Your Daily Equation #26: Einstein's General Theory of Relativity: The Essential Idea 

I’m a retired physics teacher. I used to use many of Brian’s examples from “The Elegant Universe” and “Fabric of the Cosmos” to explain Special and General Relativity. Thanks Brian!

Thank you Mr Brian Greene, this lecture means the world to me. I'm an undergrad physics student and an older one now, and still an incomplete one. But I did get a solid foundation...from a certain few inspiring excellent professors... However several years ago having long talks with an astute physicist friend of mine about physics got me started again. I didn't get to a Relativity class in my first go round ,-- set of courses completed .. I believe I can learn on my own because if the great quality of lessons online....yours is one such source for me.. Didn't Ralph Townes learn a lot of physics on his own ,( with some guidance from a professor at Columbia?)..before going on to invent the MASER?? ID rather learn physics than anything in the world, had a bit of a *rough start but I believe I can do this so thanks so very much !

These talks are phenomenally lucid. I wish the Great Courses company would take notice and offer to provide a further platform for Prof. Greene´s brilliant exposition of broad swaths of modern physics. Perhaps they already have.

I must thank you Brian. I have known of your work for many years but only recently come across Your Daily Equation. It has forced me to re-engage my recently 78 year old brain and it delights me! I will follow YDE from now on.

This is so awesome. Thank you for doing these videos. I have been meaning to ask for GR for a while. But I actually had a special request about it. Not just the equation, but also the QM equation and where the two don't relate (if that even makes sense). Thank you again for this.

Thank you RU-vid for recommending this channel. Informative, direct, and excellent explanation.

Thank you for explaining the great ideas so clearly and fluently. I fall in love with science from your performances.

Thank you once again. I look forward to these daily equation sessions.

These series are amazing!!! Please consider making it a weekly thing after the lockdown ends.

Hi Prof. Greene, Greetings from West Wales. Hope you are keeping well. Thanks for another great episode of Your Daily Equation. Looking forward to more GR. Best wishes & Stay Safe. Paul C.

Thank you Brian it was beautiful!! I am glad I discovered this site!!

Beautiful explanations and teaching techniques. May you be blessed with an ocean of knowledge!

Awesome professor Brian! .. had never heard about the example with the circular motion! Great! ... This series "Your daily equation" is the best thing that has happened to us, learning physics from one giant of our generation!! Thanks a lot professor!!

I thought I ran out of time today, then I remembered it's all relative. It's always on time.

Thanks a lot for this wonderful explanation. It is such a joy to listen in to Brian Green. And it is all for free.:-)

Thank you from Israel. I am a yoga teacher, don't know much science yet read some science books here and there. This video helped me understand some general relativity. Thank you.

Thank you so much. You are the best talker to give me an understanding about the general theory of relativity. Your talk makes me have an interest in physics. I wish i could have a good teacher like you about 50 years ago. I really enjoyed the happiness of getting a knowledge. Thank you again.

I am so thankful that there is a video like this available , now I understand more on the reasoning behind Einstein's thoughts.

This is a fabulous video! I cannot wait until the unpacking of the GR equation!!! Thank you.🙏

A beautifully clear introduction to GR. Thank you ever so much Prof Greene. May these talks continue for a long time to come, I'm learning so much.

Hey Brian I just became aware of these ‘daily equations’ which are most informative and well explained, especially for a somewhat dull tool in the shed like me. I watched this episode first then went back to E=mc^2. I’m glad that at some point you figured out the split screen thingy 😄

The 3-D animation of a space deformation by a massive object is great! ...😍 I've always wanted to see that in 3-D. Thank you! 💖

@16:01 Thankyou! Seeing this space-warp example settled a question that has been with me for some time.

Thank you for teaching us the basic. Although, you are very advanced. You have the patience to explain us the basis of these phenomena. Please go on. Thank you so much.

Could you give a lesson about tensors?

thank you ... you are so charismatic ... its so great gift to teach us for free for those great ideas ... thank you

Professor Greene explains things so clearly. Just brilliant!

This video is great. All the knowledge has been shared in a single video...

Breathtaking Class of the Einstein's General Relativity creativity of a Stunning Scientist/Physicist 🙏 I'm not a Scientist, just I love learning, from a Simple Human Being 🙏 Thank you for all you do!

Thanks to Brian Greene for this video 👍👍🙏🙏❤❤

This is the first time I have seen address to the obvious shortcomings of the rubber sheet analogy.

