Re: Lubenow

Murphy (
Tue, 24 Dec 1996 14:02:08 -0500

John W. (Burgy) Burgeson wrote:

> On page 201 he makes the argument (in cnnection with the YEC position) that
> triangulation techniques can only be done to measure out to about 300 light
> years. I seem to remember (perhaps recently) an argument that this technique
> could be used further out than that; don't see how, as the earth's orbit seems
> to be a limiting factor. Does anyone here know about this?

This limit could be overcome by using spacecraft to increase
the baseline, radio interferometry rather than optical methods, or a
combination thereof. I don't know what progress has been made with
such methods. This might allow direct measurement of trig parallax out
to around 3 x 10^8 light years.
It should be noted, though, that such measurements would not
necessarily give more "real" distances than other techniques - cluster
parallax, apparent luminosities, angular sizes, &c, though various
assumptions have to be made for all of these techniques and some care
is needed in relating determinations of distances by different methods.
Froehliche Weihnachten,
George Murphy