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Re: New rewritten version of 'annotated version of SRT'

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Am 22.03.2022 um 22:31 schrieb Michael Moroney:
> On 3/22/2022 4:11 AM, Thomas Heger wrote:
>> Am 15.03.2022 um 19:19 schrieb Michael Moroney:
>>> On 3/15/2022 3:17 AM, Thomas Heger wrote:
>>>> Am 14.03.2022 um 17:27 schrieb Michael Moroney:
>>>>> Not a problem.
>>>>>
>>>>> 1) The electron could be flying along in a straight line when at t=0,
>>>>> the (electro)magnetic field is switched on.
>>>>
>>>> ??????
>>>>
>>>> That IS a VERY serious problem, because VERY large magnets (like in a
>>>> synchroton), can take quite a while to build up a static magnetic
>>>> field.
>>>>
>>>>
>>> And what does this have to do with the price of tea in China?
>>
>>
>> It has something to do with your comment, that the magnet could be
>> switched on, once the electron enters at t=0.
>>
>> I wanted to mention, that this is not possible, because a sharp
>> steplike increase of the magnetic field strength in a magnet is
>> impossible.
>
> And...?
>
> There are no electromagnets with a perfect step function response.

But YOU wanted to switch the magnet one in that moment, when the 
electron passes by.

> There are no such things as Einstein's trains which travel at 75% of c.

Well, trains were not used in Einstein's text. They were used as means 
to illutrate SRT.

> The earth is not a perfect sphere.

Sure, but hardly anybody assumed it would be a sphere.

Most people think, the Earth is roughly a ball (a sphere is the surface 
of a ball).

> Two identical cars moving at 60 mph crashing into each other head-on
> won't collide at exactly 120 mph relative to each other.

Well, in collision we have two things: momentum and energy.

momentum is mass times velocity. Because momentum is (apparently) 
conserved, an incomming mass had to be stopped by momentum provided by 
the target.

But that is difficult, because material objects need to be accelerated 
before they reach a certain velocity.

Therefore a fast object hitting a slow target creates tremendous 
acceleration upon the impact zone. That causes great forces, which 
spread out as shock waves and deform or disrupt the target.

Momentum is now depending on mass and velocity.

Kinetic energy is e_kin = 1/2 m* v², what is growing quadratic with 
velocity.

That energy provides the power for destruction of the incoming object.

> The two cars were never identical in the first place.
> The speed of light isn't c in the atmosphere.

Yes, because speed of light is depending on the medium.

> The bottoms of the towers of the Golden Gate Bridge are closer together
> than the top of those towers.

Is this so?

...

>
> Good scientists and engineers calculate the effects of ones of
> significance as well as potential measurement effects and determine if
> they affect the outcome or can be ignored. Modern papers have a figure
> for error, meaning what are the chances the outcome isn't due to what
> they are looking for but the error effects.

'Good' was apparently meant analog to 'useful'.

But usefullness isn't really a criterium for science, while it is in 
engineering.

Engineers do not really want to know, how nature functions, but want 
their machine functioning. Physicists are doing the opposite.

...


TH

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Re: New rewritten version of 'annotated version of SRT' Thomas Heger <ttt_heg@web.de> - 2022-03-15 08:17 +0100
  Re: New rewritten version of 'annotated version of SRT' Odd Bodkin <bodkinodd@gmail.com> - 2022-03-15 10:36 +0000
  Re: New rewritten version of 'annotated version of SRT' Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-03-15 14:19 -0400
    Re: New rewritten version of 'annotated version of SRT' Buddy Good <erv@ervn.ni> - 2022-03-15 19:14 +0000
    Re: New rewritten version of 'annotated version of SRT' Thomas Heger <ttt_heg@web.de> - 2022-03-22 09:11 +0100
      Re: New rewritten version of 'annotated version of SRT' Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-03-22 17:31 -0400
        Re: New rewritten version of 'annotated version of SRT' Thomas Heger <ttt_heg@web.de> - 2022-03-23 09:36 +0100
          Re: New rewritten version of 'annotated version of SRT' Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-03-25 00:31 -0400
            Re: New rewritten version of 'annotated version of SRT' Thomas Heger <ttt_heg@web.de> - 2022-03-25 08:16 +0100
              Re: New rewritten version of 'annotated version of SRT' Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-03-26 15:43 -0400
                Re: New rewritten version of 'annotated version of SRT' Thomas Heger <ttt_heg@web.de> - 2022-03-27 19:40 +0200
                Re: New rewritten version of 'annotated version of SRT' "Paul B. Andersen" <paul.b.andersen@paulba.no> - 2022-03-28 10:07 +0200
                Re: New rewritten version of 'annotated version of SRT' Odd Bodkin <bodkinodd@gmail.com> - 2022-03-28 13:09 +0000

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