeeded completely in making a theory 46:38 which is consistent with the uncertainty principles and the quantum mechanical principles I'll discuss these principles 46:45 in another lecture now finally you will say to me yes you told 46:54 us what happens but what is this gravity where does it come from and what is it do you mean to tell me that the planet 47:00 uh looks at the Sun or sees how far it is takes the inverse of the square of the distance and then decides to move in 47:07 accordance with that law and move in other words although I've stated the ma mathematical law I hav't given 47:14 you no clue as to the mechanism I will discuss the possibility of doing this in the next 47:20 lecture which is the relation of mathematics to physics but finally in this lecture I 47:27 would like to disc to remind just at the end here to uh emphasize some 47:33 characteristics that the gravity has in common with the other laws that we have mentioned as we passed 47:40 along the first is that it's mathematical and its expression the others are that way too we'll discuss 47:47 that next time second it's not exact Einstein had to modify it we know it 47:52 isn't quite right yet because they have to put the quantum theory in that's the same with all our other laws 47:58 they're not exact there's always an edge of mystery there's always a place that we have some fiddling around to do yet 48:05 that of course is not a property probably not a property may or may not be a property of nature but it certainly is common with all the laws as we know 48:12 him today it may be only a lack of knowledge but the most impressive fact 48:19 is that gravity is simple it is simple to State the principle completely and 48:25 have no left have not left any vagueness for anybody to change the ideas about 48:30 it's simple and therefore it's beautiful it's simple in its pattern I don't mean it's simple in its actions 48:36 the Motions of the various planets and the perturbations of one on another can be quite complicated to work out what 48:42 the follow how all those stars in the globular cluster move is quite beyond our ability it's complicated in its 48:48 actions but not in the basic pattern or the the the system underneath the whole 48:54 thing is that's a simple thing that's common in all our laws they all 48:59 turn out to be simple things although complex in their actual actions finally comes the 49:06 universality of the gravitational law the fact that it extends over such enormous distances that Newton in his 49:12 mind worrying about the solar system was able to predict what would happen in an experiment of Cavendish where 49:19 cavendish's little model of the solar system the two balls attracting has to be expanded 10 million million times to 49:26 become the solar system and then 10 million million times expanded once again and we find the galaxies 49:34 attracting each other by exactly the same law nature uses only the longest threads 49:40 to Weaver patterns so that each small piece of her F of her fabric reveals the 49:46 organization of the entire tapestry thank you 50:10 [Music] Gravitation' by Richard Feynman [1080p HD Video with clear audio] ThinkOf 16.7K subscribers Subscribe 13K Share Download 529K views 1 month ago #richardfeynman #solarsystem #universe All the Credit goes to : Caltech, UCLA, BBC, Richard Feynman.... Feynman lecture Link- https://www.feynmanlectures.caltech.edu/ … 712 Comments rongmaw lin Add a comment... Pinned by @2Thinkof @2Thinkof 11 days ago Soon I'm going to delete this video, if you guys want you can download it. 12 Reply ThinkOf · 30 replies @coyotezee 1 month ago This should be required viewing for anyone claiming the earth is flat and that gravity doesn't work or hasn't been proven. I was a physics grad student at USC around 1980 and had him drop in on a grad student meeting and lecture for a few minutes. Proud to have that meeting. 31 Reply 4 replies @StefanHolmes 1 month ago Captivating. It's also refreshing to hear someone present without every other word being "um", "er" or "like". 103 Reply 9 replies @haydnj1202 1 month ago I used to lecture on clinical exercise. One year I told my students about Richard Feynman. Nobel prize winner that taught quantum theory etc using chalk and a blackboard…..so I said we are going to go all ‘Feynman’ this semester. You can read the slides online before the lecture but I’m going to teach you using a whiteboard and marker pens. Nothing more. The lectures were a huge success 33 Reply 3 replies @WsciekleMleko 1 month ago I spent close to 9 years on university studying physics. Ive done my phd on theoretical physics. But I didn't know what law of gravitational force is, nobody ever explained that to me until I watched this video. He was indeed a great teacher! I finally understood what is the meaning of this equation! 39 Reply 6 replies @agranero6 1 month ago (edited) Feynman believed he was going to a Spanish-speaking country in South America, so he started studying Spanish, but then when he was informed that he was going to Brazil he shifted to learn Portuguese. His visit is still remembered at my University. He tells in detail in Surely you're joking Mr. Feynman. 217 Reply 7 replies @HRConsultant_Jeff 1 month ago (edited) Aww lectures with the actual professor in the room, not one of his graduate students. So refreshing. And a chalk board, used sparingly but with impact to the lecture material is such a lost art now. This was how we taught the people that developed computers and landed people on the moon. These are the lectures they attended. 7 Reply 3 replies @giledgar1948 1 month ago As I watch this, tears come to my eyes with the realization that we have lost such a brilliant mind. Not all of his lectures or all of his writings comprise all of which he knew. What a terrible realization. 60 Reply 5 replies @MarcoMoreno5757 2 weeks ago It was very interesting. My physics teachers from middle school to university explained the "Law of Gravity." We did all the exercises without calculators, something the new generations might not understand. 6 Reply 1 reply @bennyksmusicalworld 1 month ago Who knows what Feynman could have achieved with today’s technology. One of the unquestionable geniuses the world has ever seen 31 Reply 3 replies @thomasbentley5544 3 weeks ago Even with the relatively clear audio, I appreciate the subtitles. I can’t always make out what someone’s saying, so they certainly help. (don’t want to miss a word this guy is saying) Thank you. 35 Reply 10 replies @gmejiabotero 1 month ago So eloquent. His teaching style and students engagement is legendary in the academic community. 161 Reply 11 replies @psdeepak321 1 month ago I am feeling... So satisfied...seeing "Gravitation' by Richard Feynman". In my school days, I used to study Galelio, Neuton's and Keplar's laws with hopes and ambitions. Now, After completing my postgraduation education in MCA i.e. Master of Computer Applications with Specialization in Machine Learning; Gravitation' by Richard Feynman makes me feel... as if I am already a master of Astronomy, also. What an explanation of Gravitation by Richard Feynman. 40 Reply 4 replies @hanszinnecker7250 4 days ago I knew Feynman's book "The Nature of Physical Law", but now for the first time, after 50 years of a life in physics & astrophysics, I hear the great man live on youtube! Thank you for providing this historic video! I hope his other lectures have been saved , too, for posteriority. 