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>> Also, I would like to ask the writer if the observable universe is a perfect sphere around us, then isnt it also a perfect sphere around a galaxy at the far edge of our perfect sphere. <<
A “wish item” for which there are no facts in evidence.
The intensity of light from a light source is inversely proportional to the square of the distance. (That's why you need multiple lamps in a large room...) And, it is why light sources at a distance appear exponentially dimmer. AND, it is why long ("deep") time exposures are required to record faint and distant light sources.
(Clicking on the following images will take you to the excellent "APOD" [Astronomy Picture Of the Day] page (with professional explanation) -- links to which are provided to FReepers by Sunken Civ via his "APOD LIST"...)
In the movie, the first "deep" Hubble image, the "HDF" or "Hubble Deep Field" image was a ten (10) day exposure:
The "HUDF" or "Hubble Ultra Deep Field" image was an eleven (11) day exposure -- made with a much more sensitive detector and with filters that admit far more light. Among other things, it was an attempt to "reach the end of the universe" -- if there is one:
The above two images are discussed in the video -- But, they were not the last attempt to "look for the end of the Universe"!!
Here is the "HXDF" or Hubble EXTREME Deep Field" image :
The HXDF was compiled over ten years of observations - and includes data from HUDF plus the Hubble INFRARED Deep Field (which I won't bother to post here...)
BTW, there are only two (2) (local galaxy) STARS in that image. Every other object is an entire, multi-billion-star GALAXY!
BOTTOM LINE: Astronomers (limited by information transport at the rate of C -- and the Inverse Square law) have made repeated, extensive, intensive and seriously expensive attempts "to see the end of the universe" AND -- IT IS NOT TO BE SEEN.
(Use evidence -- not dogma...)