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Confused about time dilation

  1. Aug 27, 2006 #1
    Iv been reading the fabric of the cosmos and its my 1st and only source on theoretical physics. I reckon i understand str from it, i can work spacetime diagrams and lorentz transforms but my understanding must b wrong somewhere.

    Str says the faster an object moves the slower time flows for it. lets say 2 objects are movin at v m/s relative 2 each other. Object A looks at B and says im stationary and ur movin at v m/s so time shud flow slower for u. Object B looks at A and says no im stationary and ur movin at v, time flows slower for u.

    I also cant see how 1 can be right since their is no difference between them
  2. jcsd
  3. Aug 27, 2006 #2

    Doc Al

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    Staff: Mentor

    STR says that the clocks in a moving frame run slower as measured by observers in the "nonmoving" frame. The faster the moving frame moves with respect to the "nonmoving" frame, the greater the effect. But in its own frame, the "moving" clock operates just like it always does. (After all, we are moving with respect to some other frame right now--do you feel time running any slower? :wink: )

    And yes, the effects of relativity (on clocks and metersticks) are completely symmetric. If B is moving with respect to A, they each measure the other's clocks as running slowly compared to their own.
  4. Aug 27, 2006 #3
    Class! They're both right is an answer i should hav assumed.

    "they each measure the other's clocks as running slowly compared to their own" was what i thought there was a problem with.

  5. Aug 27, 2006 #4


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    that's sorta what the "twin paradox" is about.
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