3 Reply @F.M.Dostoyevsky 1 month ago As a commerce student who left science long ago, this single video rekindled my interest in science again. Thank you! 255 Reply 1 reply @whiskeytango9769 2 weeks ago (edited) Feynman was a gift to us all. I watched live as he showed us exactly what caused the Shuttle to explode. Genius. 10 Reply @Karthik-kt24 13 days ago Youtube's the best source for knowledge in this day n age 6 Reply @pauliedibbs9028 2 weeks ago Men like Feynman truly come once every century, if then. 9 Reply @mybachhertzbaud3074 1 month ago So, pleased that so many of Mr. Feynman's lectures have been preserved. Always enjoy listening to him and hope generations to come take advantage.🤔 18 Reply @derekflanagan 6 days ago Bless the uploader and YouTube for keeping these lectures alive for us all ❤ 4 Reply @intractable 1 month ago This makes me so proud of humanity. 25 Reply 2 replies @AdrianSchubert88 1 month ago I like that he calls the mass "the inertia coefficient". It reminds us that we don't really know what mass is - except to say that the more of it there is in an object, the more it tends to maintain its state of motion (what we call inertia). 84 Reply 7 replies @roartolife 1 month ago What a spectacular, timeless lecture. 8 Reply @wombat5628 10 days ago Thank you for the upload! Such lectures in the past are so much more inspiring than what we see these days with modern technologies such as state of the art lecture halls with high end equipment, laser pointers,.... The lecture itself is the substance. 1 Reply @pk2712 1 month ago There will never be a other Richard Feynman. What an incredible scientist and teacher. 3 Reply @Zimbrabim 12 days ago I loved that bit about the speed of light and Jupiter's moons. He was a great ambassador for science and a great scientist in his own right. 2 Reply @erik-michael 1 month ago It's refreshing to know that great intellects throughout history, were once full of mischief. 10 Reply @NordicChrononaut 1 month ago (edited) Nothing has really changed since then: I doubt that more than 1% of today's US Americans know which main language is spoken in Brazil ... 569 Reply 107 replies @PCMcGee1 1 month ago Well done on the subtitles. Such a rarity these days. 179 Reply ThinkOf · 4 replies @susilgunaratne4267 1 month ago Brilliant mind influenced not only by abstract mathematical concepts but also by the artistic creativity, so he was beyond the normal physics descriptions in the text books. 13 Reply @piratenewscommentary 1 month ago (edited) Unbelievable lecture! I now understand the difference between Gravity and Gravitational. The first is a "Thing" and the second is an "Act". Also, the mystery of the relationship of Speed and Inertia (Mass) vs. Electricity. If we could find the "Thing" that is gravity, we could invent or devise anti-gravity. And by this I do NOT mean counter acting gravity with an illusion of being stationary but really cancelling out the actual effect or force that is that thing "Gravity". Wow, what a lecture!!!! He is the best teacher / professor I have ever witnessed. I have a very finite learning path or method whatever and learning or comprehending things delivered in ways contrary to this method has proved nearly impossible. But I understood every single word this incredible man said. Again, UBELIEVABLE!! 10 Reply @albertomezzatesta1259 2 weeks ago Amazing lecture, truly extraordinary. What a gem! Lucky the people who attended it. 1 Reply @breaneainn 1 month ago Feynman paved the way for famous Science communicators and celebrity scientists.. even before there was such a thing. 3 Reply @Darktrackerrs 1 month ago Man was hilarious. Still amazed that they were able to make so many predictions with such little technology 13 Reply 1 reply @barabbasrosebud9282 1 month ago Genius doesn't come close to describing Feynman. 15 Reply 1 reply @Pharoset 1 month ago Given during the 1962-1963 school year. 18 Reply @luisandrescabezas 1 month ago man wtf u are some magician, pls bring us more videos like this, this is so helpfull to humanity 1 Reply @Lakehurst69 1 month ago He would tell his students, and other budding scientists, that if they are unable to explain something using common everyday language, then they don't truly understand what they're talking about. 12 Reply 2 replies @GalaxyHomeA9 1 month ago This is gold 16 Reply @MarioXP2008 1 month ago Master!! amazing observations!! On great genius!! Richard!! Thanks!!! for that amazing work. 6 Reply @rojina8113 1 month ago I'm so happy. Thank you so muchhh for this video 6 Reply @billgardiner4858 2 weeks ago Thank you, Professor Feynman, for not letting Gravity get you down, and providing many moments of levity throughout your allustrious career. And now I'll shut up and continue to calculate... Reply @rayroc5938 1 month ago 'Genius- the life and science of Richard Feynman' James Gleick 7 Reply @MrBhaluFunny 1 month ago This video will cross 1M views soon ❤ 3 Reply @swaroopsahoo214 1 month ago I wish if he was my physics professor.. greatest physicist of all time prof. Feynman 6 Reply 3 replies @Andrew-tu5fm 3 weeks ago Sometimes, the extraordinary talents of great physicists include being great science communicators to the public as well as their students and colleagues. They clearly enjoy making science very learnable, and fun to listen to. Feynman was such a physicist. 1 Reply 2 replies @borgehansen501 11 days ago “… the other observatory … well their administration was different, and they found Neptune” - Classic ! 😂 (at around 26.30) - wonderful lecture - not only about some of the laws of physics but also about history of mankind especially Renaissance and “the avalanche of new discoveries over the past 400 years”. As we today stand at the brink of General Artificial Intelligence (GAI) it has never been more important for mankind to rally around a common set of moral laws for how to conduct ourselves in relation to each other … before it’s too late and mankind as such is just part of past history … along with the dinosaurs . 26:57 1 Reply @shrihanshetty8859 3 weeks ago Man, recommended just when our teacher started Gravitation at our coaching. Reply @roberttarquinio1288 1 month ago As Einstein put it, gravitation is a manifestation of space time curvature Some of my research is on gravitational physics: As space time interacts with a body of mass producing energy it curves about it producing space time curvature which deforms the fabric of space and time surrounding the body of mass causing spatial and temporal distortion which causes gravitational lensing and time dilation and 10:48 starlight to deflect as it passes through the gravitational field close to the surface of the body of mass such as the sun A gravitational field is comprised of gravitational field waves As gravitational fields interact they produce gravitational waves They say gravitational waves are ripples in space time I say they are ripples of space time The fabric of space time moves - flows - spatial hydrodynamics Time flows - temporal hydrodynamics 5 Reply 1 reply @joemalone3099 2 weeks ago (edited) What made him a great physicist is his tremendous mathematical background before switching to physics Reply @surendrasinghsikarwar4234 1 month ago What a great lecture ❤ . Waiting for one more on Machine Learning . 1 Reply @johnbeggs1951 1 month ago Thanks so much! Really enjoyable to watch 19 Reply ThinkOf · 1 reply @arkajeetbasak1802 1 month ago Nice job big brother. I am a Computer Science Student. But, I also like the concepts of physics and regularly follow shows like World Science Festival anchored by Physicist Brian Greene. I see a very decent start of a science channel in yours. 8 Reply ThinkOf · 1 reply @boredgrass 3 weeks ago All Feynman lectures need to be available as videos because clearly it is only a matter of time until they are banned in America. 