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

Spec. relativity question

  1. Dec 21, 2008 #1
    Hello, I am Valentina Russo from Potenza, in Italy, and I’m a doctor.
    I want to ask someone who knows restricted relativity: what is there in common between the path of Lorentz and that, elementary, proposed by me, that I have summed succinctly; I am not a physicist, so I ask questions. Thank you.

    Image here: http://file-city.co.uk/files/valentina79/image.doc" [Broken]

    Image that a beacon placed at the center of the circle (with wich it moves) is able to diffuse rays (such as laser) in each direction: at the center there is an observer who, staying (ideally) always stopped and out of the picture, measure distances of two points from the center (points receptors), using as meter the walk of a ray of light. The horizontal lines (those hyphens) represent the respective lengths traveled (from left to right) by two points, always sympathetic to the circle (when running);one in the left a semicircle, the other in the right. The whole segments (A and D) are the measures that the subject notes when the circle is stopped; the segments in lines and points (B and C) are the walks of the regulus-radius with circle in motion. With regard to the point that tends to flee from radius (with that given angle of incidence), that reaches it along the route B; conversely, if the radius is meeting to the other point (with the same effect), the measurer will see the regulus-radius crossing the point following the walk C. In other words, in the first case, the space walked from the regulus is longer than with the system in peace; in the second case, the successions, unfloading in area symmetrically and diametrically opposite, generate results perfectly antithetical: the walk of the radius (segment C) is smaller than the length obtained when the system is at rest (segment D). It puts an emphasis on consideration (very important) that, compared to the position of the upper point of the segment A (which is the site which the point occupies when the following radius starts), the opposite is occupied by the lower point of the segment C ( the place where the radius reaches the point that goes on the faces): this is the same, at reversed parts , even for the extreme points of the segments B and D.

    Therefore, the space measured (through the regulus-radius) when the system is in walking changes apiece the radius pursues the point-receptor, or goes in front of it; on the contrary, nothing changes if the circle is at rest: that is, and is the same thing, nothing changes for the person who is in the circle in motion. Now we convert the speech to an extent. The first ratio concerns the first case (radius that chases the point): a factor is the measurement of space while the circle is in motion ( the product obtained by multiplying the time –t1- for the speed of the ray -c-, added with the product obtained by multiplying the same time –t1- for the speed of the receiver in motion -v-); the other factor is the measurement of space while the circle is quiet (consisting of the product obtained by multiplying the time –t2- for the constant speed of the radius -c-). The second report concerns the second hypothesis (radius that goes in front of the receiver): a factor is always in the usual place of the circle in rest (the product obtained by multiplying the same time –t2- for -c-); the other factor is obtained subtracting from product obtained by multiplying the time –t1- for the constant -c- the product obtained by multiplying the same time –t1- with the speed of the receptor point –v-.
    Attention! This is a proportion of logical-mathematical nature, and not a simple geometric measurement of the contraction of space along the line of motion of the circle: so much so that the terms of the proportion are congruent in logical aspect, but are incongruent in geometric aspect.
    In other words,
    (t1c+t1v): t2c=t2c:(t1c-t2v)

    The simple developing of the proportion conduces to the Lorentz’s factor. This means that the value of 100 nanoseconds in the circle in motion (270,000 kilometers in the second) is equivalent to 233 of those in the circle in rest.
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Dec 21, 2008 #2


    User Avatar

    Staff: Mentor

    I'm sorry, I can't see your diagram. When I download it and open it in Microsoft Word (Macintosh version from 2004), I see only a box with a red X in it. Without the diagram, I can't make sense of your text. It looks like you translated it from Italian to English using Babelfish or some other translation software.

    Can you save the diagram as a GIF or JPEG file, and attach it to a message? Use the "Manage Attachments" button in the "Additional Options" section of the page where you write your message.
  4. Dec 22, 2008 #3
    I tried..

    Attached Files:

  5. Dec 22, 2008 #4

    George Jones

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Most of us are having trouble following your arguments.

    Is the following situation similar?

    In the middle of a train car, a light flash is sent towards both ends of the car. In the frame of the car, the light reaches the two ends simultaneously. In the frame of the ground (with respect to which the train moves), the light reaches the two ends at different times.
    Did you mean to write

    "In other words,
    (t1c+t1v): t2c=t2c:(t1c-t1v)"?
  6. Dec 22, 2008 #5
    The base of the postulate is similar to that wich permits to obtain the Lorentz's contraction through the Pitagora's theorem: but the Pitagora's theorem describes the geometric aspect with concern to a perfectly perpendicular cathetus to the motion's direction, while my proportion describes the logig-mathematic aspect with concern to a motion of the radius that is perfectly along the line of the sysntem's motion.
  7. Dec 22, 2008 #6
    Yes sorry, I wrote wrong.
    Yes I mean your same exemple
  8. Dec 22, 2008 #7
    Obviously, to the relativist friends, the proportion is (t1c+tiv):t2c=t2c:(t1c-t1v)
    I repeat, this proportion seems to me logically more right than the Pitagora's theorem, because the theorem presuppose wich it should have to prove: that is the invariance of the perpendicoular dimensions to the motion's direction. So, the theorem become exact only because the perpendicular cathetus is the same both for who is in the system in motion, bothh for who observes this occirance out of the system. Instead, the proportion translates in mathematics a logig concept: that is the mensuration of the space-time modeled with concern to the perfect coincidence of the direction of the motion between radius and system is action.
    Sorry for my english.If my words are not so clear, is there someone who speacks italian? I could call or send fax(u could send me your number in private message) with drafts very similar to those ot the photon that walks orizontally afore and aback in the train.
    Thank you very much!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook