On Wednesday, September 10, 2025 at 12:08:39 AM UTC-6 Brent Meeker wrote:
On 9/9/2025 10:36 PM, Alan Grayson wrote:
On Tuesday, September 9, 2025 at 11:25:37 PM UTC-6 Brent Meeker wrote:
On 9/9/2025 9:57 PM, Alan Grayson wrote:
On Tuesday, September 9, 2025 at 5:18:14 PM UTC-6 Brent Meeker wrote:
On 9/8/2025 8:45 PM, Alan Grayson wrote:
On Monday, September 8, 2025 at 9:35:09 PM UTC-6 Brent Meeker wrote:
On 9/8/2025 11:19 AM, Alan Grayson wrote:
On Monday, September 8, 2025 at 5:06:36 AM UTC-6 John Clark wrote:
On Mon, Sep 8, 2025 at 7:00 AM Alan Grayson <agrays...@gmail.com> wrote:
*> I'm not sure the impossibility of absolute simultaneity solves the
problem,*
*Watch the video! If you follow what he does step-by-step you will see that
he is right. It's not difficult. *
*I'll definitely watch it, very soon, but a-priori the impossibility of
absolute simultaneity can't solve the paradox because it's not its cause.
Can you succinctly state the cause of the paradox? It's the application of
time dilation in SR, under the mistaken assumption that the twins take
symmetric paths; that their situations are symmetric. This results in the
situation that when they meet and compare clock readings, each concludes
the other is younger. *
No that's wrong. The stay at home twin has a clock that indicates a longer
interval than the traveling twins clock. They agree that the traveling
twin is younger.
Brent
*Can't you understand English? I was stating the paradox and its cause.
With an accurate analysis, the traveling twin is younger. Also, FWIW, for
the traveling twin to return for the clock comparison, some acceleration is
necessary, although it can be minimized if the comparison is done by
fly-by. a AG *
But notice that the acceleration is entirely incidental, as illustrated by
the case in which Red and Blue each accelerates the same amount. IT'S JUST
GEOMETRY. ONE PATH IS LONGER THAN THE OTHER.
*In the original statement of the "paradox', the traveling twin must
accelerate to return so the clocks can be compared. Please explain how this
can happen without acceleration. *
I've shown two different ways without acceleration and I've also shown the
paradox with equal accelerations by both twins. Why can't you just accept
that it's geometry; that one path is longer than the other.
*If both twins are accelerating, then you've redefined the TP. *
No. But Blue does not accelerate while Red travels out and back.
*But earlier you claimed both Red and Blue have the same acceleration, and
that's what your diagram shows. AG*
*If you have two paths in spacetime, starting at the same point and ending
at the same point, or at a different point, how can you tell which is
longer? AG *
These are paths in *spacetime*. They start and end at the same *event*, a
point in 4-space.
*If the paradox is resolved, then the clocks should read different values
when finally compared. So the end point events are NOT the same. AG*
The obvious way to tell which is longer in proper time is to carry an ideal
clock along the two paths and compare the measured intervals. You could
also measure the space distance X along the paths and and compute proper
time S=\sqrt{T^2 - X^2} where T is the coordinate time difference (in the
same reference frame you measured distance).
Brent
*You seem to defying basic physics if this is your claim. I don't deny that
the original problem can be restated in a way which avoids acceleration,
and IMO this is what you've done. *
But I've done more than that. I've done it while maintaining exactly the
same paradox.
*So you admit you're defying the laws of physics? AG *
Brent
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