5 Reply @richardpark3054 1 day ago Thanks! More, please! Reply @ManojChenn 1 month ago Wow!! Did Douglas Adams get his 42 (The answer to the Ultimate Question of Life, the Universe, and Everything) from the ratio of Electrical to Gravitational forces!! Fascinating!! 20 Reply 3 replies @ПавелТупицин-х8б 6 days ago Большое Спасибо. Reply @srmxe417 2 weeks ago What a treasure of a video Reply @sobrikey 9 days ago Thanks so much , very grateful Reply @cell151 4 weeks ago I never knew Ed Norton knew so much about Physics. 3 Reply 1 reply @kylev.8248 1 month ago How is this 5 days old. This is amazing 11 Reply ThinkOf · 2 replies @isaiahingky6942 1 month ago Brilliant. Thank you for sharing. 1 Reply ThinkOf · 1 reply @turrtle3359 1 month ago physic is not boring. Only teacher is boring 31 Reply 3 replies @Savahax 1 month ago So great. Love his thick accent too. Have you got some on Paul Dirac? He was a man of very few words but surely some of those must have been captured 11 Reply @mmburgess11 1 month ago The number 42 is once again observed in life, the universe and everything. 2 Reply 1 reply @Dragon1111-q2b 7 days ago Richard Feynman was the George Burns of theoretical physics 1 Reply @lucamoriconi712 1 month ago The lectures are great, the video is great. But my chairman friend, in Brazil people speak portuguese, not spanish. The fact is that Feynman gave a whole lecture in portuguese, while all the other brazilian scientists in the (local) meeting gave their lectures in english! 6 Reply 2 replies @sliceserve234 1 month ago truly fascinating. 1 Reply @alexbenjamin5823 1 month ago This man is a legend 1 Reply @stevekem1347 4 weeks ago He was portrayed in the movie 'Oppenheimer'. He was the guy in the car saying the windshield had adequate polarization against Trinity that he did not need goggles 1 Reply @Lakehurst69 1 month ago My second favorite physicist — immediately and very closely following Einstein. I have his two volume Caltech Physics 101 lectures. One of his quirks, if you will, is he would occasionally visit a "gentlemen's joint," sit in the corner, and sketch the dancers. 1 Reply 1 reply @goobfilmcast4239 2 weeks ago March 2025: Most of the Audience members are now in their 80s or older 3 Reply @stevekem1347 4 weeks ago His lectures to students isnt as dry as this; check them out as a treat Reply @Jimserac 1 month ago The physicist who talked like a gas station attendant. It shows that it is the inquiring mind that ends up being the key to discoveries, a mind contemptuous, though respectful, of those who came before and made their attempts at the mysteries and then he examines the shortcomings of the explanations and theories as he walks back and forth just as though he were serving two cars at once. He is tireless at examining consequences, implications, cross references, failures of theory to predict and successes as well, always ever seeking the real answers which, in one case, led him to a Nobel prize. It is not social station nor the ability to hob nob in the faculty lounge or entertain the donors' wives nor the skill to suck up to the proponents of the dominant or prevailing theories in the Physics, or worse, the Archeology Dept.. In the end, it is mind, attitude, will, unrepentant questioning and reexaminations that wins the day. 6 Reply 3 replies @Cursedleftfoot 1 month ago Thank you for uploading this! 1 Reply @elif2480 1 month ago I miss him so much even though I've never met him. 2 Reply @willclark491 1 month ago Pluto: 1930-2006 Never Forget. 3 Reply 1 reply @OzymandiasWasRight 2 weeks ago Appreciate the subtitles 👍 Reply @manuelpascua 1 month ago Thanks for such a document! Reply @akshatsrivastavaaa 1 month ago Thank you! really enjoyed this 1 Reply @jasonborne5724 1 month ago I Love listening to Ed Norton give a lecture about gravity…. 3 Reply 1 reply @Strike-.e 1 month ago One of first online classes 😂 but its quality ❤❤ 22 Reply ThinkOf · 2 replies @SoumadeepJana-hw9oh 1 month ago Thank you very much! It is wonderful! 😊 7 Reply ThinkOf · 1 reply @papagen00 1 month ago 16:19 Impressive drawing skill 1 Reply @smthagario5517 1 month ago What a GOOD way to introduce his lecture! 1 Reply @jewgenijmoldawski3306 1 month ago What would Feynmann say, if he knew, that 2025 he is being permanently interrupted by ueber eat ad. 17 Reply ThinkOf · 7 replies @ProstetnikV 4 weeks ago WTF makes people to vote thumb down to this video? Flat-earthers? Oh my gosh... 3 Reply @ourniche 2 weeks ago such a brilliant guy! Reply @SindhuYatra 1 month ago Thank you sir Reply @joevalentin2450 1 month ago Are there still professors now who are as brilliant as this one? 1 Reply 1 reply @mohammadrezanargesi2439 4 days ago The way they used to speak in that time us much much different from the way they do now. At that time the lecture used to be presented as if a news reporter was on a TV correspondence. Reply @lalittripathi561 1 month ago Splendid video Reply @chapmyers9272 1 month ago Scientific performance art. 1 Reply @deirdre108 12 days ago If bellicose space aliens were orbiting the earth and demanding to be shown three reasons why they shouldn’t obliterate the planet, I would suggest this lecture as one of the reasons. Reply @mohitmahajan292 1 month ago Thanks bhai Aise video dalte rehna❤❤ Reply @pasosyhuellas1322 3 weeks ago muchas gracias Reply @antisocial_akj 1 month ago I need to study Physics again. I have forgotten a lot of stuff. 😂😂 1 Reply @knowtheunknownwithme 12 days ago Superb Reply @itzshanu89 1 month ago Bruh.....From Where did u get this masterpiece 😂?? Btw huge respect to grt Richard sir ❤❤ 2 Reply ThinkOf · 1 reply @Vikashkumarsingh09 1 month ago Don't listen to the person who has the answers; listen to the person who has the questions. ~ Albert Einstein Reply @kirdref9431 1 month ago 41:20 gravitational mass equals inertial mass !! Very important discovery. Reply @wavydaveyparker 6 days ago Olá Professor Feynman, I really enjoyed your lecture on gravitation and think your delivery was very knowledgeable and entertaining. If you’ll allow me to be slightly critical for a moment? Can I politely suggest a couple of points, which you may like to consider? Firstly, the directional vectors you mentioned, actually cancel out at the centre of the Earth and not at the barycentre. The barycentre is the equilibrium position of the Earth-Moon system and is the point around which everything remains balanced. And secondly, the final vectors you drew, need to be resolved into there respective components. The vertical component has very little effect on the ocean, because it’s in direct competition with the Earth’s own gravitational attraction. Whereas the horizontal component is free to act on the water and increase its underlying pressure, which is the true cause behind the buildup of tidal systems. One thing is for certain though, the tides have nothing whatsoever to do with the Earth be pulled towards the Moon and leaving water behind, or partially filling up bulges! Take care and well done with the lectures on physics and congratulations on the Nobel prize for your contribution to quantum electrodynamics. Ciao wavy, QED. 7 Reply 2 replies @exoplanet11 4 weeks ago His wireless mike works pretty well. Better than some modern ones! Reply 1 reply @uksonune 1 month ago Gr8 Video Reply @Skok-Vremya 1 month ago Maybe the difference of 42 units, its because of "objects" that we calls planets are, like earth are including much more protons and electrons in them, so its just balancing this way? 43:59 1 Reply @sun-p6g 1 month ago We continue to try and make sense of our existence, and we continue to keep secrets, but not among nations, among the people who live in them. Reply @heldenvaeter 7 hours ago One addition to the "uses* of😅 gravitation: earths gravity varies localy also depending on the rocks found below. Gravity maps are important sources of inforfation on oil fields, some ores and the better understanding of the lithosphere. Reply @NicleT 1 month ago Excellent audio cleanup! Are the other lectures on your roadmap? 4 Reply ThinkOf · 1 reply @shafferhomemade9044 1 month ago I wonder what the formula would be for the motion of Feynman about the stage? 3 Reply 1 reply @peterl.2927 11 days ago The formation of stars is still a mystery! Reply @blazed-space 1 month ago Why was I wasting money on college when there are many free wonderful lectures available on the internet 4 Reply @jennyjones7370 1 month ago Such a culturally healthier time Reply @toshogme 2 weeks ago REALLY COOL Reply @mkliu1882 4 weeks ago I wonder if we could regenerate this video using AI to bring Feynman more vivid to life, truely miss him. Reply @tenrec 1 month ago At 22:44, his explanation of tides doesn't make sense to me. If the water on the side of the Earth away from the Moon is raised by centrifugal force from the Earth swinging around the center of the Earth-Moon system, wouldn't that create a 𝘮𝘰𝘯𝘵𝘩𝘭𝘺 tide, rather than twice daily? 1 Reply ThinkOf · 6 replies @williamwilson6499 2 weeks ago 38:59 Glad he lived long enough to see this be proven on the Moon by David Scott, Apollo 15 astronaut. Reply @kkampy4052 7 days ago I'm guessing the cameraman was exhausted after this. Reply @atrilab 2 weeks ago ❤ Reply @DanZ3r0-u2m 1 month ago Thanks :) Reply @2BachShakur 3 weeks ago “It’s my sleepover and I get to choose the movie.” Reply @adityatrivediii 1 month ago amazing Reply @thomaslangley1571 10 days ago I wish Feynman was still alive. Reply @MarkMARk-ww6rt 3 weeks ago Thx Reply @nicholastaylor9398 6 days ago It's puzzling that the inverse square laws are not pointed out to be at least compatible with a real or virtual 'flux' centred on the source (I know that's not fashionable) distributed over the area of a sphere. It doesn't seem that can be coincidental. 1 Reply @othfrk1 1 month ago And then we figured out that gravity doesn't exist. It's just mass pinching the universe and slowing down time. 3 Reply @atlantasailor1 1 month ago Incredible teacher. We lost a genius and gained a dictator. Who could have guessed? 6 Reply 2 replies @StanNochasak 2 weeks ago That's even another level, if you will, of higher generality over and it's really (all I am talking about is) nature as seen as a Reply @sakshijha787 3 weeks ago 😊😊 Reply @wavydaveyparker 2 weeks ago "Hello, I have the privilege of calling your attention today, to what is probably one of the most far-reaching generalisation of the human mind." ~ Richard. Galileo's Friends Got It Right! Back in olden days, a smart scientist called Galileo Galilei figured out that the Earth's motion through space could be related to the motion of the tides, that's called, correlation of effects. Although, he wasn't sure about the cause, that's called, causation. He understood the principle of inertia, but hadn't quite worked out the inverse square law of gravitation. And, was subsequently put under house arrest by the inquisition, for questioning the authority and divine doctrine of holy scripture. Some time later a young scientist called Isaac Newton was walking in an orchard near his home, when he noticed an apple fall from a tree. He glazed upwards in thought, and asked himself the innocuous question, "Does the Moon also fall?" Some years later he put these thoughts into a book and called it the Principia. And, henceforth the laws of inertial motion and gravitation were born and the rest is history, so they say. So, the next time you're sitting on the dock of the bay, watching the tide roll away, remember: "The constant battle between rotational axial spin, gravitational attraction and our revolving orbital motion around a common centre of mass, has created a really strange world for the inhabitants of our precious planet Earth. Where the tides are caused by an interaction between the gravitational and centrifugal forces." With these tools at our disposal, we now have the opportunity to gain a better understanding of our place in the universe and the complex action of a tidal force due to our inertial motion through a curved spacetime. Have a wonderful day! 6 Reply 1 reply @eduardoangel923 1 month ago En qué año fue? 1 Reply 1 reply @СашаПулатова-щ3с 3 weeks ago 👍👍👍. Reply @DoDxEdgeV4 1 month ago Mordern physics in 30s is crazy 😂 3 Reply 1 reply @Prithvi_Ra 1 month ago Richard Feynman, I remember he told the difference between interference and diffraction Reply @peterdefrankrijker 4 weeks ago That bass sounds fantastic. Can anyone tell me what model this is? Reply @breaneainn 1 month ago Give him a little bit of orange juice. JUICE! JUICE! JUICE! JUICE! Reply @letsplaypokemonshiritori3174 1 month ago Different picture in thumbnail not available in the video 2 Reply @myriamlopezfernandez2089 1 month ago Gracias. Por favor tooodas las lecciones! Reply @nikprilutskiy7064 1 month ago Mr. Feynman, my respect! P.S. He is moving left-right too often =) Reply 1 reply @atabac 1 month ago are there compendium of feynman lecture in video like this? 2 Reply ThinkOf · 1 reply @Joe-iv5ks 1 month ago That was excellent. Reply @TGoat123 1 month ago Mr. Feynman - I have an old safe that I can't seem to open, could you please help? Reply @gavinvalentino1313 2 weeks ago I can't post a link and don't want to steal the thread, but I highly recommend the video "Gravitational Constant" by Type O Negative. Reply @bridog2663 10 days ago Interesting that this appears to be pre-black hole theory. When he says that it's the mass in the center of a galaxy, due to the number of stars, that holds it together, it's like we have a little secret we want to tell him! Reply @spiritofseventysix1155 1 day ago "Richard Feynman - The.Character of Physical Law - Part 1 The Law of Gravitation (full version)" https://youtu.be/j3mhkYbznBk?si=v1QjMgTqxIIPjTtj 1 Reply @Physicskamal 1 month ago More ❤❤❤❤ video upload and original resources link Reply ThinkOf · 1 reply @SpaceCowboy-u7j 6 days ago The way this man speaks reminds me of Dr. David Goodstein of California Institute of Technology. 🤓 Reply @jackcochran2581 1 month ago @30:30. It appears that Dr. Feynman had not as of this date been informed about galactic "rotation curves." Reply 1 reply @MuhammadFareedRaza 1 month ago where is the next lecture Reply @jonlaban4272 1 month ago Open access video under a open access licence from the Creative Commons. I recommend learning about this from a YouTube documentary about the life of Aaron Swartz. Aaron gave his life in the pursuit of open access science Reply @Livingstudent 1 month ago Who else sees bill cipher in the left on the thumbnail? 1 Reply @richardhole8429 1 month ago I was hoping Dr Feynman would demonstrate gravity by dropping a golf ball onto his bongo. It would have brought the house down. Reply @guypierrepoulin8074 1 month ago Any idea wich year that presentation occured? Reply ThinkOf · 1 reply @andy-xoxox 1 month ago After watching this great historical moment: Does anybody else feel like we haven´t made big jumps in physics since that days? Reply 1 reply @realkacy 1 month ago Excellent audio compared to the original. I hope there will be some AI video enhancers available to smooth out the video. 