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another B.Forums blooper: "It grows at the speed of light"
Wolram said:
if our universe is finite what is it bounded by?
best wishes.
-------------------------------------------
B.Forums replied:
Bounded by the speed of light. It grows at the speed of light.
__________________
B.Forums is a wonderful stimulus because he says one wrong thing after another in a blithely confident, firmly authoritative tone of voice.
By the U "growing" is meant the expansion of space, the increasing distances between galaxies---local movement discounted
Lots of PF folk have seen Lineweaver's article, I know, and some have mentioned printing it out. In particular we've used Figure 1 of that article as a reference several times. So I take it as known.
You can see just by inspection from that figure (similar to some at Ned Wright's cosmology site but more carefully drawn) that the light from
anything we see at redshift 3 or greater
was emitted when the thing
was receeding from us at faster than c.
(because the redshift 3 curve is entirely outside the Hubble sphere as drawn in the figure)
Well quasars with redshifts like 6.4 have been observed and there are scores of objects observed with z greater than 3
So there are scores of objects you can see whose light left them when that object was receding faster than c. It really is routine. sorry. And that light, even though it was headed towards us, was originally swept backwards in the general expansion and the distance to that packet of light was actually INCREASING for a while even tho it was headed towards us. And finally it overcame the expansion and got here.
This is not my story. This is standard contemporary cosmology and there are a bunch of good web references. I recommend printing the whole Lineweaver article, all 34 pages, because the guy knows how to communicate clearly better than anyone except maybe Ned Wright
http://arxiv.org/astro-ph/0305179 [Broken]
Wolram said:
if our universe is finite what is it bounded by?
best wishes.
-------------------------------------------
B.Forums replied:
Bounded by the speed of light. It grows at the speed of light.
__________________
B.Forums is a wonderful stimulus because he says one wrong thing after another in a blithely confident, firmly authoritative tone of voice.
By the U "growing" is meant the expansion of space, the increasing distances between galaxies---local movement discounted
Lots of PF folk have seen Lineweaver's article, I know, and some have mentioned printing it out. In particular we've used Figure 1 of that article as a reference several times. So I take it as known.
You can see just by inspection from that figure (similar to some at Ned Wright's cosmology site but more carefully drawn) that the light from
anything we see at redshift 3 or greater
was emitted when the thing
was receeding from us at faster than c.
(because the redshift 3 curve is entirely outside the Hubble sphere as drawn in the figure)
Well quasars with redshifts like 6.4 have been observed and there are scores of objects observed with z greater than 3
So there are scores of objects you can see whose light left them when that object was receding faster than c. It really is routine. sorry. And that light, even though it was headed towards us, was originally swept backwards in the general expansion and the distance to that packet of light was actually INCREASING for a while even tho it was headed towards us. And finally it overcame the expansion and got here.
This is not my story. This is standard contemporary cosmology and there are a bunch of good web references. I recommend printing the whole Lineweaver article, all 34 pages, because the guy knows how to communicate clearly better than anyone except maybe Ned Wright
http://arxiv.org/astro-ph/0305179 [Broken]
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