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From: MIT
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  • Good, I like that you share this video, I wish success always Lec 3 MIT 8.224 Exploring Black Holes

  • brilliant video

  • great vid you have here

  • brilliant video

  • i enjoyed this vid

  • really informative and interesting

  • I Love The Video Einstein's Field Equations It Can Increase My Knowledge

  • Nice Video Einstein's Field Equations That You Share , So Very Nice Thanks You

  • I Really Like The Video From Your Einstein's Field Equations (Edmund Bertschinger)

  • Your Video Einstein's Field Equations (Edmund Bertschinger) Is Very Useful Sharing

  • Why pay tens of thousands of dollars to go to college when MIT, one of the best universities in the world, puts its classes on the internet for free?!

  • By the way i am 9 yo and i am finding all lectures a trip to the beach.

  • i love youtube ! and will always love youtube !!!

  • I agree completely it's incredible to have this knowledge store available!

  • I agree completely it's incredible to have this knowledge store available!

  • im Learned this at my junior year. i have a great great graet passion for physics and mathematics :) im senior now and currently working on navier stokes equation of fluid dynamics and trying to find the existence or non-existence of the solution of the non linear PDE :)

  • @tafwolf Good luck with that, from what I've read that equation is incredibly complex.

  • I take it calculus and linear algebra will not be enough to fully understand these equations, anyone got a tip what one should learn more before studying quantum mechanics and general/special relativity?

  • @zim01001 I never took a single class like that (since I'm 17) and I can understand this. You have to study hard, find books, find sites, find information and spend hours trying to understand it. No knowledge comes without effort even if some can do it more easily. Study the laplace operator and Einstein notation and you will start understanding this a bit. Of course you need much more...

  • @IkesLc Why people like to say how young they are on advanced math lectures all around youtube ?

    Do you kids want to be adopted or perhaps a donation for buying new books?

  • @TheCHRM2 Thats a good one xD. My opinion is that this classes are far too easy. I actually learned this in my country before university, however I was just stating that for the ones that do not know this, it's very easy to learn. More interesting than my comment is the fact that your angry with people who know about this. Don't worry I'm not a very good student, I will not steal the future for anyone.

  • @zim01001 Differential equations...thats what the field equations are

  • @zim01001 you can start learnign QM with cal 3 and linear algebra, but General Relativity requires differential geometry and riemannian geometry as well as some calculus of variation. before you begin any of these you must have a fair amount of real analysis under your belt as well

  • SMALL MISTAKE at 0:46:05 - "....when I make a hydrogen atom, I bring together a proton and neutron into a bound state...." surely he meant to say Helium. Hydrogen is just one proton and one Neutron (hence relative atomic mass of 1).

  • @ecaepevolhturt He meant in isotope of Hydrogen. Hydrogen can exist with none, one or even two neutrons it's just most commonly found containing only one proton and no neutron. Also, you need two protons and two neutron to make helium.

  • @beddoefly Yes my mistake about Helium (relative atomic mass of four not two, silly me) but I still think he should've said "Isotope of hydrogen" rather than "hydrogen atom".

  • @ecaepevolhturt Fair enough :) :D

  • Anyone know this? What do the different components of the Riemann tensor represent?

  • @cdoftx the riemann tensor is made up of quadratic expressions of the christoffel symbols and their derivatives...so basically mixed and second order derivatives of the metric

  • @weweallthewayhome Is there a physical interpretation of the components? For instance, curvature of different dimensions.

  • @cdoftx well the riemann tensor tells you about the curvature on a surface (or in a space) , and the whole principle behind general relativity is that spacetime is curved in the presence of energy and that bodies that are present in this curvature follow geodesics in the space. the more curvature there is the more "un-straight" the geodesic is. but the riemann tensor doesnt show up in the equations, the ricci tensor does (which is made of the riemann tensor contracted witht he metric)

  • @weweallthewayhome Thanks for the info, I think I'm starting to put things together. I've always hated reading into new mathematics where when you come to a word you don't know, you look it up and find 5 more words you don't know.

  • @cdoftx i know the feeling lol...ive got books upon books on differential geometry and riemann geometry and it took me about a week per page lol

  • Not sure how religion got mixed in but I have a more mundane question....why should the inertial and gravitational masses be different? Aren't they both responding to forces?

  • "does the theory make any prediction that can be tested ?" <- very important question, why is it that religions don't come up with self criticizing questions like this

  • Because religions are not in the same category; religions are supposed to be top down revelations as opposed to discoveries.

  • Religion is from the least developed part of our brains. You could say it's the most primitive part of our cognitive thinking. Go ask someone if they'll give you $3.00 for an brand new invisible 2009 BMW 730i and they'll just laugh at you! Ask them how much they gave to the lord, who is just as invisible and non-existent, and the monetary answer will be in the $1000.00's!!This hold true for at least 75% of the human population if not more!! Religion stems from our most primitive brain functions.

  • nice description !

  • @pishdad - You gave a good analogy; religions or superstitions, including pseudo-sciences and magical thinking are irrational by-products of human imagination. The figure 75% is quite modest, since it's more like 95% of the population that hold some sort of irrational & primitive belief/s. Science/math on the other hand are the only systems that are based on evidence, observation & reason. They tell us how our universe actually functions.

  • MOG is an alternative theory based on Newtonian mechanics and also Enisteins theories. It is a reltavistic theory, a completely predictive theory as it is free of any free parameters, and accounts for more accurate results in specific cases that ensteins theory don't account for, such as the velocities and lensing effects. Moreover, MOG does away with the need for dark matter, as it proposes that gravity is a stronger "force" than predicted by einstein and the grav.const. may vary with spacetime

  • Interesting, do you have any resources, prefferably online resources, to provide an adequate introduction to the theory?

    I'd very much appreciate it.

  • It was a great informative lecture, but...

    there are other physicists who propose alternate gravity theories because Einstein's Field Equations give inaccurate results for glaxy cluster velocities, galaxy stability, and gravitational lensing. Although einstein predicted these phenomenon his calculations proved to be less than accurate as his equations provide smaller velocities of galaxy clusters than observed and a smaller lensing effect than observed.

  • @deadbaby86 that's not true. his orignal proposal of the equations lacked one term. this orignal set of equations was for a static universe. he saw in due time that the universe wasnt static and the extra term was added (made up of the cosmological constant and the metric). general relativity IS the ONLY theory of gravity that agrees with experimental data. with the extra term the equations fit all observed data, there has not been a single instance that GR has failed

  • The guy may be very smart but please explain the math/physics better. I got lost as soon as he started writing the equations.

  • need to read up on calculus

  • I'm in Calculus 1 right now. Were only on limits though.

  • There are pre reqs for this course, so everyone in the course is expected to know calculus.

  • interesting, i was just skipping the first 2 lessons because the lack of equations. I personally don't like that if one searches for string theory the first hits are always some lame shallow tv documentaries

  • I know exactly what you mean. I find I can only really get to grips with physics when the equations begin. Verbal descriptions just can't beat mathematical ones.

  • im not sure what u mean, but i find the "documentaries for dummys" very helpful, considering i have little or no idea wth they're talking about ^^

  • 40,000 a year and they cant give him an eraser.

  • That's terrible pay, I bet he makes more than.

  • not his pay, the tuition cost =P

  • there are erasers on the black board's ledge. guess he doesnt like to use them

  • I strongly recommend getting the notes linked in the sidebar. It makes it easier to follow along, as the upload to youtube is somewhat fuzzy and hard to read at times.

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