XPost: sci.physics.relativity
From: nospam@de-ster.demon.nl
Thomas Heger wrote:
> Am Montag000015, 15.09.2025 um 13:37 schrieb J. J. Lodder:
> ...
> >>> | We see stars in 10000 light years distance as they were and
> >>> | where they had been 10000 years ago, while we see our Sun as
> >>> | the Sun has been 8 minutes ago.
> >>> | That is a HUGE difference.
> >>> |
> >>> | The picture we see is actually 'layered in time', while
> >>> | the universe isn't.
> >>> |
> >>> | Therefore we see things, which are not real and which do
> >>> | not belong to the same time.
> >>>
> >>> We see that the star was real 10000 years ago, and if it was
> >>> a main sequence star then, we know that it still is a real
> >>> main sequence star now.
> >>>
> >>> It is indeed a weird idea that a star that was real 10000 years
> >>> ago is not real now.
> >>>
> >>> What do you think the stars we see in the telescope are?
> >>> Mirages?
> >>>
> >>> We know that the star and the Sun were 10000 light years
> >>> from Each other 10000 years ago, and we know that the star
> >>> and the Sun still are ~10000 light years away from each other.
> >>
> >> Ten-thousand years is actually nothing in cosmology, which deals with
> >> millions of light-years.
> >>
> >> well, now we have a 'little' problem:
> >>
> >> if we have millions of years as delay, then we can't call our impression
> >> of the stars 'real'.
> >>
> >> It is like a postcard from the last century, which is delivered today.
> >>
> >> sure, the picture and the content were once real.
> >>
> >> But the sender might already be dead.
> >>
> >>
> >>
> >>> And for million years the two stars have transferred energy
> >>> (light) to each other, and will keep doing so for million
> >>> of years.
> >>
> >>
> >> The main problem isn't that, but that distance is very hard to estimate
> >> in cosmology.
> >>
> >> Since everything moves within our galaxy and within the rest of the
> >> universe, an error in measurement of the distance would be equal to an
> >> error in the positions.
> >>
> >> We could see a star moving to, say, the left in the foreground and a
> >> star moving to the right in the background at the same time at a
> >> relatively close position.
> >>
> >> And because it's so hard to determine the true distance, we could
> >> actually be in error, which star is in the background and which one is
> >> actually nearer to us.
> >>
> >> So we could find a relation between two seemingly close stars, which
> >> were never that close.
> >>
> >>> The stars are at any time living side by side ~10000 light years
> >>> from each other.
> >>
> >> That is't necessarily the case, just because you see two stars that way.
> >>
> >>> That we happen to live close to one of them doesn't make them
> >>> "belong to separate times."
> >>>
> >>> They are both living at the same time.
> >> 'living' is not the right phrase for pictures of stars.
> >>
> >> I meant:
> >>
> >> if you have a depth in a picture from the night sky of several thousand
> >> light years, for instance, you need to consider, that background events
> >> belong to a different time than foreground events.
> >>
> >> The discrepancy is actually huge and can easily be millions of years.
> >>
> >> Therefore pictures of the backgrond stars and the forground stars do not
> >> belong together, but should be corrected because of different delays.
> >>
> >> Unfortunately we don't know the exact delay and we also don't know,
> >> which stars are actually the background stars and which one belong to
> >> the foreground.
> >>
> >> We only assume, that some theories are valid, which enable us to
> >> estimate the distances.
> >>
> >> But those theories are most likely wrong.TH
> >
> > You really are decades behind the times.
> > (and it is most of your opinions that are just plain wrong)
> >
> > FYI, in the meantime we have seen the Hipparcos and GAIA missions,
> > and we have direct distance measurements (by parallax)
> > of more than a billion stars, accurate to a few percent,
> > all the way out to the galactic centre.
> > Those stars have been measured repeatedly over the 10 years of the GAIA
> > mission, so we also know their proper motions accurately.
> >
>
>
>
> If you see a star in say 1 million light years distance and some stars
> in two million light years distance, than they belong to different times.
>
> The difference is actually huge, because we're talking about one million
> years, within which the stars had moved.
FYI, the galaxy is 'only' 100 000 lightyears across.
> But you cannot even estimate the direction, into which they move (up,
> down, left or right) because only the 'z-axis-movement' is measurable
> (with red- or blueshift).
See, you are ages behind the times,
and completely out of touch with reality as it is today.
> To measure the direction perpendicular to the direction of sight, you
> would need to measure at least two positions of that star. But that
> would take way too long for a single human beeing to become measurable.
See, you are ages behind the times,
and completely out of touch with reality as it is today.
> So stars move and we don't even know towards were they move and not how
> fast.
See, you are ages behind the times,
and completely out of touch with reality as it is today.
> This would be quite unfortunate, if you want to estimate their current
> distance in respect to each others, because they had 1 million years to
> move and we don't know the direction.
>
> Precision wouldn't help that much, because even the sharpest of all
> telescopes cannot make the movement of distant stars faster. And for
> geometrical reasons the angles to measure are very small, if the star is
> millions of light years away.
See, you are ages behind the times,
and completely out of touch with reality as it is today.
Why don't you learn something about reality
before you start making stupid comments on it?
Jan
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