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Concepts for Granted

  1. Mar 17, 2007 #1
    This may be inapplicable to the advanced thinkers in here, but I, at 17 am learning about special relativity for the first time and i find that i am very slow at understanding the very basics of it. I have always been slow at grasping concepts because i like to be very sure in my thinking. I wanted to ask, how many people really understand special relativity, time dilation and other stuff related trully and fully? Because i think some people can articulate ideas, but dont really understand them, taking some concepts for granted, for example a 'simple' question like 'what is time?' can be answered seemingly competently but often lacks eveidence of understanding. I am aware i may be sounding unintelligent right now. I think i just need some material which explain things very basically (weblinks would e appreciated) so i feel confident i understand it. Peace.
    Last edited: Mar 17, 2007
  2. jcsd
  3. Mar 17, 2007 #2
    Some questions barely make sense, let alone have proper answers. For example, even the best artists are unlikely to agree on any answer to "what is art?" In physics time is just a dimension, just another parameter of the equations, and we can study properties of "time", but I'm not sure that the kind of person who answers "what time is" will necessarilly be considered to have fully understood the relevent physics.
  4. Mar 17, 2007 #3


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    Great answer.

    Go deep enough with any line of questioning and you get to philosophy. That doesn't have a whole lot to do with whether or not someone understands the science involved.
  5. Mar 17, 2007 #4
    However, one can even discover "what is time" in the sense of finding that time is "this other concept A", but then one can ask: so, what is A?
    We always find something new, but then immediately ask: where this something come from?
    We can go on forever.
  6. Mar 17, 2007 #5
    I suppose thats what my problem is. I hate writing things when i dont understand them. If theres any contradictions in my mind, ill go too deep into it. I often find problems writing english literature essays also, just as i do with more theoretic physics.. although it may also be to with the fact im quite slow! I find it difficult to accept anything, i dont know why i have this problem. Sometimes knowledge just seems superficial to me and thats why i really need to secure the fundamentals.
    Last edited: Mar 17, 2007
  7. Mar 17, 2007 #6
    I know another person who was like this in the past...:wink:
  8. Mar 17, 2007 #7
    oh... what happend to them? haha, did they perish?
  9. Mar 17, 2007 #8
    you sound like you have my problem?
  10. Mar 18, 2007 #9
    Had. Then during my life I learned how to make decisions, because we all, one day, find ourselfes in situations where we have to make choices fast.

    About my questions, I do this: I formulate them in a precise way and then I write them down. I know that I will be able to think about them again, one day, so I can go on. The day I can think about them again, I write down my conclusions and my new questions, and so on.

    This gives me the feeling I don't have to leave them behind me.
  11. Mar 18, 2007 #10


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    Staff Emeritus
    Science Advisor

    That sounds like a good plan - trying to write down your questions, and be precise. An unformed non-specific general feeling of doubt isn't really very useful, a more specific question like "what chain of logic lead you from point A to point B" is a lot more likely to be productive.
  12. Mar 19, 2007 #11


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    2018 Award

    Paradoxical, you may try with this

    It would also help if you articulate your question more precisely. A well formulated question always contains a half of the answer.
  13. Mar 20, 2007 #12
    Einstein was much the same - he developed slowly - started thinking about the things that eventually lead to Special Relativity when only 16 - he worked on the problem for 10 years - first as a student and later as a Patent clerk in his spare time, He abandoned many fruitless attempts, but in his own words, "the problem was always with me....until at last it came to me that "time" was suspect." A half century later, near the end of his life, he still wondered whether it was right.
  14. Mar 25, 2007 #13
    hmm thanks yogi.
  15. Mar 25, 2007 #14
    thanks for the link. its good at explaining. and ill take your comment bout the concise question on board.
  16. Mar 28, 2007 #15
    i face the same sort of problem often.when i started relativity last year(i was 20 then) i wondered what they meant when they said 'time' and 'space'.
    i think they were talking about rulers and clocks.

    Time is usually measured by some event repeating itself in space - like say a pendulum -it starts from some point and comes back to it - again and again.We use it as a reference frame to measure time.Space measurements are made by stuff like rulers - but you have to see both ends simultaneously.

    Now if you think of 2 guys A and b moving w.r.t each other with their own clocks and rulers their readings won't match.If b is carring a pendulum or a 'photon clock' he will think well it's coming back to the same point and all,but A won't agree.it won't match his clock.Neither will A and b agree about length measurements - because same two things won't be simultaneous to them.

    you can take a quick look at einstein's book written for non-specialists -
    http://www.bartleby.com/173/ - it may help a bit.
  17. Mar 28, 2007 #16
    thanks for that. Ive began reading that some time ago, i didnt realise it was actually written by Einstein.. ??
  18. Mar 28, 2007 #17


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    Yes, that's physics- not "metaphysics"! Physicists are very pragmatic- if it can't be measured, you don't talk about it. "Time" is precisely what you read on a clock, and "space" is what you measure with meter sticks. You don't need to get more "philosophical" than that.
  19. Mar 29, 2007 #18
    i don't have any experimental evidence to prove that...it was published under Einstein's name anyway:tongue2:
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