Thank you, professor Greene! It's an art to simplify such complex concepts into courses like this. I really enjoyed it. 👏🙏

Thank you professor Greene for an excellent explanation.

Thanks Brian. You are doing Great work.

Waiting patiently for a course in Einstein's Theory of General Relativity in World Science U.

I look forward to hearing more about the time piece which I had failed to fully appreciate.

Thank you professor Brian!

I'm Blessed, to listen straight from Greene 🖖🙏♥️

I love the new location! In this period it feels good to look out of some different window...

Outstanding! Thank you.

For connecting acceleration and curvature, I always thought of it as visualising a displacement-time graph (or maybe a space-time diagram) A motion of uniform velocity would be a straight line; an accelerated motion would be a curved line.

Very nicely done - as usual!

Truly amazing ! Thank you so much .

Eagerly waiting to learn Differential Geometry in upcoming episodes to understand the Einstein Field Equation.....Thank you so much Professor.

THANK YOU PROFESSOR GREENE!

I was really waiting for this topic

Thank you, Prof. Greene. Outstanding how you can take these concepts and explain them so clearly and make them entertaining. Question: Is the same gravitational mechanism that causes Earth to orbit the sun apply to an object/person on the Earth (feeling the force of gravity)?

I enjoyed watching this post very much.

These videos are amazing!

Dr. Greene. May we learn about infinity and infinities? Thanks for your commitment to the series.

thank you so much for such a helpful information.

Good teaching style. Beginner level coverage

Thank you Professor.

Thank u sir .. u cleared my one of the greatest doubts

Now you've covered Einstein's equations for the photoelectric effect, and the special and general relativities. I'd like to see the equations that started it all, first where he calculated Avogadro's number, and then where he calculated the equations of Brownian motion and proved the existence of atoms/molecules.

Wonderful lecture

What a great explanation!

Thanks, I enjoyed it a lot.

Brain is just so clear...! Thanks!

Really gives a feeling about the GTR, I cannot wait for the derivation and the tensor math. Thank you.

Great video on General Relativity

Thank you please keep going on deconstructing the field equations and how Schwarzshild derived his exact solution. Do you find the light beam through an accelerating elevator helpful in explaining curvature of spacetime?

12:22 Just brilliant. General Relativity was the most powerful mind exercise ever.

So good! Thank you.

Hi, it would be helpful if you put everything in a playlist covering all of a certain topic such as general relativity.

Any concept you explain comes clear as water, what a gift. 21:55 tho hahahaha

Thank you

Finally someone who explains clearly a question noone answered me when I ask: if gravity is acceleration, why are we not now speeding at exponential times the speed of light? Because acceleration is also a change in curvature, not only a change of speed! Thank you professor Greene, these daily equations are just fantastic.

He is always, so full of optimism

Thebottle of water with the hole in it the dropped was a great example of the equivalence principle you used.

Great view, reminds of Scotland

From the legend, himself. Awesome stuff.

Another great presentation Brian, many thanks! Perhaps like a lot of people, I've never felt entirely comfortable with the "rubber sheet" analogy - but coming across the fairground ride/Lorentzian contraction of circumferential elements example for the first time, was - well - somehow much more satisfying 👍. PS Also very impressed by the falling leaky bottle demo!

Sir : I am at loss to find words to thank you and pay my gratitude :as siting so far away: I learnt a lot from you: as Einstein’s Special Theory of Relativity and General Theory of Relativity: oooh wow:without your help it’s pretty hard almost impossible to understand:I follow your Stage lectures as well: Your way if explanation presentation communication to make understand guys like me: and of course a lot / millions like me across the globe: that’s why I repeat that I don’t have words can’t find them at loss: how to thank you and to express my gratitude: that’s the beauty of science Legends like you only have the sensitivity to pass on your knowledge for nothing no self interest whatsoever : deserved our full appreciation: Keep up the good work beyond boundaries..!!🙏🙏

Now we need to explain "Dark Matter" and "Dark Energy" in relation to General Relativity.

love you professor, i wish i can meet up with you someday

ありがとう! Thank you

Great 🙏thanks sir 🙂☀️

21:59 "or if you put yourself in the shoes of the bottle of water, whatever that means." i don't know why, but that made me laugh hysterically.

fantastic!

Just saw World Science Festival 1995 talking about general Theory of Relativity.

hey that looks just like the place in danby where the plateks used to live back in the 90s!

