Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Special Theory of Relativity paper

  1. Pretty well.

    1 vote(s)
  2. Needs some clarification

    2 vote(s)
  1. Apr 5, 2010 #1
    Hello! I'm writing a paper on Einstein's special theory and Einstein himself for my high school freshman science class; I was told this would be the best place to post it. I'm trying to make my explanation clear; if it's not, suggestions on how to improve it would be appreciated. Thanks! :smile:

    Attached Files:

  2. jcsd
  3. Apr 5, 2010 #2
    I enjoyed the style, but there is misleading language, such as "then gravity acts on it", when it's simultaneous. That said, this is high-school, and I don't really know what's expected of you.

    The the other major issue is that what you're describing isn't really a terribly useful description of SR.

    If I might ask, what was the assignment, exactly? That would probably help people here give feedback that is useful to you, rather than being highly technical.
    Hi there, and welcome to PF!

    This is probably something you should put under Academic Guidence, although a staff member will probably move it. Not a shooting offense mind you, but by posting there, you'll be dealing with people who have the mindset to help you with THIS paper, not teaching you about Relativity from the ground up.

    That said, you could consider a start where Einstein started in 1905, with SR, trains, and flashes of light. "On The Electrodynamics of Moving Bodies" which is freely available online, quite short and comprehensible. You don't need to use trains (and kudos for the Douglas Adams reference), but if your metaphor isn't an improvement, then it needs to be reworked.

    Remember, Relativity is a fundamentally a theory of geometry, and your paper reflect some confusion and conflation of the Newtonian concept of "action at a distance", and the Relativistic theory of local geometry. You're also not correct in saying HOW Eisntein arrived at his conclusion... which isn't bad for a freshman I might add.

    That's the bottom line... this is a BIG subject... why not pick one implication of SR and use that as a model for your paper? Focus ONLY on that, but keep the light tone that makes your paper quite readable. It's good that your reach exceeds your grasp, but it's time to reel it in a bit.
  4. Apr 5, 2010 #3
    The assignment was to pick anything out of the science book we're using (Apologia Science, Exploring Creation with Physical Science) and write an essay on it. I (being the crazy girl that I am) went and checked out Relativity: the Special and the General Theory (which misleadingly says that it's a 'clear explanation that anyone can understand') by Albert Einstein. I went through the half of the book that deals with SR with my dad (who has a BA in some form of engineering) and read the paragraphs of my textbook that deal with SR. That's probably why I ended up with some misconceptions. :)
    Thanks a million for your advice!
  5. Apr 5, 2010 #4
    Ok, given that I think you're actually on the right track, and with a bit of clarification you can make this work. After all, learning is a process of error and error-correction, and you have 4 years to work on the "how" of that. Highschool, above all, is about learning HOW to learn, more than what you learn. Now, don't take that to mean you should ignore your courses, but that beyond fundmanetals, the major lessons are structural, not content.

    You're welcome, I hope it helps, and please tell your father, from one man to another, that he clearly did something right to have a daughter who reads SR with him. You're not crazy, you're smart, and curious, and that can take you such a very long way.

    Finally, I would add that if you want a really good explantion of SR, probably DaleSpam, or Doc Al, or another advisor will have had more experience relaying the core concepts to people just learning them. Sadly, my own lack of mastery makes me a poor teacher of this subject, so while I'm glad my advice is appreciated, I should point out that PF has true experts, teachers, etc.

    I'd seriously consider messaging a staff member and having this moved to "Academic Guidence", where I think you could concievably learn a great deal. After all, this paper represents a clear picture of your understanding of SR, and that is something a good teacher can work with to find where you need to start, and how to move you from point A (Alice!) to B (Bob!).
  6. Apr 5, 2010 #5

    I think you're confusing mph with ..per second, so check you can convert between them.

    I think you're misunderstanding the light-clock example. It's not how long the light takes to get to Ford, but how far Ford deduces the light has to go to get from the top mirror to the bottom mirror (and back). This distance will be greater than the height of the car, not because distance is relative but because the mirror will have moved away from its original place by the time the light reaches it again. (The discrepancy between the time periods that Zaphod and Ford infer is the justification for time dilation, which asserts that Zaphod and his watch are nearly frozen according to Ford, while he measures them zoom by. Length contraction is justified by a different thought experiment, where Zaphod bounces a second pulse of light lengthways between the rear-view mirror and the back windscreen.)
  7. Apr 5, 2010 #6
    Wait a sec, that's not a real science book!?! :yuck:

    After closely studying that book you're still going to be confused, because rather than teaching you the actual science, it is only going to distort and unscientifically pick out the parts which can be made to sound consistent with a certain conclusion that even many Christians don't agree with.

