age/distance

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low motion

age/distance

Post by low motion » Sun Oct 03, 2004 1:42 am

when the astronomers look to a distant object around 10 bi light years they see the past 10 billions of years, then how we can see the cosmos? as a sphere?

nbrosch
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How does the UNiverse look?

Post by nbrosch » Mon Oct 04, 2004 4:05 am

Essentially, we see a sphere, or at least things that are very distant from us in all directions. The limit is that of "the visible Universe", which is the location where the expansion velocity equals the speed of light. Light signals from things further away have not had time yet to reach us, but will do so in the future. Our perception of the Universe, at least in the optical band, is strongly modified by dust in our Galaxy. This blocks off a ribbon of the sky along the galactic plane that is called "the Zone of Avoidance".

Noah Brosch

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troubling

Post by Sowndbyte » Mon Oct 04, 2004 6:20 am

NRbrosch wrote
Essentially, we see a sphere, or at least things that are very distant from us in all directions. The limit is that of "the visible Universe", which is the location where the expansion velocity equals the speed of light. Light signals from things further away have not had time yet to reach us, but will do so in the future. Our perception of the Universe, at least in the optical band, is strongly modified by dust in our Galaxy. This blocks off a ribbon of the sky along the galactic plane that is called "the Zone of Avoidance".

Noah Brosch

this idea places us at a center and if correct would greatly expand the timeframe/age estimation of the universe. if we are in a sphere and the objects outside this 'sphere' have yet to give light to us, how can they be beyond visual range ? The big Bang expands which by it's own definition requires a start point, anything that originated at this start point has been transmitting light for X billions of years on its way out. Even if a Galaxy formed 10 Billion light years out from its origin point(quite plausible) and was traveling at light speed its light should be observable today (even if highly redshifted) from Earth.
the Zone of avoidance does have an impact on 'universal' observations but only inline with Galactic center, or through Outer Galactic arms. in that we can observe Vast portions of the Universe,and we can see basically the same thing in any direction, this Zone presents little critical problems.(unless Heaven is hiding on the other side of our Galaxy)
If we are in a 'steady state' versus Big Bang the lack of visual acutiy presents evidence of a finite lifetime for light. Current science believes the Big bang because of the microwave background evidence 'indicates' its existence. Yet this same science says that stars 'not' in galcatic structures represent a HUGE portion of the missing mass. I estimate that more probably the VAST numbers of Stars not Galactically bound could also create this radiation.

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Post by The Meal » Mon Oct 04, 2004 12:35 pm

The Big Bang is not an explosion in the conventional sense. There is no "center" from which we're all expanding. In fact, every point is expanding away from every other point (on the cosmic scale, Mr. Newton and the little theory I like to call gravity will show us that objects with mass aren't necessarily *all* expanding away from each other).

It's tough to wrap your head around, especially considering the name "the Big Bang," but there really is no center from which everything is expanding. Scientists will tell us to think of a rising cake or an expanding balloon, but that's not quite the reality of the universe as the theorists understand it -- both of those models suffer from having a center point. Not so in our universe, according to theory.

~The Meal
BSME, Michigan Tech 1995
MSME, Michigan Tech 2000

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