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DrdB
2007-Oct-20, 12:17 AM
Redshifts


The quasar appears as it did about 12.7 billion years ago, when the Universe was just 7 percent of its present age. Of course, the expansion of the Universe has redshifted the light. Schedler added image data extending to the near-infrared, acquired by collaborator Ken Crawford, to detect the distant quasar, with a measured redshift of 6.04.

http://antwrp.gsfc.nasa.gov/apod/ap070906.html


This supernova explosion was so inherently bright that it could be seen nearly 5 billion light years away (a redshift of 0.28) even with a small telescope.

http://antwrp.gsfc.nasa.gov/apod/ap071016.html


Hubble's law is a statement in physical cosmology which states that the redshift in light coming from distant galaxies is proportional to their distance. The law was first formulated by Edwin Hubble and Milton Humason in 1929[1] after nearly a decade of observations. It is considered the first observational basis for the expanding space paradigm and today serves as one of the most often cited pieces of evidence in support of the Big Bang.

http://en.wikipedia.org/wiki/Hubble's_constant

How can one object have a redshift >20x the Z of another object more than 1/3 as distant? Hubble law says Z proportional to distance.

Spaceman Spiff
2007-Oct-20, 01:02 AM
Try this link (http://www.atlasoftheuniverse.com/redshift.html), then for more advanced fun - try this one (http://www.astro.ucla.edu/%7Ewright/cosmo_01.htm).
To compute your own distances and lookback times and other quantities as functions of redshift, go here (http://www.astro.ucla.edu/%7Ewright/CosmoCalc.html).

I've got a webpage full of links in cosmology tutorials and FAQs, here (http://homepages.wmich.edu/%7Ekorista/cosmology.html).

Have fun! :)