2 Reply 2 replies @sun-p6g 1 month ago 'In joke' thrown in at a given point and what sounded like prescribed laughter. Reply @alexanderjohannesgibbert8906 1 month ago Is it just me or has humour become more common in the last fifty years? Reply @erockbrox8484 11 days ago I thought light was just trying to travel in a straight line and that in a gradational field, the space is bent so its path is distorted, but he is saying that light has energy thus also mass and is pulled inward by the force of gravity. 1 Reply 1 reply @ngDetecter 3 weeks ago somehow never seen a microphone necklace before 1 Reply @drewcoowoohoo 1 month ago That was a smarter crowd; a smarter time. Back when we knew that Brazil did not speak Spanish . . . Reply @rob_loblaw 3 weeks ago Gravity is necessary for the 2nd law of thermodynamics, aka entropy. Gravity is potential energy. Increasing disorder means that potential energy is being dissipated. Reply @scottnj2503 1 month ago (edited) Think about what is said that gets laughs. In this case laughs are simplest truths exposed. 1 Reply @almaxie342 2 weeks ago He resembles Art Carney.❤ Reply @dwinsemius 1 month ago @30:36 It's amusing to see Feynman missing the fact that there IS a way to check whether spiral galaxies obey the inverse square law and ...THEY DO NOT. Hence the great unsettled debate whether it's Dark Matter or and need to MOND. This was actually known at the time, but apparently not by the Great Feynman. 2 Reply 2 replies @tonyjohnson8929 2 days ago They are quite diverse there. There's, at least, a brazillion languages spoken there. Reply @malcolmtaylor518 3 weeks ago (edited) If gravity is the ability of spacetime to determine how matter trajectories operate, and spacetime is a mathematical construct, how come we're trying to detect gravitons,ie gravity particles. Can spacetime be a particle? Reply @jose.a.a.a 3 weeks ago He made gravitation Reply @pcatful 2 weeks ago Oh this is why the answer to the ultimate question of the universe is 42. Reply @Krichnu 1 month ago is there the next lecture ? 2 Reply ThinkOf · 1 reply @lambda_q 1 month ago (edited) Where can I find a video of the next lecture (that he speaks of)? Reply ThinkOf · 2 replies @betaneptune 1 month ago Clear audio, okay. But it's just a tisk out of sync with the video. Please fix. 1 Reply @T.Nastra 1 month ago 👍🏻 1 Reply ThinkOf · 1 reply @r.i.p.volodya 1 month ago What year was this lecture? 1 Reply ThinkOf · 1 reply @عليالشاكري-د4ص 1 month ago The physics from iraq ❤ Reply @kaivalyashah 2 days ago "Added a new dimension" haha nice pun Reply @server1ok 4 days ago Thank you. Now I understand why the US needs a 69 % China tariff Reply @dr97236 1 month ago (edited) Rømer (in 1676!) timed Io’s eclipses, saw delays as Earth moved away, and used a 22-min lag over 300M km to estimate light speed at ~227,000 km/s Reply 2 replies @breaneainn 1 month ago I love Feynman because he never fails to draw your attention to your own expectations, of your own perceptions, of the measurements being presented.. His remarkable and coherent graphic representations of particle interactions in his Feynman diagrams point to his extraordinary discipline in his rigorous examination of his OWN relationship with reality, and he explicitly underlines the difference between objective measurements of reality by the prosthesis of scientific rigour, AND the subjective placeholders we use via the prosthesis of language. It's a VERY clever approach to communication. He essentially engages in a conversation with himself, one representing him and the other representing the audience or students. That way he zig-zags between the two, closing that Venn diagram of language, until it overlaps enough that he can spring his trap. It is exactly the same method as a Stand-up Comedian, whereby you tell two stories in one, and the punchline is where that Venn diagram of expectations of the stories overlap, your expectations are subverted, you get a pleasant surprise...viola. Hysteria ensues. lol It is no coincidence, as this was the same time that stand-up comedy was basically being invented in the U.S... .. in Las Vegas.... in Comedy Clubs .. just next door to Los Alamos... Right? I'm convinced that if a guy like that just invents a way of graphically representing particle interactions, and everybody looks at it and says "ah, yeah, that's exactly how I kinda see it in my head..", then I reckon a guy like that could look at his Tenure at the University, consider the most efficient and useful way of getting the information to the students in his lectures, and simply copy that stand-up method wholesale like a template, and paste it onto his lecture structure... like a.. well, a template. Absolutely convinced he could do that. Don't forget they guy was also fascinated by Tuvan throat singing, or that harmonic resonant multiple-tone style of singing...where signals overlap, he's working with data outputs dealing with wave function collapse, telecommunications and satellites are exploding onto the scene, flooding him with various citizen band radio frequencies, the roots of string theory are getting around the traps in the dark corners of his office, electric guitars are prominent in the culture and the very rudiments of proto-electronic music are just beginning in the workshops of sound engineers in the basements of place like the BBC..AND the Russians have Intercontinental Nuclear Warheads (based on some of his own science) stationed in Cuba and pointed directly at the Continental United States.. ..I think we can forgive him for banging on bongos yelling about orange juice and cracking safes just to annoy people. LOL! Seems to me to be a very efficient and productive use of any excess energy generated by the stresses of day to day living if you ask me.. Reply 1 reply @gerardogamez6905 4 weeks ago Genius Reply @illumencouk 1 month ago Order from chaos. Take a few handfuls of differently graded sand and grit, place in a hydraphillic vessel full of water and stir. Electronic sorting. Each individual 'particulate' within the medium, each having certain properties and specific 'values' is directed to their appropriate ring side seat. Self-organising properties of H²O within this dynamic centrifuge forms a kind of perpendicular propshaft. Which if names actually mean something, does SaTurnUs turn us? 1 Reply @manfredbogner9799 1 month ago Sehr gut Reply @robertferraro236 1 month ago We are so primitive in our belief in this gravitational field. There is no gravitational field. Reply @chipkrug4191 2 weeks ago In what year was this lecture recorded? It should be in the description. Reply ThinkOf · 2 replies @rtt1961 1 month ago Well, all those classic lecs should be upgraded: thanks. 1 Reply ThinkOf · 1 reply @quantumechanix7583 1 month ago amazing - do you have recordings of the other lectures that he's talking about here? Reply 1 reply @PSUK 1 month ago Learnt about g and gl in physics at school. Basic physics 101 Reply 1 reply @ownSystem 1 month ago When Ted Talks were awesome Reply @stephenduffy3971 1 month ago To have been there... 1 Reply @padraiggluck2980 1 month ago Feynman reminds me of Cornel Wilde but he sounds like Art Carney. Reply @barryzeeberg3672 1 month ago Trixie will have dinner ready when he gets home :) 1 Reply 3 replies @cozygamingandvideos3914 1 month ago @ 31:54 Feynman farts. 