Re: Twin paradox revisited ll

"bill" <cosmosco@xxxxxxxxxxxxxxx> wrote in message
news:1185497595.555218.10920@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
No, you are continuing to think of time as being absolute. In a
relatively moving frame the Earths rotation does indeed slow down.
Pardon the pun but you keep going round in circles.
The earth's rotation does *not* slow down - this is merely the
personal feelings of the traveller.

No .. it really is SLOWER in the frame of the traveller .. personal feeling
have nothing to do with it.

You seem hung up on the psychology of the traveller.

I was not sure where they were supposed to be. In a relatively moving
frame the Earth's rotation does slow down. We, of course, notice nothing
because we are on the Earth.

The concept that 'the earth's rotation does slow down' is merely the
personal feelings of the traveler.


No .. it really is SLOWER in the frame of the traveller .. personal feeling
have nothing to do with it.

You seem hung up on the psychology of the traveller.

According to *Einstein* it is the non-inertial clock that ticks over
at the slower rate than the inertial clock and anyone who insists
that the inertial clock ticks over at the slower rate on the basis
that this is what the non-inertial twin observes is contradicting
Einstein. According to that article, Einstein was of the opinion that
it is *only* the non-inertial clock that, in *reality* physically,
really, actually, incurs time dilation.
No, you are misunderstanding him.
Did he, or did he not insist in that article that it is the clock
that experiences the force of acceleration which is the one that
incurs time dilation?

Relative ot the one that didn't

No he did not. Obviously clocks can be compared when
they are in motion, provided that they are in the same place.
I am of the opinion that your denial that this is what Einstein wrote
in that article is erroneous.

Please cite your reference

Of course you cannot compare the rates of two clocks by
this method because, if they are in relative motion, they will
only be at the same place for an instant
You are going round in circles again. You wrote "Obviously clocks
*can* be compared when they are in motion" and now you state "you
*cannot* compare the rates of two clocks by this method...."

There is a difference between comparing ticking rates and comparing what
time the clock shows

To compare rates, you'd need to get two clock readings and compare them ..
and then factor in the distance moved and the time light took to reach it.
ie you cannot do a direct comparison.
And it seems to me that this paradox is *precisely* what Einstein
sought to overcome.
Absolutely not. Which one would you say is correct?
I'm not talking about which one *I* would say is correct but what
*Einstein* 'said' in that article.

There is no paradox

During the turnaround the earthbound twin measures the
traveller's clock to be running more slowly, dependent only
on the traveller's relative velocity.

Having come to a stop the traveler's clock is in the same reference
frame as the earth clock hence it is ticking over at the same rate as
his twin's clock. He flips his ship end over end and during this turn
around period - on the assumption that he and his clock are at the
centre of his ship - he has *no* relative velocity other than the fact
that, during the few minutes that it takes to flip the ship over, he
is *not* moving toward, or away from, his twin. If he, having come to
a stop, simply reverses his motors he has absolutely *no* velocity
relatively to his twin so how can the latter measure his twin's clock
to be 'running more slowly'?

That is what I said. The clock is measured to be running slowly
when it is moving to and from the Earth. When it is stationary
with respect to the Earth it is measured to run at the same speed
as you quite rightly say.

No that is *not* what you said. You wrote that "*During the
turnaround* the earthbound twin measures the traveller's clock to be
running more slowly." You did *not*, in that sentence, say that "The
clock is measured to be running slowly *when it is moving to and from
the Earth.*"

You are confusing turnaround (meaning the decelleration process that slows
and then reverses the direction of travels) and a proposed stop in that
deceleration that you are adding in that is not usually included in a twin
paradox scenario (it adds unnecessary complexity).

Why does the traveller not conclude that the Earth based
clocks have run fast?

He does *not* believe that the earth based clocks have run fast on the
assumption that he is aware of and accepts Einstein's 1918 article
concept that his is the non-inertial reference fame.

What he believes dones't really matter.

Yes, because that is a completely irrelevant quote, even if it
was by Einstein.

The concept of relativistic 'Doppler' effect is based on the special
theory mathematical proposition that a moving clock ticks over at a
slower rate than a stationary clock.

It does

Your having typically resorted to personal insult terminates our
discussion.

You're good at running away.


.

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