[Physics] Physics Digest, Vol 1, Issue 25

[Ilja Schmelzer]

2016-10-24 20:02 GMT+02:00, Doug Marett <dm88dm at gmail.com>:
> This leads back exactly to the problem of how can an object be in the present
> and the future simultaneously (it is not just a contradiction in reason,
> but a contradiction in language!)

And therefore forget about this language.  If you use normal language,
use common sense for this purpose, and use tense as if they would
refer to some time-like coordinate.  And everything is fine, without
any contradictions.

> The problem is that relativity claims that the solid body rotating clock
> where time must be synchronized by definition, is actually de-synchronized
> (!), which goes against our reason and observation of the earth clocks.

No, the confusion is caused by naming clock time time, in a situation
where clocks are obviously unable to measure time.  Working clocks
would be obliged to show the same result if they start at the same
place at the same moment and measure time at the same place at the
same moment, independent on how they move between the initial and
final moment.   In relativity, clocks do not have this property, their
showings depend on the whole path they travel.  So, they simply do not
measure time, in its common sense meaning.

Where does the confusion come from?  The relativistic mainstream
simply rejects the notion of common sense time, simply because we have
no clocks to measure it, and what is not measurable does not exist.
But they use the word "time", now in a new meaning, namely as the
clock showing, in a situation where the clock showing is unable to
measure common sense time.

And, given that physicists are also humans, with common sense, they
appear unable to throw away common sense time completely.  So
sometimes they use it too.  So, they use two meanings of the word
"time", common sense time and clock "time".  And this causes
confusion.

But the cause of this confusion is not relativistic theory itself, but
how it is used and interpreted.  If one recognizes that relativity is
a theory about clocks, local clocks, which show clock time, a number
which depends on the path of the clock, and should in no way be
confused with usual common sense time, everything is fine and
unproblematic.

> we will observe
> that the speed of light is now measured to be faster at the higher
> altitude, by exactly the difference in the rate of the atomic clock error
> reading.

Forget about measuring the speed of light before having a good,
non-contradictory understanding of time as something different from
relativistic clock time.

Velocity in the common sense meaning is a coordinate velocity.  And
the coordinate speed of light is not at all constant.  The constant
speed of light is something measured with rulers and clocks, and has
nothing to do with common sense velocity.

> The reason why Einstein's theory and Lorentz theory arrive at the same
> answers for the same tests s because they are mathematically equivalent,
> they simply differ in their physical presumptions, namely they exchange a
> variable but hidden speed of light and absolute time, with a constant speed
> of light/variable time.

No, they are physically equivalent too. The moving clocks are slower,
in Lorentz theory as well as in Einstein theory.

What makes Lorentz theory different that it has, additionally, an
absolute time, which is common sense time.  Which is not measurable
with clocks.  In Einstein theory, this absolute time is also one
possible time-like coordinate, but not more.  And usual "time" simply
does not exist in Einstein's theory.  There is only a four-dimensional
spacetime and our trajectories are paths in this spacetime animal.

But there is no physical difference.  For every clock, Lorentz and
Einstein theories predict the same result.

>    -    Finally, consider H.G. Well's time machine,

No, ignore it.  It is only adding confusion.

The rough picture:  Take Lorentz theory.  It is a theory in full
agreement with common sense, no problem at all.

To obtain Einstein theory, all you have to do is to remove parts of
Lorentz theory, using stupid primitive positivism.  What you cannot
measure does not exist.

But by removing reasonable things from a reasonable theory you cannot
obtain anything new, nor time travel nor logical contradictions nor
any other nonsense.  You loose only some standard common sense notions
like usual common sense time.