Re: Einstein's Train Gedanken Re-visited

"Bruce Richmond" <bsr3997@xxxxxxxxxxx> wrote in message news:2939b7dd-20fb-43d8-9210-3f346f67e78f@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Jun 23, 8:08 am, "Whoever" <no...@xxxxxxxxxxx> wrote:
"Bruce Richmond" <bsr3...@xxxxxxxxxxx> wrote in message

news:64a13f1e-3ef0-4599-b110-d8f97cf81068@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx





> On Jun 23, 1:42 am, "Whoever" <no...@xxxxxxxxxxx> wrote:
>> "Bruce Richmond" <bsr3...@xxxxxxxxxxx> wrote in message

>>news:e5e3aac9-be6e-48e9-bb6a-2936b6dca28c@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

>> > On Jun 22, 11:38 pm, "Dono." <sa...@xxxxxxxxxxx> wrote:
>> >> On Jun 22, 5:33 pm, Bruce Richmond <bsr3...@xxxxxxxxxxx> wrote:

>> >> > The Hafele-Keating experiment *was* conducted in the non inertial
>> >> > frame of the earth's surface. That is why the two directions did
>> >> > not
>> >> > give the same result.

>> >> The HKX was conducted in the air, about 30,000 ft from the eart's
>> >> surface.
>> >> The calculations for it were executed in the frame of reference >> >> whose
>> >> origin is coincident with the center of the Earth. This is the same
>> >> frame of reference as the one used by GPS calculations (called EFI >> >> in
>> >> the GPS). This frame is as close to an inertial frame as we can >> >> get.
>> >> The reason the clocks showed different elapsed times is the same >> >> one
>> >> as the one in the little problem I challenged Whoever to solve: the
>> >> palnes with the clocks on board had different speeds wrt EFI.

>> > But the bottom line is that when the clocks were brought back >> > together
>> > on the surface of the earth their settings had changed. We're not
>> > talking about "according to calculations" here, we are talking their
>> > actual settings as *measured* in the real world.

>> I think he means that the calculations of the expected results. And >> the
>> observed results verified that (within experimental error).

> I read it that you could change the results by choosing a different
> frame to do the calculations in. That's why I pointed out that the
> experiment provided the actual result.

>> So .. what would happen if we moved the clocks apart at the same speed
>> according to the (almost) inertial frame of the center of the earth. >> So
>> (for example) the one moving with the earth would stay 'still' >> (relative
>> to
>> the earth) and the other one move away at twice the speed of earth's
>> rotation in the opposite direction.

> You would still get the effects.

Are you sure about that ?

Yes.

For starters what you proposed and what you described were not the
same thing.

Yes .. they are

Your discription still had the clock(s) moving on the
earth's surface.

No .. it clearly didn't. Only one of them.

==
>> So .. what would happen if we moved the clocks apart at the same speed
>> according to the (almost) inertial frame of the center of the earth. >> So
>> (for example) the one moving with the earth would stay 'still' >> (relative
>> to
>> the earth) and the other one move away at twice the speed of earth's
>> rotation in the opposite direction.
==

See there "the one moving with the earth would stay 'still' (relative to the earth) "

So they are still moving along curved paths in the
ECI system.

Yes they are

Combine that with the fact that even the ECI system is
not truly inertial and it becomes very unlikely that the effects will
cancel out.

http://en.wikipedia.org/wiki/Earth_Centered_Inertial

"It should be noted that ECI frames are not truly inertial since the
Earth itself is accelerating as it travels in its orbit about the
Sun."

Grr ... Picky .. so the only affect is due to the movement of the earth around the sun and the sun around galactic core, and whatever non-inertial movement the galaxy may have.

So .. ignoring those effects .. treating the ECI as inertial for the sake of this thought experiment .. (which seemed to be obvious from context, but I see we need to make it explicit) what do you claim about the clocks as described?


.

Relevant Pages

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