Re: Is "malfunctioning" absolute or relative?

Uncle Ben wrote:
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


news:535fef37-ef6a-4d68-bb1e-2889d94026b0@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
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.

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. 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.

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.

The Bell spaceship paradox is a Paradox,
the string actually would not break.
If all acceleration and such is the same for both ships simultaneously,
No string break occurs.


.

Relevant Pages