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Re: Let's talk about "TECHNICAL aspects".

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On 19/10/2015 8:57 PM, mlwozniak@wp.pl wrote:
> W dniu poniedziałek, 19 października 2015 10:56:34 UTC+2 użytkownik Sylvia Else napisał:
>> I'm not sure what your concern is. If it's that there are gravitational
>> effects that distort the result, that's true. But it's also true of
>> simple time and distance measurements, so the space-time interval is no
>> less valid than those.
>
> What a heresy. There is no gravitational distortion
> in time and distance measurements. They are valid -
> in our non-inertial frame, from our non-inertial
> point of view. And they can't be used to determine
> interval, at least the simple way.
>
>>
>> As for doing the measurements - we know where and when these events
>> occurred - that is, most of the measuring has already been done.
>
> In non-inertial frame. You can't put results to inertial
> formula. Neither the time, nor the distance matches.

You can transform them into an inertial frame.

>
>
>   To get
>> the space-time interval, we need only transform those measurements into
>> some arbitrary inertial frame, and combine the results.
>>
>> In practice, of course, neither event is a point in space-time - both
>> are diffuse both in time and in space.
>
> In practic, "a point" can be whole Earth. Or just a
> city. Or a corner of two streets. Or something
> smaller, too. Depending on context.
> In practic, "event" is a 4 dimensional equivalent of
> "point", and it always was.
>
>
>> That completely overwhelms any
>> possible error introduced by ignoring the various gravitational fields.
>
> Maybe. But, suppose I want a precise value?
> And, not just calculated. Calculations are theory
> dependent. To be sure I should measure, shouldn't
> I?
>

You cannot make any measurements at all without a theoretical framework. 
Even using a metre rule requires a theory that says that distances 
compose by simple addition.

Time measurements are even more complicated, and typically involve 
calculations even if they're being done by analogue machinery.

Sylvia.

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Thread

Let's talk about "TECHNICAL aspects". Maciej Woźniak <mlwozniak@wp.pl> - 2015-10-18 14:27 +0200
  Re: Let's talk about "TECHNICAL aspects". JanPB <filmart@gmail.com> - 2015-10-18 18:53 -0700
    Re: Let's talk about "TECHNICAL aspects". mlwozniak@wp.pl - 2015-10-18 23:13 -0700
  Re: Let's talk about "TECHNICAL aspects". Sylvia Else <sylvia@not.at.this.address> - 2015-10-19 16:36 +1100
    Re: Let's talk about "TECHNICAL aspects". mlwozniak@wp.pl - 2015-10-18 23:01 -0700
      Re: Let's talk about "TECHNICAL aspects". Sylvia Else <sylvia@not.at.this.address> - 2015-10-19 18:52 +1100
        Re: Let's talk about "TECHNICAL aspects". mlwozniak@wp.pl - 2015-10-19 01:25 -0700
          Re: Let's talk about "TECHNICAL aspects". Sylvia Else <sylvia@not.at.this.address> - 2015-10-19 19:56 +1100
            Re: Let's talk about "TECHNICAL aspects". mlwozniak@wp.pl - 2015-10-19 02:57 -0700
              Re: Let's talk about "TECHNICAL aspects". Sylvia Else <sylvia@not.at.this.address> - 2015-10-20 12:22 +1100
                Re: Let's talk about "TECHNICAL aspects". mlwozniak@wp.pl - 2015-10-19 23:27 -0700
                Re: Let's talk about "TECHNICAL aspects". Sylvia Else <sylvia@not.at.this.address> - 2015-10-20 19:29 +1100
                Re: Let's talk about "TECHNICAL aspects". mlwozniak@wp.pl - 2015-10-20 02:14 -0700
                Re: Let's talk about "TECHNICAL aspects". Sylvia Else <sylvia@not.at.this.address> - 2015-10-20 20:29 +1100
                Re: Let's talk about "TECHNICAL aspects". mlwozniak@wp.pl - 2015-10-20 02:45 -0700
    Re: Let's talk about "TECHNICAL aspects". alsor@interia.pl - 2015-10-19 12:02 -0700
      Re: Let's talk about "TECHNICAL aspects". paparios <paparios@gmail.com> - 2015-10-19 12:25 -0700
        Re: Let's talk about "TECHNICAL aspects". Maciej Woźniak <mlwozniak@wp.pl> - 2015-10-19 22:55 +0200
          Re: Let's talk about "TECHNICAL aspects". paparios <paparios@gmail.com> - 2015-10-19 17:14 -0700
            Re: Let's talk about "TECHNICAL aspects". mlwozniak@wp.pl - 2015-10-19 23:39 -0700
      Re: Let's talk about "TECHNICAL aspects". Sylvia Else <sylvia@not.at.this.address> - 2015-10-20 12:24 +1100

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