Re: Is "malfunctioning" absolute or relative?

On Oct 15, 6:44 pm, "harry" <harald.vanlintelButNotT...@xxxxxxx>
wrote:
"Uncle Ben" <b...@xxxxxxxxxxx> wrote in message

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On Oct 15, 9:03 am, "harry" <harald.NOTTHISvanlin...@xxxxxxx> wrote:





Uncle Ben wrote:
On Oct 14, 6:23 pm, "harry" <harald.vanlintelButNotT...@xxxxxxx>
wrote:
"Uncle Ben" <b...@xxxxxxxxxxx> wrote in message

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On Oct 14, 7:12 am, papa_r...@xxxxxxxxxxx wrote:> On 14 oct, 02:23,
Uncle Ben <b...@xxxxxxxxxxx> wrote:

[...]

This is so simple. An even simpler example: distance. Can we say
that Chicago is really "farther"? No, it depends on the reference
point. "Fartherness" is not absolute. Chicago is farther than
Buffalo w.r.t. Albany. It is not farther w.r.t. Evanston. Both
distances are real, not illusory, but they are relative to a point
of reference.

It seems not so clear when we turn to rates of clocks, because for
all of human history since clock have existed, we have thought of
time as absolute. Now Einstein tells us that time is not absolute;
it, too, is defined only w.r.t. a frame of reference. This defies
our common sense, but SR tells us that it is just as real as
distance being defined relative to a point of reference.

Why do you say that it "defies our common sense"? When one is
clueless about
possible models it would be appropriate. Contrary to QM that defies
common
sense as no plausible model has been proposed (so far, AFAIK),
people did
come up with different models that can help to make sense of SRT,
even while SRT was developed.

Regards,
Harald

I can agree about length contraction, since we have experience with
magnetic forces that are velocity-dependent and can exert stresses,
but as for time being frame dependent, I have no clue as to how to
make that appeal to common sense.

Do you? If so, I'd love to hear about it.

There are several ways to make sense of it, with strong proponents and
opponents on either side:

- For starters, the Lorentz transformations were originally (1904-1905)
derived based on a stationary ether model (a modification of Newton's
Absolute Space) that was adjusted to comply with the Principle of
Relativity. Strong proponents for that explanation were Lorentz (who laid
the foundation for SRT), Langevin (who described SRT as an extension to
Newtonian mechancis and who introduced what later became the Twin paradox)
and Ives (who performed the first successful "time dilation" experiment).
Although not perfect and out of fashion, such a model certainly appeals to
my common sense as it explains how absolute effects are possible as the
result of motion eventhough all observations are "relative". According to
that explanation, those who think that all SRT effects are physically real
and those who think that the effects are only apparent are both mistaken.
I
must admit that armed with that knowledge, sometimes I follow a debate
between such camps purely for entertainment.

- Minkowski had great success with his suggestion to interpret space-time
diagrams at face value, so that nowadays the idea of a physical Spacetime
in
which time is like a 4th dimension has become popular. In that "geometric"
view, Spacetime takes the role of an "absolute" background but nothing
physical happens to clocks in motion as they follow a different path
through
spacetime. Minkowski diagrams are certainly a handy tool that can simplify
calculations but physically it doesn't make sense to me; thus I'm not the
best to explain it. Of course, there are many proponents of that
interpretation around who will be happy to do so.

Note: Einstein appears to have flip-flopped between the two explanations
mentioned here above so that it's up to you to conclude which one he
really
favoured, if any.
For some time I thought that in 1920 he proposed a rather impossible
interpretation (and nobody here came up with an explanation), but recently
I
came to the conclusion that he simply used overly positivistic language
when
he summarized his position.

- There may be other interpretations (perhaps someone else here will
provide
one).

Regards,
Harald- Hide quoted text -

- Show quoted text -

: Harald, I am persuaded that time is relative, in the sense of this
: discussion, but I didn't learn anything from your dissertation that
: makes it appeal to common sense.

"Relative in the sense of this discussion" has been explained in the two
above opposing ways. I only introduced in a nutshell what those explanations
are; neither 2-sentence sketch should be called a "dissertation". If you
want to make sense of either of them, you would have to study them first
(that requires at least contemplating several quality articles for each
explanation). I wonder if you did.
Assuming that you did study both models without prejudice:

1. What about the ether model explanation did not make sence to you?
2. What about the absolute spacetime model explanation did not make sence to
you?

: And when I say that a clock really runs slow w.r.t. a moving frame, I
: don't mean that the clock is altered physically.

Good!

: W.r.t. its proper
: frame, nothing has changed.  But the slowness w.r.t. the other frame
: is real enough to *mimic* a physical change in the clock.

Sure.

: The best example I have is the Bell spaceship paradox.  The sense of
: "real" I intend is the one that says the string really breaks. There
: are those who say that the L contraction is an illusion, but illusions
: don't break strings.

We cannot say to what extent the string breaks due to Lorentz contraction
and to what extent due to asynchronous departure. Of course, I agree that
something does happen physically.

Regards,
Harald- Hide quoted text -

- Show quoted text -

Harald, I confess that I did not spend as much time pondering your
explanations as you expected. I will go back and give them more
respect.

With respect to what causes the string to break, I say that the
explanation depends on the frame of reference. In one frame, there is
asynchonous departure. In the other there is not. Physics can be done
from either frame; either explanation should be sufficient. So in the
latter, there is no asynchronous departue, and we have only one
explanation: L C against restraints. Each theory is correct and
sufficient where it applies.

Uncle Ben
.

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