Forums → WEPR → How old do you think the universe is?
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i know some scientist/astronomer that does not have the idea that it is flat.
it was indeed a sphere he was talking about. but not the "big rip" kind.
Sphere would result in a Big Crunch. A Big Rip would be likely if the universe was hyperbolic.
One of the main reasons we think the universe is flat is because a flat universe is the model that best fits what we really see in the microwave background radiation.
For further comparison.
This is the final result of the picture.
"The mottled structure of the CMBR, with its tiny temperature fluctuations reflecting the primordial density variations from which todayâs cosmic structure originated, is clearly visible in the high-latitude regions of the map. The central band is the plane of our Galaxy. A large portion of the image is dominated by the diffuse emission from its gas and dust. The image was derived from data collected by Planck during its first all-sky survey and comes from observations taken between August 2009 and June 2010. This image is a low- resolution version of the full data set."
Assuming the universe was created in a big bang, would it not manifest in the form of a sphere, rather than being flat or, as you suggested, hyperbolic? It seems that all matter would spread outward equally in every direction.
It's talking about the geometry of it.
The universe is Euclidean meaning the lines won't intersect like you can see in the picture above the laser beams will just keep going.
"when we say the universe is flat it is not in the same sense that a piece of paper is flat, but rather means that the geometry of the universe is such that parallel lines will never cross, the angles in a triangle will always add up to 180 degress, and the corners of cubes will always make right angles. We call this kind of geometry (the kind you learned in school) Euclidean geometry.
It's easy to make examples in 2D space (ie. a flat piece of paper vs. a curved piece of paper, or the surface of a balloon). It's not so easy to illustrate flat 3D space - since we are 3D! So it's totally understandable that the concept is confusing" -source
More on Euclidean space.
http://en.wikipedia.org/wiki/Euclidean_space
still going by the laser pictures. this is the case for all of them.
In the open universe the two lines will curve away from each other, in this scenario a triangle wouldn't always add up to 180 degrees. The lines wouldn't remain parallel.
With the closed universe you can have parallel lines cross.
As seen here how parallel lines can cross on a sphere.
as for the last picture on page 15:
the view we have now is our sky (our point of view)
(it's looks kinda like a flat earth. but you gotta see it like a flat sky.)
you can see on the sides that there is beside the plane also a big "cloud" (they cut right through it)
if our point of view would be 90 degree to the left or right. then we would see a complete different picture. one where the "cloud" is in the middle. what would suggest a sphere shape universe.
The three dimension we move around in doesn't determine the geometry of the universe. Also there really isn't anything particular about our location in space. What we are looking at is going to be the same no matter where we are in the universe.
i think we have a other idea of parallel. i'm not seeing them in this picture.
except for the dot lines forming the open cube in the background.
Would you say these two lines are parallel to each other?
is the red-ish part of the picture part of the walls/universe? or only the blue-ish part.
The whole thing is, what we are looking at in that first picture is the heat from the microwave radiation. The density is what allows us to determine the shape of the universe.
maybe we get a other pics over 3 billion years or so.
That would be like you giving different geometry of the room you're in than a person standing in the opposite corner. You're perspective of the "walls" from inside the room isn't going to change depending on where you stand in the room.