Comments on: Astronomers Spy Oldest Object In Universe

Satellites Catch Gamma-Ray Burst From Star's Death That Occurred Over 13 Billion Years Ago

[Void_Master]

As I understand it, the rate of expansion is increasing. Is that not correct? How accurately do we "know" the rate of expansion?

[realnews12]

Still I would like to better understand the method they are using. Parallax will not work that far away and I am aware of no other method that actually measures (rather than logically deduces) a radial distance.

Posted by Void_Master at 6:08 PM : Apr 28, 2009

The Universe is expanding at a known rate. In other words, the expansion velocity is a function of distance. The radial velocity (i.e., along the line of sight to the object) can be measured by the Doppler shift of the object's spectral lines. Hence, the distance of the object is determined.

[Void_Master]

Parallax works. You take a measurement in summer while you are at one sector of the orbit around the sun, and another measurement in winter when you are aproximately 180 million miles on the other side. Of course you have to take into consideration the suns motion and relativistic effects. But Parallax works really well.

Posted by McHineguy
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I know Parallax that and how works. I have done the calculations before. But Parallax only works out to about 1600 light years. Using the Hippaccaros probe, I think they expect to expand that to something like 15,000. But beyond that extreme, Parallax cannot work because the angles you are measuring become to narrow to distinguish them. So as far as I can tall, measuring the distance of anything beyond that is an educated guess at best.

[McHineguy]

Ok, after re-reading your post, that sort of makes sense. Still I would like to better understand the method they are using. Parallax will not work that far away and I am aware of no other method that actually measures (rather than logically deduces) a radial distance.
Posted by Void_Master at 6:08 PM : Apr 28, 2009

Parallax works. You take a measurement in summer while you are at one sector of the orbit around the sun, and another measurement in winter when you are aproximately 180 million miles on the other side. Of course you have to take into consideration the suns motion and relativistic effects. But Parallax works really well.

[Void_Master]

Your headline... Do ya' mean like that 'stunt' flyover of the statute of Liberty?

Posted by virulent3
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Was that not a great practical joke or what?

[Void_Master]

There is a phrase for people who believe science is a waste of time: less evolved.

[Void_Master]

Astrology is worthless and a waste of our tax money. Astrology is a occupation invented for lazy people to make money sightseeing and making up stories to make us believe their are intelligent. Unemployed astrologist are so lazy they become clergy or bird watchers.

Posted by sky_five
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What does astrology have to do with this story?

[pepperwood2]

Astronomers Spy Oldest Object In Universe........probably was Hagliary out in space riding her broom. cackle cackle cackle

[virulent3]

Your headline... Do ya' mean like that 'stunt' flyover of the statute of Liberty?

[Void_Master]

A few hours later, Tanvir's team confirmed the distance using one of the European Very Large Telescopes on Cerro Paranal in Chile.

Posted by legacyabq
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Ok, after re-reading your post, that sort of makes sense. Still I would like to better understand the method they are using. Parallax will not work that far away and I am aware of no other method that actually measures (rather than logically deduces) a radial distance.