[Physics] Some comments on Physics Digest, Vol 3, Issue 21

[Ilja Schmelzer]

2016-12-28 12:00 GMT+01:00, physics-request at tuks.nl <physics-request at tuks.nl>:
> Even the "mainstream physics
> community" have not gotten past Kepler here. Kepler's ideas that everything
> in the Solar System are entirely dependent on the Sun's mass, is STILL
> assumed to apply to the Milky Way Galaxy, and so people argue today that the
> Spiral Arms fail to comply with Kepler's Laws in having any chance of being
> stable. The mainstream physics community should also check their historical
> records, to see that Newton had also resolved that a hundred years after
> Kepler, by stating that Calculus must be used regarding the DISTRIBUTED MASS
> of any entity like the Galaxy, where Kepler's assumption of a POINT MASS of
> the Sun was relatively accurate for the Solar System.

Sorry, but this is simply wrong.  The mainstream often uses NT instead
of GR, because
NT seems sufficiently accurate for such large distance weak fields,
but they use,
of course, NT with distributed sources if they consider galaxies.

This holds for visible matter as well as for the dark matter they need to get
agreement with observation.

> When we are still not sure that what exactly is space and what  exactly is
> time, isn't it humorous when we declare that time-dilates  and space bends
> without a full understanding of space and time  itself .

Not really.  "Time dilation" is a misleading phrase for the dilation of what
is measured with clocks.  Whatever it is, it is not necessary to know if the
claim is that two clocks of the same construction show different results
if they travel along different trajectories, and if one has a mathematical
formula which allows to compute (and predict) the numbers which these
clocks will show.

> Then the experiment was conducted and its was concluded that none of the
> above assumptions are correct. And based upon this it was concluded that
> "aether do not exist"

That MMX falsifies only a few simple ether theories, but not all of them,
in particular not the Lorentz ether, is well known.  Of course, the actual
education in physics is quite bad in regard of this, so one has, from time
to time, to remember the people these elementary facts already known to
Lorentz as well as Einstein.  Such is life.

> On the other hand,  no idea should be out-rightly  rejected, just due to
> reason that they do not match with theories (based upon some  initial
> assumptions) possibly accepted as facts by many. There is no way to know,
> that which idea  has *that element of truth *which may lead us into the
> right direction.

Nobody proposes here to reject from the start some ideas.  On the other
hand, if one develops some new theory, one has to make choices. And
every such choice means that one rejects all other choices.

One may change these choices, if one does not reach any success,
and then try another choice,  but this only modifies the much longer list
of choices which you simply reject.  We have no time to try out everything.
So, or we end up trying nothing, or we end up trying a few things, and
rejecting everything else.  Such is life.