Please do a video on Electrodynamics

Beautiful

I love the 3d depiction because thats how ive always pictured it. Whats nice about that is you can see a 2D plain of space time being bent in all directions. Above, below, beside, behind and in front of the object, and how when the object is further away the fabric bends less. So instead of Newtons' theory having instant influence from one object to another the object would instead have a instant influence on space time. Pretty cool

Love the intro 💕

amazing

Is the approach of sticking together different LISes an equivalent reasoning for linking curvature with gravity to the tornado ride you mentioned, or is it conceptually little bit different?

At the expense of great mathematical complexity, GR has pushed the "what's the mechanism" question one step further down the road. It enables calculation of the curvature of space-time by mass-energy and the motion of things in that curved space-time (and many other wonderful results), but it provides no physical mechanism by which the curvature of space-time is produced. The problem appears to be that we do not yet really understand the structure and composition of space-time. Is space-time discretized at the Planck scale? Does it consist of a grid of nodal points connected by elastic "strings" of Planck Length? Are there short range forces that would bind nodes (or string ends) if they were brought in proximity by local folding and/or rotation of the Planck grid? Does mass-energy warp the geometry of space-time because mass-energy IS distorted space-time? Whatever the answers to these questions may be, we would still have to explain the mechanism by which those forces are produced. The rabbit hole of physics appears infinitely deep.

In the UK 🇬🇧 we call the tornado ride the rotor and Einstein uses this analogy in one of his books for a non mathematical reader like me. In other words on the rotor you are stuck or pushed against the wall as though gravity pulls you to it. When it stops gravity is restored to pulling you down in other words there is equivalence between the two.

Love to see him on discovery channel

Thanks for the great, clear explanation! The animation at 16:00 is how I'd been picturing "gravity" in my head (...and yes, with just a single object - more than one gets hard for me to imagine). It'd be really interesting to see something similar with two or three objects influencing each other (orbiting, passing by) in a "3D grid" rather than just a single object all by itself. Does anyone have a link to animations like that? :)

Is there a similarity between the influence that massive objects have on space and hence other objects, and the force electrons have on other electrons on the electromagnetic field? I'm interested in how logic naturally forms in the human brain by means of how neural networks find the lowest local minima of functions representing how effectively they can express or just 'do'... things. I'm wondering if there is some kind of entropy involved in the em field that counters the second law of thermodynamics

May God bless you sir

The rubber sheet and 2-D graphics omit the profound gravitational influence of time (in spacetime) on planet orbits.

Can anyone explain why it takes more rulers to measure the inside? I don't understand that.

Iv got a very long question and was really hoping you can help. We always mention these amazing minds throughout history like Newton Maxwell Einstein etc that where leaps and bounds ahead of everyone and push our knowledge further. My question has a few questions in it. Like, when do you think the next big mind will push use forward again? Do you think they already exist but will only find out in the future?maybe we won't see another mind jump us forward again as maybe there are no new big physics questions left? or we have to wait for technology to catch up to prove these theory's correct? Or maybe we now have lots of these magnificent brains in our current mix and it's hard for someone to stand out? Do you think maybe the next Einstein will be in a diffrent filled like technology that pushed are knowledge further? I would love you to do a piece on this and have your thoughts. Thank you

29:58 Right but the connection isn't of the same nature of that of the equivalency principal , where there's no test you can perform to tell you otherwise, (assuming you're not allowed to look out the windows of the space craft) how can being on the inside of a spinning ellipse or circle be acceleration , if you were in deep space and stopped the engine spinning the room, it would continue to spin forever assuming zero friction with the particles outside or the atmosphere inside keeping you alive right? When I think of acceleration and gravity y I think of the need to constantly add more energy to the system, you not just moving fast, your moving fast quicker than you were the previous second , Also is there a name for increasing acceleration. Like increasing speed is called acceleration what about increasing acceleration. Like perhaps a second ago your speed was increasing by 9 meters per second, evey second, but now it's increasing at 10 meters per second, per second. Accelerating acceleration. Can't you just follow that down an endless rabbit hole. Turtles all the way down type of thing ? I don't really know what I'm saying. What about the Earth is the Earth accelerating through the galactic medium or is it at a static velocity that is slowly decreasing, or does it go through periods of be acceleration due to gravitational interactions, and deceleration to the other gravitational interactions and friction within the galactic medium. ?

Its good you started GR. Just wanted to know how to solve GR equations.

It would be amazing if you could expand on your comment at the end that it is actually the warping of TIME, not space, that is the dominant influence.