Edwin Hubble's original data

In article , Richard
writes:

[[Mod. note -- What's observed is redshift. To within the accuracy
of the data, that redshift isn't going to change over a human lifespan.
(That is, any acceleration or deacelleration isn't going to be measurable
as a redshift change -- the accuracy of the redshift measurements are
orders of magnitude too poor to see this change in a human lifespan.)

I believe Avi Loeb had a paper a few years ago in which he pointed out
that with high-resolution spectrographs (NOT the ones used in typical
redshift surveys), one could just about detect a change in redshift over
a few decades.

Trying to convert an observed redshift to a recession velocity is a
dubious thing, because even *defining* a recession velocity is tricky
(may even impossible) in the context of cosmology. This is explained
very clearly in Edward R. Harrison's book "Cosmology: The Science of
the Universe". From the questions you're asking, I think you would
find this book *very* valuable.
-- jt]]

One cannot recommend this book too much. Everyone interested in
cosmology should read it.

"PHCtr" == Phillip Helbig---remove CLOTHES to reply writes:

PHCtr In article , Richard
PHCtr writes:

[[Mod. note -- What's observed is redshift. To within the accuracy
of the data, that redshift isn't going to change over a human
lifespan. (That is, any acceleration or deacelleration isn't going
to be measurable as a redshift change -- the accuracy of the
redshift measurements are orders of magnitude too poor to see this
change in a human lifespan.)

PHC I believe Avi Loeb had a paper a few years ago in which he
PHC pointed out that with high-resolution spectrographs (...), one
PHC could just about detect a change in redshift over a few decades.

An idea attributed originally to Sandage, and expanded upon by Avi
(URL: http://lanl.arxiv.org/abs/astro-ph/9802122 ). It's since been
termed the Sandage-Loeb test.

Showing my biases, even though radio spectroscopy can obtain much
higher precision than optical spectroscopy, the number of sources is
so much smaller in the radio that it is actually better to do this in
the optical.

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