# [bi|sur|in]jective coordinates

Discussion in 'Physics & Math' started by RJBeery, Sep 29, 2010.

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1. ### prometheusviva voce!Registered Senior Member

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You started a thread on what covariant means and you don't even know the ranges of spherical coordinates?! This isn't a case of running before you can walk, it's a case of flying to the moon before you can hold up your empty head.

3. ### Green DestinyBannedBanned

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wtf?

Have I ever said I am a fucking genius? Have I ever claimed I should know these things?

I have never worked on black holes, or anything to do with spherical coordinates, but you still somehow think I should frikken know eh? And how is this necesserily something part and parcel of wanting to know a bloody terminology?

Prom - go walk in front of something fast. And hard.

Last edited: Oct 17, 2010

5. ### temurman of no wordsRegistered Senior Member

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What are the lines $r=\mathrm{const}$? What is $r=1$? What are $\theta=\mathrm{const}$? What is $\theta=0$? $\theta=\pi$? What is $\theta=2\pi$?

7. ### Green DestinyBannedBanned

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I understand work is required here. I will go do some investigating and get back ASAP.

8. ### prometheusviva voce!Registered Senior Member

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The problem isn't that you don't understand spherical coordinates, the problem is you start threads on the Dirac Sea, gravitons and stress tensors. If you know enough about those things to be asking technical questions then you absolutely must have seen and worked with spherical coordinates. For example, in basic, and I mean basic electromagnetism there's a standard exercise to show Coulombs law for a point charge using Gauss' law, and since the field only depends on the radial distance from the point charge, that means using spherical coordinates. What is it exactly that makes you think a knowledge of black holes is the only thing that implies understanding of spherical coordinates?

As for your last statement, it's not my fault that your stupidity is making you feel inadequate. I'm only one of the people pointing out to you how ridiculous what you are doing actually is. Maybe some psychoanalysis would help?

9. ### Green DestinyBannedBanned

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Don't be a sanctimonious little shit.

People have created far more advanced topics to discuss with very little knowledge on the subject - most times, these topics are discussed so they may gain a little knowledge on them.

My dirac sea thread was an example of this. As I said to alphanumeric, I can talk a great deal now on the dirac equation, without running into complexities involving pauli matrices.

10. ### Green DestinyBannedBanned

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And that's enough prom. I am keeping this a clean act here. I am in talks with temur, who is being a great deal more appreciative of teaching than you ever have been.

11. ### Green DestinyBannedBanned

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But if you want to contribute, you can tell me one thing in the hope of advancement. Exactly where else are spherical coordinates used? I could think possibly some subjects, but I would be guessing.

I've done a lot of work on physics, and never really came across them, so perhaps you can enlighten me to their other possible uses?

12. ### funkstarratsknufValued Senior Member

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1,390
No, you really can't.

At your current aptitude level you're years (and not a few, at that) of dedicated full-time study away from being able to do anything close to that. You simply have no idea how far out of your depth you are.

13. ### Green DestinyBannedBanned

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Well, I can reitterate everything I have learned. I think that counts.

14. ### AlphaNumericFully ionizedRegistered Senior Member

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They come up in more than just black holes. They are basic coordinates uses in 1st year electromagnetism and gravity. If you've ever written down $F = k\frac{1}{r^{2}}$, either Coulombs law or Newtonian gravity, then you've used them. You have started threads on electromagnetism. In fact I specifically remember you saying that in your thread on electromagnetism that your 'result' lead through to Gauss's law, which is an expression to do with integrals over spherical coordinates!!

Would you like me to link to it or are you going to admit you've lied without needing further evidence?

As can anyone who reads Wikipedia or copies and pastes from papers. Can you do quantum field theory without knowing about the Pauli matrices? I'd say not and I imagine a quick poll among the other people who have done quantum field theory here would result in similar replies.

Electromagnetism, as I just pointed out and you supposedly already know, gravity (both Newtonian and relativistic), quantum mechanics (the Hydrogen atom), signal analysis (wavelet decompositions, which form the basis of pretty much all image compression), fluid mechanics, the combinations of these, like magnetohydrodynamics.

Stick a pin in a physics textbook and you'll find an area which has had spherical coordinates used at some point or other. You simply cannot do physics and get to the Dirac equation without having seen them. They are required knowledge and taught in every single physics degree in the world.

You've been asked a very simple question about a very simple topic and its beyond you. Rather than admit you don't know you come up with excuses which become so ludicrous its daft of you to even continue to tell them. Give it up GD, no one here thinks you're anything but a liar.

15. ### Green DestinyBannedBanned

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Wow, not a half decent post. Until the end/

What have I lied about alpha?

16. ### Green DestinyBannedBanned

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I will need to ask some questions. What is meant by, ''the lines'' - I need to know what I am looking for.

17. ### Green DestinyBannedBanned

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You're the frikken liar. Where have I claimed that I knew what spherical coordinates where? I even said to temur I did not do any work on black holes involving these concepts.

You are lying, and now I am reporting you. I've had enough of this attitude.

18. ### temurman of no wordsRegistered Senior Member

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Lines means curves. For example, the curves x=const in the ordinary xy-coordinate system are vertical lines.

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Oh ok.

Search time!

20. ### AlphaNumericFully ionizedRegistered Senior Member

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That you can do electromagnetism. That you can do anything to do with the Dirac equation. That you have in the past learnt vector calculus, linear algebra, quantum mechanics and anything else beyond high school physics.

And before you say "Where did I say I learnt vector calculus?" you have claimed you're trying "trying to remember what you call ''basic stuff.'' ", which implies once you knew it. You said that in reference to me pointing out how you botched up things like linear combinations, calculus, Hilbert spaces, superspace, interactions and vectors.

Clearly you are trying to put across the impression you've done this stuff in the past but are a little rusty. Its clear from threads like this one, where you can't even do basic polar coordinates, that you have never known this stuff. Therefore you have lied.

*sigh* Looks like my comment about Gauss's law was too subtle, yet another testament to the fact you don't know what you're talking about.

Here you say your 'work' (which was also nonsense, as I explained in the thread) is such that "one can derive the law of Gauss". Thus you are implying you know and understand the details of Gauss's law. Except that the canonical example of Gauss's law is that of a spherically symmetric distribution of charge. No one can learn Gauss's law and not come across polar coordinates in that regard. Likewise for Newtonian gravity.

But to not have come across polar coordinates would mean you didn't do any work on electromagnetism, classical mechanics, angular momentum, gravity or quantum mechanics nor could you have done anything even vaguely resembling a basic course in mathematical methods in physics, as they specifically cover different coordinate systems because of their huge application to physics.

You seem to be failing to realise that saying "But I haven't done anything to do with black holes" isn't an excuse because polar coordinates are everywhere in physics. You simply cannot do physics and not have come across them, it'd be like claiming you're an expect in history and yet not have heard of World War II.

I've given you plenty of opportunity to respond to the specifics of what I've said. You've failed to retort anything, you just whine and then start a new thread with new nonsense. If I'm so wrong then put me in my place by demonstrating your understanding. All you've managed so far is to jam your foot even further down your throat.