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  • Re: Demolishing Doppler Part One

    From Sylvia Else@21:1/5 to patdolan on Sun Dec 10 14:33:10 2023
    On 10-Dec-23 8:24 am, patdolan wrote:
    When the distant observer and BB are separated by one light year

    I'm sure you've been told before that this is meaningless, and that the
    rest of your argument falls apart accordingly.

    Sylvia.

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  • From Sylvia Else@21:1/5 to patdolan on Sun Dec 10 21:51:09 2023
    On 10-Dec-23 2:43 pm, patdolan wrote:
    On Saturday, December 9, 2023 at 7:33:14 PM UTC-8, Sylvia Else wrote:
    On 10-Dec-23 8:24 am, patdolan wrote:
    When the distant observer and BB are separated by one light year
    I'm sure you've been told before that this is meaningless, and that the
    rest of your argument falls apart accordingly.

    Sylvia.
    Sylvia, does this mean that the statement below from Cal-Tech Cosmos is also meaningless? If not, why not?

    "Proxima Centauri is a small, low-mass star located 4.2465 light-years (1.3020 pc) away from the Sun"

    No. The main reason is that it's not referencing a distance at two
    different places. Also, the star is not moving at a significant fraction
    of the speed of light relative to the solar system.

    Sylvia.

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  • From Sylvia Else@21:1/5 to patdolan on Mon Dec 11 16:36:23 2023
    On 11-Dec-23 11:56 am, patdolan wrote:
    On Sunday, December 10, 2023 at 2:51:14 AM UTC-8, Sylvia Else wrote:
    On 10-Dec-23 2:43 pm, patdolan wrote:
    On Saturday, December 9, 2023 at 7:33:14 PM UTC-8, Sylvia Else wrote: >>>> On 10-Dec-23 8:24 am, patdolan wrote:
    When the distant observer and BB are separated by one light year
    I'm sure you've been told before that this is meaningless, and that the >>>> rest of your argument falls apart accordingly.

    Sylvia.
    Sylvia, does this mean that the statement below from Cal-Tech Cosmos is also meaningless? If not, why not?

    "Proxima Centauri is a small, low-mass star located 4.2465 light-years (1.3020 pc) away from the Sun"
    No. The main reason is that it's not referencing a distance at two
    different places. Also, the star is not moving at a significant fraction
    of the speed of light relative to the solar system.

    Sylvia.
    Sylvia, thank you for broaching the subject of relativistic velocity qua perceived distances. You have doubtlessly noticed the 2:1 ratio of the helical turn counts. You know what that implies in view of gamma = 2. You obviously understand what is
    at issue here. Yet you quail at making the full argument. Please do so. It is essential to my ultimate dismantling of the relativistic doppler.

    Your argument doesn't work. I've told you why.

    Sylvia.

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  • From Tom Roberts@21:1/5 to patdolan on Mon Dec 11 21:08:22 2023
    On 12/9/23 3:24 PM, patdolan wrote:
    Consider a distant observer traveling towards Big Ben in London at
    the customary .867c. When the distant observer and BB are separated
    by one light year, between them lies a helical path of light
    originating from the tip of Big Ben's little hand. At the aforesaid
    distance of one light year, the reader can easily calculate that the aforesaid helix has precisely 730.5 turns.

    Yes. 365.25*2 = 730.6. The little hand makes two revolutions per day in
    the earth rest frame. Note the number of turns in the helical path
    between these two fixed points is invariant.

    At a velocity of .867c it will take the distant observer 1.1534
    years to travel one light year and reach Big Ben, during which time
    Big Ben's little hand will have produced another 848.33 turns of the
    helix, for a total of 1579 turns. So the distant observer is able
    to count at most 1579 turns of the helix on his 1.1534 light year
    trip to Big Ben from one light year away at a velocity of .867c

    Not "at most 1579 turns", that is the number they must count during this
    trip. Note also that the duration of 1.1534 years is in the earth rest
    frame.

    Now we apply the relativistic Doppler formula to the revolution of
    Big Ben's little hand from the stand point of the distant observer.
    With the direction of travel towards BB, and beta equal to .867, we
    arrived at a doppler multiplier of 3.747. Therefore the distant
    observer must count 2738 revolutions per year due to relativistic
    doppler, for a source frequency of 730.5 revolutions per year. So
    during his 1.1534 year trip, according to the relativistic doppler
    formula, the distant observer must count 3158 revolutions of Big
    Ben's little hand.

    Nope. You used the Doppler formula for the moving observer, so you must consider this from their frame. The trip takes 1.1534 years in the earth
    rest frame. The gamma for v=0.866c is 2.000, so the trip takes 0.5767
    years in the moving observer's frame, and they count 1579 turns.

    You made the newbie's mistake of using the wrong frame.

    Gentle reader, I ask you to consider which answer to this conundrum
    are we to choose?

    Either calculation, WHEN THEY ARE PERFORMED CORRECTLY. Both predict the
    moving observer will count 1579 turns.

    Your attempt to "demolish Doppler" fails due to you elementary mistake.

    Tom Roberts

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