6 Reply 1 reply @paulcontursi5982 1 month ago Reading Genius by James Gleick Reply @cesarjom 1 month ago The observations and evidence of "dark matter" in the Universe is challenging the completeness of Newton's Law (inverse square) and even Einstein's (General Relativity) theory of gravitation. A modification of these current theories may be needed but we do not yet understand the real nature of dark matter; at least enough to form a theory or extend either Newton's or Einstein's. Reply 1 reply @pushkar-tm5wi 1 month ago The fact that Prof. Doubts the inverse square law at the galactic scale and yet believes that it will hold, is a statement of profound Confidence. In hind-sight it gets a chuckle as research today concerns why galaxies can be held together as the Baryonic mass is not sufficient to produce the flat rotation curves which follow v_inf Ln[r]. Where v_inf is the asymptotic velocity for rotation. just to accept nature as she is, absurd. Reply @Studentofgosset 1 month ago Not a whole lot of variety in the comments here. Makes me wonder how many of them are simply generated by bots. 1 Reply @raspas99 1 month ago It's so sad to see advertisements on this video Reply 1 reply @ahmedalshalchi 1 month ago Who made these laws ?!.... Was it random act by none ?!.... Reply @citoyenatterre4234 12 days ago too many ads to this video. it's a disgrace 1 Reply @danielnofal 1 month ago What a gem 1 Reply @MarceloVianna-r6j 1 month ago 🕶 Reply @TheNewForestObservatory 1 month ago So even the great Richard Feynman didn't put the necessary minus sign in front of the G in the gravitational force equation. Amazing! You don't think the minus sign is essential? Then integrate the force with respect to the distance (r) to find the work done in separating the two masses. 1 Reply 3 replies @lifebasics813 13 days ago ❤ Reply @林柏辰-m7i 1 month ago Maybe the smartest in 20century Reply @Hik-n7p 1 month ago Большая наука это новые эксперименты, свежие идеи, впрочем выбирать Вам. Результаты опыта Майкельсона Морли 1887 г это был сюрпризом для БОЛЬШОЙ науки из 50%, а результаты «Гибрид гироскопа Майкельсона» это сюрприз из 100% для большой науки где увидим, большую интригу. Эйнштейн написал СТО именно для результата опыта Майкельсона Морли, этот опыт проделывается и как регистратор гравитационных волн и 2024 году. Где в общем опыт выполнен всего на 50%. Обращаюсь к Вам с предложением на совместное изобретения ГИБРИД гироскопа ИЗ НЕКРУГЛЫХ, двух катушек с новым типом оптического волокна с «полой сердцевиной из фотоно-замещенной вакуумной зоной или (NANF)», где - свет в каждом плече проходит по 500 (в дальномере «+» опорных 1000) км., при этом, не превышает параметры 94/94/94 см., и вес - 64кг. Предприятия по выпуску "Волоконно - оптических гироскопов" может выпускать ГИБРИД гироскопы и дальномеры, для учебно практического применения в школах и высших учебных заведений. Эйнштейна мечтал измерить скорость самолёта; 200, 300, 400, 500 м/сек - через опыт Майкельсона Морли 1881/2024 г., и только тогда, опыт будет прямой для СТО. И это возможно выполнить с помощью оптоволоконного ГИБРИД гироскопа. Вот исходя из выполненного более 70% опыта Майкельсона, возможно увидим доказательства постулат: Свет - это упорядоченная вибрация гравитационных квантов и доминантные гравитационные поля корректируют скорость света в вакууме. Предполагается, совершать научные открытия; в космологии астрономии, астрофизике, теоретической и экспериментальной физике,.. 2 Reply @MrShobar 1 month ago They were not "bongos". They were congas. Reply @MironaJojo 1 month ago but they say there would be no gravity. it's just different density in the process of buoyancy in the air. How to attract the water and air? 🤔 Reply @sangzuala5848 1 month ago Better give colors with modern technology... Reply @andii7337 1 month ago Bill cipher in the thumbnail??? Reply @HarryFredricks 1 month ago 25:38 ....So even back then they have changed the pronunciation of Uranus to avoid the dirty part of the body reference Reply @unitedstatesforus 1 month ago Source of this brother Reply @PeterFamiko-lw8ue 1 month ago Mercury circulation is dificult explain easily Reply @New-dr9bv 1 month ago Объясните, что такое масса в уравнении. Reply @stevecostello4278 1 month ago Brooklyn's Einstein. Reply 2 replies @daemonnice 4 weeks ago @7:06 With respect to Professor Feynman, but the law of gravitation as you have presented it is nothing more than a mathematical description. It does not in any way suggest any kind of natural mechanism and while science may be fine with its mathematical equations, the natural philosopher, such as I is not. To date there is no natural mechanism that explains how gravity works(Einstein's GR is not a natural mechanism but abstract mathematics). @7:57 Aristarchus was a lone Greek who proposed a heliocentric model of the solar system, but it was Prolemy's geocentric model which dominated until Copernicus who on his death bed released it. It should also be said, that the math for this geocentric model worked quite well for what they needed, though on occasion things did not work out as predicted, so new math was incorporated and epicycles and other odd explanations were added to explain these anomalies. You see math is really good at propping up wrong models. It should also be noted, Copernicus merely adopted Ptolemy's geocentric math and merely centered it on the sun. Eventually Kepler would figure out the orbits as we sorta know them today. But, it is interesting to note that Kepler tried to do this using pure mathematics and geometry but failed. Eventually he went to work for Brahe who on his death bequeathed Kepler his notes of a lifetime of astronomical observations and based on these observations determined the elliptical nature of the orbits. @19:27 It is interesting to note that Professor Feynman is using the word "fall" with respect to the planets attraction to the sun. This is not an accurate word to use, for in space there is no up or down, therefore, how can something fall? And while he credits Newton with figuring out that gravity is involved, it should be said that that might be a bit presumptuous. It could be argued, that since Newton had zero knowledge of extraterrestrial space that such a claim is a speculative assumption at best. It can now be argued now, that Zwicky and Rubin have both shown that gravity is not the fundamental force of the cosmos. Gravity's failure to predict the observed mass of galaxies and galactic clusters, according Modus Tollens, is a refutation of gravity as the fundamental force of the cosmos, and that invoking an unknown hypothetical to avoid such a model refuting observation is the very essence of pseudo science. Professor Feynman earlier in the lecture spoke of the tediousness of data collecting via his Brahe story. He says science collects the data. In the last 50 odd years, the solar system has been revealed to be populated with plasma and a plethora of electromagnetic phenomena unknown in Einstein's time and not predicted by any of the gravitational models. In fact at the time of these lecture Feynman would not have known either. Newton, back in the day in a private letter wrote that he considered it absurd to believe that "inanimate brute matter" could communicate without an intermediary. Faraday circa early 1800, proposed a relationship between the electric force and gravity. By the way, Coulomb's law is also an inverse square law. Gravity is not a force unto itself or a geometry, it is, I suspect an effect produced by the electric force on mass. 1 Reply 1 reply @carnivaltym 2 weeks ago Not bad in a pub fight either! Reply @roberttarquinio1288 1 month ago Further and additional explanation From some of my notes on time and temporal dynamics and time travel which I think entails quantum entanglement, general relativity, time dilation, gravitation (a manifestation of space time curvature), and quantum gravitation (same as gravitation but at the quantum level) Gravitational spatial distortion (gravitational lensing) and gravitational time dilation (temporal distortion) Space, the fabric of space, is fluidic; it flows - spatial hydrodynamics. Time, the fabric of time, is fluidic; it flows - temporal hydrodynamics Combined, space and time where time flows within space is called space-time Space - spatial coordinates: x, y, z; - x, - y, - z Time - temporal coordinates: t; - t Time can flow forward and backward; time travel may be possible going backward as well as forward in time - temporal dynamics - and may even be able to select destination spatial location as well as temporal location (forward or backward in time) Time moves slower or faster depending on distance from the surface of a body of mass such as the sun, a planet such as the earth, etc Time slows closer to a body of mass and speeds up - moves - flows - faster the further away from it Gravitational time dilation is a form of time dilation; it affects the flow of time causing it to move slower or faster depending on distance close to or further away from a body of mass such as the sun Gravitational field is comprised of gravitational field waves Interacting gravitational fields produce gravitational waves They say gravitational waves are ripples in space time. I say they are ripples of space time Space flows and propagates like wave. As space - space time - flows and interacts with a body of mass such as the sun it curves about it causing space time to manifest as gravitation and distorts the surrounding fabric of space and time producing gravitational lensing effect as well as time dilation Quantum general relativity is same as general relativity but at the quantum level and the equations would or may include gravitational wave function term, Psi sub g 1 Reply 2 replies @ellogaymers1431 1 month ago 24:20 1 Reply @McDonnelMark 1 month ago Wonderful to listen to his words. No doubt. But his nervous pacing back and forth is distracting. 1 Reply @burrbonus 8 days ago 6:00 Reply @PrinceSarraf0314 1 month ago Any Competative exam student here...??😊 Reply @jorymil 1 month ago I love The Feynman Lectures, but they weren't successful at their intended purpose of teaching undergraduates. They are fabulous as a secondary resource, but man... I see some really glowing comments here about finally understanding gravity, and I wonder if folks just didn't have good teachers or something. If this were a more advanced concept like Lagrangian/Hamiltonian mechanics, sure, but this is taught in high school, then again at the introductory undergrad level, then again at a higher undergrad level, then again at the grad level. It's absolutely bedrock stuff. 1 Reply @SicoTechnologys 1 month ago 13:20 😂😂 1 Reply @erasmusmiranda587 7 days ago Learning spanish to go to Brazil. How very american... Reply @optimusprimum 1 month ago Wasn’t the answer to life in Idiocracy 42? Reply 1 reply @MartinBraden-j4r 4 weeks ago The generalization assumed is that gravity is an attraction force rather than pressure. The misnomer, "law of gravitation" presumes fact. Reply @KokkachiTech 2 weeks ago I'm 15 Reply @tenrec 1 month ago If you like Feynman, you should read his book: "Surely You're Joking, Mr. Feynman" It's excellent and really gives insight into his personality. 1 Reply 1 reply @BenilNishi 1 month ago Watching a 360p video on 1080p😅 Reply ThinkOf · 2 replies @veervishalmishra4526 1 month ago (edited) 46:49 Reply @marshallodom1388 1 month ago Except Dark Matter Reply @veervishalmishra4526 1 month ago 44:03 ......... Reply @veervishalmishra4526 1 month ago 23:31 Reply ThinkOf · 2 replies @dabudion 1 month ago (edited) @2ThinkOf hew did you get sharper/clearer video recording, I've been looking for better versions of his '64 lectures. 1 Reply @jonlaban4272 1 month ago Methinks he got his sense of humour from his English wife Reply @rayhassan6573 11 days ago Newton was a genius. Reply @erockbrox8484 11 days ago At the 32:00 mins mark in the video. Feynman: Gravity has few applications I'm pretty confident this should be a joke. Here are some applications: Rollercoasters GPS: Google Maps Grandfather clocks Swings on playground Predicting asteroids that might collide with the Earth Reply @bnathand 1 month ago What do you all think Feynman meant by saying (at 33:40), "That's the strange world we live in, that all the advances and understanding are used only to continue the nonsense which has existed for 2000 years." ??? What exactly is he talking about? https://youtu.be/q_edsSpDzHg?si=p2Y7NFptjymh0Kfe&t=2020 Reply @MACS6USMC 2 weeks ago Nice Law. How does the moon move 687,984,862,853 gal of water every second for 100,000,000,000 yrs or more. How many nuclear power plants would we need? Reply @DomenicoBellissimo 7 days ago They speak Portuguese in Brazil, not Spanish. Reply @veervishalmishra4526 1 month ago 33:32 Op Reply @williamwalker8107 4 weeks ago Why 2000 years? Dr. Feynman? Reply @nathan43082 2 weeks ago This is VHS-quality content, not true 1080p. Reply @afterthesmash 1 month ago The like counter is not showing the like count, which makes it as stupid as Google made the dislike counter. 1 Reply ThinkOf · 1 reply @navinsahu2946 3 weeks ago so funny video Reply @TheM41a 1 month ago “B-b-b-but he was mean to women!” Reply 1 reply @Listhp1337 1 month ago Gain 0? Reply @WorldView22 1 month ago (edited) Actually, that’s not correct, 7:46 ; it was not discovered independently by Copernicus… he plagiarised the Greek scientist Aristarchus of Samos, and before he died he confessed that he had removed two pages from his manuscript acknowledging Aristarchus. Reply @JohnAlbertRigali 3 weeks ago Engaging lecture, but too many ads to make it worth my while. 👎🏻 Reply @samuelbenicio5380 1 month ago The people in the Brazil, speak portuguese Reply @amsirnoormitchel 11 days ago Damn, it is tasty Reply @jewman3972 1 month ago HAHAHAHAHA! THE GREATEST MIND (BUNK). Reply @honumoorea873 1 month ago Ok those are pretty basics laws, and my professors at Orsay university were as good and as interesting as Mr Feynman. Reply @FengXingFengXing 2 days ago Should join public domain already if US Congress no corupt. Copyright monopoly law maxium 57 years when create this video: 1964 + 57 = 2021. ¿Also tax money help pay for this? ¿Caltech is public unversity? Any thing from tax money always should become public domain. ¿If Cornel Unversity record this then they control it? Reply @pete7971 3 weeks ago Why are a large number of students in the audience wearing glasses?? Reply 1 reply @spiritofseventysix1155 1 day ago "Richard Feynman - The Character of Physical Law (1964) - Complete - Better Audio" https://youtu.be/kEx-gRfuhhk?si=lmjkzpfjfAw7r5ey Reply @jonwebb2300 2 weeks ago The guy is pacing back and forth uncontrollably. Very difficult to watch. I would love to watch more but had to shut it off because it was so disturbing. Reply @roberthead9149 8 hours ago His constant walking back and forth is difficult to watch Reply @QuickCanon 1 month ago Oshs Riner Reply @HugoHabicht12 13 days ago To keep this law the scientists invented dark matter, what is just theoretical. Therefore this law is maybe not universal. 1 Reply 9 replies @ortegoortego4963 3 weeks ago не морочьте людям голову... 1 Reply @DanielSmith-lv5ed 1 month ago Gravity? Ill give a shot. It acts like magnetism.... There are water molecules in the air called vapor.... Some unseen forces ricochet off of other things, like water and water vapor.... the reason people don't think its magnetic is because it seems as if we should stick to it the same way a magnet does. But that is a dumb way to think about it because we don't really collide. This isn't to degrade faith at all If gravity and a person walked up to me and punched me, I'd knock the gravity out. The person too, but for different reasons. Take that gravity! Id love to hear what this guy has to say, but I like when people tick people off with simplicity lol Dont worry, it took me about 15 hours to realize the stars were nothing like what is commonly taught, provable by reading and or glancing at your favorite star, which is 2. They, are 4, and they, are 8. They just keep splitting lol 1 Reply @slowneutron6163 1 month ago He learned Spanish before his lectures in Brazil? I have no doubt that he learned the language quickly. However, since they mainly speak Portuguese, I don't know what good it did him. Reply 2 replies @WilberWiley 1 day ago SO THIS GUY IS BRILLIANT AT WHAT? OBSERVING WHAT ALLREADY EXISTS? SO? WITH ALL THE BLACK BOARD CALCS, MAN STILLS KNOWS ALMOST NOTHING OF THE UNIVERSE. BIG DEAL. Reply @StarNumbers 3 weeks ago Cavendish experiment has never been duplicated. This experiment, as done, is not stable and the balls kept oscillating. Then the error comes in because the thin string had to have known elasticity, which could not be measured but simply assumed. The few attempts at duplication show that nicely and you will have hard time finding any vids duplicating the Cavendish experiment -- at the end they just assume the oscillating cause. Oh, and Cavendish used a telescope to watch his setup at a distance for his mere presence threw off the oscillation. The gravitation as presented in this lecture is false, or, better yet, BS. Reply @EricGarbett 1 month ago What a pity that at 22.27 he uses centrifugal force in his explanation! He has just shown that any force due to circular motion is towards the centre, not away from it. Reply 2 replies @Besdayz 2 weeks ago too bad he didnt talk about spacetime curvature and the real reason why objects in space move and orbit namely the effect mass has on the curvature of space. there is no intrinsic force of gravity Reply @smalltown2223 3 weeks ago It’s all wrong, he didn’t carry the two. Reply @DontMansion 10 days ago (edited) I know what gravity is. Einstain is wrong Reply @keefebaby 1 month ago Am I the only one getting annoyed by the laughter Reply @אלִיהו-ז8ס 3 weeks ago There is No gravity or gravitation. Reply @jinnahkhan4841 3 weeks ago State department Colombia plaza Bank VK inside 💠 bouw up from inside VK at oil week More aminsa chwasty lightning leep Year old no still seem Blue 🔵 Reply @rosegarden6622 7 days ago Kiraan ini banyak yang salah Pemikairaan kami yang citik ini Kalau kamu kira bulu2 itik bagai mana ia Reply @merkinsniffs 1 month ago You have ruined the flow of this video with your greed for an ad every 5 minutes Reply @glywnniswells9480 1 month ago We going in an ellipse? So are we much hotter and closer to the sun at certain times?? Cant be an elipse Reply 2 replies @stanisawk1385 1 month ago you are WRONG! Because the Angels doeas exist! Reply @Photoshop729 1 month ago This guy seems pretty smart. Wonder what became of him. Reply 1 reply @esheppshepard 1 month ago Was this a remote streamnon zoom or teams? Telling people nothing changes should life 1 week 50 years before today. Reply @mariobertora 9 days ago Studied under professor Feynman 2 years.......Odd Caracter, Biased, Severe, often talk of rubbish...... Reply 3 replies @rockerbie 3 weeks ago Stop walking around. Reply 1 reply @Carletdesiles 1 month ago 5:55 my wife is dumb... 😂 1 Reply @keithmchugh20 3 weeks ago Isn't it funny how when you're getting electrocuted you're stuck to the item electrocuting you, seems a little gravitational pull their, lol Reply 2 replies @JerryCalvert-x9u 2 weeks ago Utter nonsense. Reply @qafmbr 1 month ago Aaaaaaaaand they still don't know where gravity comes from. And have redshift assumptions that are all wrong. Reply 1 reply @hansstopfer878 1 month ago Unfortunately, gravity is not that easy on a galactic scale because dark matter plays a role. Its interesting that you let a Nobel Prize winner in quantum electrodynamics talk about gravity. Unfortunately, he had no idea about the superstring theory, which makes a unified theory of the four fundamental forces possible. Read: The elegant universum, Superstrings. hidden Dimensions by W.W. Norton Reply 1 reply @onetruekeeper 1 month ago He describes the dynamics of gravitational force between astronomical bodies. But he does not know what gravity is. It is unlikely anyone ever will since asking such a question is meaningless. Reply ThinkOf · 9 replies @TrustintheSon1 1 month ago I wouldn’t mock the idea of angels moving the planets. For God makes his servants wind and flames of fire. For any object in its own state cannot change itself unless acted upon by an outside force. God did set the planets in motion according to His own word. According to God every single cell is created by him and nothing that alive has life apart from his will. Reply @seed_of_the_woman 4 weeks ago question: if the earth is not the center of the universe, how did newton know the moon went around the earth? since feynman is a quantum physicist, how does he explain gravity? btw, know that he is wrong. the stars in the outer arms of our galaxy travel very much faster and in a linear relationship, not inverse square to the center. this is a fact. anyone can explain? it’s cause is electricity, not a mythical force known as gravity. aside from that, gravity varies much more than physics believes or acknowledges, and it’s not due to relativity. and the speed of light is decreasing as the complexity of the universe increases, our brains not the least of that complexity. anyone explain? laugh about what people used to believe, but we’re no better now. aliens don’t even count for anything in the complexity of the universe, btw, because they don’t have souls. you can laugh at me, now. anyone explain? does time travel, or do we travel through it? love, david Reply @davidweber5833 1 month ago Not likely a DEI hire. Reply @nickcaci7238 1 month ago Why can’t we think way outside the box. Say…. gravity is a push instead of a pull. It’s just a 180 degree directional action to the same outcome. I like to think gravity is a Omni directional transmittal energy that intertwines and exchanges with all matter and molecules equally. It’s the universal fuel that each atom uses and passes on to the next. When this transmissions is blocked by a greater blocking mass, then illusion of the larger mass is pulling from that object. Depending an Elements atomic number and how it clusters together within other elements the same or otherwise will show its weight result upon contact of a larger block. Hay have a laugh , I’m talking junk outside the box. Reply @0118uhauha 2 weeks ago Listening to persons like Feynman is like medicine for the brain. For long times I have only watched YouTube to see news about politics. I feared my brain was deteriorating with dementia. Things I watched appeared to become less and less logical. President Biden stammering, Trump stating that Ukraine attacked Russia although on my screen the military vehicles appeared to move in the opposite direction. Reply @Chicken_Little_Syndrome 1 month ago If you can believe on object can fall from an altitude it never achieved, you can believe in Newton's fallacious orbit explanation. Projectile physics demonstrates the undeniable fact that Newton's orbits are physically impossible. Perpendicular/horizontal motion is not impacted by falling or weight. Each motion is independent. One motion cannot influence the other. This reality is something that you have to ignore to accept Newton's illogical folly. Reply 1 reply