    For example, you can't expect to learn nuclear physics from an author who doesn't want you to understand radio-dating. You're just lucky that Americans don't believe all those bible verses about the earth sitting on pillars (and the sun going around it) or they would also discourage you from understanding rockets, gravity and relativity. If the author doesn't want you to understand evolution properly, how will you learn why there is a new flu vaccine each year, and why antibiotics are losing their effectivenesses?
    Last edited: Apr 5, 2010
  8. Apr 5, 2010 #7
    Sad, but true, but then we can hardly tell her to protest in her freshman year... maybe offering online resources as an alternative would be prudent?
  9. Apr 5, 2010 #8
    Hi. My first suggestion would be to limit the paper to SR if you plan to cover the content. On the other hand if you stay with a historical coverage without dealing directly with the content then SR and GR together would be fine. I have been thinking about SR off and on for >30 years and I still do not "have a feel for it". I can do the math but that is just the beginning. I would say the most interesting feature of spacetime at speeds of the order of c (the speed of light) is the fact that position and time are NOT independent as they are approximately at low speeds (everyday human experience). To say when something occurs it is not enough to, say when, you must say also where. An event happens at a spacetime point (a point in time and a point in space).
  10. Apr 5, 2010 #9
    I do believe you just handed the young lady an A edpell. :wink: Well said!
  11. Apr 6, 2010 #10
    I'm sorry; I seem to have caused a bit of confusion. That particular volume in Apologia Science deals with earth science, introductory chemistry, and introductory physics. There's only a couple paragraphs in it that deal with relativity; since the curriculum was written for seventh graders (I took chemistry in a different curriculum before I took physical, so I had to go back a year), Dr. Wile probably didn't want to be confusing.
    Also, since I checked out a book written by a genius (who used an example I tried to copy and apparently didn't succeed. Darn. :rolleyes:), I did have some trouble understanding what he meant. I guess I'll have to look over it again. :)
    Dr. Wile, at least, has a PhD in nuclear chemistry. I think he understands radio dating! Could you please point me to the verses dealing with the earth sitting on a pillar in the middle of the sun? And new flu vaccines/less effective antibiotics seem to be a problem of mutation, not evolution.
    Last edited: Apr 6, 2010
  12. Apr 6, 2010 #11
    Thank you! I'll be sure to talk to someone about moving the thread, and about SR. :)
    My dad says thank you also.
  13. Apr 6, 2010 #12
    Antibiotic resistence is one of the better examples of evolution in action. Mutation is the basis of evolution after all. The issue is that the microbes have some mutations, so a FEW sometimes surivive antiobiotics, or people take a partial course. This is usually the perfect example of evolution in action:

    Environmental Stress + Adaptation (read: Mutation) + Persistance of that mutation = EVOLTION.

    EDIT: Well, please tell your father that it is my pleasure, and good luck with your paper. :smile:
  14. Apr 6, 2010 #13
    The reason I chose to limit myself to special relativity is that we didn't have the time to go through the second half of the book; also, with a limited understanding of math and science (seeing as I'm only a freshman), I thought it would be best to stick with the half that deals with uniform motion! :) I do think that GR, with what I know of it, is more interesting, but I was attempting not to bite off more than I can chew.

    edit: I didn't see that from what I read; it's really cool! Kind of like velocity, in that it has two different aspects..
  15. Apr 6, 2010 #14
    If that's your understanding of evolution in all aspects of the word, then I don't disagree with you; I used 'mutation' because evolution is so often interpreted as the idea that it's possible for information to be added to the genome by evolution, instead of it creating a more isolated gene pool, if you will. In the case of plants, animals, etc., anyway...
    I'll be sure to! Thanks! :)
    Last edited: Apr 6, 2010
  16. Apr 6, 2010 #15
    The net result is less diversity in terms of numbers of species, but the genes themselves are often conserved.

    For example...

  17. Apr 6, 2010 #16


    User Avatar
    Science Advisor

    Would you consider starting a thread on evolutionary issues in the biology forum? I would say that mutations do add information to the gene pool, by definition, but in many cases this new information is harmful rather than beneficial. Natural selection weeds out the harmful mutations and preserves the beneficial ones. If you take a population of a single species and split it into two reproductively isolated populations (by a geographic barrier, for example), then over time each population will acquire a large enough number of distinct beneficial (or neutral) mutations in their gene pool to become separate species. For example, consider the example of a ring species (click the 'larger image' link for a nice diagram) where populations on opposite ends of the "ring" cannot interbreed, but one can find a continuous chain of intermediate populations between them, each able to interbreed with its neighbors...if the links in the middle were to die off then the populations on the ends would have to be considered entirely distinct species, and yet the interbreeding of nearby links pretty clearly indicates common ancestry.

    Incidentally, does Dr. Wile actually accept radioactive dating, and thus accept that the Earth is billions of years old, or does he find some reason to propose that decay rates have changed (in violation of known physics) or something along those lines?
  18. Apr 6, 2010 #17
    If you choose to make that thread, please let me know, I'd really love to engage in that disucssion in such a civilized forum.
  19. Apr 6, 2010 #18
    So in the http://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment" [Broken], you think the mutations were decreasing the amount of information in the genome (even the mutation that conferred the ability for the organism to live off a food that the wild varieties are unable to consume)?

    You sound like an inquisitive person, aren't you more curious to know the exact reasons why many experts have thoughtfully reached a viewpoint that is different from one that your parents grew up with? (I mean, it can't be heresy if even the http://en.wikipedia.org/wiki/Catholic_Church_and_evolution" [Broken] doesn't disagree with evolution, can it?)
    Last edited by a moderator: May 4, 2017
  20. Apr 6, 2010 #19
    http://hypertextbook.com/eworld/geocentric.shtml" [Broken] seems to be a list.
    Last edited by a moderator: May 4, 2017
  21. Apr 6, 2010 #20
    If you have a continuing interest in the topic I recommend "A Journey into Gravity and Spacetime" by John Archibald Wheeler. It covers both SR and GR. It is light on math in the sense that there are few equations and the ones that are used are simple. On the other hand there are ideas used that are some of the most profound ever and offer endless hours of thoughtful consideration. Hope you have fun.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook