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In what year do you learn GR?

  1. Jul 18, 2012 #1
    When is the first time a student of physics works with Einsteins field equation and does Friedmann cosmology?
     
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  3. Jul 18, 2012 #2

    f95toli

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    For most students that would be if they decide to do PhD student in cosmology.
    There are Masters programs that cover GR, but they are not very common.

    Note that GR is complettely unneccesary for the vast majority of physicists simply because there are few fields of modern physics where gravity plays a role at all, and when it does you can get away with newtonian mechanics.
    Hence, most will never study GR "properly" (I certainly never did).
     
  4. Jul 18, 2012 #3

    haushofer

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    I did it in my Bachelor/undergraduate (third year) at the level of Carroll's notes and the book by d'Inverno, which is quite feasible I think.
     
  5. Jul 18, 2012 #4
    If you want GR you need to seek it out. Some schools offer it at undergrad level, but I don't think any require it. I have a professor who has never taken a GR course. He knows a fair amount about it because he's a bright guy, but he did his PhD in Quantum info which doesn't require any knowledge of GR.
    Currently my school doesn't offer a PhD, but will starting Fall '13 (they have it planned out, but didn't finish in time to accept students this year). There is no plan to offer any GR courses.
     
  6. Jul 18, 2012 #5

    George Jones

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    I have Ph.D. in physics, but I never took any courses on GR or cosmology.
     
    Last edited: Jul 18, 2012
  7. Jul 18, 2012 #6

    bcrowell

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    It's relatively recently that GR has started to be offered widely as an elective undergrad course. I think the most influential book is Hartle's Gravity, which dumped the traditional pedagogy of developing tensors and then deriving everything from the field equations.

    My PhD program (at Yale) didn't require GR, but I took it. Some of my colleagues never took GR in grad school.

    If the motivation for the OP's original question is that s/he wants to learn GR now, then I would just suggest simply going ahead. There are GR books at all levels, including books like Geroch's Relativity from A to B, which uses no math at all but is nevertheless very logically rigorous. Just pick a book that's way too easy and go ahead and read it. Keep going until you reach the point where self-study becomes too difficult or time-consuming, then quit and wait to take a formal course.
     
  8. Jul 18, 2012 #7
    I began learning GR when I was 15.
     
  9. Jul 18, 2012 #8
    It's a shame that, at least intro, GR isn't typically required at the undergrad level...
     
  10. Jul 18, 2012 #9
    At my school (I go to a UC) you can take GR as an elective for physics/astro. It's not required. It's also got so many pre reqs that you probably wouldn't be able to take it until your senior year.
     
  11. Jul 18, 2012 #10

    bcrowell

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    One of the great things about majoring in physics is that the number of units of required courses is relatively small (compared to, e.g., engineering or music), so you can get a real liberal arts education. I'd hate to see that changed by throwing in more requirements.
     
  12. Jul 18, 2012 #11

    George Jones

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    The June 2012 issue of Physics Today has an interesting article, "Teaching general relativity to undergraduates"

    http://www.physicstoday.org/resource/1/phtoad/v65/i6/p41_s1 [Broken]

    Click on the figures to expand them. Fig. 2 is quite interesting. I once taught a course that used Taylor and Wheeler's Exploring Black Holes as text, and that had only first-year physics and calculus as prerequisites.
     
    Last edited by a moderator: May 6, 2017
  13. Jul 18, 2012 #12

    Doc Al

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    I took a GR course as an undergrad. (A long, long time ago.) We used Adler, Bazin, & Schiffer. But long before that I read Lillian Lieber's delightful book which I found in my high school library.
     
  14. Jul 18, 2012 #13
    Where did you major in physics? I have to take a fifth year! (granted, only part of it, but still.)
     
  15. Jul 18, 2012 #14

    bcrowell

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    Berkeley. I'm not saying it's an easy or low-unit major, but it does require far fewer units than engineering or music.
     
  16. Jul 19, 2012 #15

    mfb

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    If you are lucky, you can find a course which covers the required mathematics, too - not in depth as a mathematical course would do, but enough to get the concepts of GR. In this case, the usual bachelor courses should be sufficient to follow.

