Re: Twin paradox revisited ll

"bill" <cosmosco@xxxxxxxxxxxxxxx> wrote in message
news:1185235954.440484.53780@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Jul 22, 10:26 pm, "Martin Hogbin" <goatREMOVETHIS...@xxxxxxxxxx>
wrote:
"bill" <cosmo...@xxxxxxxxxxxxxxx> wrote in
messagenews:1184981064.527191.20310@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Jul 20, 7:11 pm, "Martin Hogbin" <goatREMOVETHIS...@xxxxxxxxxx>
wrote:

No I would not. I cannot accept that the traveler *really* believes
that the earth is orbiting the sun at around 1m-s nor do I believe
that this is what would 'really' be happening.

This is the crux of the problem. The problem we have is that the
English language has evolved to describe things we see in
normal life. It turns out that, when high speeds are involved,
things are very different and we do not have words to adequately
describe what happens. Thus, is the current context, words
like 'really' and 'physically' do not have any useful meaning.

In everyday life, if I say something 'really' or 'physically'
happens, there is no need to explain what I mean; everybody
knows.

So, what can we do to come to any form of agreement?

Firstly, we can state the facts that are undisputed and
explicable without ambiguity in the English language. For
example, we agree that on his return, the traveller has
aged less then the inertial twin. We can also agree that
in the inertial frame of any twin nothing unusual happens.

Secondly, we can state what we expect the results of any
measurement will be. For example, during the cruise phase,
if either twin measures the clock of the other they will
measure it to be running slower than their own. This
statement applies to any and every sensible method of
measurement. In other words, there are no sensible
measurements whatsoever that do not show the results
described above. Is this real? How real do you want?
It is as real as the fact your head hurts when you hit it.

I agree that the travelling twin will see that the earth clock
*appears* to be running slower than his own clock

It is

but if he insists
that it *is* physically ticking over at a slower rate than his own
clock he is denying Einstein's 1918 article

No .. he is not

by insisting that he,
having experienced the force of acceleration, is *not* the moving
twin.

Both twins are moving relative to the other .. can't you understand that?

[snip]
Do you accept that in *Einstein's* opinion it is the accelerated clock
that incurs time dilation *not* that the other clock incurs time
*contraction*? I'm not referring to what some physicists now believe
but what *Einstein* believed!

Its the same thing .. its all relative .. if my clock is slower than yours
that is no different from saying that your clock is faster then mine

[snip]

On the other hand, *I* would say that the mutual slowing of clocks is
a solipsist nonsense which introduced a paradox that Einstein,
apparently unsuccessfully, attempted to solve.

It is one of the fundamental results of SR. Its not a paradox

[snip]

If we 'measured' or 'determined' the shape of a steel rod placed in a
tank of water we would *assume* that it has bent at the surface of the
water however we *then * apply our knowledge (as Confucius suggested
we should) and come to the conclusion that *in reality* the rod has
*not* been deformed but that this is only a visual illusion in the
same way that the *apparent* slowing down of a *stationary* clock is
the result of a visual illusion created by *our* motion relative to
*it*.

That is a n optical illusion .. SR effects are NOT optical illusions


[snip]
That the traveler destroys all life on the planet.
By that definition, there is no change on Earth 'physically'.
In his opinion, all life is extinguished

Where do you get this nonsense idea that all life is extinguished?

yet you classify this as being 'no change'?

But it is wrong .. unless he was away so long that all life became exteinct

If I was in his position I would head for the nearest star.

I wish you would :)

[snip]

I just cannot see why you are having trouble with the idea that if less time
elapses for the traveller then he has aged less than the at-home twin, and
the at-home twin has aged more than the traveller. Why is that such a
problem for you?


.

Relevant Pages

  • Re: Grandfather Clocks and Relativity
    ... same inertial frame and never have a relative velocity. ... this twin Ta because he will be accelerating later. ... clock always read zero, as long as gravitometers at each clock always ... can make the acceleration instantaneous, or the distance L between the ...
    (sci.physics.relativity)
  • Re: Grandfather Clocks and Relativity
    ... this twin Ta because he will be accelerating later. ... clock always read zero, as long as gravitometers at each clock always ... can make the acceleration instantaneous, or the distance L between the ... That's the sense in which the tick rates of moving clocks change in Relativity, and once you're able to appreciate the dichotomy between a clock's tick rate and measurements of a clock's tick rate, those logical dilemmas won't arise. ...
    (sci.physics.relativity)
  • Re: Circular motion in SR
    ... slower than an identical clock on earth. ... precisely also why the traveling twin comes back younger. ... That is precisely the misconception that the twin puzzle is aimed to ...
    (sci.physics.relativity)
  • Re: SPACETIME AND CONSCIOUSNESS
    ... dimension, and whose three dimensional surface is ... at the same rate as his clock." ... about the "The Twin Paradox" Pardox ... to relativity, if one twin travels on a journey ...
    (sci.physics)
  • Re: Grandfather Clocks and Relativity
    ... same inertial frame and never have a relative velocity. ... this twin Ta because he will be accelerating later. ... clock always read zero, as long as gravitometers at each clock always ... can make the acceleration instantaneous, or the distance L between the ...
    (sci.physics.relativity)