Re: We do not know the distance of stars


Richard Forrest wrote:
jcon wrote:
mccoy@xxxxxxxxxx wrote:
<snipped>

[comment: astronomers calculate supposed distances based on triangles
that are less than 1 degrees angles]


Garsh, that sounds hard!

Standard early 19th century surveyor's transits could measure
angles down to a few arc-minutes.

A good Theodolite can measure angles to better than
one arc-second.

Astronomers use even more sophisticated techniques.


The techniques are not particularly sophisticated.

An astronomical telescope is basically just a giant camera. You take a
picture of a small part of the night sky, and compare it with a picture
of the same part taken six months later. The very distant stars are in
the same position on both images. Stars close to us shift. It's very
easy to measure the shift, and it's easy to calculate the parallax from
the angular distance between stars whose position is known on the same
plate. The mathematics is elementary.

RF


"Sophisticated" was probably the wrong word. "Careful" might
have been better. My point was that any any decent surveyor
can get an accuracy that would mystify McKook, but astronomers
work even harder to push the envelope. The Hipparchos
satellite is down in the few milli-arc-second range (how's
that for an eclectic unit?).

Of course, all parallax techniques are limited to a few hundred
light years. After that you have to go to variable Cepheids,
type 1A supernovea, etc.

Scientists derive confidence from the fact that all of these
various techniques give consistent answers in the ranges
where they overlap, but this means nothing to Flat (er, excuse
me, "Young") Earthers. They are happy to postulate lots
and lots of tiny, dim, stars and galaxies lurking just beyond
the range of parallax, operating with weird laws of physics
known only to God. That way you can get a whole universe
a few thousand years old without having to worry about the
pesky speed of light problem.

This is known as "Young Earth Cosmology".

-jc






Anyone with a basic knowledge of math can calculate
the triangulation error associated with a particular
angular accuracy.

It's always so hard theignorant to accept that some
people have real skills.

-jc

.

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