    Usually, it is not required, but it is one of the two fundamental theories of modern physics. It is my personal opinion, but I think without GR, you are missing something.
     
  17. Jul 19, 2012 #16
    I studied GR for the first time at the third year of university, but it was an optional course for physicist. And at master level there is a second exam about GR.
    It depends on what your university offers, or if you want to study it by your self, you can start after high school!
     
  18. Jul 19, 2012 #17
    GR requires a lot of effort to fully grasp it. Those tensors are real headache and they have practically very few real-life applications. Had I not spent so much time doing GR I would have easily learned 1 year of college-level physics instead. Yet something always fascinates me to understand GR. I think that only at GR level you can really appreciate the hidden deep beauty of mathematical thought.
     
  19. Jul 19, 2012 #18

    vanhees71

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    GRstudent, I've to contradict you vehemently :-).

    GR is a pretty straight-forward subject, concerning the physics. It's just a classical field theory for gravity and thus doesn't cause too much headaches (compared to quantum theory, which is much harder to swallow).

    Scalars, vectors, tensors, and the corresponding fields are applicable everywhere in physics and engineering, and thus are affecting our everyday life to a great extent.

    Last but not least GR is simply beautyful!
     
  20. Jul 19, 2012 #19
    ^
    If you are so comfortable with messy equations why don't you help me find the Einstein Tensor of Schwarzschild Interior metric? You help on this important issue would be much appreciated!

    Math part of GR consists of all math: Calculus, Multivariable Calculus, Linear Algebra, Differential Equations, etc. What I mean what differential geometry which is used only in topology and GR.
     
  21. Jul 19, 2012 #20
    Santa Cruz. To be fair, I started on my physics requirements a little late, so I had to play a bit of catch-up, but my schedule was always packed with classes. I'm not sure how it compares to a lot of other majors though. I do know it is a highly regimented major, once you get in, it's basically a straight road as far as what classes you're taking when, and there's little chance for deviance outside of your elective choices (And there aren't many to choose from). Compared to, say, the psychology major, where I happen to know, at my school, you pretty much take classes willy-nilly. I do know a lot of physics majors who were able to do a minor (usually math, though I have no idea why they would have wanted to do that.)
     
  22. Jul 19, 2012 #21

    PeterDonis

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    I guess this depends on what you consider "real-life applications". A quick list:

    * GR is essential in making GPS work;

    * GR is essential in understanding cosmology;

    * GR is essential in understanding neutron stars and black holes.
     
  23. Jul 19, 2012 #22
    Special Relativity is used in GPS making. The speed of a satellite is ~4km/sec so it has some time dilation. What strange is that, when I challenge the applications of GR, people always defend by making GPS example.

    These skills are not so crucial for most engineers. I doubt that average Engineer needs geometry of neutron stars or black holes to do his job. GR is purely theoretical insight--no more than that.
     
  24. Jul 19, 2012 #23

    PeterDonis

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    So is GR. And SR is a subset of GR.

    The GPS satellites are also orbiting at 4.2 Earth radii, which is high enough that gravitational time dilation has a significant effect. So both SR and GR are necessary to make GPS work. But, as above, since SR is just a subset of GR, this is really the same as saying that GR is necessary to make GPS work.

    This is true, unless he's an engineer working on devices that are meant to observe these phenomena. But not everyone is an engineer. There are a lot of working scientists who deal with neutron stars and black holes, and cosmology.

    I assume you mean "for most engineers". For people like those working scientists who deal with neutron stars and black holes, and cosmology, GR is required to explain observed data.
     
  25. Jul 19, 2012 #24
    I highly doubt that there are more neutron star and black hole physicists in the world than there are Engineers. I don't think that many students would do arduous work for relatively low salary.
     
  26. Jul 19, 2012 #25

    mfb

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    While effects of GR are relevant for GPS, the system could work without knowledge of the theory, too: With classical mechanics, you could simply observe the frequency shift, and correct for it.

    Most engineers do not need any modern physics, classical mechanics is a good approximation in most applications.
     
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