Re: Spacetime

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Sujet : Re: Spacetime
De : hitlong (at) *nospam* yahoo.com (gharnagel)
Groupes : sci.physics.relativity
Date : 27. Jun 2024, 19:32:57
Autres entêtes
Organisation : novaBBS
Message-ID : <aa1b8ce99f8dc2406be92550817af4d7@www.novabbs.com>
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Thomas Heger wrote:
>
Am Mittwoch000026, 26.06.2024 um 01:26 schrieb gharnagel:
>
Thomas Heger wrote:
>
Am Dienstag000025, 25.06.2024 um 14:20 schrieb gharnagel:
>
“spacetime is likely to be an approximate description of
something quite different.” – Steven Carlip
>
It's interesting how most physicists describe spacetime
as an actual "fabric."  It's really a mental model that
may not have any existence at all.  The equations of
relativity describe what actually happens quite well,
but the "fabric" of spacetime may be an invention.
>
I think the things that are real are THINGS.  I find the
basic concept of string theory very compelling: that is,
elementary particles are not points as the standard model
posits.  In the real world there are no such things as
dimensionless points.  It's a very good assumption because
the string theory particles are way smaller than we can
 > detect, but presuming elementary particles have extension
in space is surely correct, even though strings may not be.
>
My own view:
spacetime is real and particles are not.
>
I guess we'll have to agree to disagree :-)
>
As 'proof of concept' I had effects, where seeminly matter comes
from
nothing or disappears without a trace.
>
I don't believe that has ever been observed happening.  Conservation
of
mass-energy is quite firmy established.
>
Examples for 'matter out of nothing':
'magic dust'
>
I'm not familiar with such.
>
Growing Earth
>
An unscientific speculation.
>
Matter is something I tried to explain as 'timelike stable patterns'
(of/in spacetime).
See my 'book' about this idea:
 >
https://docs.google.com/presentation/d/1Ur3_giuk2l439fxUa8QHX4wTDxBEaM6lOlgVUa0cFU4/edit?usp=sharing
>
TH
>
"It's based entirely on geometrical relations within a smooth
continuum,
that is supposed to be the spacetime of GR."
>
Yes, in GR fields are real things.  But as Feinman said in Q.E.D.,
photons are PARTICLES.  QFT has tried to get around this by going back
to
fields, but string theory started out with particles.  I'm with
Feinman.
>
Well, I personally think, that material objects like particles are
'timelike stable patterns'.
>
This was my assumption, which I needed to connect GR and QM.
>
As proof of concept I had 'growing Earth' in mind.
>
This is so, because the growth of Earth is happening from the inside of
the planet, where no particles from out space are supposed to be.
>
(Actually I have always disliked the 'particle concept' and wanted a way
to disprove it.)
>
Particles are too 'materialistic' for my taste. They also attempt to
exlain particles by particles (quarks), but make no attempts to explain
quarks. (string theory is actually worse)
Them's fightin' words!  Put up your dukes!

My own approach is very different and based on spacetime of GR as
'real'.
>
Now I only needed VERY few assumption!
>
that are mainly: points have features and space is a subset of something
with higher dimensions.
Ah, sounds like M-theory :-))

Also: systems are what you call system and have imaginary borders, which
are infinetely thin.
"Infinitely thin" means nonexistent.

"We treat ourselves as more or less as at rest and base observations
on
our own state of being."
>
This is essentially the first postulate of SR.
>
"By this definitions we turn imaginary phenomena into real
observations.
But our observations are real only to us"
>
I don't believe in "imaginary phenomena."  What we observe IS the real
world.
>
No, we don't, because we can only see a subset of the real world, that
is visible to us.
I disagree.  Your use of "visible" is too constrictive.  Gamma rays
aren't
"visible" but they ARE detectable by scientific instruments.  It's
improper
to call a phenomenon imaginary just because we haven't invented
equipment
to detect it.

E.g. we cannot see beyond the horizon, even if there is a 'world'
behind.

But visibility is also very limiited to us, because from the wast range
of the em-spectrum we can see only a very small part.
See? You're scope is too limited.

But time is also an issue, because we are bond to what I call 'Time
domaine'.
>
This is so, because we like to stay material objects and do not want to
dissipate into the environment.
>
But we could imagine, that such a 'universe around the corner' would
exist, where time runs into a different direction than our time.
>
Such a world would be entirely invisible, even if it could be really
close.
Sounds more and more like M-theory (brane theory).

So, in effect we can only observe some parts of reality and need to
guess, how the rest of the universe may look like.
>
TH
Brane theory began with string theory and was built up by logical steps.
Have you read "The Fabric of the Universe" by Brian Greene or Leonard
Susskind's string theory videos on YouTube?
"Spin more than one hypothesis. If there’s something to be explained,
think of all the different ways in which it could be explained. Then
think of tests by which you might systematically disprove each of the
alternatives. What survives, the hypothesis that resists disproof in
this Darwinian selection among “multiple working hypotheses,” has a
much better chance of being the right answer than if you had simply
run with the first idea that caught your fancy.
"Try not to get overly attached to a hypothesis just because it’s
yours."

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