Re: Un calcolo (forse) impossibile

From: LuigiFortunati <fortunati.luigi_at_gmail.com>
Date: Sun, 30 Jul 2017 17:52:56 +0200

Sylvia Else alle ore 04:44:55 del 30/07/2017 ha scritto:
>> The traveling twin starts and goes back to Earth where he finds his
>> 80-year-old brother aged as he is only 10 years old.
>>
>> The wristwatch on the twin traveler's wrist marks (of course) the
>> 10-year time.
>>
>> The earth twin during the years of the trip has been flashing every 10
>> years (his).
>>
>> The last lightning is emitted at the time of the return of the ship,
>> when the Earth clock marks the 80-year time and the wrist watch on
>> the twin traveler marks 10 years.
>>
>> Calculation (perhaps) impossible is this: at the ejection of the
>> penultimate lightning (when the Earth clock marked 70 years) what time
>> was the watch on the wrist of the traveling twin?
>>
>
> This not answerable as it stands, because you have not specified which
> frame (Earth or travelling twin) is to be used.

  Io ho specificato che voglio il tempo dell'orologio al polso del
gemello viaggiatore e non il tempo della Terra.
(I have specified that I want the time of the watch on the traveler's
twin wrist and not the time of the Earth).

> Indeed, other observers moving at different relative speeds will get
> different answers.

  Degli altri osservatori non m'interessa alcunché.
(Of the other observers I have nothing to do with it).

> The problem here is that you're talking about events (flash and time on
> watch) that are separated in space.

  Certamente!! La simultaneità riguarda sempre gli aventi separati
nello spazio.
  E io cerco la simultaneità del gemello viaggiatore con gli eventi
terrestri.
(Of course!! Simultaneousness always applies to those who are separated
in space. And I seek the simultaneity of the traveling twin with
earthly events).

> You might prefer a question that has unique answer, such as what time
> will the travelling twin's watch show when he sees the flash?

  Quando il gemello viaggiatore *vede* il lampo, l'evento "emissione" è
già avvenuto.
(When the twin traveler sees the flash, the "emission" event has
already occurred).

> Sylvia.

Luigi.

-- 
Luigi Fortunati
Credere e' piu' facile che pensare
Believing is easier than thinking
Received on Sun Jul 30 2017 - 17:52:56 CEST

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